From ff172d4818ad32dba433dae189e36684e43c5c74 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Thu, 14 Dec 2023 14:29:35 +0100 Subject: [PATCH] riscv: Use hugepage mappings for vmemmap This will allow better TLB utilization and then should be more performant. Before: ---[ vmemmap start ]--- 0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PTE . .. .. D A G . . W R V ---[ vmemmap end ]--- After: ---[ vmemmap start ]--- 0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PMD . .. .. D A G . . W R V ---[ vmemmap end ]--- Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20231214132935.212864-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index a65937336cdc8..f533dd667a83a 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1387,10 +1387,29 @@ void __init misc_mem_init(void) } #ifdef CONFIG_SPARSEMEM_VMEMMAP +void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, + unsigned long addr, unsigned long next) +{ + pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL); +} + +int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node, + unsigned long addr, unsigned long next) +{ + vmemmap_verify((pte_t *)pmdp, node, addr, next); + return 1; +} + int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { - return vmemmap_populate_basepages(start, end, node, NULL); + /* + * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we + * can't use hugepage mappings for 2-level page table because in case of + * memory hotplug, we are not able to update all the page tables with + * the new PMDs. + */ + return vmemmap_populate_hugepages(start, end, node, NULL); } #endif -- 2.30.2