summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/alternative.c
diff options
context:
space:
mode:
authorJames Morse <james.morse@arm.com>2018-01-08 15:38:06 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2018-01-13 10:44:33 +0000
commit6d99b68933fbcf51f84fcbba49246ce1209ec193 (patch)
tree894dd012b15f34f5c31f952fb52fc51485f24e9b /arch/arm64/kernel/alternative.c
parentc97e166e54b662717d20ec2e36761758d2b6a7c2 (diff)
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.c9
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(&region, true);
/* Barriers provided by the cache flushing */
- WRITE_ONCE(patched, 1);
+ WRITE_ONCE(alternatives_applied, 1);
}
return 0;