From 3f1e782998cdf6dac037588b99b10b787b00810a Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Sun, 6 Jun 2021 17:20:50 +0200 Subject: riscv: add ASID-based tlbflushing methods Implement optimized version of the tlb flushing routines for systems using ASIDs. These are behind the use_asid_allocator static branch to not affect existing systems not using ASIDs. Signed-off-by: Guo Ren [hch: rebased on top of previous cleanups, use the same algorithm as the non-ASID based code for local vs global flushes, keep functions as local as possible] Signed-off-by: Christoph Hellwig Tested-by: Guo Ren Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/mmu_context.h | 2 ++ arch/riscv/mm/context.c | 2 +- arch/riscv/mm/tlbflush.c | 47 ++++++++++++++++++++++++++++++------ 3 files changed, 43 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/riscv/include/asm/mmu_context.h b/arch/riscv/include/asm/mmu_context.h index b0659413a080..7030837adc1a 100644 --- a/arch/riscv/include/asm/mmu_context.h +++ b/arch/riscv/include/asm/mmu_context.h @@ -33,6 +33,8 @@ static inline int init_new_context(struct task_struct *tsk, return 0; } +DECLARE_STATIC_KEY_FALSE(use_asid_allocator); + #include #endif /* _ASM_RISCV_MMU_CONTEXT_H */ diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c index 25cb406737d4..ee3459cb6750 100644 --- a/arch/riscv/mm/context.c +++ b/arch/riscv/mm/context.c @@ -18,7 +18,7 @@ #ifdef CONFIG_MMU -static DEFINE_STATIC_KEY_FALSE(use_asid_allocator); +DEFINE_STATIC_KEY_FALSE(use_asid_allocator); static unsigned long asid_bits; static unsigned long num_asids; diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c index b458949fa8df..64f8201237c2 100644 --- a/arch/riscv/mm/tlbflush.c +++ b/arch/riscv/mm/tlbflush.c @@ -4,6 +4,24 @@ #include #include #include +#include + +static inline void local_flush_tlb_all_asid(unsigned long asid) +{ + __asm__ __volatile__ ("sfence.vma x0, %0" + : + : "r" (asid) + : "memory"); +} + +static inline void local_flush_tlb_page_asid(unsigned long addr, + unsigned long asid) +{ + __asm__ __volatile__ ("sfence.vma %0, %1" + : + : "r" (addr), "r" (asid) + : "memory"); +} void flush_tlb_all(void) { @@ -16,21 +34,36 @@ static void __sbi_tlb_flush_range(struct mm_struct *mm, unsigned long start, struct cpumask *cmask = mm_cpumask(mm); struct cpumask hmask; unsigned int cpuid; + bool broadcast; if (cpumask_empty(cmask)) return; cpuid = get_cpu(); + /* check if the tlbflush needs to be sent to other CPUs */ + broadcast = cpumask_any_but(cmask, cpuid) < nr_cpu_ids; + if (static_branch_unlikely(&use_asid_allocator)) { + unsigned long asid = atomic_long_read(&mm->context.id); - if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) { - /* local cpu is the only cpu present in cpumask */ - if (size <= stride) + if (broadcast) { + riscv_cpuid_to_hartid_mask(cmask, &hmask); + sbi_remote_sfence_vma_asid(cpumask_bits(&hmask), + start, size, asid); + } else if (size <= stride) { + local_flush_tlb_page_asid(start, asid); + } else { + local_flush_tlb_all_asid(asid); + } + } else { + if (broadcast) { + riscv_cpuid_to_hartid_mask(cmask, &hmask); + sbi_remote_sfence_vma(cpumask_bits(&hmask), + start, size); + } else if (size <= stride) { local_flush_tlb_page(start); - else + } else { local_flush_tlb_all(); - } else { - riscv_cpuid_to_hartid_mask(cmask, &hmask); - sbi_remote_sfence_vma(cpumask_bits(&hmask), start, size); + } } put_cpu(); -- cgit v1.2.3