[MIPS] IP28: added cache barrier to assembly routines

IP28 needs special treatment to avoid speculative accesses. gcc
takes care for .c code, but for assembly code we need to do it
manually.

This is taken from Peter Fuersts IP28 patches.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S
index aded7b15905243661667a31df385cc505f42260a..01e450b1ebc9a7da9ac97eb78aab6446b1b47517 100644 (file)
--- a/arch/mips/lib/memcpy.S
+++ b/arch/mips/lib/memcpy.S
@@ -199,6 +199,7 @@ FEXPORT(__copy_user)
         */
 #define rem t8
 
+       R10KCBARRIER(0(ra))
        /*
         * The "issue break"s below are very approximate.
         * Issue delays for dcache fills will perturb the schedule, as will
@@ -231,6 +232,7 @@ both_aligned:
        PREF(   1, 3*32(dst) )
        .align  4
 1:
+       R10KCBARRIER(0(ra))
 EXC(   LOAD    t0, UNIT(0)(src),       l_exc)
 EXC(   LOAD    t1, UNIT(1)(src),       l_exc_copy)
 EXC(   LOAD    t2, UNIT(2)(src),       l_exc_copy)
@@ -272,6 +274,7 @@ EXC(        LOAD    t2, UNIT(2)(src),       l_exc_copy)
 EXC(   LOAD    t3, UNIT(3)(src),       l_exc_copy)
        SUB     len, len, 4*NBYTES
        ADD     src, src, 4*NBYTES
+       R10KCBARRIER(0(ra))
 EXC(   STORE   t0, UNIT(0)(dst),       s_exc_p4u)
 EXC(   STORE   t1, UNIT(1)(dst),       s_exc_p3u)
 EXC(   STORE   t2, UNIT(2)(dst),       s_exc_p2u)
@@ -287,6 +290,7 @@ less_than_4units:
        beq     rem, len, copy_bytes
         nop
 1:
+       R10KCBARRIER(0(ra))
 EXC(   LOAD    t0, 0(src),             l_exc)
        ADD     src, src, NBYTES
        SUB     len, len, NBYTES
@@ -334,6 +338,7 @@ EXC(        LDFIRST t3, FIRST(0)(src),      l_exc)
 EXC(   LDREST  t3, REST(0)(src),       l_exc_copy)
        SUB     t2, t2, t1      # t2 = number of bytes copied
        xor     match, t0, t1
+       R10KCBARRIER(0(ra))
 EXC(   STFIRST t3, FIRST(0)(dst),      s_exc)
        beq     len, t2, done
         SUB    len, len, t2
@@ -354,6 +359,7 @@ src_unaligned_dst_aligned:
  * It's OK to load FIRST(N+1) before REST(N) because the two addresses
  * are to the same unit (unless src is aligned, but it's not).
  */
+       R10KCBARRIER(0(ra))
 EXC(   LDFIRST t0, FIRST(0)(src),      l_exc)
 EXC(   LDFIRST t1, FIRST(1)(src),      l_exc_copy)
        SUB     len, len, 4*NBYTES
@@ -384,6 +390,7 @@ cleanup_src_unaligned:
        beq     rem, len, copy_bytes
         nop
 1:
+       R10KCBARRIER(0(ra))
 EXC(   LDFIRST t0, FIRST(0)(src),      l_exc)
 EXC(   LDREST  t0, REST(0)(src),       l_exc_copy)
        ADD     src, src, NBYTES
@@ -399,6 +406,7 @@ copy_bytes_checklen:
         nop
 copy_bytes:
        /* 0 < len < NBYTES  */
+       R10KCBARRIER(0(ra))
 #define COPY_BYTE(N)                   \
 EXC(   lb      t0, N(src), l_exc);     \
        SUB     len, len, 1;            \
@@ -528,6 +536,7 @@ LEAF(__rmemcpy)                                     /* a0=dst a1=src a2=len */
        ADD     a1, a2                          # src = src + len
 
 r_end_bytes:
+       R10KCBARRIER(0(ra))
        lb      t0, -1(a1)
        SUB     a2, a2, 0x1
        sb      t0, -1(a0)
@@ -542,6 +551,7 @@ r_out:
         move   a2, zero
 
 r_end_bytes_up:
+       R10KCBARRIER(0(ra))
        lb      t0, (a1)
        SUB     a2, a2, 0x1
        sb      t0, (a0)

diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index 3bf38422342f3a882fafb4cfe370b97106a56c65..c018a4721693dba157c0282d0ef665d2a114fc5b 100644 (file)
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -86,6 +86,7 @@ FEXPORT(__bzero)
        .set            at
 #endif
 
+       R10KCBARRIER(0(ra))
 #ifdef __MIPSEB__
        EX(LONG_S_L, a1, (a0), first_fixup)     /* make word/dword aligned */
 #endif
@@ -103,11 +104,13 @@ FEXPORT(__bzero)
        PTR_ADDU        t1, a0                  /* end address */
        .set            reorder
 1:     PTR_ADDIU       a0, 64
+       R10KCBARRIER(0(ra))
        f_fill64 a0, -64, a1, fwd_fixup
        bne             t1, a0, 1b
        .set            noreorder
 
 memset_partial:
+       R10KCBARRIER(0(ra))
        PTR_LA          t1, 2f                  /* where to start */
 #if LONGSIZE == 4
        PTR_SUBU        t1, t0
@@ -129,6 +132,7 @@ memset_partial:
 
        beqz            a2, 1f
         PTR_ADDU       a0, a2                  /* What's left */
+       R10KCBARRIER(0(ra))
 #ifdef __MIPSEB__
        EX(LONG_S_R, a1, -1(a0), last_fixup)
 #endif
@@ -143,6 +147,7 @@ small_memset:
         PTR_ADDU       t1, a0, a2
 
 1:     PTR_ADDIU       a0, 1                   /* fill bytewise */
+       R10KCBARRIER(0(ra))
        bne             t1, a0, 1b
         sb             a1, -1(a0)
 

diff --git a/arch/mips/lib/strncpy_user.S b/arch/mips/lib/strncpy_user.S
index 5c8fb9d6b7f97fa9d672e5578dec99c4c0473da9..8a63f72b81d33ac0bf5b5d32c4a0c04d14362d87 100644 (file)
--- a/arch/mips/lib/strncpy_user.S
+++ b/arch/mips/lib/strncpy_user.S
@@ -38,6 +38,7 @@ FEXPORT(__strncpy_from_user_nocheck_asm)
        .set            noreorder
 1:     EX(lbu, t0, (v1), fault)
        PTR_ADDIU       v1, 1
+       R10KCBARRIER(0(ra))
        beqz            t0, 2f
         sb             t0, (a0)
        PTR_ADDIU       v0, 1

diff --git a/include/asm-mips/asm.h b/include/asm-mips/asm.h
index 12e17581b823819187101d6277ff084d413e7ce5..608cfcfbb3eaad36da1e19f539bb3efa5084cfef 100644 (file)
--- a/include/asm-mips/asm.h
+++ b/include/asm-mips/asm.h
@@ -398,4 +398,12 @@ symbol             =       value
 
 #define SSNOP          sll zero, zero, 1
 
+#ifdef CONFIG_SGI_IP28
+/* Inhibit speculative stores to volatile (e.g.DMA) or invalid addresses. */
+#include <asm/cacheops.h>
+#define R10KCBARRIER(addr)  cache   Cache_Barrier, addr;
+#else
+#define R10KCBARRIER(addr)
+#endif
+
 #endif /* __ASM_ASM_H */