From e3ecf2fdc8f39a898f9e06481e935b460a097e10 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:44 +0200 Subject: [PATCH 01/11] riscv: mm: Properly forward vmemmap_populate() altmap parameter MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure that the altmap parameter is properly passed on to vmemmap_populate_hugepages(). Reviewed-by: Alexandre Ghiti Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-2-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index e3218d65f21d..ecd4e716c995 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1438,7 +1438,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, * memory hotplug, we are not able to update all the page tables with * the new PMDs. */ - return vmemmap_populate_hugepages(start, end, node, NULL); + return vmemmap_populate_hugepages(start, end, node, altmap); } #endif From 66673099f734fd6512055fee353b5c81dafec216 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:45 +0200 Subject: [PATCH 02/11] riscv: mm: Pre-allocate vmemmap/direct map/kasan PGD entries MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The RISC-V port copies the PGD table from init_mm/swapper_pg_dir to all userland page tables, which means that if the PGD level table is changed, other page tables has to be updated as well. Instead of having the PGD changes ripple out to all tables, the synchronization can be avoided by pre-allocating the PGD entries/pages at boot, avoiding the synchronization all together. This is currently done for the bpf/modules, and vmalloc PGD regions. Extend this scheme for the PGD regions touched by memory hotplugging. Prepare the RISC-V port for memory hotplug by pre-allocate vmemmap/direct map/kasan entries at the PGD level. This will roughly waste ~128 (plus 32 if KASAN is enabled) worth of 4K pages when memory hotplugging is enabled in the kernel configuration. Reviewed-by: Alexandre Ghiti Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-3-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/kasan.h | 4 ++-- arch/riscv/mm/init.c | 9 +++++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/kasan.h b/arch/riscv/include/asm/kasan.h index 0b85e363e778..e6a0071bdb56 100644 --- a/arch/riscv/include/asm/kasan.h +++ b/arch/riscv/include/asm/kasan.h @@ -6,8 +6,6 @@ #ifndef __ASSEMBLY__ -#ifdef CONFIG_KASAN - /* * The following comment was copied from arm64: * KASAN_SHADOW_START: beginning of the kernel virtual addresses. @@ -34,6 +32,8 @@ */ #define KASAN_SHADOW_START ((KASAN_SHADOW_END - KASAN_SHADOW_SIZE) & PGDIR_MASK) #define KASAN_SHADOW_END MODULES_LOWEST_VADDR + +#ifdef CONFIG_KASAN #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) void kasan_init(void); diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index ecd4e716c995..85f076b80a12 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -28,6 +28,7 @@ #include #include +#include #include #include #include @@ -1492,11 +1493,19 @@ static void __init preallocate_pgd_pages_range(unsigned long start, unsigned lon panic("Failed to pre-allocate %s pages for %s area\n", lvl, area); } +#define PAGE_END KASAN_SHADOW_START + void __init pgtable_cache_init(void) { preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc"); if (IS_ENABLED(CONFIG_MODULES)) preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules"); + if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) { + preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap"); + preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map"); + if (IS_ENABLED(CONFIG_KASAN)) + preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan"); + } } #endif From fe122b89da670be155f3474c0cb28af2fbcd2ecc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:46 +0200 Subject: [PATCH 03/11] riscv: mm: Change attribute from __init to __meminit for page functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Prepare for memory hotplugging support by changing from __init to __meminit for the page table functions that are used by the upcoming architecture specific callbacks. Changing the __init attribute to __meminit, avoids that the functions are removed after init. The __meminit attribute makes sure the functions are kept in the kernel text post init, but only if memory hotplugging is enabled for the build. Reviewed-by: Alexandre Ghiti Reviewed-by: David Hildenbrand Reviewed-by: Oscar Salvador Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-4-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/mmu.h | 4 +-- arch/riscv/include/asm/pgtable.h | 2 +- arch/riscv/mm/init.c | 56 ++++++++++++++------------------ 3 files changed, 28 insertions(+), 34 deletions(-) diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h index 947fd60f9051..c9e03e9da3dc 100644 --- a/arch/riscv/include/asm/mmu.h +++ b/arch/riscv/include/asm/mmu.h @@ -31,8 +31,8 @@ typedef struct { #define cntx2asid(cntx) ((cntx) & SATP_ASID_MASK) #define cntx2version(cntx) ((cntx) & ~SATP_ASID_MASK) -void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot); +void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, + pgprot_t prot); #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_MMU_H */ diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index aad8b8ca51f1..41f1b2c6f949 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -165,7 +165,7 @@ struct pt_alloc_ops { #endif }; -extern struct pt_alloc_ops pt_ops __initdata; +extern struct pt_alloc_ops pt_ops __meminitdata; #ifdef CONFIG_MMU /* Number of PGD entries that a user-mode program can use */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 85f076b80a12..55c01c90e154 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -296,7 +296,7 @@ static void __init setup_bootmem(void) } #ifdef CONFIG_MMU -struct pt_alloc_ops pt_ops __initdata; +struct pt_alloc_ops pt_ops __meminitdata; pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; @@ -358,7 +358,7 @@ static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa) return (pte_t *)set_fixmap_offset(FIX_PTE, pa); } -static inline pte_t *__init get_pte_virt_late(phys_addr_t pa) +static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa) { return (pte_t *) __va(pa); } @@ -377,7 +377,7 @@ static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va) return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); } -static phys_addr_t __init alloc_pte_late(uintptr_t va) +static phys_addr_t __meminit alloc_pte_late(uintptr_t va) { struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0); @@ -385,9 +385,8 @@ static phys_addr_t __init alloc_pte_late(uintptr_t va) return __pa((pte_t *)ptdesc_address(ptdesc)); } -static void __init create_pte_mapping(pte_t *ptep, - uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot) +static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz, + pgprot_t prot) { uintptr_t pte_idx = pte_index(va); @@ -441,7 +440,7 @@ static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa) return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); } -static pmd_t *__init get_pmd_virt_late(phys_addr_t pa) +static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa) { return (pmd_t *) __va(pa); } @@ -458,7 +457,7 @@ static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va) return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); } -static phys_addr_t __init alloc_pmd_late(uintptr_t va) +static phys_addr_t __meminit alloc_pmd_late(uintptr_t va) { struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0); @@ -466,9 +465,9 @@ static phys_addr_t __init alloc_pmd_late(uintptr_t va) return __pa((pmd_t *)ptdesc_address(ptdesc)); } -static void __init create_pmd_mapping(pmd_t *pmdp, - uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot) +static void __meminit create_pmd_mapping(pmd_t *pmdp, + uintptr_t va, phys_addr_t pa, + phys_addr_t sz, pgprot_t prot) { pte_t *ptep; phys_addr_t pte_phys; @@ -504,7 +503,7 @@ static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa) return (pud_t *)set_fixmap_offset(FIX_PUD, pa); } -static pud_t *__init get_pud_virt_late(phys_addr_t pa) +static pud_t *__meminit get_pud_virt_late(phys_addr_t pa) { return (pud_t *)__va(pa); } @@ -522,7 +521,7 @@ static phys_addr_t __init alloc_pud_fixmap(uintptr_t va) return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); } -static phys_addr_t alloc_pud_late(uintptr_t va) +static phys_addr_t __meminit alloc_pud_late(uintptr_t va) { unsigned long vaddr; @@ -542,7 +541,7 @@ static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa) return (p4d_t *)set_fixmap_offset(FIX_P4D, pa); } -static p4d_t *__init get_p4d_virt_late(phys_addr_t pa) +static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa) { return (p4d_t *)__va(pa); } @@ -560,7 +559,7 @@ static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va) return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); } -static phys_addr_t alloc_p4d_late(uintptr_t va) +static phys_addr_t __meminit alloc_p4d_late(uintptr_t va) { unsigned long vaddr; @@ -569,9 +568,8 @@ static phys_addr_t alloc_p4d_late(uintptr_t va) return __pa(vaddr); } -static void __init create_pud_mapping(pud_t *pudp, - uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot) +static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, + pgprot_t prot) { pmd_t *nextp; phys_addr_t next_phys; @@ -596,9 +594,8 @@ static void __init create_pud_mapping(pud_t *pudp, create_pmd_mapping(nextp, va, pa, sz, prot); } -static void __init create_p4d_mapping(p4d_t *p4dp, - uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot) +static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, + pgprot_t prot) { pud_t *nextp; phys_addr_t next_phys; @@ -654,9 +651,8 @@ static void __init create_p4d_mapping(p4d_t *p4dp, #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) #endif /* __PAGETABLE_PMD_FOLDED */ -void __init create_pgd_mapping(pgd_t *pgdp, - uintptr_t va, phys_addr_t pa, - phys_addr_t sz, pgprot_t prot) +void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, + pgprot_t prot) { pgd_next_t *nextp; phys_addr_t next_phys; @@ -681,8 +677,7 @@ void __init create_pgd_mapping(pgd_t *pgdp, create_pgd_next_mapping(nextp, va, pa, sz, prot); } -static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va, - phys_addr_t size) +static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size) { if (debug_pagealloc_enabled()) return PAGE_SIZE; @@ -718,7 +713,7 @@ asmlinkage void __init __copy_data(void) #endif #ifdef CONFIG_STRICT_KERNEL_RWX -static __init pgprot_t pgprot_from_va(uintptr_t va) +static __meminit pgprot_t pgprot_from_va(uintptr_t va) { if (is_va_kernel_text(va)) return PAGE_KERNEL_READ_EXEC; @@ -743,7 +738,7 @@ void mark_rodata_ro(void) set_memory_ro); } #else -static __init pgprot_t pgprot_from_va(uintptr_t va) +static __meminit pgprot_t pgprot_from_va(uintptr_t va) { if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va)) return PAGE_KERNEL; @@ -1235,9 +1230,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) pt_ops_set_fixmap(); } -static void __init create_linear_mapping_range(phys_addr_t start, - phys_addr_t end, - uintptr_t fixed_map_size) +static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end, + uintptr_t fixed_map_size) { phys_addr_t pa; uintptr_t va, map_size; From 007480fe84a9963b6deaa6dceb7039eec03ac007 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:47 +0200 Subject: [PATCH 04/11] riscv: mm: Refactor create_linear_mapping_range() for memory hot add MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a parameter to the direct map setup function, so it can be used in arch_add_memory() later. Reviewed-by: Alexandre Ghiti Reviewed-by: David Hildenbrand Reviewed-by: Oscar Salvador Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-5-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 55c01c90e154..691600c96ead 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1231,7 +1231,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) } static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end, - uintptr_t fixed_map_size) + uintptr_t fixed_map_size, const pgprot_t *pgprot) { phys_addr_t pa; uintptr_t va, map_size; @@ -1242,7 +1242,7 @@ static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t best_map_size(pa, va, end - pa); create_pgd_mapping(swapper_pg_dir, va, pa, map_size, - pgprot_from_va(va)); + pgprot ? *pgprot : pgprot_from_va(va)); } } @@ -1286,22 +1286,19 @@ static void __init create_linear_mapping_page_table(void) if (end >= __pa(PAGE_OFFSET) + memory_limit) end = __pa(PAGE_OFFSET) + memory_limit; - create_linear_mapping_range(start, end, 0); + create_linear_mapping_range(start, end, 0, NULL); } #ifdef CONFIG_STRICT_KERNEL_RWX - create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0); - create_linear_mapping_range(krodata_start, - krodata_start + krodata_size, 0); + create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL); + create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL); memblock_clear_nomap(ktext_start, ktext_size); memblock_clear_nomap(krodata_start, krodata_size); #endif #ifdef CONFIG_KFENCE - create_linear_mapping_range(kfence_pool, - kfence_pool + KFENCE_POOL_SIZE, - PAGE_SIZE); + create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL); memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); #endif From 6e6c5e21b8cbe94b89d2e848afad4e6fe2a7abd8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:48 +0200 Subject: [PATCH 05/11] riscv: mm: Add pfn_to_kaddr() implementation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The pfn_to_kaddr() function is used by KASAN's memory hotplugging path. Add the missing function to the RISC-V port, so that it can be built with MHP and CONFIG_KASAN. Signed-off-by: Björn Töpel Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240605114100.315918-6-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/page.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 115ac98b8d72..235fd45d998d 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -188,6 +188,11 @@ extern phys_addr_t __phys_addr_symbol(unsigned long x); unsigned long kaslr_offset(void); +static __always_inline void *pfn_to_kaddr(unsigned long pfn) +{ + return __va(pfn << PAGE_SHIFT); +} + #endif /* __ASSEMBLY__ */ #define virt_addr_valid(vaddr) ({ \ From c75a74f4ba19c904c0ae1e011ae2568449409ae4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:49 +0200 Subject: [PATCH 06/11] riscv: mm: Add memory hotplugging support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For an architecture to support memory hotplugging, a couple of callbacks needs to be implemented: arch_add_memory() This callback is responsible for adding the physical memory into the direct map, and call into the memory hotplugging generic code via __add_pages() that adds the corresponding struct page entries, and updates the vmemmap mapping. arch_remove_memory() This is the inverse of the callback above. vmemmap_free() This function tears down the vmemmap mappings (if CONFIG_SPARSEMEM_VMEMMAP is enabled), and also deallocates the backing vmemmap pages. Note that for persistent memory, an alternative allocator for the backing pages can be used; The vmem_altmap. This means that when the backing pages are cleared, extra care is needed so that the correct deallocation method is used. arch_get_mappable_range() This functions returns the PA range that the direct map can map. Used by the MHP internals for sanity checks. The page table unmap/teardown functions are heavily based on code from the x86 tree. The same remove_pgd_mapping() function is used in both vmemmap_free() and arch_remove_memory(), but in the latter function the backing pages are not removed. Signed-off-by: Björn Töpel Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240605114100.315918-7-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 267 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 267 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 691600c96ead..201ebb190b10 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1533,3 +1533,270 @@ struct execmem_info __init *execmem_arch_setup(void) } #endif /* CONFIG_MMU */ #endif /* CONFIG_EXECMEM */ + +#ifdef CONFIG_MEMORY_HOTPLUG +static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd) +{ + struct page *page = pmd_page(*pmd); + struct ptdesc *ptdesc = page_ptdesc(page); + pte_t *pte; + int i; + + for (i = 0; i < PTRS_PER_PTE; i++) { + pte = pte_start + i; + if (!pte_none(*pte)) + return; + } + + pagetable_pte_dtor(ptdesc); + if (PageReserved(page)) + free_reserved_page(page); + else + pagetable_free(ptdesc); + pmd_clear(pmd); +} + +static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud) +{ + struct page *page = pud_page(*pud); + struct ptdesc *ptdesc = page_ptdesc(page); + pmd_t *pmd; + int i; + + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd = pmd_start + i; + if (!pmd_none(*pmd)) + return; + } + + pagetable_pmd_dtor(ptdesc); + if (PageReserved(page)) + free_reserved_page(page); + else + pagetable_free(ptdesc); + pud_clear(pud); +} + +static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d) +{ + struct page *page = p4d_page(*p4d); + pud_t *pud; + int i; + + for (i = 0; i < PTRS_PER_PUD; i++) { + pud = pud_start + i; + if (!pud_none(*pud)) + return; + } + + if (PageReserved(page)) + free_reserved_page(page); + else + free_pages((unsigned long)page_address(page), 0); + p4d_clear(p4d); +} + +static void __meminit free_vmemmap_storage(struct page *page, size_t size, + struct vmem_altmap *altmap) +{ + int order = get_order(size); + + if (altmap) { + vmem_altmap_free(altmap, size >> PAGE_SHIFT); + return; + } + + if (PageReserved(page)) { + unsigned int nr_pages = 1 << order; + + while (nr_pages--) + free_reserved_page(page++); + return; + } + + free_pages((unsigned long)page_address(page), order); +} + +static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end, + bool is_vmemmap, struct vmem_altmap *altmap) +{ + unsigned long next; + pte_t *ptep, pte; + + for (; addr < end; addr = next) { + next = (addr + PAGE_SIZE) & PAGE_MASK; + if (next > end) + next = end; + + ptep = pte_base + pte_index(addr); + pte = ptep_get(ptep); + if (!pte_present(*ptep)) + continue; + + pte_clear(&init_mm, addr, ptep); + if (is_vmemmap) + free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap); + } +} + +static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end, + bool is_vmemmap, struct vmem_altmap *altmap) +{ + unsigned long next; + pte_t *pte_base; + pmd_t *pmdp, pmd; + + for (; addr < end; addr = next) { + next = pmd_addr_end(addr, end); + pmdp = pmd_base + pmd_index(addr); + pmd = pmdp_get(pmdp); + if (!pmd_present(pmd)) + continue; + + if (pmd_leaf(pmd)) { + pmd_clear(pmdp); + if (is_vmemmap) + free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap); + continue; + } + + pte_base = (pte_t *)pmd_page_vaddr(*pmdp); + remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap); + free_pte_table(pte_base, pmdp); + } +} + +static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end, + bool is_vmemmap, struct vmem_altmap *altmap) +{ + unsigned long next; + pud_t *pudp, pud; + pmd_t *pmd_base; + + for (; addr < end; addr = next) { + next = pud_addr_end(addr, end); + pudp = pud_base + pud_index(addr); + pud = pudp_get(pudp); + if (!pud_present(pud)) + continue; + + if (pud_leaf(pud)) { + if (pgtable_l4_enabled) { + pud_clear(pudp); + if (is_vmemmap) + free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap); + } + continue; + } + + pmd_base = pmd_offset(pudp, 0); + remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap); + + if (pgtable_l4_enabled) + free_pmd_table(pmd_base, pudp); + } +} + +static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end, + bool is_vmemmap, struct vmem_altmap *altmap) +{ + unsigned long next; + p4d_t *p4dp, p4d; + pud_t *pud_base; + + for (; addr < end; addr = next) { + next = p4d_addr_end(addr, end); + p4dp = p4d_base + p4d_index(addr); + p4d = p4dp_get(p4dp); + if (!p4d_present(p4d)) + continue; + + if (p4d_leaf(p4d)) { + if (pgtable_l5_enabled) { + p4d_clear(p4dp); + if (is_vmemmap) + free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap); + } + continue; + } + + pud_base = pud_offset(p4dp, 0); + remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap); + + if (pgtable_l5_enabled) + free_pud_table(pud_base, p4dp); + } +} + +static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap, + struct vmem_altmap *altmap) +{ + unsigned long addr, next; + p4d_t *p4d_base; + pgd_t *pgd; + + for (addr = va; addr < end; addr = next) { + next = pgd_addr_end(addr, end); + pgd = pgd_offset_k(addr); + + if (!pgd_present(*pgd)) + continue; + + if (pgd_leaf(*pgd)) + continue; + + p4d_base = p4d_offset(pgd, 0); + remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap); + } + + flush_tlb_all(); +} + +static void __meminit remove_linear_mapping(phys_addr_t start, u64 size) +{ + unsigned long va = (unsigned long)__va(start); + unsigned long end = (unsigned long)__va(start + size); + + remove_pgd_mapping(va, end, false, NULL); +} + +struct range arch_get_mappable_range(void) +{ + struct range mhp_range; + + mhp_range.start = __pa(PAGE_OFFSET); + mhp_range.end = __pa(PAGE_END - 1); + return mhp_range; +} + +int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) +{ + int ret = 0; + + create_linear_mapping_range(start, start + size, 0, ¶ms->pgprot); + ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params); + if (ret) { + remove_linear_mapping(start, size); + goto out; + } + + max_pfn = PFN_UP(start + size); + max_low_pfn = max_pfn; + + out: + flush_tlb_all(); + return ret; +} + +void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) +{ + __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap); + remove_linear_mapping(start, size); + flush_tlb_all(); +} + +void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap) +{ + remove_pgd_mapping(start, end, true, altmap); +} +#endif /* CONFIG_MEMORY_HOTPLUG */ From 37992b7f1097ba79ca75ba5a26ddcf0f54f91a08 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:50 +0200 Subject: [PATCH 07/11] riscv: mm: Take memory hotplug read-lock during kernel page table dump MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During memory hot remove, the ptdump functionality can end up touching stale data. Avoid any potential crashes (or worse), by holding the memory hotplug read-lock while traversing the page table. This change is analogous to arm64's commit bf2b59f60ee1 ("arm64/mm: Hold memory hotplug lock while walking for kernel page table dump"). Reviewed-by: David Hildenbrand Reviewed-by: Oscar Salvador Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-8-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/ptdump.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c index 1289cc6d3700..9d5f657a251b 100644 --- a/arch/riscv/mm/ptdump.c +++ b/arch/riscv/mm/ptdump.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include @@ -370,7 +371,9 @@ bool ptdump_check_wx(void) static int ptdump_show(struct seq_file *m, void *v) { + get_online_mems(); ptdump_walk(m, m->private); + put_online_mems(); return 0; } From f8c2a240556eb4fcfcd3ee8e5ececce5be1ae734 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:51 +0200 Subject: [PATCH 08/11] riscv: Enable memory hotplugging for RISC-V MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Enable ARCH_ENABLE_MEMORY_HOTPLUG and ARCH_ENABLE_MEMORY_HOTREMOVE for RISC-V. Reviewed-by: Alexandre Ghiti Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-9-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index b94176e25be1..676377e3f7f7 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -16,6 +16,8 @@ config RISCV select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ARCH_DMA_DEFAULT_COHERENT select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION + select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP + select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_BINFMT_FLAT @@ -46,6 +48,7 @@ config RISCV select ARCH_HAS_UBSAN select ARCH_HAS_VDSO_DATA select ARCH_KEEP_MEMBLOCK if ACPI + select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT select ARCH_STACKWALK From 0546d7043e55becec78fa262f2e84c76a96f6e52 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:52 +0200 Subject: [PATCH 09/11] virtio-mem: Enable virtio-mem for RISC-V MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that RISC-V has memory hotplugging support, virtio-mem can be used on the platform. Acked-by: David Hildenbrand Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-10-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- drivers/virtio/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 6284538a8184..42a48ac763ee 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -122,7 +122,7 @@ config VIRTIO_BALLOON config VIRTIO_MEM tristate "Virtio mem driver" - depends on X86_64 || ARM64 + depends on X86_64 || ARM64 || RISCV depends on VIRTIO depends on MEMORY_HOTPLUG depends on MEMORY_HOTREMOVE From 216e04bf1e4d933fe8338e486a9dff93c208601e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:53 +0200 Subject: [PATCH 10/11] riscv: mm: Add support for ZONE_DEVICE MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ZONE_DEVICE pages need DEVMAP PTEs support to function (ARCH_HAS_PTE_DEVMAP). Claim another RSW (reserved for software) bit in the PTE for DEVMAP mark, add the corresponding helpers, and enable ARCH_HAS_PTE_DEVMAP for riscv64. Reviewed-by: Alexandre Ghiti Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20240605114100.315918-11-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/pgtable-64.h | 20 ++++++++++++++++++++ arch/riscv/include/asm/pgtable-bits.h | 1 + arch/riscv/include/asm/pgtable.h | 17 +++++++++++++++++ 4 files changed, 39 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 676377e3f7f7..c7e7e568dd01 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -37,6 +37,7 @@ config RISCV select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API select ARCH_HAS_PREPARE_SYNC_CORE_CMD + select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SET_DIRECT_MAP if MMU select ARCH_HAS_SET_MEMORY if MMU diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h index 8c36a8818432..0897dd99ab8d 100644 --- a/arch/riscv/include/asm/pgtable-64.h +++ b/arch/riscv/include/asm/pgtable-64.h @@ -398,4 +398,24 @@ static inline struct page *pgd_page(pgd_t pgd) #define p4d_offset p4d_offset p4d_t *p4d_offset(pgd_t *pgd, unsigned long address); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline int pte_devmap(pte_t pte); +static inline pte_t pmd_pte(pmd_t pmd); + +static inline int pmd_devmap(pmd_t pmd) +{ + return pte_devmap(pmd_pte(pmd)); +} + +static inline int pud_devmap(pud_t pud) +{ + return 0; +} + +static inline int pgd_devmap(pgd_t pgd) +{ + return 0; +} +#endif + #endif /* _ASM_RISCV_PGTABLE_64_H */ diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h index 179bd4afece4..a8f5205cea54 100644 --- a/arch/riscv/include/asm/pgtable-bits.h +++ b/arch/riscv/include/asm/pgtable-bits.h @@ -19,6 +19,7 @@ #define _PAGE_SOFT (3 << 8) /* Reserved for software */ #define _PAGE_SPECIAL (1 << 8) /* RSW: 0x1 */ +#define _PAGE_DEVMAP (1 << 9) /* RSW, devmap */ #define _PAGE_TABLE _PAGE_PRESENT /* diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 41f1b2c6f949..dd4d52940106 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -390,6 +390,13 @@ static inline int pte_special(pte_t pte) return pte_val(pte) & _PAGE_SPECIAL; } +#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP +static inline int pte_devmap(pte_t pte) +{ + return pte_val(pte) & _PAGE_DEVMAP; +} +#endif + /* static inline pte_t pte_rdprotect(pte_t pte) */ static inline pte_t pte_wrprotect(pte_t pte) @@ -431,6 +438,11 @@ static inline pte_t pte_mkspecial(pte_t pte) return __pte(pte_val(pte) | _PAGE_SPECIAL); } +static inline pte_t pte_mkdevmap(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_DEVMAP); +} + static inline pte_t pte_mkhuge(pte_t pte) { return pte; @@ -721,6 +733,11 @@ static inline pmd_t pmd_mkdirty(pmd_t pmd) return pte_pmd(pte_mkdirty(pmd_pte(pmd))); } +static inline pmd_t pmd_mkdevmap(pmd_t pmd) +{ + return pte_pmd(pte_mkdevmap(pmd_pte(pmd))); +} + static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { From 4705c1571ad39d9469321d2817faf4c4b78ddffb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Wed, 5 Jun 2024 13:40:54 +0200 Subject: [PATCH 11/11] riscv: Enable DAX VMEMMAP optimization MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that DAX is usable, enable the DAX VMEMMAP optimization as well. Signed-off-by: Björn Töpel Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240605114100.315918-12-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index c7e7e568dd01..e6d589c47acc 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -73,6 +73,7 @@ config RISCV select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT select ARCH_WANT_HUGE_PMD_SHARE if 64BIT select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL + select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP select ARCH_WANTS_NO_INSTR select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE