On Wed, 4 Dec 2024 15:46:47 -0700 Dave Jiang <dave.jiang@xxxxxxxxx> wrote: > The current cxl region size only indicates the size of the CXL memory > region without accounting for the extended linear cache size. Retrieve the > cache size from HMAT and append that to the cxl region size for the cxl > region range that matches the SRAT range that has extended linear cache > enabled. > > The SRAT defines the whole memory range that includes the extended linear > cache and the CXL memory region. The new HMAT ECN/ECR to the Memory Side > Cache Information Structure defines the size of the extended linear cache > size and matches to the SRAT Memory Affinity Structure by the memory > proxmity domain. Add a helper to match the cxl range to the SRAT memory > range in order to retrieve the cache size. > > There are several places that checks the cxl region range against the > decoder range. Use new helper to check between the two ranges and address > the new cache size. > > Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx> Hi Dave, A few minor comments inline given you are going around again for the issue Li Ming spotted. Jonathan > --- > RFC: > - Minor refactors (Jonathan) > - Fix grammar (Jonathan) > --- > drivers/acpi/numa/hmat.c | 39 ++++++++++++++++++++++ > drivers/cxl/core/Makefile | 1 + > drivers/cxl/core/acpi.c | 11 ++++++ > drivers/cxl/core/core.h | 3 ++ > drivers/cxl/core/region.c | 70 ++++++++++++++++++++++++++++++++++++--- > drivers/cxl/cxl.h | 2 ++ > include/linux/acpi.h | 19 +++++++++++ > tools/testing/cxl/Kbuild | 1 + > 8 files changed, 142 insertions(+), 4 deletions(-) > create mode 100644 drivers/cxl/core/acpi.c > > diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c > index 976b3e1a6c2a..1c5b3c37ac29 100644 > --- a/drivers/acpi/numa/hmat.c > +++ b/drivers/acpi/numa/hmat.c > @@ -108,6 +108,45 @@ static struct memory_target *find_mem_target(unsigned int mem_pxm) > return NULL; > } > > +/** > + * hmat_get_extended_linear_cache_size - Retrieve the extended linear cache size > + * @backing_res: resource from the backing media > + * @nid: node id for the memory region > + * @cache_size: (Output) size of extended linear cache. > + * > + * Return: 0 on success. Errno on failure. > + * > + */ > +int hmat_get_extended_linear_cache_size(struct resource *backing_res, int nid, > + resource_size_t *cache_size) > +{ > + unsigned int pxm = node_to_pxm(nid); > + struct memory_target *target; > + struct target_cache *tcache; > + struct resource *res; > + > + target = find_mem_target(pxm); > + if (!target) > + return -ENOENT; > + > + list_for_each_entry(tcache, &target->caches, node) { > + if (tcache->cache_attrs.address_mode == > + NODE_CACHE_ADDR_MODE_EXTENDED_LINEAR) > + continue; > + > + res = &target->memregions; > + if (!resource_contains(res, backing_res)) > + continue; > + > + *cache_size = tcache->cache_attrs.size; > + return 0; > + } > + > + *cache_size = 0; > + return 0; > +} > +EXPORT_SYMBOL_NS_GPL(hmat_get_extended_linear_cache_size, CXL); Needs quotes around "CXL" now I think. > + > static struct memory_target *acpi_find_genport_target(u32 uid) > { > struct memory_target *target; > diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile > index 9259bcc6773c..1a0c9c6ca818 100644 > --- a/drivers/cxl/core/Makefile > +++ b/drivers/cxl/core/Makefile > @@ -14,5 +14,6 @@ cxl_core-y += pci.o > cxl_core-y += hdm.o > cxl_core-y += pmu.o > cxl_core-y += cdat.o > +cxl_core-y += acpi.o > cxl_core-$(CONFIG_TRACING) += trace.o > cxl_core-$(CONFIG_CXL_REGION) += region.o > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 70d0a017e99c..72ede9842dab 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -824,6 +824,21 @@ static int match_free_decoder(struct device *dev, void *data) > return 1; > } > > +static bool region_res_match_cxl_range(struct cxl_region_params *p, > + struct range *range) > +{ > + if (!p->res) > + return false; > + > + /* > + * The CXL range is assumed to be fronted by the DRAM range in > + * current known implementation. This assumption will be made > + * until a variant implementation exists. Start with: If an extended linear cache region then the CXL range is... Otherwise the comment sounds more general that it is. > + */ > + return p->res->start + p->cache_size == range->start && > + p->res->end == range->end; > +} > + > static int match_auto_decoder(struct device *dev, void *data) > { > struct cxl_region_params *p = data; > @@ -836,7 +851,7 @@ static int match_auto_decoder(struct device *dev, void *data) > cxld = to_cxl_decoder(dev); > r = &cxld->hpa_range; > > - if (p->res && p->res->start == r->start && p->res->end == r->end) > + if (region_res_match_cxl_range(p, r)) > return 1; > > return 0; > @@ -1413,8 +1428,7 @@ static int cxl_port_setup_targets(struct cxl_port *port, > if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) { > if (cxld->interleave_ways != iw || > cxld->interleave_granularity != ig || > - cxld->hpa_range.start != p->res->start || > - cxld->hpa_range.end != p->res->end || > + !region_res_match_cxl_range(p, &cxld->hpa_range) || > ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) { > dev_err(&cxlr->dev, > "%s:%s %s expected iw: %d ig: %d %pr\n", > + > /* Establish an empty region covering the given HPA range */ > static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > struct cxl_endpoint_decoder *cxled) > @@ -3256,6 +3306,18 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > > *res = DEFINE_RES_MEM_NAMED(hpa->start, range_len(hpa), > dev_name(&cxlr->dev)); > + > + rc = cxl_extended_linear_cache_resize(cxlr, res); > + if (rc) { > + /* > + * Failing to support extended linear cache region resize does not > + * prevent the region from functioning. Only cause cxl list showing Only causes cxl list to show incorrect region size > + * incorrect region size. > + */ > + dev_warn(cxlmd->dev.parent, > + "Failed to support extended linear cache.\n"); > + } > + > rc = insert_resource(cxlrd->res, res); > if (rc) { > /* > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index f6015f24ad38..61df87a31e02 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -492,6 +492,7 @@ enum cxl_config_state { > * @res: allocated iomem capacity for this region > * @targets: active ordered targets in current decoder configuration > * @nr_targets: number of targets > + * @cache_size: extended linear cache size, if exists otherwise zero. (as you don't check for existence - or remove "if exists" and just have "extended linear cache size" > * > * State transitions are protected by the cxl_region_rwsem > */ > @@ -503,6 +504,7 @@ struct cxl_region_params { > struct resource *res; > struct cxl_endpoint_decoder *targets[CXL_DECODER_MAX_INTERLEAVE]; > int nr_targets; > + resource_size_t cache_size; > }; > > /*