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| author | Michal Suchanek <msuchanek@suse.de> | 2018-04-24 06:15:55 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-06-03 12:43:44 +0200 |
| commit | 2eea7f067f495e33b8b116b35b5988ab2b8aec55 (patch) | |
| tree | ed00f86636a5220a2ddd369284af72cf1deb79ff /arch/powerpc/include | |
| parent | powerpc/64s: Add barrier_nospec (diff) | |
| download | linux-2eea7f067f495e33b8b116b35b5988ab2b8aec55.tar.xz linux-2eea7f067f495e33b8b116b35b5988ab2b8aec55.zip | |
powerpc/64s: Add support for ori barrier_nospec patching
Based on the RFI patching. This is required to be able to disable the
speculation barrier.
Only one barrier type is supported and it does nothing when the
firmware does not enable it. Also re-patching modules is not supported
So the only meaningful thing that can be done is patching out the
speculation barrier at boot when the user says it is not wanted.
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/barrier.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/feature-fixups.h | 9 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/setup.h | 1 |
3 files changed, 11 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index e582d2c88092..f67b3f6e36be 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -81,7 +81,7 @@ do { \ * Prevent execution of subsequent instructions until preceding branches have * been fully resolved and are no longer executing speculatively. */ -#define barrier_nospec_asm ori 31,31,0 +#define barrier_nospec_asm NOSPEC_BARRIER_FIXUP_SECTION; nop // 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/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h index 1e82eb3caabd..86ac59e75f36 100644 --- a/arch/powerpc/include/asm/feature-fixups.h +++ b/arch/powerpc/include/asm/feature-fixups.h @@ -195,11 +195,20 @@ label##3: \ FTR_ENTRY_OFFSET 951b-952b; \ .popsection; +#define NOSPEC_BARRIER_FIXUP_SECTION \ +953: \ + .pushsection __barrier_nospec_fixup,"a"; \ + .align 2; \ +954: \ + FTR_ENTRY_OFFSET 953b-954b; \ + .popsection; + #ifndef __ASSEMBLY__ #include <linux/types.h> extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup; +extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup; void apply_feature_fixups(void); void setup_feature_keys(void); diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h index 27fa52ed6d00..afc7280cce3b 100644 --- a/arch/powerpc/include/asm/setup.h +++ b/arch/powerpc/include/asm/setup.h @@ -52,6 +52,7 @@ enum l1d_flush_type { void setup_rfi_flush(enum l1d_flush_type, bool enable); void do_rfi_flush_fixups(enum l1d_flush_type types); +void do_barrier_nospec_fixups(bool enable); #endif /* !__ASSEMBLY__ */ |