From: Diana Craciun <diana.craciun@xxxxxxx>
commit ebcd1bfc33c7a90df941df68a6e5d4018c022fba upstream.
Implement the barrier_nospec as a isync;sync instruction sequence.
The implementation uses the infrastructure built for BOOK3S 64.
Signed-off-by: Diana Craciun <diana.craciun@xxxxxxx>
[mpe: Add PPC_INST_ISYNC for backport]
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 2 +-
arch/powerpc/include/asm/barrier.h | 8 ++++++-
arch/powerpc/include/asm/ppc-opcode.h | 1 +
arch/powerpc/lib/feature-fixups.c | 31 +++++++++++++++++++++++++++
4 files changed, 40 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9d16459632bb..01b6c00a7060 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -165,7 +165,7 @@ config PPC
config PPC_BARRIER_NOSPEC
bool
default y
- depends on PPC_BOOK3S_64
+ depends on PPC_BOOK3S_64 || PPC_FSL_BOOK3E
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index a422e4a69c1a..e7cb72cdb2ba 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -92,12 +92,18 @@ do { \
#define smp_mb__after_atomic() smp_mb()
#define smp_mb__before_spinlock() smp_mb()
+#ifdef CONFIG_PPC_BOOK3S_64
+#define NOSPEC_BARRIER_SLOT nop
+#elif defined(CONFIG_PPC_FSL_BOOK3E)
+#define NOSPEC_BARRIER_SLOT nop; nop
+#endif
+
#ifdef CONFIG_PPC_BARRIER_NOSPEC
/*
* Prevent execution of subsequent instructions until preceding branches have
* been fully resolved and are no longer executing speculatively.
*/
-#define barrier_nospec_asm NOSPEC_BARRIER_FIXUP_SECTION; nop
+#define barrier_nospec_asm NOSPEC_BARRIER_FIXUP_SECTION; NOSPEC_BARRIER_SLOT
// This also acts as a compiler barrier due to the memory clobber.
#define barrier_nospec() asm (stringify_in_c(barrier_nospec_asm) ::: "memory")
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 7ab04fc59e24..faf1bb045dee 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -147,6 +147,7 @@
#define PPC_INST_LWSYNC 0x7c2004ac
#define PPC_INST_SYNC 0x7c0004ac
#define PPC_INST_SYNC_MASK 0xfc0007fe
+#define PPC_INST_ISYNC 0x4c00012c
#define PPC_INST_LXVD2X 0x7c000698
#define PPC_INST_MCRXR 0x7c000400
#define PPC_INST_MCRXR_MASK 0xfc0007fe
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 64f216af3c1f..68e089a48b2f 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -315,6 +315,37 @@ void do_barrier_nospec_fixups(bool enable)
}
#endif /* CONFIG_PPC_BARRIER_NOSPEC */
+#ifdef CONFIG_PPC_FSL_BOOK3E
+void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
+{
+ unsigned int instr[2], *dest;
+ long *start, *end;
+ int i;
+
+ start = fixup_start;
+ end = fixup_end;
+
+ instr[0] = PPC_INST_NOP;
+ instr[1] = PPC_INST_NOP;
+
+ if (enable) {
+ pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
+ instr[0] = PPC_INST_ISYNC;
+ instr[1] = PPC_INST_SYNC;
+ }
+
+ for (i = 0; start < end; start++, i++) {
+ dest = (void *)start + *start;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+ patch_instruction(dest, instr[0]);
+ patch_instruction(dest + 1, instr[1]);
+ }
+
+ printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
+}
+#endif /* CONFIG_PPC_FSL_BOOK3E */
+
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
long *start, *end;
--
2.20.1
