From 4fe82279580d10ba63c1461ff404f2c6c82ff1d5 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Wed, 14 Jan 2026 17:48:18 +0100 Subject: [PATCH] cxl/region: Store root decoder in struct cxl_region A region is always bound to a root decoder. The region's associated root decoder is often needed. Add it to struct cxl_region. This simplifies the code by removing dynamic lookups and the root decoder argument from the function argument list where possible. Patch is a prerequisite to implement address translation which uses struct cxl_region to store all relevant region and interleaving parameters. It changes the argument list of __construct_region() in preparation of adding a context argument. Additionally the arg list of cxl_region_attach_position() is simplified and the use of to_cxl_root_decoder() removed, which always reconstructs and checks the pointer. The pointer never changes and is frequently used. Code becomes more readable as this amphazises the binding between both objects. Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Reviewed-by: Gregory Price Reviewed-by: Alison Schofield Signed-off-by: Robert Richter Link: https://patch.msgid.link/20260114164837.1076338-3-rrichter@amd.com Signed-off-by: Dave Jiang --- drivers/cxl/core/region.c | 37 +++++++++++++++++++------------------ drivers/cxl/cxl.h | 2 ++ 2 files changed, 21 insertions(+), 18 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 51f1a55453248..22bd8ff37cefe 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -489,9 +489,9 @@ static ssize_t interleave_ways_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent); - struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct cxl_region *cxlr = to_cxl_region(dev); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; + struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct cxl_region_params *p = &cxlr->params; unsigned int val, save; int rc; @@ -552,9 +552,9 @@ static ssize_t interleave_granularity_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent); - struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct cxl_region *cxlr = to_cxl_region(dev); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; + struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; struct cxl_region_params *p = &cxlr->params; int rc, val; u16 ig; @@ -628,7 +628,7 @@ static DEVICE_ATTR_RO(mode); static int alloc_hpa(struct cxl_region *cxlr, resource_size_t size) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_region_params *p = &cxlr->params; struct resource *res; u64 remainder = 0; @@ -1373,7 +1373,7 @@ static int cxl_port_setup_targets(struct cxl_port *port, struct cxl_region *cxlr, struct cxl_endpoint_decoder *cxled) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; int parent_iw, parent_ig, ig, iw, rc, pos = cxled->pos; struct cxl_port *parent_port = to_cxl_port(port->dev.parent); struct cxl_region_ref *cxl_rr = cxl_rr_load(port, cxlr); @@ -1731,10 +1731,10 @@ static int cxl_region_validate_position(struct cxl_region *cxlr, } static int cxl_region_attach_position(struct cxl_region *cxlr, - struct cxl_root_decoder *cxlrd, struct cxl_endpoint_decoder *cxled, const struct cxl_dport *dport, int pos) { + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd; struct cxl_decoder *cxld = &cxlsd->cxld; @@ -1971,7 +1971,7 @@ static int cxl_region_sort_targets(struct cxl_region *cxlr) static int cxl_region_attach(struct cxl_region *cxlr, struct cxl_endpoint_decoder *cxled, int pos) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); struct cxl_dev_state *cxlds = cxlmd->cxlds; struct cxl_region_params *p = &cxlr->params; @@ -2076,8 +2076,7 @@ static int cxl_region_attach(struct cxl_region *cxlr, ep_port = cxled_to_port(cxled); dport = cxl_find_dport_by_dev(root_port, ep_port->host_bridge); - rc = cxl_region_attach_position(cxlr, cxlrd, cxled, - dport, i); + rc = cxl_region_attach_position(cxlr, cxled, dport, i); if (rc) return rc; } @@ -2100,7 +2099,7 @@ static int cxl_region_attach(struct cxl_region *cxlr, if (rc) return rc; - rc = cxl_region_attach_position(cxlr, cxlrd, cxled, dport, pos); + rc = cxl_region_attach_position(cxlr, cxled, dport, pos); if (rc) return rc; @@ -2396,8 +2395,8 @@ static const struct attribute_group *region_groups[] = { static void cxl_region_release(struct device *dev) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent); struct cxl_region *cxlr = to_cxl_region(dev); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; int id = atomic_read(&cxlrd->region_id); /* @@ -2480,10 +2479,12 @@ static struct cxl_region *cxl_region_alloc(struct cxl_root_decoder *cxlrd, int i * region id allocations */ get_device(dev->parent); + cxlr->cxlrd = cxlrd; + cxlr->id = id; + device_set_pm_not_required(dev); dev->bus = &cxl_bus_type; dev->type = &cxl_region_type; - cxlr->id = id; cxl_region_set_lock(cxlr, &cxlrd->cxlsd.cxld); return cxlr; @@ -3115,7 +3116,7 @@ EXPORT_SYMBOL_FOR_MODULES(cxl_calculate_hpa_offset, "cxl_translate"); u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd, u64 dpa) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_region_params *p = &cxlr->params; struct cxl_endpoint_decoder *cxled = NULL; u64 dpa_offset, hpa_offset, hpa; @@ -3168,7 +3169,7 @@ static int region_offset_to_dpa_result(struct cxl_region *cxlr, u64 offset, struct dpa_result *result) { struct cxl_region_params *p = &cxlr->params; - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_endpoint_decoder *cxled; u64 hpa, hpa_offset, dpa_offset; u16 eig = 0; @@ -3522,7 +3523,7 @@ static int match_region_by_range(struct device *dev, const void *data) static int cxl_extended_linear_cache_resize(struct cxl_region *cxlr, struct resource *res) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent); + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_region_params *p = &cxlr->params; resource_size_t size = resource_size(res); resource_size_t cache_size, start; @@ -3558,9 +3559,9 @@ static int cxl_extended_linear_cache_resize(struct cxl_region *cxlr, } static int __construct_region(struct cxl_region *cxlr, - struct cxl_root_decoder *cxlrd, struct cxl_endpoint_decoder *cxled) { + struct cxl_root_decoder *cxlrd = cxlr->cxlrd; struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); struct range *hpa_range = &cxled->cxld.hpa_range; struct cxl_region_params *p; @@ -3656,7 +3657,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, return cxlr; } - rc = __construct_region(cxlr, cxlrd, cxled); + rc = __construct_region(cxlr, cxled); if (rc) { devm_release_action(port->uport_dev, unregister_region, cxlr); return ERR_PTR(rc); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index ba17fa86d249e..10ce9c3a8a553 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -529,6 +529,7 @@ enum cxl_partition_mode { * struct cxl_region - CXL region * @dev: This region's device * @id: This region's id. Id is globally unique across all regions + * @cxlrd: Region's root decoder * @mode: Operational mode of the mapped capacity * @type: Endpoint decoder target type * @cxl_nvb: nvdimm bridge for coordinating @cxlr_pmem setup / shutdown @@ -542,6 +543,7 @@ enum cxl_partition_mode { struct cxl_region { struct device dev; int id; + struct cxl_root_decoder *cxlrd; enum cxl_partition_mode mode; enum cxl_decoder_type type; struct cxl_nvdimm_bridge *cxl_nvb; -- 2.47.3