Re: [PATCH v2 1/8] memregion: Support fine grained invalidate by cpu_cache_invalidate_memregion()
From: <hidden>
Date: 2025-07-09 22:31:55
Also in:
linux-acpi, linux-arch, linux-cxl, linux-mm
Jonathan Cameron wrote:
From: Yicong Yang <yangyicong@hisilicon.com> Extend cpu_cache_invalidate_memregion() to support invalidate certain range of memory. Control of types of invlidation is left for when
s/invlidation/invalidation/
quoted hunk ↗ jump to hunk
usecases turn up. For now everything is Clean and Invalidate. Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com> --- arch/x86/mm/pat/set_memory.c | 2 +- drivers/cxl/core/region.c | 6 +++++- drivers/nvdimm/region.c | 3 ++- drivers/nvdimm/region_devs.c | 3 ++- include/linux/memregion.h | 8 ++++++-- 5 files changed, 16 insertions(+), 6 deletions(-)diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 46edc11726b7..8b39aad22458 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c@@ -368,7 +368,7 @@ bool cpu_cache_has_invalidate_memregion(void) } EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, "DEVMEM"); -int cpu_cache_invalidate_memregion(int res_desc) +int cpu_cache_invalidate_memregion(int res_desc, phys_addr_t start, size_t len) { if (WARN_ON_ONCE(!cpu_cache_has_invalidate_memregion())) return -ENXIO;diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 6e5e1460068d..6e6e8ace0897 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c@@ -237,7 +237,11 @@ static int cxl_region_invalidate_memregion(struct cxl_region *cxlr) return -ENXIO; } - cpu_cache_invalidate_memregion(IORES_DESC_CXL); + if (!cxlr->params.res) + return -ENXIO; + cpu_cache_invalidate_memregion(IORES_DESC_CXL, + cxlr->params.res->start, + resource_size(cxlr->params.res));
So lets abandon the never used @res_desc argument. It was originally there for documentation and the idea that with HDM-DB CXL invalidation could be triggered from the device. However, that never came to pass, and the continued existence of the option is confusing especially if the range may not be a strict subset of the res_desc. Alternatively, keep the @res_desc parameter and have the backend lookup the ranges to flush from the descriptor, but I like that option less.