Add support for handling runtime service requests
authorJeenu Viswambharan <jeenu.viswambharan@arm.com>
Thu, 6 Feb 2014 10:36:15 +0000 (10:36 +0000)
committerDan Handley <dan.handley@arm.com>
Mon, 17 Feb 2014 18:51:44 +0000 (18:51 +0000)
This patch uses the reworked exception handling support to handle
runtime service requests through SMCs following the SMC calling
convention. This is a giant commit since all the changes are
inter-related. It does the following:

1. Replace the old exception handling mechanism with the new one
2. Enforce that SP_EL0 is used C runtime stacks.
3. Ensures that the cold and warm boot paths use the 'cpu_context'
   structure to program an ERET into the next lower EL.
4. Ensures that SP_EL3 always points to the next 'cpu_context'
   structure prior to an ERET into the next lower EL
5. Introduces a PSCI SMC handler which completes the use of PSCI as a
   runtime service

Change-Id: I661797f834c0803d2c674d20f504df1b04c2b852
Co-authored-by: Achin Gupta <achin.gupta@arm.com>
19 files changed:
bl31/aarch64/bl31_entrypoint.S
bl31/aarch64/exception_handlers.c [deleted file]
bl31/aarch64/runtime_exceptions.S
bl31/aarch64/runtime_exceptions_next.S [deleted file]
bl31/bl31.mk
bl31/bl31_main.c
bl31/context_mgmt.c
common/psci/psci_common.c
common/psci/psci_entry.S
common/psci/psci_main.c
common/psci/psci_private.h
common/psci/psci_setup.c
common/runtime_svc.c
include/aarch64/arch.h
include/asm_macros.S
include/context.h
include/context_mgmt.h
include/runtime_svc.h
lib/arch/aarch64/misc_helpers.S

index cd0c02356cc3e31c5dd4efb0a59c584fb45231b9..1b8488d6f701500b9e1da9e3d0e7411bd34fe241 100644 (file)
@@ -31,6 +31,7 @@
 #include <bl_common.h>
 #include <platform.h>
 #include <arch.h>
+#include "cm_macros.S"
 
 
        .globl  bl31_entrypoint
@@ -129,6 +130,12 @@ bl31_entrypoint: ; .type bl31_entrypoint, %function
        ldr     x1, =__COHERENT_RAM_UNALIGNED_SIZE__
        bl      zeromem16
 
+       /* ---------------------------------------------
+        * Use SP_EL0 for the C runtime stack.
+        * ---------------------------------------------
+        */
+       msr     spsel, #0
+
        /* --------------------------------------------
         * Give ourselves a small coherent stack to
         * ease the pain of initializing the MMU
@@ -155,32 +162,26 @@ bl31_entrypoint: ; .type bl31_entrypoint, %function
        bl      platform_set_stack
 
        /* ---------------------------------------------
-        * Use the more complex exception vectors now
-        * the stacks are setup.
+        * Jump to main function.
         * ---------------------------------------------
         */
-       adr     x1, runtime_exceptions
-       msr     vbar_el3, x1
+       bl      bl31_main
 
        /* ---------------------------------------------
-        * Use SP_EL0 to initialize BL31. It allows us
-        * to jump to the next image without having to
-        * come back here to ensure all of the stack's
-        * been popped out. run_image() is not nice
-        * enough to reset the stack pointer before
-        * handing control to the next stage.
+        * Use the more complex exception vectors now
+        * that context management is setup. SP_EL3 is
+        * pointing to a 'cpu_context' structure which
+        * has an exception stack allocated. Since
+        * we're just about to leave this EL with ERET,
+        * we don't need an ISB here
         * ---------------------------------------------
         */
-       mov     x0, sp
-       msr     sp_el0, x0
-       msr     spsel, #0
-       isb
+       adr     x1, runtime_exceptions
+       msr     vbar_el3, x1
 
-       /* ---------------------------------------------
-        * Jump to main function.
-        * ---------------------------------------------
-        */
-       bl      bl31_main
+       zero_callee_saved_regs
+       b       el3_exit
 
 _panic:
+       wfi
        b       _panic
diff --git a/bl31/aarch64/exception_handlers.c b/bl31/aarch64/exception_handlers.c
deleted file mode 100644 (file)
index 3151294..0000000
+++ /dev/null
@@ -1,184 +0,0 @@
-/*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <arch_helpers.h>
-#include <platform.h>
-#include <bl_common.h>
-#include <bl31.h>
-#include <psci.h>
-#include <assert.h>
-#include <runtime_svc.h>
-
-/*******************************************************************************
- * This function checks whether this is a valid smc e.g.
- * the function id is correct, top word of args are zeroed
- * when aarch64 makes an aarch32 call etc.
- ******************************************************************************/
-int validate_smc(gp_regs *regs)
-{
-       unsigned int rw = GET_RW(regs->spsr);
-       unsigned int cc = GET_SMC_CC(regs->x0);
-
-       /* Check if there is a difference in the caller RW and SMC CC */
-       if (rw == cc) {
-
-               /* Check whether the caller has chosen the right func. id */
-               if (cc == SMC_64) {
-                       regs->x0 = SMC_UNK;
-                       return SMC_UNK;
-               }
-
-               /*
-                * Paranoid check to zero the top word of passed args
-                * irrespective of caller's register width.
-                *
-                * TODO: Check if this needed if the caller is aarch32
-                */
-               regs->x0 &= (unsigned int) 0xFFFFFFFF;
-               regs->x1 &= (unsigned int) 0xFFFFFFFF;
-               regs->x2 &= (unsigned int) 0xFFFFFFFF;
-               regs->x3 &= (unsigned int) 0xFFFFFFFF;
-               regs->x4 &= (unsigned int) 0xFFFFFFFF;
-               regs->x5 &= (unsigned int) 0xFFFFFFFF;
-               regs->x6 &= (unsigned int) 0xFFFFFFFF;
-       }
-
-       return 0;
-}
-
-/* TODO: Break down the SMC handler into fast and standard SMC handlers. */
-void smc_handler(unsigned type, unsigned long esr, gp_regs *regs)
-{
-       /* Check if the SMC has been correctly called */
-       if (validate_smc(regs) != 0)
-               return;
-
-       switch (regs->x0) {
-       case PSCI_VERSION:
-               regs->x0 = psci_version();
-               break;
-
-       case PSCI_CPU_OFF:
-               regs->x0 = __psci_cpu_off();
-               break;
-
-       case PSCI_CPU_SUSPEND_AARCH64:
-       case PSCI_CPU_SUSPEND_AARCH32:
-               regs->x0 = __psci_cpu_suspend(regs->x1, regs->x2, regs->x3);
-               break;
-
-       case PSCI_CPU_ON_AARCH64:
-       case PSCI_CPU_ON_AARCH32:
-               regs->x0 = psci_cpu_on(regs->x1, regs->x2, regs->x3);
-               break;
-
-       case PSCI_AFFINITY_INFO_AARCH32:
-       case PSCI_AFFINITY_INFO_AARCH64:
-               regs->x0 = psci_affinity_info(regs->x1, regs->x2);
-               break;
-
-       default:
-               regs->x0 = SMC_UNK;
-       }
-
-       return;
-}
-
-void irq_handler(unsigned type, unsigned long esr, gp_regs *regs)
-{
-       plat_report_exception(type);
-       assert(0);
-}
-
-void fiq_handler(unsigned type, unsigned long esr, gp_regs *regs)
-{
-       plat_report_exception(type);
-       assert(0);
-}
-
-void serror_handler(unsigned type, unsigned long esr, gp_regs *regs)
-{
-       plat_report_exception(type);
-       assert(0);
-}
-
-void sync_exception_handler(unsigned type, gp_regs *regs)
-{
-       unsigned long esr = read_esr();
-       unsigned int ec = EC_BITS(esr);
-
-       switch (ec) {
-
-       case EC_AARCH32_SMC:
-       case EC_AARCH64_SMC:
-               smc_handler(type, esr, regs);
-               break;
-
-       default:
-               plat_report_exception(type);
-               assert(0);
-       }
-       return;
-}
-
-void async_exception_handler(unsigned type, gp_regs *regs)
-{
-       unsigned long esr = read_esr();
-
-       switch (type) {
-
-       case IRQ_SP_EL0:
-       case IRQ_SP_ELX:
-       case IRQ_AARCH64:
-       case IRQ_AARCH32:
-               irq_handler(type, esr, regs);
-               break;
-
-       case FIQ_SP_EL0:
-       case FIQ_SP_ELX:
-       case FIQ_AARCH64:
-       case FIQ_AARCH32:
-               fiq_handler(type, esr, regs);
-               break;
-
-       case SERROR_SP_EL0:
-       case SERROR_SP_ELX:
-       case SERROR_AARCH64:
-       case SERROR_AARCH32:
-               serror_handler(type, esr, regs);
-               break;
-
-       default:
-               plat_report_exception(type);
-               assert(0);
-       }
-
-       return;
-}
index 92835dcbccb18d00795341680c37eb9631ffd110..10e65dc8b1441054093545d2b8a3a360bbb2f424 100644 (file)
 
 #include <arch.h>
 #include <runtime_svc.h>
+#include <platform.h>
+#include <context.h>
+#include "cm_macros.S"
 
        .globl  runtime_exceptions
-
-
-#include <asm_macros.S>
-
+       .globl  el3_exit
+       .globl  get_exception_stack
 
        .section        .vectors, "ax"; .align 11
 
@@ -46,39 +47,32 @@ runtime_exceptions:
         * -----------------------------------------------------
         */
 sync_exception_sp_el0:
-       exception_entry save_regs
-       mov     x0, #SYNC_EXCEPTION_SP_EL0
-       mov     x1, sp
-       bl      sync_exception_handler
-       exception_exit restore_regs
-       eret
+       /* -----------------------------------------------------
+        * We don't expect any synchronous exceptions from EL3
+        * -----------------------------------------------------
+        */
+       wfi
+       b       sync_exception_sp_el0
 
        .align  7
+       /* -----------------------------------------------------
+        * EL3 code is non-reentrant. Any asynchronous exception
+        * is a serious error. Loop infinitely.
+        * -----------------------------------------------------
+        */
 irq_sp_el0:
-       exception_entry save_regs
-       mov     x0, #IRQ_SP_EL0
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception IRQ_SP_EL0
+       b       irq_sp_el0
 
        .align  7
 fiq_sp_el0:
-       exception_entry save_regs
-       mov     x0, #FIQ_SP_EL0
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception FIQ_SP_EL0
+       b       fiq_sp_el0
 
        .align  7
 serror_sp_el0:
-       exception_entry save_regs
-       mov     x0, #SERROR_SP_EL0
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception SERROR_SP_EL0
+       b       serror_sp_el0
 
        /* -----------------------------------------------------
         * Current EL with SPx: 0x200 - 0x380
@@ -86,39 +80,35 @@ serror_sp_el0:
         */
        .align  7
 sync_exception_sp_elx:
-       exception_entry save_regs
-       mov     x0, #SYNC_EXCEPTION_SP_ELX
-       mov     x1, sp
-       bl      sync_exception_handler
-       exception_exit restore_regs
-       eret
+       /* -----------------------------------------------------
+        * This exception will trigger if anything went wrong
+        * during a previous exception entry or exit or while
+        * handling an earlier unexpected synchronous exception.
+        * In any case we cannot rely on SP_EL3. Switching to a
+        * known safe area of memory will corrupt at least a
+        * single register. It is best to enter wfi in loop as
+        * that will preserve the system state for analysis
+        * through a debugger later.
+        * -----------------------------------------------------
+        */
+       wfi
+       b       sync_exception_sp_elx
 
+       /* -----------------------------------------------------
+        * As mentioned in the previous comment, all bets are
+        * off if SP_EL3 cannot be relied upon. Report their
+        * occurrence.
+        * -----------------------------------------------------
+        */
        .align  7
 irq_sp_elx:
-       exception_entry save_regs
-       mov     x0, #IRQ_SP_ELX
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
-
+       b       irq_sp_elx
        .align  7
 fiq_sp_elx:
-       exception_entry save_regs
-       mov     x0, #FIQ_SP_ELX
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
-
+       b       fiq_sp_elx
        .align  7
 serror_sp_elx:
-       exception_entry save_regs
-       mov     x0, #SERROR_SP_ELX
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       b       serror_sp_elx
 
        /* -----------------------------------------------------
         * Lower EL using AArch64 : 0x400 - 0x580
@@ -126,39 +116,35 @@ serror_sp_elx:
         */
        .align  7
 sync_exception_aarch64:
-       exception_entry save_regs
-       mov     x0, #SYNC_EXCEPTION_AARCH64
-       mov     x1, sp
-       bl      sync_exception_handler
-       exception_exit restore_regs
-       eret
+       /* -----------------------------------------------------
+        * This exception vector will be the entry point for
+        * SMCs and traps that are unhandled at lower ELs most
+        * commonly. SP_EL3 should point to a valid cpu context
+        * where the general purpose and system register state
+        * can be saved.
+        * -----------------------------------------------------
+        */
+       handle_sync_exception
 
        .align  7
+       /* -----------------------------------------------------
+        * Asynchronous exceptions from lower ELs are not
+        * currently supported. Report their occurrence.
+        * -----------------------------------------------------
+        */
 irq_aarch64:
-       exception_entry save_regs
-       mov     x0, #IRQ_AARCH64
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception IRQ_AARCH64
+       b       irq_aarch64
 
        .align  7
 fiq_aarch64:
-       exception_entry save_regs
-       mov     x0, #FIQ_AARCH64
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception FIQ_AARCH64
+       b       fiq_aarch64
 
        .align  7
 serror_aarch64:
-       exception_entry save_regs
-       mov     x0, #IRQ_AARCH32
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception SERROR_AARCH64
+       b       serror_aarch64
 
        /* -----------------------------------------------------
         * Lower EL using AArch32 : 0x600 - 0x780
@@ -166,39 +152,281 @@ serror_aarch64:
         */
        .align  7
 sync_exception_aarch32:
-       exception_entry save_regs
-       mov     x0, #SYNC_EXCEPTION_AARCH32
-       mov     x1, sp
-       bl      sync_exception_handler
-       exception_exit restore_regs
-       eret
+       /* -----------------------------------------------------
+        * This exception vector will be the entry point for
+        * SMCs and traps that are unhandled at lower ELs most
+        * commonly. SP_EL3 should point to a valid cpu context
+        * where the general purpose and system register state
+        * can be saved.
+        * -----------------------------------------------------
+        */
+       handle_sync_exception
 
        .align  7
+       /* -----------------------------------------------------
+        * Asynchronous exceptions from lower ELs are not
+        * currently supported. Report their occurrence.
+        * -----------------------------------------------------
+        */
 irq_aarch32:
-       exception_entry save_regs
-       mov     x0, #IRQ_AARCH32
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception IRQ_AARCH32
+       b       irq_aarch32
 
        .align  7
 fiq_aarch32:
-       exception_entry save_regs
-       mov     x0, #FIQ_AARCH32
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
-       eret
+       handle_async_exception FIQ_AARCH32
+       b       fiq_aarch32
 
        .align  7
 serror_aarch32:
-       exception_entry save_regs
-       mov     x0, #SERROR_AARCH32
-       mov     x1, sp
-       bl      async_exception_handler
-       exception_exit restore_regs
+       handle_async_exception SERROR_AARCH32
+       b       serror_aarch32
+       .align  7
+
+       .section        .text, "ax"
+       /* -----------------------------------------------------
+        * The following code handles secure monitor calls.
+        * Depending upon the execution state from where the SMC
+        * has been invoked, it frees some general purpose
+        * registers to perform the remaining tasks. They
+        * involve finding the runtime service handler that is
+        * the target of the SMC & switching to runtime stacks
+        * (SP_EL0) before calling the handler.
+        *
+        * Note that x30 has been explicitly saved and can be
+        * used here
+        * -----------------------------------------------------
+        */
+smc_handler32:
+       /* Check whether aarch32 issued an SMC64 */
+       tbnz    x0, #FUNCID_CC_SHIFT, smc_prohibited
+
+       /* -----------------------------------------------------
+        * Since we're are coming from aarch32, x8-x18 need to
+        * be saved as per SMC32 calling convention. If a lower
+        * EL in aarch64 is making an SMC32 call then it must
+        * have saved x8-x17 already therein.
+        * -----------------------------------------------------
+        */
+       stp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
+       stp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
+       stp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
+       stp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
+       stp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
+
+       /* x4-x7, x18, sp_el0 are saved below */
+
+smc_handler64:
+       /* -----------------------------------------------------
+        * Populate the parameters for the SMC handler. We
+        * already have x0-x4 in place. x5 will point to a
+        * cookie (not used now). x6 will point to the context
+        * structure (SP_EL3) and x7 will contain flags we need
+        * to pass to the handler Hence save x5-x7. Note that x4
+        * only needs to be preserved for AArch32 callers but we
+        * do it for AArch64 callers as well for convenience
+        * -----------------------------------------------------
+        */
+       stp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
+       stp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
+
+       mov     x5, xzr
+       mov     x6, sp
+
+       /* Get the unique owning entity number */
+       ubfx    x16, x0, #FUNCID_OEN_SHIFT, #FUNCID_OEN_WIDTH
+       ubfx    x15, x0, #FUNCID_TYPE_SHIFT, #FUNCID_TYPE_WIDTH
+       orr     x16, x16, x15, lsl #FUNCID_OEN_WIDTH
+
+       adr     x11, (__RT_SVC_DESCS_START__ + RT_SVC_DESC_HANDLE)
+
+       /* Load descriptor index from array of indices */
+       adr     x14, rt_svc_descs_indices
+       ldrb    w15, [x14, x16]
+
+       /* Save x18 and SP_EL0 */
+       mrs     x17, sp_el0
+       stp     x18, x17, [x6, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
+
+       /* -----------------------------------------------------
+        * Restore the saved C runtime stack value which will
+        * become the new SP_EL0 i.e. EL3 runtime stack. It was
+        * saved in the 'cpu_context' structure prior to the last
+        * ERET from EL3.
+        * -----------------------------------------------------
+        */
+       ldr     x12, [x6, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
+
+       /*
+        * Any index greater than 127 is invalid. Check bit 7 for
+        * a valid index
+        */
+       tbnz    w15, 7, smc_unknown
+
+       /* Switch to SP_EL0 */
+       msr     spsel, #0
+
+       /* -----------------------------------------------------
+        * Get the descriptor using the index
+        * x11 = (base + off), x15 = index
+        *
+        * handler = (base + off) + (index << log2(size))
+        * -----------------------------------------------------
+        */
+       lsl     w10, w15, #RT_SVC_SIZE_LOG2
+       ldr     x15, [x11, w10, uxtw]
+
+       /* -----------------------------------------------------
+        * Save the SPSR_EL3, ELR_EL3, & SCR_EL3 in case there
+        * is a world switch during SMC handling.
+        * TODO: Revisit if all system registers can be saved
+        * later.
+        * -----------------------------------------------------
+        */
+       mrs     x16, spsr_el3
+       mrs     x17, elr_el3
+       mrs     x18, scr_el3
+       stp     x16, x17, [x6, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
+       stp     x18, xzr, [x6, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
+
+       /* Copy SCR_EL3.NS bit to the flag to indicate caller's security */
+       bfi     x7, x18, #0, #1
+
+       mov     sp, x12
+
+       /* -----------------------------------------------------
+        * Call the Secure Monitor Call handler and then drop
+        * directly into el3_exit() which will program any
+        * remaining architectural state prior to issuing the
+        * ERET to the desired lower EL.
+        * -----------------------------------------------------
+        */
+#if DEBUG
+       cbz     x15, rt_svc_fw_critical_error
+#endif
+       blr     x15
+
+       /* -----------------------------------------------------
+        * This routine assumes that the SP_EL3 is pointing to
+        * a valid context structure from where the gp regs and
+        * other special registers can be retrieved.
+        * -----------------------------------------------------
+        */
+el3_exit: ; .type el3_exit, %function
+       /* -----------------------------------------------------
+        * Save the current SP_EL0 i.e. the EL3 runtime stack
+        * which will be used for handling the next SMC. Then
+        * switch to SP_EL3
+        * -----------------------------------------------------
+        */
+       mov     x17, sp
+       msr     spsel, #1
+       str     x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
+
+       /* -----------------------------------------------------
+        * Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET
+        * -----------------------------------------------------
+        */
+       ldp     x18, xzr, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
+       ldp     x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
+       msr     scr_el3, x18
+       msr     spsr_el3, x16
+       msr     elr_el3, x17
+
+       /* Restore saved general purpose registers and return */
+       bl      restore_scratch_registers
+       ldp     x30, xzr, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
        eret
 
-       .align  7
+smc_unknown:
+       /*
+        * Here we restore x4-x18 regardless of where we came from. AArch32
+        * callers will find the registers contents unchanged, but AArch64
+        * callers will find the registers modified (with stale earlier NS
+        * content). Either way, we aren't leaking any secure information
+        * through them
+        */
+       bl      restore_scratch_registers_callee
+
+smc_prohibited:
+       ldp     x30, xzr, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+       mov     w0, #SMC_UNK
+       eret
+
+rt_svc_fw_critical_error:
+       b       rt_svc_fw_critical_error
+
+       /* -----------------------------------------------------
+        * The following functions are used to saved and restore
+        * all the caller saved registers as per the aapcs_64.
+        * These are not macros to ensure their invocation fits
+        * within the 32 instructions per exception vector.
+        * -----------------------------------------------------
+        */
+save_scratch_registers: ; .type save_scratch_registers, %function
+       stp     x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
+       stp     x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
+       stp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
+       stp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
+       stp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
+       stp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
+       stp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
+       stp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
+       stp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
+       mrs     x17, sp_el0
+       stp     x18, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
+       ret
+
+restore_scratch_registers: ; .type restore_scratch_registers, %function
+       ldp     x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
+       ldp     x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
+
+restore_scratch_registers_callee:
+       ldp     x18, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
+
+       ldp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
+       ldp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
+       ldp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
+       ldp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
+       ldp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
+       ldp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
+
+       msr     sp_el0, x17
+       ldp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
+       ret
+
+       /* -----------------------------------------------------
+        * 256 bytes of exception stack for each cpu
+        * -----------------------------------------------------
+        */
+#if DEBUG
+#define PCPU_EXCEPTION_STACK_SIZE      0x300
+#else
+#define PCPU_EXCEPTION_STACK_SIZE      0x100
+#endif
+       /* -----------------------------------------------------
+        * void get_exception_stack (uint64_t mpidr) : This
+        * function is used to allocate a small stack for
+        * reporting unhandled exceptions
+        * -----------------------------------------------------
+        */
+get_exception_stack: ; .type get_exception_stack, %function
+       mov     x10, x30 // lr
+       bl      platform_get_core_pos
+       add     x0, x0, #1
+       mov     x1, #PCPU_EXCEPTION_STACK_SIZE
+       mul     x0, x0, x1
+       ldr     x1, =pcpu_exception_stack
+       add     x0, x1, x0
+       ret     x10
+
+       /* -----------------------------------------------------
+        * Per-cpu exception stacks in normal memory.
+        * -----------------------------------------------------
+        */
+       .section        data, "aw", %nobits; .align 6
+
+pcpu_exception_stack:
+       /* Zero fill */
+       .space (PLATFORM_CORE_COUNT * PCPU_EXCEPTION_STACK_SIZE), 0
 
diff --git a/bl31/aarch64/runtime_exceptions_next.S b/bl31/aarch64/runtime_exceptions_next.S
deleted file mode 100644 (file)
index 10e65dc..0000000
+++ /dev/null
@@ -1,432 +0,0 @@
-/*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <arch.h>
-#include <runtime_svc.h>
-#include <platform.h>
-#include <context.h>
-#include "cm_macros.S"
-
-       .globl  runtime_exceptions
-       .globl  el3_exit
-       .globl  get_exception_stack
-
-       .section        .vectors, "ax"; .align 11
-
-       .align  7
-runtime_exceptions:
-       /* -----------------------------------------------------
-        * Current EL with _sp_el0 : 0x0 - 0x180
-        * -----------------------------------------------------
-        */
-sync_exception_sp_el0:
-       /* -----------------------------------------------------
-        * We don't expect any synchronous exceptions from EL3
-        * -----------------------------------------------------
-        */
-       wfi
-       b       sync_exception_sp_el0
-
-       .align  7
-       /* -----------------------------------------------------
-        * EL3 code is non-reentrant. Any asynchronous exception
-        * is a serious error. Loop infinitely.
-        * -----------------------------------------------------
-        */
-irq_sp_el0:
-       handle_async_exception IRQ_SP_EL0
-       b       irq_sp_el0
-
-       .align  7
-fiq_sp_el0:
-       handle_async_exception FIQ_SP_EL0
-       b       fiq_sp_el0
-
-       .align  7
-serror_sp_el0:
-       handle_async_exception SERROR_SP_EL0
-       b       serror_sp_el0
-
-       /* -----------------------------------------------------
-        * Current EL with SPx: 0x200 - 0x380
-        * -----------------------------------------------------
-        */
-       .align  7
-sync_exception_sp_elx:
-       /* -----------------------------------------------------
-        * This exception will trigger if anything went wrong
-        * during a previous exception entry or exit or while
-        * handling an earlier unexpected synchronous exception.
-        * In any case we cannot rely on SP_EL3. Switching to a
-        * known safe area of memory will corrupt at least a
-        * single register. It is best to enter wfi in loop as
-        * that will preserve the system state for analysis
-        * through a debugger later.
-        * -----------------------------------------------------
-        */
-       wfi
-       b       sync_exception_sp_elx
-
-       /* -----------------------------------------------------
-        * As mentioned in the previous comment, all bets are
-        * off if SP_EL3 cannot be relied upon. Report their
-        * occurrence.
-        * -----------------------------------------------------
-        */
-       .align  7
-irq_sp_elx:
-       b       irq_sp_elx
-       .align  7
-fiq_sp_elx:
-       b       fiq_sp_elx
-       .align  7
-serror_sp_elx:
-       b       serror_sp_elx
-
-       /* -----------------------------------------------------
-        * Lower EL using AArch64 : 0x400 - 0x580
-        * -----------------------------------------------------
-        */
-       .align  7
-sync_exception_aarch64:
-       /* -----------------------------------------------------
-        * This exception vector will be the entry point for
-        * SMCs and traps that are unhandled at lower ELs most
-        * commonly. SP_EL3 should point to a valid cpu context
-        * where the general purpose and system register state
-        * can be saved.
-        * -----------------------------------------------------
-        */
-       handle_sync_exception
-
-       .align  7
-       /* -----------------------------------------------------
-        * Asynchronous exceptions from lower ELs are not
-        * currently supported. Report their occurrence.
-        * -----------------------------------------------------
-        */
-irq_aarch64:
-       handle_async_exception IRQ_AARCH64
-       b       irq_aarch64
-
-       .align  7
-fiq_aarch64:
-       handle_async_exception FIQ_AARCH64
-       b       fiq_aarch64
-
-       .align  7
-serror_aarch64:
-       handle_async_exception SERROR_AARCH64
-       b       serror_aarch64
-
-       /* -----------------------------------------------------
-        * Lower EL using AArch32 : 0x600 - 0x780
-        * -----------------------------------------------------
-        */
-       .align  7
-sync_exception_aarch32:
-       /* -----------------------------------------------------
-        * This exception vector will be the entry point for
-        * SMCs and traps that are unhandled at lower ELs most
-        * commonly. SP_EL3 should point to a valid cpu context
-        * where the general purpose and system register state
-        * can be saved.
-        * -----------------------------------------------------
-        */
-       handle_sync_exception
-
-       .align  7
-       /* -----------------------------------------------------
-        * Asynchronous exceptions from lower ELs are not
-        * currently supported. Report their occurrence.
-        * -----------------------------------------------------
-        */
-irq_aarch32:
-       handle_async_exception IRQ_AARCH32
-       b       irq_aarch32
-
-       .align  7
-fiq_aarch32:
-       handle_async_exception FIQ_AARCH32
-       b       fiq_aarch32
-
-       .align  7
-serror_aarch32:
-       handle_async_exception SERROR_AARCH32
-       b       serror_aarch32
-       .align  7
-
-       .section        .text, "ax"
-       /* -----------------------------------------------------
-        * The following code handles secure monitor calls.
-        * Depending upon the execution state from where the SMC
-        * has been invoked, it frees some general purpose
-        * registers to perform the remaining tasks. They
-        * involve finding the runtime service handler that is
-        * the target of the SMC & switching to runtime stacks
-        * (SP_EL0) before calling the handler.
-        *
-        * Note that x30 has been explicitly saved and can be
-        * used here
-        * -----------------------------------------------------
-        */
-smc_handler32:
-       /* Check whether aarch32 issued an SMC64 */
-       tbnz    x0, #FUNCID_CC_SHIFT, smc_prohibited
-
-       /* -----------------------------------------------------
-        * Since we're are coming from aarch32, x8-x18 need to
-        * be saved as per SMC32 calling convention. If a lower
-        * EL in aarch64 is making an SMC32 call then it must
-        * have saved x8-x17 already therein.
-        * -----------------------------------------------------
-        */
-       stp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
-       stp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
-       stp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
-       stp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
-       stp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
-
-       /* x4-x7, x18, sp_el0 are saved below */
-
-smc_handler64:
-       /* -----------------------------------------------------
-        * Populate the parameters for the SMC handler. We
-        * already have x0-x4 in place. x5 will point to a
-        * cookie (not used now). x6 will point to the context
-        * structure (SP_EL3) and x7 will contain flags we need
-        * to pass to the handler Hence save x5-x7. Note that x4
-        * only needs to be preserved for AArch32 callers but we
-        * do it for AArch64 callers as well for convenience
-        * -----------------------------------------------------
-        */
-       stp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
-       stp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
-
-       mov     x5, xzr
-       mov     x6, sp
-
-       /* Get the unique owning entity number */
-       ubfx    x16, x0, #FUNCID_OEN_SHIFT, #FUNCID_OEN_WIDTH
-       ubfx    x15, x0, #FUNCID_TYPE_SHIFT, #FUNCID_TYPE_WIDTH
-       orr     x16, x16, x15, lsl #FUNCID_OEN_WIDTH
-
-       adr     x11, (__RT_SVC_DESCS_START__ + RT_SVC_DESC_HANDLE)
-
-       /* Load descriptor index from array of indices */
-       adr     x14, rt_svc_descs_indices
-       ldrb    w15, [x14, x16]
-
-       /* Save x18 and SP_EL0 */
-       mrs     x17, sp_el0
-       stp     x18, x17, [x6, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
-
-       /* -----------------------------------------------------
-        * Restore the saved C runtime stack value which will
-        * become the new SP_EL0 i.e. EL3 runtime stack. It was
-        * saved in the 'cpu_context' structure prior to the last
-        * ERET from EL3.
-        * -----------------------------------------------------
-        */
-       ldr     x12, [x6, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
-
-       /*
-        * Any index greater than 127 is invalid. Check bit 7 for
-        * a valid index
-        */
-       tbnz    w15, 7, smc_unknown
-
-       /* Switch to SP_EL0 */
-       msr     spsel, #0
-
-       /* -----------------------------------------------------
-        * Get the descriptor using the index
-        * x11 = (base + off), x15 = index
-        *
-        * handler = (base + off) + (index << log2(size))
-        * -----------------------------------------------------
-        */
-       lsl     w10, w15, #RT_SVC_SIZE_LOG2
-       ldr     x15, [x11, w10, uxtw]
-
-       /* -----------------------------------------------------
-        * Save the SPSR_EL3, ELR_EL3, & SCR_EL3 in case there
-        * is a world switch during SMC handling.
-        * TODO: Revisit if all system registers can be saved
-        * later.
-        * -----------------------------------------------------
-        */
-       mrs     x16, spsr_el3
-       mrs     x17, elr_el3
-       mrs     x18, scr_el3
-       stp     x16, x17, [x6, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
-       stp     x18, xzr, [x6, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
-
-       /* Copy SCR_EL3.NS bit to the flag to indicate caller's security */
-       bfi     x7, x18, #0, #1
-
-       mov     sp, x12
-
-       /* -----------------------------------------------------
-        * Call the Secure Monitor Call handler and then drop
-        * directly into el3_exit() which will program any
-        * remaining architectural state prior to issuing the
-        * ERET to the desired lower EL.
-        * -----------------------------------------------------
-        */
-#if DEBUG
-       cbz     x15, rt_svc_fw_critical_error
-#endif
-       blr     x15
-
-       /* -----------------------------------------------------
-        * This routine assumes that the SP_EL3 is pointing to
-        * a valid context structure from where the gp regs and
-        * other special registers can be retrieved.
-        * -----------------------------------------------------
-        */
-el3_exit: ; .type el3_exit, %function
-       /* -----------------------------------------------------
-        * Save the current SP_EL0 i.e. the EL3 runtime stack
-        * which will be used for handling the next SMC. Then
-        * switch to SP_EL3
-        * -----------------------------------------------------
-        */
-       mov     x17, sp
-       msr     spsel, #1
-       str     x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
-
-       /* -----------------------------------------------------
-        * Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET
-        * -----------------------------------------------------
-        */
-       ldp     x18, xzr, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
-       ldp     x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
-       msr     scr_el3, x18
-       msr     spsr_el3, x16
-       msr     elr_el3, x17
-
-       /* Restore saved general purpose registers and return */
-       bl      restore_scratch_registers
-       ldp     x30, xzr, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
-       eret
-
-smc_unknown:
-       /*
-        * Here we restore x4-x18 regardless of where we came from. AArch32
-        * callers will find the registers contents unchanged, but AArch64
-        * callers will find the registers modified (with stale earlier NS
-        * content). Either way, we aren't leaking any secure information
-        * through them
-        */
-       bl      restore_scratch_registers_callee
-
-smc_prohibited:
-       ldp     x30, xzr, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
-       mov     w0, #SMC_UNK
-       eret
-
-rt_svc_fw_critical_error:
-       b       rt_svc_fw_critical_error
-
-       /* -----------------------------------------------------
-        * The following functions are used to saved and restore
-        * all the caller saved registers as per the aapcs_64.
-        * These are not macros to ensure their invocation fits
-        * within the 32 instructions per exception vector.
-        * -----------------------------------------------------
-        */
-save_scratch_registers: ; .type save_scratch_registers, %function
-       stp     x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
-       stp     x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
-       stp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
-       stp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
-       stp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
-       stp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
-       stp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
-       stp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
-       stp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
-       mrs     x17, sp_el0
-       stp     x18, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
-       ret
-
-restore_scratch_registers: ; .type restore_scratch_registers, %function
-       ldp     x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
-       ldp     x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
-
-restore_scratch_registers_callee:
-       ldp     x18, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
-
-       ldp     x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
-       ldp     x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
-       ldp     x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
-       ldp     x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
-       ldp     x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
-       ldp     x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
-
-       msr     sp_el0, x17
-       ldp     x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
-       ret
-
-       /* -----------------------------------------------------
-        * 256 bytes of exception stack for each cpu
-        * -----------------------------------------------------
-        */
-#if DEBUG
-#define PCPU_EXCEPTION_STACK_SIZE      0x300
-#else
-#define PCPU_EXCEPTION_STACK_SIZE      0x100
-#endif
-       /* -----------------------------------------------------
-        * void get_exception_stack (uint64_t mpidr) : This
-        * function is used to allocate a small stack for
-        * reporting unhandled exceptions
-        * -----------------------------------------------------
-        */
-get_exception_stack: ; .type get_exception_stack, %function
-       mov     x10, x30 // lr
-       bl      platform_get_core_pos
-       add     x0, x0, #1
-       mov     x1, #PCPU_EXCEPTION_STACK_SIZE
-       mul     x0, x0, x1
-       ldr     x1, =pcpu_exception_stack
-       add     x0, x1, x0
-       ret     x10
-
-       /* -----------------------------------------------------
-        * Per-cpu exception stacks in normal memory.
-        * -----------------------------------------------------
-        */
-       .section        data, "aw", %nobits; .align 6
-
-pcpu_exception_stack:
-       /* Zero fill */
-       .space (PLATFORM_CORE_COUNT * PCPU_EXCEPTION_STACK_SIZE), 0
-
index 280aa8821f0b75924fce5d02dd2dcf94018816b4..fec8ebe249643066030984f63aaf79d92a9ab4ac 100644 (file)
@@ -49,7 +49,6 @@ vpath                 %.S     lib/arch/${ARCH}                        \
 
 BL31_OBJS              +=      bl31_arch_setup.o                       \
                                bl31_entrypoint.o                       \
-                               exception_handlers.o                    \
                                runtime_exceptions.o                    \
                                bl31_main.o                             \
                                psci_entry.o                            \
index dc65b602904a56ecdd913bb5b8d22fe226d18403..9d2dc299559d69cf778f411a68914994497a386b 100644 (file)
@@ -48,15 +48,18 @@ void bl31_lib_init()
        cm_init();
 }
 
-void bl31_arch_next_el_setup(void);
-
 /*******************************************************************************
  * BL31 is responsible for setting up the runtime services for the primary cpu
- * before passing control to the bootloader (UEFI) or Linux.
+ * before passing control to the bootloader (UEFI) or Linux. This function calls
+ * runtime_svc_init() which initializes all registered runtime services. The run
+ * time services would setup enough context for the core to swtich to the next
+ * exception level. When this function returns, the core will switch to the
+ * programmed exception level via. an ERET.
  ******************************************************************************/
 void bl31_main(void)
 {
-       el_change_info *image_info;
+       el_change_info *next_image_info;
+       uint32_t scr;
 
        /* Perform remaining generic architectural setup from EL3 */
        bl31_arch_setup();
@@ -76,10 +79,27 @@ void bl31_main(void)
        /* Clean caches before re-entering normal world */
        dcsw_op_all(DCCSW);
 
-       image_info = bl31_get_next_image_info();
+       /*
+        * Setup minimal architectural state of the next highest EL to
+        * allow execution in it immediately upon entering it.
+        */
        bl31_arch_next_el_setup();
-       change_el(image_info);
 
-       /* There is no valid reason for change_el() to return */
-       assert(0);
+       /* Program EL3 registers to enable entry into the next EL */
+       next_image_info = bl31_get_next_image_info();
+       scr = read_scr();
+       if (next_image_info->security_state == NON_SECURE)
+               scr |= SCR_NS_BIT;
+
+       /*
+        * Tell the context mgmt. library to ensure that SP_EL3 points to
+        * the right context to exit from EL3 correctly.
+        */
+       cm_set_el3_eret_context(next_image_info->security_state,
+                       next_image_info->entrypoint,
+                       next_image_info->spsr,
+                       scr);
+
+       /* Finally set the next context */
+       cm_set_next_eret_context(next_image_info->security_state);
 }
index bbdbad2ca8df2869b6e6e0c4e28626d78c7926af..44ef0d92cca886afb2db3efdfa44c27fd328c095 100644 (file)
@@ -143,11 +143,31 @@ void cm_el1_sysregs_context_restore(uint32_t security_state)
 }
 
 /*******************************************************************************
- * This function is used to program SP_EL3 to point to the 'cpu_context'
- * structure which will be used for programming the EL3 architectural state to
- * enable an ERET into a lower EL e.g. general purpose registers and system
- * registers like SCR_EL3, SPSR_EL3, SCR_EL3 etc. The same structure will be
- * used to save the same registers after an exception entry from the lower EL.
+ * This function function populates 'cpu_context' pertaining to the given
+ * security state with the entrypoint, SPSR and SCR values so that an ERET from
+ * this securit state correctly restores corresponding values to drop the CPU to
+ * the next exception level
+ ******************************************************************************/
+void cm_set_el3_eret_context(uint32_t security_state, uint64_t entrypoint,
+               uint32_t spsr, uint32_t scr)
+{
+       cpu_context *ctx;
+       el3_state *state;
+
+       ctx = cm_get_context(read_mpidr(), security_state);
+       assert(ctx);
+
+       /* Populate EL3 state so that we've the right context before doing ERET */
+       state = get_el3state_ctx(ctx);
+       write_ctx_reg(state, CTX_SPSR_EL3, spsr);
+       write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
+       write_ctx_reg(state, CTX_SCR_EL3, scr);
+}
+
+/*******************************************************************************
+ * This function is used to program the context that's used for exception
+ * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
+ * the required security state
  ******************************************************************************/
 void cm_set_next_eret_context(uint32_t security_state)
 {
@@ -155,6 +175,7 @@ void cm_set_next_eret_context(uint32_t security_state)
 #if DEBUG
        uint64_t sp_mode;
 #endif
+
        ctx = cm_get_context(read_mpidr(), security_state);
        assert(ctx);
 
@@ -174,3 +195,22 @@ void cm_set_next_eret_context(uint32_t security_state)
                         "msr   spsel, #0\n"
                         : : "r" (ctx));
 }
+
+/*******************************************************************************
+ * This function is used to program exception stack in the 'cpu_context'
+ * structure. This is the initial stack used for taking and handling exceptions
+ * at EL3. This stack is expected to be initialized once by each security state
+ ******************************************************************************/
+void cm_init_exception_stack(uint64_t mpidr, uint32_t security_state)
+{
+       cpu_context *ctx;
+       el3_state *state;
+
+       ctx = cm_get_context(mpidr, security_state);
+       assert(ctx);
+
+       /* Set exception stack in the context */
+       state = get_el3state_ctx(ctx);
+
+       write_ctx_reg(state, CTX_EXCEPTION_SP, get_exception_stack(mpidr));
+}
index 193655ddc834860a446bacaa6b6ec6015edb3f5e..214db7808278b555397136207950b179541f0c94 100644 (file)
@@ -36,6 +36,7 @@
 #include <platform.h>
 #include <psci.h>
 #include <psci_private.h>
+#include <context_mgmt.h>
 #include <runtime_svc.h>
 #include "debug.h"
 
@@ -86,7 +87,8 @@ int get_power_on_target_afflvl(unsigned long mpidr)
        unsigned int state;
 
        /* Retrieve our node from the topology tree */
-       node = psci_get_aff_map_node(mpidr & MPIDR_AFFINITY_MASK, MPIDR_AFFLVL0);
+       node = psci_get_aff_map_node(mpidr & MPIDR_AFFINITY_MASK,
+                       MPIDR_AFFLVL0);
        assert(node);
 
        /*
@@ -222,13 +224,12 @@ int psci_validate_mpidr(unsigned long mpidr, int level)
 void psci_get_ns_entry_info(unsigned int index)
 {
        unsigned long sctlr = 0, scr, el_status, id_aa64pfr0;
-       gp_regs *ns_gp_regs;
+       uint64_t mpidr = read_mpidr();
+       cpu_context *ns_entry_context;
+       gp_regs *ns_entry_gpregs;
 
        scr = read_scr();
 
-       /* Switch to the non-secure view of the registers */
-       write_scr(scr | SCR_NS_BIT);
-
        /* Find out which EL we are going to */
        id_aa64pfr0 = read_id_aa64pfr0_el1();
        el_status = (id_aa64pfr0 >> ID_AA64PFR0_EL2_SHIFT) &
@@ -257,23 +258,29 @@ void psci_get_ns_entry_info(unsigned int index)
                write_sctlr_el1(sctlr);
 
        /* Fulfill the cpu_on entry reqs. as per the psci spec */
-       write_scr(scr);
-       write_elr(psci_ns_entry_info[index].eret_info.entrypoint);
+       ns_entry_context = (cpu_context *) cm_get_context(mpidr, NON_SECURE);
+       assert(ns_entry_context);
 
        /*
-        * Set the general purpose registers to ~0 upon entry into the
-        * non-secure world except for x0 which should contain the
-        * context id & spsr. This is done directly on the "would be"
-        * stack pointer. Prior to entry into the non-secure world, an
-        * offset equivalent to the size of the 'gp_regs' structure is
-        * added to the sp. This general purpose register context is
-        * retrieved then.
+        * Setup general purpose registers to return the context id and
+        * prevent leakage of secure information into the normal world.
         */
-       ns_gp_regs = (gp_regs *) platform_get_stack(read_mpidr());
-       ns_gp_regs--;
-       memset(ns_gp_regs, ~0, sizeof(*ns_gp_regs));
-       ns_gp_regs->x0 = psci_ns_entry_info[index].context_id;
-       ns_gp_regs->spsr = psci_ns_entry_info[index].eret_info.spsr;
+       ns_entry_gpregs = get_gpregs_ctx(ns_entry_context);
+       write_ctx_reg(ns_entry_gpregs,
+                     CTX_GPREG_X0,
+                     psci_ns_entry_info[index].context_id);
+
+       /*
+        * Tell the context management library to setup EL3 system registers to
+        * be able to ERET into the ns state, and SP_EL3 points to the right
+        * context to exit from EL3 correctly.
+        */
+       cm_set_el3_eret_context(NON_SECURE,
+                       psci_ns_entry_info[index].eret_info.entrypoint,
+                       psci_ns_entry_info[index].eret_info.spsr,
+                       scr);
+
+       cm_set_next_eret_context(NON_SECURE);
 }
 
 /*******************************************************************************
@@ -344,7 +351,7 @@ int psci_set_ns_entry_info(unsigned int index,
                 */
                spsr |= DAIF_ABT_BIT | DAIF_IRQ_BIT | DAIF_FIQ_BIT;
                spsr <<= PSR_DAIF_SHIFT;
-               if(ee)
+               if (ee)
                        spsr |= SPSR32_EE_BIT;
                spsr |= mode;
 
@@ -500,7 +507,7 @@ void psci_afflvl_power_on_finish(unsigned long mpidr,
        mpidr_aff_map_nodes mpidr_nodes;
        int rc;
 
-       mpidr &= MPIDR_AFFINITY_MASK;;
+       mpidr &= MPIDR_AFFINITY_MASK;
 
        /*
         * Collect the pointers to the nodes in the topology tree for
index 28a41436cecbfdb3b1d8609b9a28fdbf819956d8..15e074c3977df0aea72180c961199c6cd2faf979 100644 (file)
@@ -34,6 +34,7 @@
 #include <psci_private.h>
 #include <runtime_svc.h>
 #include <asm_macros.S>
+#include <cm_macros.S>
 
        .globl  psci_aff_on_finish_entry
        .globl  psci_aff_suspend_finish_entry
@@ -74,6 +75,13 @@ psci_aff_common_finish_entry:
        msr     vbar_el3, x0
        isb
 
+       /* ---------------------------------------------
+        * Use SP_EL0 for the C runtime stack.
+        * ---------------------------------------------
+        */
+       msr     spsel, #0
+       isb
+
        bl      read_mpidr
        mov     x19, x0
        bl      platform_set_coherent_stack
@@ -102,31 +110,19 @@ psci_aff_common_finish_entry:
        bl      platform_set_stack
 
        /* ---------------------------------------------
-        * Now that the execution stack has been set
+        * Now that the context management has been set
         * up, enable full runtime exception handling.
-        * Since we're just about to leave this EL with
-        * ERET, we don't need an ISB here
+        * SP_EL3 is pointing to a 'cpu_context'
+        * structure which has an exception stack
+        * allocated. Since we're just about to leave
+        * this EL with ERET, we don't need an ISB here
         * ---------------------------------------------
         */
        adr     x0, runtime_exceptions
        msr     vbar_el3, x0
 
-       /* --------------------------------------------
-        * Use the size of the general purpose register
-        * context to restore the register state
-        * stashed by earlier code
-        * --------------------------------------------
-        */
-       sub     sp, sp, #SIZEOF_GPREGS
-       exception_exit  restore_regs
-
-       /* --------------------------------------------
-        * Jump back to the non-secure world assuming
-        * that the elr and spsr setup has been done
-        * by the finishers
-        * --------------------------------------------
-        */
-       eret
+       zero_callee_saved_regs
+       b       el3_exit
 _panic:
        b       _panic
 
index a70a21ae858686298cb75e19fa3b96865aa205e1..67f189d1aa65f391f4f0a3e4b527515bad536134 100644 (file)
@@ -35,6 +35,9 @@
 #include <console.h>
 #include <platform.h>
 #include <psci_private.h>
+#include <runtime_svc.h>
+#include <debug.h>
+#include <context_mgmt.h>
 
 /*******************************************************************************
  * PSCI frontend api for servicing SMCs. Described in the PSCI spec.
@@ -199,3 +202,70 @@ void psci_system_reset(void)
        assert(0);
 }
 
+/*******************************************************************************
+ * PSCI top level handler for servicing SMCs.
+ ******************************************************************************/
+uint64_t psci_smc_handler(uint32_t smc_fid,
+                         uint64_t x1,
+                         uint64_t x2,
+                         uint64_t x3,
+                         uint64_t x4,
+                         void *cookie,
+                         void *handle,
+                         uint64_t flags)
+{
+       uint64_t rc;
+
+       switch (smc_fid) {
+       case PSCI_VERSION:
+               rc = psci_version();
+               break;
+
+       case PSCI_CPU_OFF:
+               rc = __psci_cpu_off();
+               break;
+
+       case PSCI_CPU_SUSPEND_AARCH64:
+       case PSCI_CPU_SUSPEND_AARCH32:
+               rc = __psci_cpu_suspend(x1, x2, x3);
+               break;
+
+       case PSCI_CPU_ON_AARCH64:
+       case PSCI_CPU_ON_AARCH32:
+               rc = psci_cpu_on(x1, x2, x3);
+               break;
+
+       case PSCI_AFFINITY_INFO_AARCH32:
+       case PSCI_AFFINITY_INFO_AARCH64:
+               rc = psci_affinity_info(x1, x2);
+               break;
+
+       case PSCI_MIG_AARCH32:
+       case PSCI_MIG_AARCH64:
+               rc = psci_migrate(x1);
+               break;
+
+       case PSCI_MIG_INFO_TYPE:
+               rc = psci_migrate_info_type();
+               break;
+
+       case PSCI_MIG_INFO_UP_CPU_AARCH32:
+       case PSCI_MIG_INFO_UP_CPU_AARCH64:
+               rc = psci_migrate_info_up_cpu();
+               break;
+
+       case PSCI_SYSTEM_OFF:
+               psci_system_off();
+               assert(0);
+
+       case PSCI_SYSTEM_RESET:
+               psci_system_reset();
+               assert(0);
+
+       default:
+               rc = SMC_UNK;
+               WARN("Unimplemented psci call -> 0x%x \n", smc_fid);
+       }
+
+       SMC_RET1(handle, rc);
+}
index de9c291793aa8ec5b87f807012f92b38c0597f02..3d7ae749e3a66ccd6e7b7f69216695de00842bdc 100644 (file)
@@ -151,6 +151,16 @@ extern int psci_afflvl_suspend(unsigned long,
                               int,
                               int);
 extern unsigned int psci_afflvl_suspend_finish(unsigned long, int, int);
+
+/* Private exported functions from psci_main.c */
+extern uint64_t psci_smc_handler(uint32_t smc_fid,
+                                uint64_t x1,
+                                uint64_t x2,
+                                uint64_t x3,
+                                uint64_t x4,
+                                void *cookie,
+                                void *handle,
+                                uint64_t flags);
 #endif /*__ASSEMBLY__*/
 
 #endif /* __PSCI_PRIVATE_H__ */
index c471d1f531b5207757fca3ce0b1853a23b0fc21e..8d7903c19496f267742f93d953ba12092caf1807 100644 (file)
@@ -195,6 +195,9 @@ static void psci_init_aff_map_node(unsigned long mpidr,
                cm_set_context(mpidr,
                                (void *) &psci_ns_context[linear_id],
                                NON_SECURE);
+
+               /* Initialize exception stack in the context */
+               cm_init_exception_stack(mpidr, NON_SECURE);
        }
 
        return;
@@ -348,5 +351,5 @@ DECLARE_RT_SVC(
                OEN_STD_END,
                SMC_TYPE_FAST,
                psci_setup,
-               NULL
+               psci_smc_handler
 );
index 0ea1bf55a2b27c529a970eaf37c77bd5052868d8..6e8a1bb093ded63fb2cecc111f9eee562b2b703a 100644 (file)
@@ -41,6 +41,7 @@
 #include <runtime_svc.h>
 #include <context.h>
 #include <debug.h>
+#include <context_mgmt.h>
 
 /*******************************************************************************
  * The 'rt_svc_descs' array holds the runtime service descriptors exported by
@@ -146,7 +147,7 @@ error:
 
 void fault_handler(void *handle)
 {
-       gp_regs_next *gpregs_ctx = get_gpregs_ctx(handle);
+       gp_regs *gpregs_ctx = get_gpregs_ctx(handle);
        ERROR("Unhandled synchronous fault. Register dump @ 0x%x \n",
              gpregs_ctx);
        panic();
index e8773d93e3c16cc7975974ad50ab64b7937b312a..69926a3b43c5b4e4f733adc0ef7393d8dcac9b32 100644 (file)
@@ -320,7 +320,7 @@ extern void runtime_exceptions(void);
 extern void bl1_arch_setup(void);
 extern void bl2_arch_setup(void);
 extern void bl31_arch_setup(void);
-
+extern void bl31_arch_next_el_setup(void);
 #endif /*__ASSEMBLY__*/
 
 #endif /* __ARCH_H__ */
index 9de135ca77259003c6391679f8eff1aaca2caf1c..decef0b952d3e84c87e86a240169e8ccbe68dc1f 100644 (file)
        .endm
 
 
-       .macro  exception_entry  func
-       stp     x29, x30, [sp, #-(SIZEOF_GPREGS - GPREGS_FP_OFF)]!
-       bl      \func
-       .endm
-
-
-       .macro  exception_exit  func
-       bl      \func
-       ldp     x29, x30, [sp], #(SIZEOF_GPREGS - GPREGS_FP_OFF)
-       .endm
-
-
        .macro  smc_check  label
        bl      read_esr
        ubfx    x0, x0, #ESR_EC_SHIFT, #ESR_EC_LENGTH
index 1c1a3a22dcb5c0808f1e660112e1c6a26b9250a8..082e511db34c479c4819a0bc3e21121d4cc75d7a 100644 (file)
  * callee saved registers if used by the C runtime and the assembler
  * does not touch the remaining.
  */
-DEFINE_REG_STRUCT(gp_regs_next, CTX_GPREG_ALL);
+DEFINE_REG_STRUCT(gp_regs, CTX_GPREG_ALL);
 
 /*
  * AArch64 EL1 system register context structure for preserving the
@@ -233,7 +233,7 @@ DEFINE_REG_STRUCT(el3_state, CTX_EL3STATE_ALL);
  * correspond to either the secure or the non-secure state.
  */
 typedef struct {
-       gp_regs_next gpregs_ctx;
+       gp_regs gpregs_ctx;
        el3_state el3state_ctx;
        el1_sys_regs sysregs_ctx;
        fp_regs fpregs_ctx;
index 2150a55d1c3b051c9887eb7fa25f0f730f2a780b..b8c80779b3ad64fe326cf1624a4156e0ebb0747d 100644 (file)
@@ -46,6 +46,9 @@ extern void cm_el3_sysregs_context_save(uint32_t security_state);
 extern void cm_el3_sysregs_context_restore(uint32_t security_state);
 extern void cm_el1_sysregs_context_save(uint32_t security_state);
 extern void cm_el1_sysregs_context_restore(uint32_t security_state);
+extern void cm_set_el3_eret_context(uint32_t security_state, uint64_t entrypoint,
+               uint32_t spsr, uint32_t scr);
 extern void cm_set_next_eret_context(uint32_t security_state);
+extern void cm_init_exception_stack(uint64_t mpidr, uint32_t security_state);
 #endif /*__ASSEMBLY__*/
 #endif /* __CM_H__ */
index 3ee043ef880adc7539ed11d074e891af0a123a2e..ad202a9437bea27e79fd33681a7b6f935a30a650 100644 (file)
 #define SERROR_AARCH32                 0xf
 
 /*******************************************************************************
- * Constants that allow assembler code to access members of the 'gp_regs'
- * structure at their correct offsets.
+ * Structure definition, typedefs & constants for the runtime service framework
  ******************************************************************************/
-#define SIZEOF_GPREGS          0x110
-#define GPREGS_X0_OFF          0x0
-#define GPREGS_X1_OFF          0x8
-#define GPREGS_X2_OFF          0x10
-#define GPREGS_X3_OFF          0x18
-#define GPREGS_X4_OFF          0x20
-#define GPREGS_X5_OFF          0x28
-#define GPREGS_X6_OFF          0x30
-#define GPREGS_X7_OFF          0x38
-#define GPREGS_X8_OFF          0x40
-#define GPREGS_X9_OFF          0x48
-#define GPREGS_X10_OFF         0x50
-#define GPREGS_X11_OFF         0x58
-#define GPREGS_X12_OFF         0x60
-#define GPREGS_X13_OFF         0x68
-#define GPREGS_X14_OFF         0x70
-#define GPREGS_X15_OFF         0x78
-#define GPREGS_X16_OFF         0x80
-#define GPREGS_X17_OFF         0x88
-#define GPREGS_X18_OFF         0x90
-#define GPREGS_X19_OFF         0x98
-#define GPREGS_X20_OFF         0xA0
-#define GPREGS_X21_OFF         0xA8
-#define GPREGS_X22_OFF         0xB0
-#define GPREGS_X23_OFF         0xB8
-#define GPREGS_X24_OFF         0xC0
-#define GPREGS_X25_OFF         0xC8
-#define GPREGS_X26_OFF         0xD0
-#define GPREGS_X27_OFF         0xD8
-#define GPREGS_X28_OFF         0xE0
-#define GPREGS_SP_EL0_OFF      0xE8
-#define GPREGS_SPSR_OFF                0xF0
-#define GPREGS_FP_OFF          0x100
-#define GPREGS_LR_OFF          0x108
 
 /*
  * Constants to allow the assembler access a runtime service
@@ -218,46 +183,6 @@ typedef uint64_t (*rt_svc_handle)(uint32_t smc_fid,
                                  void *cookie,
                                  void *handle,
                                  uint64_t flags);
-typedef struct {
-       uint64_t x0;
-       uint64_t x1;
-       uint64_t x2;
-       uint64_t x3;
-       uint64_t x4;
-       uint64_t x5;
-       uint64_t x6;
-       uint64_t x7;
-       uint64_t x8;
-       uint64_t x9;
-       uint64_t x10;
-       uint64_t x11;
-       uint64_t x12;
-       uint64_t x13;
-       uint64_t x14;
-       uint64_t x15;
-       uint64_t x16;
-       uint64_t x17;
-       uint64_t x18;
-       uint64_t x19;
-       uint64_t x20;
-       uint64_t x21;
-       uint64_t x22;
-       uint64_t x23;
-       uint64_t x24;
-       uint64_t x25;
-       uint64_t x26;
-       uint64_t x27;
-       uint64_t x28;
-       uint64_t sp_el0;
-       uint32_t spsr;
-       /*
-        * Alignment constraint which allows save & restore of fp & lr on the
-        * stack during exception handling
-        */
-       uint64_t fp __aligned(16);
-       uint64_t lr;
-} __aligned(16) gp_regs;
-
 typedef struct {
        uint8_t start_oen;
        uint8_t end_oen;
@@ -280,16 +205,6 @@ typedef struct {
                        _setup, \
                        _smch }
 
-/*******************************************************************************
- * Compile time assertions to ensure that:
- * 1)  the assembler code's view of the size of the 'gp_regs' data structure is
- *     the same as the actual size of this data structure.
- * 2)  the assembler code's view of the offset of the frame pointer member of
- *     the 'gp_regs' structure is the same as the actual offset of this member.
- ******************************************************************************/
-CASSERT((sizeof(gp_regs) == SIZEOF_GPREGS), assert_sizeof_gpregs_mismatch);
-CASSERT(GPREGS_FP_OFF == __builtin_offsetof(gp_regs, fp), \
-       assert_gpregs_fp_offset_mismatch);
 /*
  * Compile time assertions related to the 'rt_svc_desc' structure to:
  * 1. ensure that the assembler and the compiler view of the size
@@ -323,6 +238,7 @@ CASSERT(RT_SVC_DESC_HANDLE == __builtin_offsetof(rt_svc_desc, handle), \
 extern void runtime_svc_init();
 extern uint64_t __RT_SVC_DESCS_START__;
 extern uint64_t __RT_SVC_DESCS_END__;
-
+extern uint64_t get_exception_stack(uint64_t mpidr);
+extern void fault_handler(void *handle);
 #endif /*__ASSEMBLY__*/
 #endif /* __RUNTIME_SVC_H__ */
index 37258e1e573937464528bfad5c15ff08300ab277..324be765d7f9b3d2213d9b980f4257315a452364 100644 (file)
@@ -31,9 +31,6 @@
 #include <arch_helpers.h>
 #include <runtime_svc.h>
 
-       .globl  save_regs
-       .globl  restore_regs
-
        .globl  enable_irq
        .globl  disable_irq
 
 
        .section        .text, "ax"
 
-save_regs: ; .type save_regs, %function
-       sub     sp, sp, #GPREGS_FP_OFF
-       stp     x0, x1, [sp, #GPREGS_X0_OFF]
-       stp     x2, x3, [sp, #GPREGS_X2_OFF]
-       stp     x4, x5, [sp, #GPREGS_X4_OFF]
-       stp     x6, x7, [sp, #GPREGS_X6_OFF]
-       stp     x8, x9, [sp, #GPREGS_X8_OFF]
-       stp     x10, x11, [sp, #GPREGS_X10_OFF]
-       stp     x12, x13, [sp, #GPREGS_X12_OFF]
-       stp     x14, x15, [sp, #GPREGS_X14_OFF]
-       stp     x16, x17, [sp, #GPREGS_X16_OFF]
-       stp     x18, x19, [sp, #GPREGS_X18_OFF]
-       stp     x20, x21, [sp, #GPREGS_X20_OFF]
-       stp     x22, x23, [sp, #GPREGS_X22_OFF]
-       stp     x24, x25, [sp, #GPREGS_X24_OFF]
-       stp     x26, x27, [sp, #GPREGS_X26_OFF]
-       mrs     x0, sp_el0
-       stp     x28, x0, [sp, #GPREGS_X28_OFF]
-       mrs     x0, spsr_el3
-       str     w0, [sp, #GPREGS_SPSR_OFF]
-       ret
-
-
-restore_regs: ; .type restore_regs, %function
-       ldr     w9, [sp, #GPREGS_SPSR_OFF]
-       msr     spsr_el3, x9
-       ldp     x28, x9, [sp, #GPREGS_X28_OFF]
-       msr     sp_el0, x9
-       ldp     x26, x27, [sp, #GPREGS_X26_OFF]
-       ldp     x24, x25, [sp, #GPREGS_X24_OFF]
-       ldp     x22, x23, [sp, #GPREGS_X22_OFF]
-       ldp     x20, x21, [sp, #GPREGS_X20_OFF]
-       ldp     x18, x19, [sp, #GPREGS_X18_OFF]
-       ldp     x16, x17, [sp, #GPREGS_X16_OFF]
-       ldp     x14, x15, [sp, #GPREGS_X14_OFF]
-       ldp     x12, x13, [sp, #GPREGS_X12_OFF]
-       ldp     x10, x11, [sp, #GPREGS_X10_OFF]
-       ldp     x8, x9, [sp, #GPREGS_X8_OFF]
-       ldp     x6, x7, [sp, #GPREGS_X6_OFF]
-       ldp     x4, x5, [sp, #GPREGS_X4_OFF]
-       ldp     x2, x3, [sp, #GPREGS_X2_OFF]
-       ldp     x0, x1, [sp, #GPREGS_X0_OFF]
-       add     sp, sp, #GPREGS_FP_OFF
-       ret
-
 get_afflvl_shift: ; .type get_afflvl_shift, %function
        cmp     x0, #3
        cinc    x0, x0, eq