+++ /dev/null
-/*
- * ICSWX and ACOP Management
- *
- * Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/uaccess.h>
-
-#include "icswx.h"
-
-/*
- * The processor and its L2 cache cause the icswx instruction to
- * generate a COP_REQ transaction on PowerBus. The transaction has no
- * address, and the processor does not perform an MMU access to
- * authenticate the transaction. The command portion of the PowerBus
- * COP_REQ transaction includes the LPAR_ID (LPID) and the coprocessor
- * Process ID (PID), which the coprocessor compares to the authorized
- * LPID and PID held in the coprocessor, to determine if the process
- * is authorized to generate the transaction. The data of the COP_REQ
- * transaction is 128-byte or less in size and is placed in cacheable
- * memory on a 128-byte cache line boundary.
- *
- * The task to use a coprocessor should use use_cop() to mark the use
- * of the Coprocessor Type (CT) and context switching. On a server
- * class processor, the PID register is used only for coprocessor
- * management + * and so a coprocessor PID is allocated before
- * executing icswx + * instruction. Drop_cop() is used to free the
- * coprocessor PID.
- *
- * Example:
- * Host Fabric Interface (HFI) is a PowerPC network coprocessor.
- * Each HFI have multiple windows. Each HFI window serves as a
- * network device sending to and receiving from HFI network.
- * HFI immediate send function uses icswx instruction. The immediate
- * send function allows small (single cache-line) packets be sent
- * without using the regular HFI send FIFO and doorbell, which are
- * much slower than immediate send.
- *
- * For each task intending to use HFI immediate send, the HFI driver
- * calls use_cop() to obtain a coprocessor PID for the task.
- * The HFI driver then allocate a free HFI window and save the
- * coprocessor PID to the HFI window to allow the task to use the
- * HFI window.
- *
- * The HFI driver repeatedly creates immediate send packets and
- * issues icswx instruction to send data through the HFI window.
- * The HFI compares the coprocessor PID in the CPU PID register
- * to the PID held in the HFI window to determine if the transaction
- * is allowed.
- *
- * When the task to release the HFI window, the HFI driver calls
- * drop_cop() to release the coprocessor PID.
- */
-
-void switch_cop(struct mm_struct *next)
-{
-#ifdef CONFIG_PPC_ICSWX_PID
- mtspr(SPRN_PID, next->context.cop_pid);
-#endif
- mtspr(SPRN_ACOP, next->context.acop);
-}
-
-/**
- * Start using a coprocessor.
- * @acop: mask of coprocessor to be used.
- * @mm: The mm the coprocessor to associate with. Most likely current mm.
- *
- * Return a positive PID if successful. Negative errno otherwise.
- * The returned PID will be fed to the coprocessor to determine if an
- * icswx transaction is authenticated.
- */
-int use_cop(unsigned long acop, struct mm_struct *mm)
-{
- int ret;
-
- if (!cpu_has_feature(CPU_FTR_ICSWX))
- return -ENODEV;
-
- if (!mm || !acop)
- return -EINVAL;
-
- /* The page_table_lock ensures mm_users won't change under us */
- spin_lock(&mm->page_table_lock);
- spin_lock(mm->context.cop_lockp);
-
- ret = get_cop_pid(mm);
- if (ret < 0)
- goto out;
-
- /* update acop */
- mm->context.acop |= acop;
-
- sync_cop(mm);
-
- /*
- * If this is a threaded process then there might be other threads
- * running. We need to send an IPI to force them to pick up any
- * change in PID and ACOP.
- */
- if (atomic_read(&mm->mm_users) > 1)
- smp_call_function(sync_cop, mm, 1);
-
-out:
- spin_unlock(mm->context.cop_lockp);
- spin_unlock(&mm->page_table_lock);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(use_cop);
-
-/**
- * Stop using a coprocessor.
- * @acop: mask of coprocessor to be stopped.
- * @mm: The mm the coprocessor associated with.
- */
-void drop_cop(unsigned long acop, struct mm_struct *mm)
-{
- int free_pid;
-
- if (!cpu_has_feature(CPU_FTR_ICSWX))
- return;
-
- if (WARN_ON_ONCE(!mm))
- return;
-
- /* The page_table_lock ensures mm_users won't change under us */
- spin_lock(&mm->page_table_lock);
- spin_lock(mm->context.cop_lockp);
-
- mm->context.acop &= ~acop;
-
- free_pid = disable_cop_pid(mm);
- sync_cop(mm);
-
- /*
- * If this is a threaded process then there might be other threads
- * running. We need to send an IPI to force them to pick up any
- * change in PID and ACOP.
- */
- if (atomic_read(&mm->mm_users) > 1)
- smp_call_function(sync_cop, mm, 1);
-
- if (free_pid != COP_PID_NONE)
- free_cop_pid(free_pid);
-
- spin_unlock(mm->context.cop_lockp);
- spin_unlock(&mm->page_table_lock);
-}
-EXPORT_SYMBOL_GPL(drop_cop);
-
-static int acop_use_cop(int ct)
-{
- /* There is no alternate policy, yet */
- return -1;
-}
-
-/*
- * Get the instruction word at the NIP
- */
-static u32 acop_get_inst(struct pt_regs *regs)
-{
- u32 inst;
- u32 __user *p;
-
- p = (u32 __user *)regs->nip;
- if (!access_ok(VERIFY_READ, p, sizeof(*p)))
- return 0;
-
- if (__get_user(inst, p))
- return 0;
-
- return inst;
-}
-
-/**
- * @regs: registers at time of interrupt
- * @address: storage address
- * @error_code: Fault code, usually the DSISR or ESR depending on
- * processor type
- *
- * Return 0 if we are able to resolve the data storage fault that
- * results from a CT miss in the ACOP register.
- */
-int acop_handle_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
-{
- int ct;
- u32 inst = 0;
-
- if (!cpu_has_feature(CPU_FTR_ICSWX)) {
- pr_info("No coprocessors available");
- _exception(SIGILL, regs, ILL_ILLOPN, address);
- }
-
- if (!user_mode(regs)) {
- /* this could happen if the HV denies the
- * kernel access, for now we just die */
- die("ICSWX from kernel failed", regs, SIGSEGV);
- }
-
- /* Some implementations leave us a hint for the CT */
- ct = ICSWX_GET_CT_HINT(error_code);
- if (ct < 0) {
- /* we have to peek at the instruction word to figure out CT */
- u32 ccw;
- u32 rs;
-
- inst = acop_get_inst(regs);
- if (inst == 0)
- return -1;
-
- rs = (inst >> (31 - 10)) & 0x1f;
- ccw = regs->gpr[rs];
- ct = (ccw >> 16) & 0x3f;
- }
-
- /*
- * We could be here because another thread has enabled acop
- * but the ACOP register has yet to be updated.
- *
- * This should have been taken care of by the IPI to sync all
- * the threads (see smp_call_function(sync_cop, mm, 1)), but
- * that could take forever if there are a significant amount
- * of threads.
- *
- * Given the number of threads on some of these systems,
- * perhaps this is the best way to sync ACOP rather than whack
- * every thread with an IPI.
- */
- if ((acop_copro_type_bit(ct) & current->active_mm->context.acop) != 0) {
- sync_cop(current->active_mm);
- return 0;
- }
-
- /* check for alternate policy */
- if (!acop_use_cop(ct))
- return 0;
-
- /* at this point the CT is unknown to the system */
- pr_warn("%s[%d]: Coprocessor %d is unavailable\n",
- current->comm, current->pid, ct);
-
- /* get inst if we don't already have it */
- if (inst == 0) {
- inst = acop_get_inst(regs);
- if (inst == 0)
- return -1;
- }
-
- /* Check if the instruction is the "record form" */
- if (inst & 1) {
- /*
- * the instruction is "record" form so we can reject
- * using CR0
- */
- regs->ccr &= ~(0xful << 28);
- regs->ccr |= ICSWX_RC_NOT_FOUND << 28;
-
- /* Move on to the next instruction */
- regs->nip += 4;
- } else {
- /*
- * There is no architected mechanism to report a bad
- * CT so we could either SIGILL or report nothing.
- * Since the non-record version should only bu used
- * for "hints" or "don't care" we should probably do
- * nothing. However, I could see how some people
- * might want an SIGILL so it here if you want it.
- */
-#ifdef CONFIG_PPC_ICSWX_USE_SIGILL
- _exception(SIGILL, regs, ILL_ILLOPN, address);
-#else
- regs->nip += 4;
-#endif
- }
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(acop_handle_fault);
+++ /dev/null
-#ifndef _ARCH_POWERPC_MM_ICSWX_H_
-#define _ARCH_POWERPC_MM_ICSWX_H_
-
-/*
- * ICSWX and ACOP Management
- *
- * Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- */
-
-#include <asm/mmu_context.h>
-
-/* also used to denote that PIDs are not used */
-#define COP_PID_NONE 0
-
-static inline void sync_cop(void *arg)
-{
- struct mm_struct *mm = arg;
-
- if (mm == current->active_mm)
- switch_cop(current->active_mm);
-}
-
-#ifdef CONFIG_PPC_ICSWX_PID
-extern int get_cop_pid(struct mm_struct *mm);
-extern int disable_cop_pid(struct mm_struct *mm);
-extern void free_cop_pid(int free_pid);
-#else
-#define get_cop_pid(m) (COP_PID_NONE)
-#define disable_cop_pid(m) (COP_PID_NONE)
-#define free_cop_pid(p)
-#endif
-
-/*
- * These are implementation bits for architected registers. If this
- * ever becomes architecture the should be moved to reg.h et. al.
- */
-/* UCT is the same bit for Server and Embedded */
-#define ICSWX_DSI_UCT 0x00004000 /* Unavailable Coprocessor Type */
-
-#ifdef CONFIG_PPC_BOOK3E
-/* Embedded implementation gives us no hints as to what the CT is */
-#define ICSWX_GET_CT_HINT(x) (-1)
-#else
-/* Server implementation contains the CT value in the DSISR */
-#define ICSWX_DSISR_CTMASK 0x00003f00
-#define ICSWX_GET_CT_HINT(x) (((x) & ICSWX_DSISR_CTMASK) >> 8)
-#endif
-
-#define ICSWX_RC_STARTED 0x8 /* The request has been started */
-#define ICSWX_RC_NOT_IDLE 0x4 /* No coprocessor found idle */
-#define ICSWX_RC_NOT_FOUND 0x2 /* No coprocessor found */
-#define ICSWX_RC_UNDEFINED 0x1 /* Reserved */
-
-extern int acop_handle_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code);
-
-static inline u64 acop_copro_type_bit(unsigned int type)
-{
- return 1ULL << (63 - type);
-}
-
-#endif /* !_ARCH_POWERPC_MM_ICSWX_H_ */
+++ /dev/null
-/*
- * ICSWX and ACOP/PID Management
- *
- * Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/spinlock.h>
-#include <linux/idr.h>
-#include <linux/module.h>
-#include "icswx.h"
-
-#define COP_PID_MIN (COP_PID_NONE + 1)
-#define COP_PID_MAX (0xFFFF)
-
-static DEFINE_SPINLOCK(mmu_context_acop_lock);
-static DEFINE_IDA(cop_ida);
-
-static int new_cop_pid(struct ida *ida, int min_id, int max_id,
- spinlock_t *lock)
-{
- int index;
- int err;
-
-again:
- if (!ida_pre_get(ida, GFP_KERNEL))
- return -ENOMEM;
-
- spin_lock(lock);
- err = ida_get_new_above(ida, min_id, &index);
- spin_unlock(lock);
-
- if (err == -EAGAIN)
- goto again;
- else if (err)
- return err;
-
- if (index > max_id) {
- spin_lock(lock);
- ida_remove(ida, index);
- spin_unlock(lock);
- return -ENOMEM;
- }
-
- return index;
-}
-
-int get_cop_pid(struct mm_struct *mm)
-{
- int pid;
-
- if (mm->context.cop_pid == COP_PID_NONE) {
- pid = new_cop_pid(&cop_ida, COP_PID_MIN, COP_PID_MAX,
- &mmu_context_acop_lock);
- if (pid >= 0)
- mm->context.cop_pid = pid;
- }
- return mm->context.cop_pid;
-}
-
-int disable_cop_pid(struct mm_struct *mm)
-{
- int free_pid = COP_PID_NONE;
-
- if ((!mm->context.acop) && (mm->context.cop_pid != COP_PID_NONE)) {
- free_pid = mm->context.cop_pid;
- mm->context.cop_pid = COP_PID_NONE;
- }
- return free_pid;
-}
-
-void free_cop_pid(int free_pid)
-{
- spin_lock(&mmu_context_acop_lock);
- ida_remove(&cop_ida, free_pid);
- spin_unlock(&mmu_context_acop_lock);
-}
projects / openwrt / staging / blogic.git / commitdiff