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powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3E 

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: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hifive-unleashed-5.1
Diana Craciun 2018-07-28 09:06:37 +10:00 committed by Michael Ellerman
parent 406d2b6ae3
commit ebcd1bfc33
3 changed files with 39 additions and 2 deletions
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2
arch/powerpc/Kconfig
View File

@ -245,7 +245,7 @@ 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 n

8
arch/powerpc/include/asm/barrier.h
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@ -78,12 +78,18 @@ do { \
___p1; \
})
#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")

31
arch/powerpc/lib/feature-fixups.c
View File

@ -318,6 +318,37 @@ 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;