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| author | James Morse <james.morse@arm.com> | 2018-01-08 15:38:06 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-13 10:44:33 +0000 |
| commit | 6d99b68933fbcf51f84fcbba49246ce1209ec193 (patch) | |
| tree | 894dd012b15f34f5c31f952fb52fc51485f24e9b /arch/arm64/kernel/alternative.c | |
| parent | c97e166e54b662717d20ec2e36761758d2b6a7c2 (diff) | |
| download | lwn-6d99b68933fbcf51f84fcbba49246ce1209ec193.tar.gz lwn-6d99b68933fbcf51f84fcbba49246ce1209ec193.zip | |
arm64: alternatives: use tpidr_el2 on VHE hosts
Now that KVM uses tpidr_el2 in the same way as Linux's cpu_offset in
tpidr_el1, merge the two. This saves KVM from save/restoring tpidr_el1
on VHE hosts, and allows future code to blindly access per-cpu variables
without triggering world-switch.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/alternative.c')
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 6dd0a3a3e5c9..414288a558c8 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -32,6 +32,8 @@ #define ALT_ORIG_PTR(a) __ALT_PTR(a, orig_offset) #define ALT_REPL_PTR(a) __ALT_PTR(a, alt_offset) +int alternatives_applied; + struct alt_region { struct alt_instr *begin; struct alt_instr *end; @@ -143,7 +145,6 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias) */ static int __apply_alternatives_multi_stop(void *unused) { - static int patched = 0; struct alt_region region = { .begin = (struct alt_instr *)__alt_instructions, .end = (struct alt_instr *)__alt_instructions_end, @@ -151,14 +152,14 @@ 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(patched)) + while (!READ_ONCE(alternatives_applied)) cpu_relax(); isb(); } else { - BUG_ON(patched); + BUG_ON(alternatives_applied); __apply_alternatives(®ion, true); /* Barriers provided by the cache flushing */ - WRITE_ONCE(patched, 1); + WRITE_ONCE(alternatives_applied, 1); } return 0; |