Commit 448a60e8 authored by Huaisheng Ye's avatar Huaisheng Ye Committed by Dave Jiang
Browse files

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: default avatarHuaisheng Ye <huaisheng.ye@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20250115152600.26482-2-huaisheng.ye@intel.com


Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
parent 6cdbd84d

drivers/cxl/core/regs.c

+34 −22
Original line number Diff line number Diff line
@@ -289,20 +289,16 @@ 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,

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;
@@ -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");

drivers/cxl/cxl.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

drivers/cxl/pci.c

+5 −1
Original line number Diff line number Diff line
@@ -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;