From: Vincent Chen Date: Wed, 17 Jan 2024 14:03:33 +0000 (+0800) Subject: riscv: mm: execute local TLB flush after populating vmemmap X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d9807d60c145836043ffa602328ea1d66dc458b1;p=linux.git riscv: mm: execute local TLB flush after populating vmemmap The spare_init() calls memmap_populate() many times to create VA to PA mapping for the VMEMMAP area, where all "struct page" are located once CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later initialized in the zone_sizes_init() function. However, during this process, no sfence.vma instruction is executed for this VMEMMAP area. This omission may cause the hart to fail to perform page table walk because some data related to the address translation is invisible to the hart. To solve this issue, the local_flush_tlb_kernel_range() is called right after the sparse_init() to execute a sfence.vma instruction for this VMEMMAP area, ensuring that all data related to the address translation is visible to the hart. Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: Vincent Chen Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240117140333.2479667-1-vincent.chen@sifive.com Fixes: 7a92fc8b4d20 ("mm: Introduce flush_cache_vmap_early()") Signed-off-by: Palmer Dabbelt --- diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h index 928f096dca21b..4112cc8d1d69f 100644 --- a/arch/riscv/include/asm/tlbflush.h +++ b/arch/riscv/include/asm/tlbflush.h @@ -75,6 +75,7 @@ static inline void flush_tlb_kernel_range(unsigned long start, #define flush_tlb_mm(mm) flush_tlb_all() #define flush_tlb_mm_range(mm, start, end, page_size) flush_tlb_all() +#define local_flush_tlb_kernel_range(start, end) flush_tlb_all() #endif /* !CONFIG_SMP || !CONFIG_MMU */ #endif /* _ASM_RISCV_TLBFLUSH_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 32cad6a65ccd2..fa34cf55037bd 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1385,6 +1385,10 @@ void __init misc_mem_init(void) early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); arch_numa_init(); sparse_init(); +#ifdef CONFIG_SPARSEMEM_VMEMMAP + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); +#endif zone_sizes_init(); arch_reserve_crashkernel(); memblock_dump_all(); diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c index 8d12b26f5ac37..dffb0e5bd9425 100644 --- a/arch/riscv/mm/tlbflush.c +++ b/arch/riscv/mm/tlbflush.c @@ -66,9 +66,10 @@ static inline void local_flush_tlb_range_asid(unsigned long start, local_flush_tlb_range_threshold_asid(start, size, stride, asid); } +/* Flush a range of kernel pages without broadcasting */ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end) { - local_flush_tlb_range_asid(start, end, PAGE_SIZE, FLUSH_TLB_NO_ASID); + local_flush_tlb_range_asid(start, end - start, PAGE_SIZE, FLUSH_TLB_NO_ASID); } static void __ipi_flush_tlb_all(void *info)