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authorJulien Grall <julien.grall@arm.com>2019-05-30 12:30:58 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2019-06-04 14:48:26 +0100
commit27e6e7d63fc2b43334ce79070a727a9ca6e58700 (patch)
treed0b4a6abbe15fed80c4b288739a814bbbd28b9a7
parent0c1f14ed12262f45a3af1d588e4d7bd12438b8f5 (diff)
arm64/cpufeature: Convert hook_lock to raw_spin_lock_t in cpu_enable_ssbs()
cpu_enable_ssbs() is called via stop_machine() as part of the cpu_enable callback. A spin lock is used to ensure the hook is registered before the rest of the callback is executed. On -RT spin_lock() may sleep. However, all the callees in stop_machine() are expected to not sleep. Therefore a raw_spin_lock() is required here. Given this is already done under stop_machine() and the work done under the lock is quite small, the latency should not increase too much. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/kernel/cpufeature.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index ca27e08e3d8a..2a7159fda3ce 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1194,14 +1194,14 @@ static struct undef_hook ssbs_emulation_hook = {
static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
{
static bool undef_hook_registered = false;
- static DEFINE_SPINLOCK(hook_lock);
+ static DEFINE_RAW_SPINLOCK(hook_lock);
- spin_lock(&hook_lock);
+ raw_spin_lock(&hook_lock);
if (!undef_hook_registered) {
register_undef_hook(&ssbs_emulation_hook);
undef_hook_registered = true;
}
- spin_unlock(&hook_lock);
+ raw_spin_unlock(&hook_lock);
if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);