From: Diana Craciun diana.craciun@nxp.com
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@nxp.com [mpe: Add PPC_INST_ISYNC for backport] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- 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 --- 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") --- 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 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -315,6 +315,37 @@ void do_barrier_nospec_fixups(bool enabl } #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;