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charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 439BAA0010 X-Stat-Signature: jw1ztoo1uc48xd5rdgi7oahda71niubx X-Rspam-User: X-HE-Tag: 1788346269-301880 X-HE-Meta: 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 s/QuV5bt 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Keeping last-level mappings is interesting on some architectures as it allows mapping/unmapping pages from the kernel direct map without the risk of splitting blocks which, under the break-before-make rule, may trigger page-faults the kernel can't handle. However, mapping the entire direct map at PTE-level is costly. So instead, create a new memblock flag MEMBLOCK_LLMAP to enable the system to decide which region must be covered by mappings up to the last-level. Signed-off-by: Vincent Donnefort diff --git a/include/linux/memblock.h b/include/linux/memblock.h index d62db9e776cf..d40a5ded188d 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -52,6 +52,7 @@ extern unsigned long long max_possible_pfn; * kernel that we know is good to use. It is the only memory that * allocations may happen from in this phase. * @MEMBLOCK_RSRV_HUGETLB: memory is reserved for hugetlb pages + * @MEMBLOCK_LLMAP: memory region to be mapped using last-level mapping */ enum memblock_flags { MEMBLOCK_NONE = 0x0, /* No special request */ @@ -63,6 +64,7 @@ enum memblock_flags { MEMBLOCK_RSRV_KERN = 0x20, /* memory reserved for kernel use */ MEMBLOCK_KHO_SCRATCH = 0x40, /* scratch memory for kexec handover */ MEMBLOCK_RSRV_HUGETLB = 0x80, /* memory reserved for hugetlb pages */ + MEMBLOCK_LLMAP = 0x100,/* last-level mapping */ }; /** @@ -160,6 +162,8 @@ int memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size); int memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size); int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size); int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size); +int memblock_mark_llmap(phys_addr_t base, phys_addr_t size); +int memblock_clear_llmap(phys_addr_t base, phys_addr_t size); void memblock_free(void *ptr, size_t size); void reset_all_zones_managed_pages(void); @@ -306,6 +310,11 @@ static inline bool memblock_is_kho_scratch(struct memblock_region *m) return m->flags & MEMBLOCK_KHO_SCRATCH; } +static inline bool memblock_is_llmap(struct memblock_region *m) +{ + return m->flags & MEMBLOCK_LLMAP; +} + int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn, unsigned long *end_pfn); void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, diff --git a/mm/memblock.c b/mm/memblock.c index 9ce86349a29f..1591b50503ed 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1119,6 +1119,16 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size) */ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) { + struct memblock_region *r; + + memblock_cap_size(base, &size); + + for_each_mem_region(r) { + if (memblock_is_llmap(r) && + memblock_addrs_overlap(base, size, r->base, r->size)) + return -EINVAL; + } + return memblock_setclr_flag(&memblock.memory, base, size, 1, MEMBLOCK_NOMAP); } @@ -1204,6 +1214,45 @@ __init int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size) MEMBLOCK_KHO_SCRATCH); } +/** + * memblock_mark_llmap - Mark a memory region with flag MEMBLOCK_LLMAP. + * @base: the base phys addr of the region + * @size: the size of the region + * + * If supported by the architecture, such region is mapped at the last-level in + * the kernel direct map. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_mark_llmap(phys_addr_t base, phys_addr_t size) +{ + struct memblock_region *r; + + memblock_cap_size(base, &size); + + for_each_mem_region(r) { + if (memblock_is_nomap(r) && + memblock_addrs_overlap(base, size, r->base, r->size)) + return -EINVAL; + } + + return memblock_setclr_flag(&memblock.memory, base, size, 1, + MEMBLOCK_LLMAP); +} + +/** + * memblock_clear_llmap - Clear flag MEMBLOCK_LLMAP for a specified region. + * @base: the base phys addr of the region + * @size: the size of the region + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_clear_llmap(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.memory, base, size, 0, + MEMBLOCK_LLMAP); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2886,6 +2935,7 @@ static const char * const flagname[] = { [ilog2(MEMBLOCK_RSRV_NOINIT)] = "RSV_NIT", [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN", [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH", + [ilog2(MEMBLOCK_LLMAP)] = "LLMAP", }; static int memblock_debug_show(struct seq_file *m, void *private) -- 2.55.0.970.g62bdec98f9-goog From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.trustedfirmware.org (lists.trustedfirmware.org [18.214.241.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E3A1C624D0 for ; Wed, 2 Sep 2026 10:51:47 +0000 (UTC) Received: from lists.trustedfirmware.org (localhost [127.0.0.1]) by lists.trustedfirmware.org (Postfix) with ESMTP id 6A093453C9 for ; 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However, mapping the entire direct map at PTE-level is costly. So instead, create a new memblock flag MEMBLOCK_LLMAP to enable the system to decide which region must be covered by mappings up to the last-level. Signed-off-by: Vincent Donnefort diff --git a/include/linux/memblock.h b/include/linux/memblock.h index d62db9e776cf..d40a5ded188d 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -52,6 +52,7 @@ extern unsigned long long max_possible_pfn; * kernel that we know is good to use. It is the only memory that * allocations may happen from in this phase. * @MEMBLOCK_RSRV_HUGETLB: memory is reserved for hugetlb pages + * @MEMBLOCK_LLMAP: memory region to be mapped using last-level mapping */ enum memblock_flags { MEMBLOCK_NONE = 0x0, /* No special request */ @@ -63,6 +64,7 @@ enum memblock_flags { MEMBLOCK_RSRV_KERN = 0x20, /* memory reserved for kernel use */ MEMBLOCK_KHO_SCRATCH = 0x40, /* scratch memory for kexec handover */ MEMBLOCK_RSRV_HUGETLB = 0x80, /* memory reserved for hugetlb pages */ + MEMBLOCK_LLMAP = 0x100,/* last-level mapping */ }; /** @@ -160,6 +162,8 @@ int memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size); int memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size); int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size); int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size); +int memblock_mark_llmap(phys_addr_t base, phys_addr_t size); +int memblock_clear_llmap(phys_addr_t base, phys_addr_t size); void memblock_free(void *ptr, size_t size); void reset_all_zones_managed_pages(void); @@ -306,6 +310,11 @@ static inline bool memblock_is_kho_scratch(struct memblock_region *m) return m->flags & MEMBLOCK_KHO_SCRATCH; } +static inline bool memblock_is_llmap(struct memblock_region *m) +{ + return m->flags & MEMBLOCK_LLMAP; +} + int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn, unsigned long *end_pfn); void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, diff --git a/mm/memblock.c b/mm/memblock.c index 9ce86349a29f..1591b50503ed 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1119,6 +1119,16 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size) */ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) { + struct memblock_region *r; + + memblock_cap_size(base, &size); + + for_each_mem_region(r) { + if (memblock_is_llmap(r) && + memblock_addrs_overlap(base, size, r->base, r->size)) + return -EINVAL; + } + return memblock_setclr_flag(&memblock.memory, base, size, 1, MEMBLOCK_NOMAP); } @@ -1204,6 +1214,45 @@ __init int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size) MEMBLOCK_KHO_SCRATCH); } +/** + * memblock_mark_llmap - Mark a memory region with flag MEMBLOCK_LLMAP. + * @base: the base phys addr of the region + * @size: the size of the region + * + * If supported by the architecture, such region is mapped at the last-level in + * the kernel direct map. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_mark_llmap(phys_addr_t base, phys_addr_t size) +{ + struct memblock_region *r; + + memblock_cap_size(base, &size); + + for_each_mem_region(r) { + if (memblock_is_nomap(r) && + memblock_addrs_overlap(base, size, r->base, r->size)) + return -EINVAL; + } + + return memblock_setclr_flag(&memblock.memory, base, size, 1, + MEMBLOCK_LLMAP); +} + +/** + * memblock_clear_llmap - Clear flag MEMBLOCK_LLMAP for a specified region. + * @base: the base phys addr of the region + * @size: the size of the region + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_clear_llmap(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.memory, base, size, 0, + MEMBLOCK_LLMAP); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2886,6 +2935,7 @@ static const char * const flagname[] = { [ilog2(MEMBLOCK_RSRV_NOINIT)] = "RSV_NIT", [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN", [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH", + [ilog2(MEMBLOCK_LLMAP)] = "LLMAP", }; static int memblock_debug_show(struct seq_file *m, void *private) -- 2.55.0.970.g62bdec98f9-goog