@@ -14,8 +14,6 @@
#include <linux/stddef.h>
#include <linux/stringify.h>
-extern int alternatives_applied;
-
struct alt_instr {
s32 orig_offset; /* offset to original instruction */
s32 alt_offset; /* offset to replacement instruction */
@@ -28,6 +26,7 @@ typedef void (*alternative_cb_t)(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void __init apply_alternatives_all(void);
+bool alternative_is_applied(u16 cpufeature);
#ifdef CONFIG_MODULES
void apply_alternatives_module(void *start, size_t length);
@@ -32,13 +32,23 @@
#define ALT_ORIG_PTR(a) __ALT_PTR(a, orig_offset)
#define ALT_REPL_PTR(a) __ALT_PTR(a, alt_offset)
-int alternatives_applied;
+static int all_alternatives_applied;
+
+static DECLARE_BITMAP(applied_alternatives, ARM64_NCAPS);
struct alt_region {
struct alt_instr *begin;
struct alt_instr *end;
};
+bool alternative_is_applied(u16 cpufeature)
+{
+ if (WARN_ON(cpufeature >= ARM64_NCAPS))
+ return false;
+
+ return test_bit(cpufeature, applied_alternatives);
+}
+
/*
* Check if the target PC is within an alternative block.
*/
@@ -192,6 +202,9 @@ static void __apply_alternatives(void *alt_region, bool is_module)
dsb(ish);
__flush_icache_all();
isb();
+
+ /* We applied all that was available */
+ bitmap_copy(applied_alternatives, cpu_hwcaps, ARM64_NCAPS);
}
}
@@ -208,14 +221,14 @@ static int __apply_alternatives_multi_stop(void *unused)
/* We always have a CPU 0 at this point (__init) */
if (smp_processor_id()) {
- while (!READ_ONCE(alternatives_applied))
+ while (!READ_ONCE(all_alternatives_applied))
cpu_relax();
isb();
} else {
- BUG_ON(alternatives_applied);
+ BUG_ON(all_alternatives_applied);
__apply_alternatives(®ion, false);
/* Barriers provided by the cache flushing */
- WRITE_ONCE(alternatives_applied, 1);
+ WRITE_ONCE(all_alternatives_applied, 1);
}
return 0;
@@ -1068,7 +1068,7 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
* that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
* do anything here.
*/
- if (!alternatives_applied)
+ if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
}
#endif
In preparation for the application of alternatives at different points during the boot process, provide the possibility to check whether alternatives for a feature of interest was already applied instead of having a global boolean for all alternatives. Make VHE enablement code check for the VHE feature instead of considering all alternatives. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Marc Zyngier <Marc.Zyngier@arm.com> Cc: Christoffer Dall <Christoffer.Dall@arm.com> --- arch/arm64/include/asm/alternative.h | 3 +-- arch/arm64/kernel/alternative.c | 21 +++++++++++++++++---- arch/arm64/kernel/cpufeature.c | 2 +- 3 files changed, 19 insertions(+), 7 deletions(-)