diff options
| -rw-r--r-- | arch/arm64/include/asm/mmu_context.h | 19 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 28 |
2 files changed, 47 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index 2bb847ac7d10..70b1d831f12c 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -127,6 +127,25 @@ static inline void cpu_install_idmap(void) } /* + * Atomically replaces the active TTBR1_EL1 PGD with a new VA-compatible PGD, + * avoiding the possibility of conflicting TLB entries being allocated. + */ +static inline void cpu_replace_ttbr1(pgd_t *pgd) +{ + typedef void (ttbr_replace_func)(phys_addr_t); + extern ttbr_replace_func idmap_cpu_replace_ttbr1; + ttbr_replace_func *replace_phys; + + phys_addr_t pgd_phys = virt_to_phys(pgd); + + replace_phys = (void *)virt_to_phys(idmap_cpu_replace_ttbr1); + + cpu_install_idmap(); + replace_phys(pgd_phys); + cpu_uninstall_idmap(); +} + +/* * It would be nice to return ASIDs back to the allocator, but unfortunately * that introduces a race with a generation rollover where we could erroneously * free an ASID allocated in a future generation. We could workaround this by diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index f204862314ed..1d460089f4bc 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -141,6 +141,34 @@ ENTRY(cpu_do_switch_mm) ret ENDPROC(cpu_do_switch_mm) + .pushsection ".idmap.text", "ax" +/* + * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd) + * + * This is the low-level counterpart to cpu_replace_ttbr1, and should not be + * called by anything else. It can only be executed from a TTBR0 mapping. + */ +ENTRY(idmap_cpu_replace_ttbr1) + mrs x2, daif + msr daifset, #0xf + + adrp x1, empty_zero_page + msr ttbr1_el1, x1 + isb + + tlbi vmalle1 + dsb nsh + isb + + msr ttbr1_el1, x0 + isb + + msr daif, x2 + + ret +ENDPROC(idmap_cpu_replace_ttbr1) + .popsection + /* * __cpu_setup * |