[PATCH v4 5/6] powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3E
Diana Craciun
diana.craciun at nxp.com
Tue Jul 17 21:09:56 AEST 2018
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 at nxp.com>
---
History:
v3-->v4
- fixed compilation issues
v2-->v3
- added PPC_NOSPEC Kconfig
- addressed the review comments
It was a discussion at the previous review cycle about the place in the code
where to call setup_barrier_nospec. I have chosen to call the function in the
common code in order to be re-used on multiple platforms. However, I am not sure
that changes concerning powernv/pseries are correct, I need some input here.
arch/powerpc/include/asm/barrier.h | 12 +++++++++---
arch/powerpc/include/asm/setup.h | 6 +++++-
arch/powerpc/kernel/Makefile | 3 ++-
arch/powerpc/kernel/module.c | 4 +++-
arch/powerpc/kernel/setup-common.c | 2 ++
arch/powerpc/kernel/vmlinux.lds.S | 4 +++-
arch/powerpc/lib/feature-fixups.c | 35 +++++++++++++++++++++++++++++++++-
arch/powerpc/platforms/powernv/setup.c | 1 -
arch/powerpc/platforms/pseries/setup.c | 1 -
9 files changed, 58 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index f67b3f6..0bdfa81 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -77,19 +77,25 @@ do { \
})
#ifdef CONFIG_PPC_BOOK3S_64
+#define NOSPEC_BARRIER_SLOT nop
+#elif defined(CONFIG_PPC_FSL_BOOK3E)
+#define NOSPEC_BARRIER_SLOT nop; nop
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_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")
-#else /* !CONFIG_PPC_BOOK3S_64 */
+#else /* !CONFIG_PPC_NOSPEC */
#define barrier_nospec_asm
#define barrier_nospec()
-#endif
+#endif /* CONFIG_PPC_NOSPEC */
#include <asm-generic/barrier.h>
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 8721fd0..a794a40 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -52,11 +52,15 @@ enum l1d_flush_type {
void setup_rfi_flush(enum l1d_flush_type, bool enable);
void do_rfi_flush_fixups(enum l1d_flush_type types);
+#ifdef CONFIG_PPC_NOSPEC
void setup_barrier_nospec(void);
+#else
+static inline void setup_barrier_nospec(void) { };
+#endif
void do_barrier_nospec_fixups(bool enable);
extern bool barrier_nospec_enabled;
-#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_NOSPEC
void do_barrier_nospec_fixups_range(bool enable, void *start, void *end);
#else
static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2b4c40b2..cd0eb38 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -42,9 +42,10 @@ obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
-obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o security.o
+obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o
obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o
+obj-$(CONFIG_PPC_NOSPEC) += security.o
obj-$(CONFIG_PPC64) += vdso64/
obj-$(CONFIG_ALTIVEC) += vecemu.o
obj-$(CONFIG_PPC_970_NAP) += idle_power4.o
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 1b3c683..a0c4967 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -72,13 +72,15 @@ int module_finalize(const Elf_Ehdr *hdr,
do_feature_fixups(powerpc_firmware_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
+#endif /* CONFIG_PPC64 */
+#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_FSL_BOOK3E)
sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
if (sect != NULL)
do_barrier_nospec_fixups_range(barrier_nospec_enabled,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
-#endif
+#endif /* CONFIG_PPC64 || CONFIG_PPC_FSL_BOOK3E */
sect = find_section(hdr, sechdrs, "__lwsync_fixup");
if (sect != NULL)
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 40b44bb..93fa0c9 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -972,6 +972,8 @@ void __init setup_arch(char **cmdline_p)
if (ppc_md.setup_arch)
ppc_md.setup_arch();
+ setup_barrier_nospec();
+
paging_init();
/* Initialize the MMU context management stuff. */
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 5baac79..6087b02 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -153,14 +153,16 @@ SECTIONS
*(__rfi_flush_fixup)
__stop___rfi_flush_fixup = .;
}
+#endif /* CONFIG_PPC64 */
+#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_FSL_BOOK3E)
. = ALIGN(8);
__spec_barrier_fixup : AT(ADDR(__spec_barrier_fixup) - LOAD_OFFSET) {
__start___barrier_nospec_fixup = .;
*(__barrier_nospec_fixup)
__stop___barrier_nospec_fixup = .;
}
-#endif
+#endif /* CONFIG_PPC64 || CONFIG_PPC_FSL_BOOK3E */
EXCEPTION_TABLE(0)
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 8b69f86..41f372e 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -304,6 +304,9 @@ void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_
printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_NOSPEC
void do_barrier_nospec_fixups(bool enable)
{
void *start, *end;
@@ -313,8 +316,38 @@ void do_barrier_nospec_fixups(bool enable)
do_barrier_nospec_fixups_range(enable, start, end);
}
+#endif /* CONFIG_PPC_NOSPEC */
-#endif /* CONFIG_PPC_BOOK3S_64 */
+#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)
{
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index f96df0a..1ab6dc7 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -124,7 +124,6 @@ static void pnv_setup_rfi_flush(void)
security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
setup_rfi_flush(type, enable);
- setup_barrier_nospec();
}
static void __init pnv_setup_arch(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 139f0af..fdb32e0 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -534,7 +534,6 @@ void pseries_setup_rfi_flush(void)
security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR);
setup_rfi_flush(types, enable);
- setup_barrier_nospec();
}
#ifdef CONFIG_PCI_IOV
--
2.5.5
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