From 9c0fc1d37f531fd33abc9b3a009b818ff1bddc22 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 28 Nov 2025 13:23:03 -0800 Subject: [PATCH] drivers/nvdimm: Use local kmaps Replace the now deprecated kmap_atomic() with kmap_local_page(). Optimizing nvdimm/pmem for highmem makes no sense as this is always 64bit, and the mapped regions for both btt and pmem do not require disabling preemption and pagefaults. Specifically, kmap does not care about the caller's atomic context (such as reads holding the btt arena spinlock) or NVDIMM_IO_ATOMIC semantics to avoid error handling when accessing the btt arena in general. Same for the memcpy cases. kmap local temporary mappings will hold valid across any context switches. Signed-off-by: Davidlohr Bueso Reviewed-by: Dave Jiang > --- Link: https://patch.msgid.link/20251128212303.2170933-1-dave@stgolabs.net Signed-off-by: Ira Weiny --- drivers/nvdimm/btt.c | 12 ++++++------ drivers/nvdimm/pmem.c | 8 ++++---- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index a933db961ed70..237edfa1c624b 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1104,10 +1104,10 @@ static int btt_data_read(struct arena_info *arena, struct page *page, { int ret; u64 nsoff = to_namespace_offset(arena, lba); - void *mem = kmap_atomic(page); + void *mem = kmap_local_page(page); ret = arena_read_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC); - kunmap_atomic(mem); + kunmap_local(mem); return ret; } @@ -1117,20 +1117,20 @@ static int btt_data_write(struct arena_info *arena, u32 lba, { int ret; u64 nsoff = to_namespace_offset(arena, lba); - void *mem = kmap_atomic(page); + void *mem = kmap_local_page(page); ret = arena_write_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC); - kunmap_atomic(mem); + kunmap_local(mem); return ret; } static void zero_fill_data(struct page *page, unsigned int off, u32 len) { - void *mem = kmap_atomic(page); + void *mem = kmap_local_page(page); memset(mem + off, 0, len); - kunmap_atomic(mem); + kunmap_local(mem); } #ifdef CONFIG_BLK_DEV_INTEGRITY diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 05785ff21a8bd..92c67fbbc1c85 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -128,10 +128,10 @@ static void write_pmem(void *pmem_addr, struct page *page, void *mem; while (len) { - mem = kmap_atomic(page); + mem = kmap_local_page(page); chunk = min_t(unsigned int, len, PAGE_SIZE - off); memcpy_flushcache(pmem_addr, mem + off, chunk); - kunmap_atomic(mem); + kunmap_local(mem); len -= chunk; off = 0; page++; @@ -147,10 +147,10 @@ static blk_status_t read_pmem(struct page *page, unsigned int off, void *mem; while (len) { - mem = kmap_atomic(page); + mem = kmap_local_page(page); chunk = min_t(unsigned int, len, PAGE_SIZE - off); rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk); - kunmap_atomic(mem); + kunmap_local(mem); if (rem) return BLK_STS_IOERR; len -= chunk; -- 2.47.3