[mirror_ubuntu-hirsute-kernel.git] / drivers / pci / ecam.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2016 Broadcom
 */

#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci-ecam.h>
#include <linux/slab.h>

/*
 * On 64-bit systems, we do a single ioremap for the whole config space
 * since we have enough virtual address range available.  On 32-bit, we
 * ioremap the config space for each bus individually.
 */
static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);

/*
 * Create a PCI config space window
 *  - reserve mem region
 *  - alloc struct pci_config_window with space for all mappings
 *  - ioremap the config space
 */
struct pci_config_window *pci_ecam_create(struct device *dev,
		struct resource *cfgres, struct resource *busr,
		const struct pci_ecam_ops *ops)
{
	unsigned int bus_shift = ops->bus_shift;
	struct pci_config_window *cfg;
	unsigned int bus_range, bus_range_max, bsz;
	struct resource *conflict;
	int i, err;

	if (busr->start > busr->end)
		return ERR_PTR(-EINVAL);

	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
	if (!cfg)
		return ERR_PTR(-ENOMEM);

	/* ECAM-compliant platforms need not supply ops->bus_shift */
	if (!bus_shift)
		bus_shift = PCIE_ECAM_BUS_SHIFT;

	cfg->parent = dev;
	cfg->ops = ops;
	cfg->busr.start = busr->start;
	cfg->busr.end = busr->end;
	cfg->busr.flags = IORESOURCE_BUS;
	bus_range = resource_size(&cfg->busr);
	bus_range_max = resource_size(cfgres) >> bus_shift;
	if (bus_range > bus_range_max) {
		bus_range = bus_range_max;
		cfg->busr.end = busr->start + bus_range - 1;
		dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n",
			 cfgres, &cfg->busr, busr);
	}
	bsz = 1 << bus_shift;

	cfg->res.start = cfgres->start;
	cfg->res.end = cfgres->end;
	cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
	cfg->res.name = "PCI ECAM";

	conflict = request_resource_conflict(&iomem_resource, &cfg->res);
	if (conflict) {
		err = -EBUSY;
		dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
			&cfg->res, conflict->name, conflict);
		goto err_exit;
	}

	if (per_bus_mapping) {
		cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL);
		if (!cfg->winp)
			goto err_exit_malloc;
		for (i = 0; i < bus_range; i++) {
			cfg->winp[i] =
				pci_remap_cfgspace(cfgres->start + i * bsz,
						   bsz);
			if (!cfg->winp[i])
				goto err_exit_iomap;
		}
	} else {
		cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
		if (!cfg->win)
			goto err_exit_iomap;
	}

	if (ops->init) {
		err = ops->init(cfg);
		if (err)
			goto err_exit;
	}
	dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
	return cfg;

err_exit_iomap:
	dev_err(dev, "ECAM ioremap failed\n");
err_exit_malloc:
	err = -ENOMEM;
err_exit:
	pci_ecam_free(cfg);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(pci_ecam_create);

void pci_ecam_free(struct pci_config_window *cfg)
{
	int i;

	if (per_bus_mapping) {
		if (cfg->winp) {
			for (i = 0; i < resource_size(&cfg->busr); i++)
				if (cfg->winp[i])
					iounmap(cfg->winp[i]);
			kfree(cfg->winp);
		}
	} else {
		if (cfg->win)
			iounmap(cfg->win);
	}
	if (cfg->res.parent)
		release_resource(&cfg->res);
	kfree(cfg);
}
EXPORT_SYMBOL_GPL(pci_ecam_free);

/*
 * Function to implement the pci_ops ->map_bus method
 */
void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
			       int where)
{
	struct pci_config_window *cfg = bus->sysdata;
	unsigned int bus_shift = cfg->ops->bus_shift;
	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
	unsigned int busn = bus->number;
	void __iomem *base;
	u32 bus_offset, devfn_offset;

	if (busn < cfg->busr.start || busn > cfg->busr.end)
		return NULL;

	busn -= cfg->busr.start;
	if (per_bus_mapping) {
		base = cfg->winp[busn];
		busn = 0;
	} else
		base = cfg->win;

	if (cfg->ops->bus_shift) {
		bus_offset = (busn & PCIE_ECAM_BUS_MASK) << bus_shift;
		devfn_offset = (devfn & PCIE_ECAM_DEVFN_MASK) << devfn_shift;
		where &= PCIE_ECAM_REG_MASK;

		return base + (bus_offset | devfn_offset | where);
	}

	return base + PCIE_ECAM_OFFSET(busn, devfn, where);
}
EXPORT_SYMBOL_GPL(pci_ecam_map_bus);

/* ECAM ops */
const struct pci_ecam_ops pci_generic_ecam_ops = {
	.pci_ops	= {
		.map_bus	= pci_ecam_map_bus,
		.read		= pci_generic_config_read,
		.write		= pci_generic_config_write,
	}
};
EXPORT_SYMBOL_GPL(pci_generic_ecam_ops);

#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
/* ECAM ops for 32-bit access only (non-compliant) */
const struct pci_ecam_ops pci_32b_ops = {
	.pci_ops	= {
		.map_bus	= pci_ecam_map_bus,
		.read		= pci_generic_config_read32,
		.write		= pci_generic_config_write32,
	}
};

/* ECAM ops for 32-bit read only (non-compliant) */
const struct pci_ecam_ops pci_32b_read_ops = {
	.pci_ops	= {
		.map_bus	= pci_ecam_map_bus,
		.read		= pci_generic_config_read32,
		.write		= pci_generic_config_write,
	}
};
#endif
Commit	Line	Data
8cfab3cf	1	// SPDX-License-Identifier: GPL-2.0
35ff9477 J	2	/*
35ff9477 J	3	* Copyright 2016 Broadcom
35ff9477 J	4	*/
	5
	6	#include <linux/device.h>
	7	#include <linux/io.h>
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/pci.h>
80955f9e	11	#include <linux/pci-ecam.h>
35ff9477 J	12	#include <linux/slab.h>
35ff9477 J	13
35ff9477 J	14	/*
	15	* On 64-bit systems, we do a single ioremap for the whole config space
	16	* since we have enough virtual address range available. On 32-bit, we
	17	* ioremap the config space for each bus individually.
	18	*/
97f2645f	19	static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);
35ff9477 J	20
	21	/*
	22	* Create a PCI config space window
	23	* - reserve mem region
	24	* - alloc struct pci_config_window with space for all mappings
	25	* - ioremap the config space
	26	*/
	27	struct pci_config_window pci_ecam_create(struct device dev,
	28	struct resource cfgres, struct resource busr,
0b104773	29	const struct pci_ecam_ops *ops)
35ff9477	30	{
e7708f5b	31	unsigned int bus_shift = ops->bus_shift;
35ff9477 J	32	struct pci_config_window *cfg;
	33	unsigned int bus_range, bus_range_max, bsz;
	34	struct resource *conflict;
	35	int i, err;
	36
	37	if (busr->start > busr->end)
	38	return ERR_PTR(-EINVAL);
	39
	40	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
	41	if (!cfg)
	42	return ERR_PTR(-ENOMEM);
	43
e7708f5b KW	44	/* ECAM-compliant platforms need not supply ops->bus_shift */
	45	if (!bus_shift)
	46	bus_shift = PCIE_ECAM_BUS_SHIFT;
	47
5c3d14f7	48	cfg->parent = dev;
35ff9477 J	49	cfg->ops = ops;
	50	cfg->busr.start = busr->start;
	51	cfg->busr.end = busr->end;
	52	cfg->busr.flags = IORESOURCE_BUS;
	53	bus_range = resource_size(&cfg->busr);
e7708f5b	54	bus_range_max = resource_size(cfgres) >> bus_shift;
35ff9477 J	55	if (bus_range > bus_range_max) {
	56	bus_range = bus_range_max;
	57	cfg->busr.end = busr->start + bus_range - 1;
	58	dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n",
	59	cfgres, &cfg->busr, busr);
	60	}
e7708f5b	61	bsz = 1 << bus_shift;
35ff9477 J	62
	63	cfg->res.start = cfgres->start;
	64	cfg->res.end = cfgres->end;
	65	cfg->res.flags = IORESOURCE_MEM \| IORESOURCE_BUSY;
	66	cfg->res.name = "PCI ECAM";
	67
	68	conflict = request_resource_conflict(&iomem_resource, &cfg->res);
	69	if (conflict) {
	70	err = -EBUSY;
	71	dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
	72	&cfg->res, conflict->name, conflict);
	73	goto err_exit;
	74	}
	75
	76	if (per_bus_mapping) {
	77	cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL);
	78	if (!cfg->winp)
	79	goto err_exit_malloc;
	80	for (i = 0; i < bus_range; i++) {
053497ce LP	81	cfg->winp[i] =
	82	pci_remap_cfgspace(cfgres->start + i * bsz,
	83	bsz);
35ff9477 J	84	if (!cfg->winp[i])
	85	goto err_exit_iomap;
	86	}
	87	} else {
053497ce	88	cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
35ff9477 J	89	if (!cfg->win)
	90	goto err_exit_iomap;
	91	}
	92
	93	if (ops->init) {
5c3d14f7	94	err = ops->init(cfg);
35ff9477 J	95	if (err)
	96	goto err_exit;
	97	}
	98	dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
	99	return cfg;
	100
	101	err_exit_iomap:
	102	dev_err(dev, "ECAM ioremap failed\n");
	103	err_exit_malloc:
	104	err = -ENOMEM;
	105	err_exit:
	106	pci_ecam_free(cfg);
	107	return ERR_PTR(err);
	108	}
0c59c06a	109	EXPORT_SYMBOL_GPL(pci_ecam_create);
35ff9477 J	110
	111	void pci_ecam_free(struct pci_config_window *cfg)
	112	{
	113	int i;
	114
	115	if (per_bus_mapping) {
	116	if (cfg->winp) {
	117	for (i = 0; i < resource_size(&cfg->busr); i++)
	118	if (cfg->winp[i])
	119	iounmap(cfg->winp[i]);
	120	kfree(cfg->winp);
	121	}
	122	} else {
	123	if (cfg->win)
	124	iounmap(cfg->win);
	125	}
	126	if (cfg->res.parent)
	127	release_resource(&cfg->res);
	128	kfree(cfg);
	129	}
0c59c06a	130	EXPORT_SYMBOL_GPL(pci_ecam_free);
35ff9477 J	131
	132	/*
	133	* Function to implement the pci_ops ->map_bus method
	134	*/
	135	void __iomem pci_ecam_map_bus(struct pci_bus bus, unsigned int devfn,
	136	int where)
	137	{
	138	struct pci_config_window *cfg = bus->sysdata;
e7708f5b	139	unsigned int bus_shift = cfg->ops->bus_shift;
35ff9477 J	140	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
	141	unsigned int busn = bus->number;
	142	void __iomem *base;
e7708f5b	143	u32 bus_offset, devfn_offset;
35ff9477 J	144
	145	if (busn < cfg->busr.start \|\| busn > cfg->busr.end)
	146	return NULL;
	147
	148	busn -= cfg->busr.start;
e7708f5b	149	if (per_bus_mapping) {
35ff9477	150	base = cfg->winp[busn];
e7708f5b KW	151	busn = 0;
	152	} else
	153	base = cfg->win;
	154
	155	if (cfg->ops->bus_shift) {
	156	bus_offset = (busn & PCIE_ECAM_BUS_MASK) << bus_shift;
	157	devfn_offset = (devfn & PCIE_ECAM_DEVFN_MASK) << devfn_shift;
	158	where &= PCIE_ECAM_REG_MASK;
	159
	160	return base + (bus_offset \| devfn_offset \| where);
	161	}
	162
	163	return base + PCIE_ECAM_OFFSET(busn, devfn, where);
35ff9477	164	}
0c59c06a	165	EXPORT_SYMBOL_GPL(pci_ecam_map_bus);
35ff9477 J	166
35ff9477 J	167	/* ECAM ops */
0b104773	168	const struct pci_ecam_ops pci_generic_ecam_ops = {
35ff9477 J	169	.pci_ops = {
	170	.map_bus = pci_ecam_map_bus,
	171	.read = pci_generic_config_read,
	172	.write = pci_generic_config_write,
	173	}
	174	};
0c59c06a	175	EXPORT_SYMBOL_GPL(pci_generic_ecam_ops);
2ca5b8dd CC	176
	177	#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
	178	/* ECAM ops for 32-bit access only (non-compliant) */
0b104773	179	const struct pci_ecam_ops pci_32b_ops = {
2ca5b8dd CC	180	.pci_ops = {
	181	.map_bus = pci_ecam_map_bus,
	182	.read = pci_generic_config_read32,
	183	.write = pci_generic_config_write32,
	184	}
	185	};
877c1a5f TP	186
	187	/* ECAM ops for 32-bit read only (non-compliant) */
	188	const struct pci_ecam_ops pci_32b_read_ops = {
877c1a5f TP	189	.pci_ops = {
	190	.map_bus = pci_ecam_map_bus,
	191	.read = pci_generic_config_read32,
	192	.write = pci_generic_config_write,
	193	}
	194	};
2ca5b8dd	195	#endif