diff options
| author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2020-02-27 09:34:47 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-03-02 12:10:38 +0000 |
| commit | 9abd515a6e4a5c58c6eb4d04110430325eb5f5ac (patch) | |
| tree | a28cd22425a5ecb8c68df9aec0ff08c26c041c91 /arch | |
| parent | 3ba52ad55b533760a1f65836aa0ec9d35e36bb4f (diff) | |
arm64: context: Fix ASID limit in boot messages
Since commit f88f42f853a8 ("arm64: context: Free up kernel ASIDs if KPTI
is not in use"), the NUM_USER_ASIDS macro doesn't correspond to the
effective number of ASIDs when KPTI is enabled. Get an accurate number
of available ASIDs in an arch_initcall, once we've discovered all CPUs'
capabilities and know if we still need to halve the ASID space for KPTI.
Fixes: f88f42f853a8 ("arm64: context: Free up kernel ASIDs if KPTI is not in use")
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/mm/context.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 8ef73e89d514..d89bb22589f6 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -260,14 +260,26 @@ asmlinkage void post_ttbr_update_workaround(void) CONFIG_CAVIUM_ERRATUM_27456)); } -static int asids_init(void) +static int asids_update_limit(void) { - asid_bits = get_cpu_asid_bits(); + unsigned long num_available_asids = NUM_USER_ASIDS; + + if (arm64_kernel_unmapped_at_el0()) + num_available_asids /= 2; /* * Expect allocation after rollover to fail if we don't have at least * one more ASID than CPUs. ASID #0 is reserved for init_mm. */ - WARN_ON(NUM_USER_ASIDS - 1 <= num_possible_cpus()); + WARN_ON(num_available_asids - 1 <= num_possible_cpus()); + pr_info("ASID allocator initialised with %lu entries\n", + num_available_asids); + return 0; +} +arch_initcall(asids_update_limit); + +static int asids_init(void) +{ + asid_bits = get_cpu_asid_bits(); atomic64_set(&asid_generation, ASID_FIRST_VERSION); asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS), sizeof(*asid_map), GFP_KERNEL); @@ -282,8 +294,6 @@ static int asids_init(void) */ if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) set_kpti_asid_bits(); - - pr_info("ASID allocator initialised with %lu entries\n", NUM_USER_ASIDS); return 0; } early_initcall(asids_init); |