From 448a60e85ae2afe2cb760f5d2ed2c8a49d2bd1b4 Mon Sep 17 00:00:00 2001 From: Huaisheng Ye Date: Wed, 15 Jan 2025 23:26:00 +0800 Subject: [PATCH] cxl/core/regs: Refactor out functions to count regblocks of given type cxl_find_regblock_instance() counts the number of instances of a register block as a side effect of searching through all available register blocks. cxl_count_regblock() throws away that work and recounts all the register blocks by asking cxl_find_regblock_instance() to redo work it has already done until it finally returns an error, that is needlessly wasteful. Let cxl_count_regblock() leverage the counting that cxl_find_regblock_instance() already does by passing in a sentinel value (CXL_INSTANCES_COUNT) that triggers the count to be returned. [ davej: Updated to more concise commit log supplied by djbw ] [ davej: Fix up checkpatch formatting warnings ] Signed-off-by: Huaisheng Ye Reviewed-by: Jonathan Cameron Reviewed-by: Dan Williams Link: https://patch.msgid.link/20250115152600.26482-2-huaisheng.ye@intel.com Signed-off-by: Dave Jiang --- drivers/cxl/core/regs.c | 56 +++++++++++++++++++++++++---------------- drivers/cxl/cxl.h | 3 ++- drivers/cxl/pci.c | 6 ++++- 3 files changed, 41 insertions(+), 24 deletions(-) diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c index 59cb35b40c7e5..117c2e94c761d 100644 --- a/drivers/cxl/core/regs.c +++ b/drivers/cxl/core/regs.c @@ -289,21 +289,17 @@ static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi, return true; } -/** - * cxl_find_regblock_instance() - Locate a register block by type / index - * @pdev: The CXL PCI device to enumerate. - * @type: Register Block Indicator id - * @map: Enumeration output, clobbered on error - * @index: Index into which particular instance of a regblock wanted in the - * order found in register locator DVSEC. - * - * Return: 0 if register block enumerated, negative error code otherwise +/* + * __cxl_find_regblock_instance() - Locate a register block or count instances by type / index + * Use CXL_INSTANCES_COUNT for @index if counting instances. * - * A CXL DVSEC may point to one or more register blocks, search for them - * by @type and @index. + * __cxl_find_regblock_instance() may return: + * 0 - if register block enumerated. + * >= 0 - if counting instances. + * < 0 - error code otherwise. */ -int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type, - struct cxl_register_map *map, int index) +static int __cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type, + struct cxl_register_map *map, int index) { u32 regloc_size, regblocks; int instance = 0; @@ -342,8 +338,30 @@ int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type, } map->resource = CXL_RESOURCE_NONE; + if (index == CXL_INSTANCES_COUNT) + return instance; + return -ENODEV; } + +/** + * cxl_find_regblock_instance() - Locate a register block by type / index + * @pdev: The CXL PCI device to enumerate. + * @type: Register Block Indicator id + * @map: Enumeration output, clobbered on error + * @index: Index into which particular instance of a regblock wanted in the + * order found in register locator DVSEC. + * + * Return: 0 if register block enumerated, negative error code otherwise + * + * A CXL DVSEC may point to one or more register blocks, search for them + * by @type and @index. + */ +int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type, + struct cxl_register_map *map, unsigned int index) +{ + return __cxl_find_regblock_instance(pdev, type, map, index); +} EXPORT_SYMBOL_NS_GPL(cxl_find_regblock_instance, "CXL"); /** @@ -360,7 +378,7 @@ EXPORT_SYMBOL_NS_GPL(cxl_find_regblock_instance, "CXL"); int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, struct cxl_register_map *map) { - return cxl_find_regblock_instance(pdev, type, map, 0); + return __cxl_find_regblock_instance(pdev, type, map, 0); } EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, "CXL"); @@ -371,19 +389,13 @@ EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, "CXL"); * * Some regblocks may be repeated. Count how many instances. * - * Return: count of matching regblocks. + * Return: non-negative count of matching regblocks, negative error code otherwise. */ int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type) { struct cxl_register_map map; - int rc, count = 0; - while (1) { - rc = cxl_find_regblock_instance(pdev, type, &map, count); - if (rc) - return count; - count++; - } + return __cxl_find_regblock_instance(pdev, type, &map, CXL_INSTANCES_COUNT); } EXPORT_SYMBOL_NS_GPL(cxl_count_regblock, "CXL"); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index fdac3ddb8635b..dcf2a127efc7f 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -302,10 +302,11 @@ int cxl_map_device_regs(const struct cxl_register_map *map, struct cxl_device_regs *regs); int cxl_map_pmu_regs(struct cxl_register_map *map, struct cxl_pmu_regs *regs); +#define CXL_INSTANCES_COUNT -1 enum cxl_regloc_type; int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type); int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type, - struct cxl_register_map *map, int index); + struct cxl_register_map *map, unsigned int index); int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, struct cxl_register_map *map); int cxl_setup_regs(struct cxl_register_map *map); diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 6d94ff4a4f1a6..a96e54c6259e1 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -907,7 +907,8 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) struct cxl_dev_state *cxlds; struct cxl_register_map map; struct cxl_memdev *cxlmd; - int i, rc, pmu_count; + int rc, pmu_count; + unsigned int i; bool irq_avail; /* @@ -1009,6 +1010,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) return rc; pmu_count = cxl_count_regblock(pdev, CXL_REGLOC_RBI_PMU); + if (pmu_count < 0) + return pmu_count; + for (i = 0; i < pmu_count; i++) { struct cxl_pmu_regs pmu_regs; -- 2.49.0