diff options
| author | Julien Grall <julien.grall@arm.com> | 2019-05-30 12:30:58 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-04 14:48:26 +0100 |
| commit | 27e6e7d63fc2b43334ce79070a727a9ca6e58700 (patch) | |
| tree | d0b4a6abbe15fed80c4b288739a814bbbd28b9a7 | |
| parent | 0c1f14ed12262f45a3af1d588e4d7bd12438b8f5 (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.c | 6 |
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); |