diff options
Diffstat (limited to 'arch/arm64/mm/context.c')
| -rw-r--r-- | arch/arm64/mm/context.c | 52 |
1 files changed, 45 insertions, 7 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 8ef73e89d514..9b26f9a88724 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -6,6 +6,7 @@ * Copyright (C) 2012 ARM Ltd. */ +#include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/sched.h> #include <linux/slab.h> @@ -254,20 +255,59 @@ switch_mm_fastpath: /* Errata workaround post TTBRx_EL1 update. */ asmlinkage void post_ttbr_update_workaround(void) { + if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) + return; + asm(ALTERNATIVE("nop; nop; nop", "ic iallu; dsb nsh; isb", - ARM64_WORKAROUND_CAVIUM_27456, - CONFIG_CAVIUM_ERRATUM_27456)); + ARM64_WORKAROUND_CAVIUM_27456)); } -static int asids_init(void) +void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm) { - asid_bits = get_cpu_asid_bits(); + unsigned long ttbr1 = read_sysreg(ttbr1_el1); + unsigned long asid = ASID(mm); + unsigned long ttbr0 = phys_to_ttbr(pgd_phys); + + /* Skip CNP for the reserved ASID */ + if (system_supports_cnp() && asid) + ttbr0 |= TTBR_CNP_BIT; + + /* SW PAN needs a copy of the ASID in TTBR0 for entry */ + if (IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN)) + ttbr0 |= FIELD_PREP(TTBR_ASID_MASK, asid); + + /* Set ASID in TTBR1 since TCR.A1 is set */ + ttbr1 &= ~TTBR_ASID_MASK; + ttbr1 |= FIELD_PREP(TTBR_ASID_MASK, asid); + + write_sysreg(ttbr1, ttbr1_el1); + isb(); + write_sysreg(ttbr0, ttbr0_el1); + isb(); + post_ttbr_update_workaround(); +} + +static int asids_update_limit(void) +{ + 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 +322,6 @@ 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); |