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Commit ebcd1bfc authored by Diana Craciun's avatar Diana Craciun Committed by Michael Ellerman
Browse files

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: default avatarDiana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 406d2b6a

arch/powerpc/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/powerpc/include/asm/barrier.h

+7 −1
Original line number Diff line number Diff line
@@ -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")

arch/powerpc/lib/feature-fixups.c

+31 −0
Original line number Diff line number Diff line
@@ -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;