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charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6421440006 X-Stat-Signature: n5ecxk3u6srezr3dbfa8mwueu446s73g X-HE-Tag: 1789988459-352396 X-HE-Meta: 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 wLMaQ3F3 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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 PTE-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_PTEMAP to selectively apply a PTE-level mapping. Signed-off-by: Vincent Donnefort --- include/linux/memblock.h | 18 ++++++++++++++++++ mm/memblock.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index aa845f488327..13263055996d 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_PTEMAP: memory region to be mapped using PTE-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_PTEMAP = 0x100,/* PTE-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_ptemap(phys_addr_t base, phys_addr_t size); +int memblock_clear_ptemap(phys_addr_t base, phys_addr_t size); void memblock_free(void *ptr, size_t size); @@ -285,8 +289,16 @@ static inline bool memblock_is_mirror(struct memblock_region *m) return m->flags & MEMBLOCK_MIRROR; } +static inline void memblock_warn_invalid_map_flags(struct memblock_region *m) +{ + enum memblock_flags map_flags = MEMBLOCK_NOMAP | MEMBLOCK_PTEMAP; + + WARN_ON_ONCE((m->flags & map_flags) == map_flags); +} + static inline bool memblock_is_nomap(struct memblock_region *m) { + memblock_warn_invalid_map_flags(m); return m->flags & MEMBLOCK_NOMAP; } @@ -305,6 +317,12 @@ static inline bool memblock_is_kho_scratch(struct memblock_region *m) return m->flags & MEMBLOCK_KHO_SCRATCH; } +static inline bool memblock_is_ptemap(struct memblock_region *m) +{ + memblock_warn_invalid_map_flags(m); + return m->flags & MEMBLOCK_PTEMAP; +} + 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 ea0de4b5f356..8a87d4d2516d 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1204,6 +1204,35 @@ __init int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size) MEMBLOCK_KHO_SCRATCH); } +/** + * memblock_mark_ptemap - Mark a memory region with flag MEMBLOCK_PTEMAP. + * @base: the base phys addr of the region + * @size: the size of the region + * + * If supported by the architecture, such region is mapped using PTE-level + * mappings in the kernel direct map. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_mark_ptemap(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.memory, base, size, 1, + MEMBLOCK_PTEMAP); +} + +/** + * memblock_clear_ptemap - Clear flag MEMBLOCK_PTEMAP 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_ptemap(phys_addr_t base, phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.memory, base, size, 0, + MEMBLOCK_PTEMAP); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2880,6 +2909,7 @@ static const char * const flagname[] = { [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN", [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH", [ilog2(MEMBLOCK_RSRV_HUGETLB)] = "RSV_HUGETLB", + [ilog2(MEMBLOCK_PTEMAP)] = "PTEMAP", }; static int memblock_debug_show(struct seq_file *m, void *private) -- 2.55.0.1082.g2b9226bbc0-goog