[mirror_ubuntu-zesty-kernel.git] / arch / x86 / pci / i386.c

/*
 *	Low-Level PCI Access for i386 machines
 *
 * Copyright 1993, 1994 Drew Eckhardt
 *      Visionary Computing
 *      (Unix and Linux consulting and custom programming)
 *      Drew@Colorado.EDU
 *      +1 (303) 786-7975
 *
 * Drew's work was sponsored by:
 *	iX Multiuser Multitasking Magazine
 *	Hannover, Germany
 *	hm@ix.de
 *
 * Copyright 1997--2000 Martin Mares <mj@ucw.cz>
 *
 * For more information, please consult the following manuals (look at
 * http://www.pcisig.com/ for how to get them):
 *
 * PCI BIOS Specification
 * PCI Local Bus Specification
 * PCI to PCI Bridge Specification
 * PCI System Design Guide
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/bootmem.h>

#include <asm/pat.h>
#include <asm/e820.h>
#include <asm/pci_x86.h>
#include <asm/io_apic.h>


static int
skip_isa_ioresource_align(struct pci_dev *dev) {

	if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) &&
	    !(dev->bus->bridge_ctl & PCI_BRIDGE_CTL_ISA))
		return 1;
	return 0;
}

/*
 * We need to avoid collisions with `mirrored' VGA ports
 * and other strange ISA hardware, so we always want the
 * addresses to be allocated in the 0x000-0x0ff region
 * modulo 0x400.
 *
 * Why? Because some silly external IO cards only decode
 * the low 10 bits of the IO address. The 0x00-0xff region
 * is reserved for motherboard devices that decode all 16
 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
 * but we want to try to avoid allocating at 0x2900-0x2bff
 * which might have be mirrored at 0x0100-0x03ff..
 */
void
pcibios_align_resource(void *data, struct resource *res,
			resource_size_t size, resource_size_t align)
{
	struct pci_dev *dev = data;

	if (res->flags & IORESOURCE_IO) {
		resource_size_t start = res->start;

		if (skip_isa_ioresource_align(dev))
			return;
		if (start & 0x300) {
			start = (start + 0x3ff) & ~0x3ff;
			res->start = start;
		}
	}
}
EXPORT_SYMBOL(pcibios_align_resource);

/*
 *  Handle resources of PCI devices.  If the world were perfect, we could
 *  just allocate all the resource regions and do nothing more.  It isn't.
 *  On the other hand, we cannot just re-allocate all devices, as it would
 *  require us to know lots of host bridge internals.  So we attempt to
 *  keep as much of the original configuration as possible, but tweak it
 *  when it's found to be wrong.
 *
 *  Known BIOS problems we have to work around:
 *	- I/O or memory regions not configured
 *	- regions configured, but not enabled in the command register
 *	- bogus I/O addresses above 64K used
 *	- expansion ROMs left enabled (this may sound harmless, but given
 *	  the fact the PCI specs explicitly allow address decoders to be
 *	  shared between expansion ROMs and other resource regions, it's
 *	  at least dangerous)
 *
 *  Our solution:
 *	(1) Allocate resources for all buses behind PCI-to-PCI bridges.
 *	    This gives us fixed barriers on where we can allocate.
 *	(2) Allocate resources for all enabled devices.  If there is
 *	    a collision, just mark the resource as unallocated. Also
 *	    disable expansion ROMs during this step.
 *	(3) Try to allocate resources for disabled devices.  If the
 *	    resources were assigned correctly, everything goes well,
 *	    if they weren't, they won't disturb allocation of other
 *	    resources.
 *	(4) Assign new addresses to resources which were either
 *	    not configured at all or misconfigured.  If explicitly
 *	    requested by the user, configure expansion ROM address
 *	    as well.
 */

static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
{
	struct pci_bus *bus;
	struct pci_dev *dev;
	int idx;
	struct resource *r;

	/* Depth-First Search on bus tree */
	list_for_each_entry(bus, bus_list, node) {
		if ((dev = bus->self)) {
			for (idx = PCI_BRIDGE_RESOURCES;
			    idx < PCI_NUM_RESOURCES; idx++) {
				r = &dev->resource[idx];
				if (!r->flags)
					continue;
				if (!r->start ||
				    pci_claim_resource(dev, idx) < 0) {
					dev_info(&dev->dev, "BAR %d: can't allocate resource\n", idx);
					/*
					 * Something is wrong with the region.
					 * Invalidate the resource to prevent
					 * child resource allocations in this
					 * range.
					 */
					r->flags = 0;
				}
			}
		}
		pcibios_allocate_bus_resources(&bus->children);
	}
}

static void __init pcibios_allocate_resources(int pass)
{
	struct pci_dev *dev = NULL;
	int idx, disabled;
	u16 command;
	struct resource *r;

	for_each_pci_dev(dev) {
		pci_read_config_word(dev, PCI_COMMAND, &command);
		for (idx = 0; idx < PCI_ROM_RESOURCE; idx++) {
			r = &dev->resource[idx];
			if (r->parent)		/* Already allocated */
				continue;
			if (!r->start)		/* Address not assigned at all */
				continue;
			if (r->flags & IORESOURCE_IO)
				disabled = !(command & PCI_COMMAND_IO);
			else
				disabled = !(command & PCI_COMMAND_MEMORY);
			if (pass == disabled) {
				dev_dbg(&dev->dev, "resource %#08llx-%#08llx (f=%lx, d=%d, p=%d)\n",
					(unsigned long long) r->start,
					(unsigned long long) r->end,
					r->flags, disabled, pass);
				if (pci_claim_resource(dev, idx) < 0) {
					dev_info(&dev->dev, "BAR %d: can't allocate resource\n", idx);
					/* We'll assign a new address later */
					r->end -= r->start;
					r->start = 0;
				}
			}
		}
		if (!pass) {
			r = &dev->resource[PCI_ROM_RESOURCE];
			if (r->flags & IORESOURCE_ROM_ENABLE) {
				/* Turn the ROM off, leave the resource region,
				 * but keep it unregistered. */
				u32 reg;
				dev_dbg(&dev->dev, "disabling ROM\n");
				r->flags &= ~IORESOURCE_ROM_ENABLE;
				pci_read_config_dword(dev,
						dev->rom_base_reg, &reg);
				pci_write_config_dword(dev, dev->rom_base_reg,
						reg & ~PCI_ROM_ADDRESS_ENABLE);
			}
		}
	}
}

static int __init pcibios_assign_resources(void)
{
	struct pci_dev *dev = NULL;
	struct resource *r;

	if (!(pci_probe & PCI_ASSIGN_ROMS)) {
		/*
		 * Try to use BIOS settings for ROMs, otherwise let
		 * pci_assign_unassigned_resources() allocate the new
		 * addresses.
		 */
		for_each_pci_dev(dev) {
			r = &dev->resource[PCI_ROM_RESOURCE];
			if (!r->flags || !r->start)
				continue;
			if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
				r->end -= r->start;
				r->start = 0;
			}
		}
	}

	pci_assign_unassigned_resources();

	return 0;
}

void __init pcibios_resource_survey(void)
{
	DBG("PCI: Allocating resources\n");
	pcibios_allocate_bus_resources(&pci_root_buses);
	pcibios_allocate_resources(0);
	pcibios_allocate_resources(1);

	e820_reserve_resources_late();
	/*
	 * Insert the IO APIC resources after PCI initialization has
	 * occured to handle IO APICS that are mapped in on a BAR in
	 * PCI space, but before trying to assign unassigned pci res.
	 */
	ioapic_insert_resources();
}

/**
 * called in fs_initcall (one below subsys_initcall),
 * give a chance for motherboard reserve resources
 */
fs_initcall(pcibios_assign_resources);

void __weak x86_pci_root_bus_res_quirks(struct pci_bus *b)
{
}

/*
 *  If we set up a device for bus mastering, we need to check the latency
 *  timer as certain crappy BIOSes forget to set it properly.
 */
unsigned int pcibios_max_latency = 255;

void pcibios_set_master(struct pci_dev *dev)
{
	u8 lat;
	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
	if (lat < 16)
		lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
	else if (lat > pcibios_max_latency)
		lat = pcibios_max_latency;
	else
		return;
	dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat);
	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}

static const struct vm_operations_struct pci_mmap_ops = {
	.access = generic_access_phys,
};

int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
			enum pci_mmap_state mmap_state, int write_combine)
{
	unsigned long prot;

	/* I/O space cannot be accessed via normal processor loads and
	 * stores on this platform.
	 */
	if (mmap_state == pci_mmap_io)
		return -EINVAL;

	prot = pgprot_val(vma->vm_page_prot);
	if (pat_enabled && write_combine)
		prot |= _PAGE_CACHE_WC;
	else if (pat_enabled || boot_cpu_data.x86 > 3)
		/*
		 * ioremap() and ioremap_nocache() defaults to UC MINUS for now.
		 * To avoid attribute conflicts, request UC MINUS here
		 * aswell.
		 */
		prot |= _PAGE_CACHE_UC_MINUS;

	vma->vm_page_prot = __pgprot(prot);

	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
			       vma->vm_end - vma->vm_start,
			       vma->vm_page_prot))
		return -EAGAIN;

	vma->vm_ops = &pci_mmap_ops;

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Low-Level PCI Access for i386 machines
	3	*
	4	* Copyright 1993, 1994 Drew Eckhardt
	5	* Visionary Computing
	6	* (Unix and Linux consulting and custom programming)
	7	* Drew@Colorado.EDU
	8	* +1 (303) 786-7975
	9	*
	10	* Drew's work was sponsored by:
	11	* iX Multiuser Multitasking Magazine
	12	* Hannover, Germany
	13	* hm@ix.de
	14	*
	15	* Copyright 1997--2000 Martin Mares <mj@ucw.cz>
	16	*
	17	* For more information, please consult the following manuals (look at
	18	* http://www.pcisig.com/ for how to get them):
	19	*
	20	* PCI BIOS Specification
	21	* PCI Local Bus Specification
	22	* PCI to PCI Bridge Specification
	23	* PCI System Design Guide
	24	*
	25	*/
	26
	27	#include <linux/types.h>
	28	#include <linux/kernel.h>
	29	#include <linux/pci.h>
	30	#include <linux/init.h>
	31	#include <linux/ioport.h>
	32	#include <linux/errno.h>
03d72aa1	33	#include <linux/bootmem.h>
	34
	35	#include <asm/pat.h>
58f7c988	36	#include <asm/e820.h>
82487711	37	#include <asm/pci_x86.h>
857fdc53	38	#include <asm/io_apic.h>
1da177e4	39
1da177e4	40
036fff4c GH	41	static int
	42	skip_isa_ioresource_align(struct pci_dev *dev) {
	43
	44	if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) &&
11949255	45	!(dev->bus->bridge_ctl & PCI_BRIDGE_CTL_ISA))
036fff4c GH	46	return 1;
	47	return 0;
	48	}
	49
1da177e4 LT	50	/*
	51	* We need to avoid collisions with `mirrored' VGA ports
	52	* and other strange ISA hardware, so we always want the
	53	* addresses to be allocated in the 0x000-0x0ff region
	54	* modulo 0x400.
	55	*
	56	* Why? Because some silly external IO cards only decode
	57	* the low 10 bits of the IO address. The 0x00-0xff region
	58	* is reserved for motherboard devices that decode all 16
	59	* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
	60	* but we want to try to avoid allocating at 0x2900-0x2bff
	61	* which might have be mirrored at 0x0100-0x03ff..
	62	*/
	63	void
	64	pcibios_align_resource(void data, struct resource res,
e31dd6e4	65	resource_size_t size, resource_size_t align)
1da177e4	66	{
036fff4c GH	67	struct pci_dev *dev = data;
036fff4c GH	68
1da177e4	69	if (res->flags & IORESOURCE_IO) {
e31dd6e4	70	resource_size_t start = res->start;
1da177e4	71
036fff4c GH	72	if (skip_isa_ioresource_align(dev))
036fff4c GH	73	return;
1da177e4 LT	74	if (start & 0x300) {
	75	start = (start + 0x3ff) & ~0x3ff;
	76	res->start = start;
	77	}
	78	}
	79	}
6c00a61e	80	EXPORT_SYMBOL(pcibios_align_resource);
1da177e4 LT	81
	82	/*
	83	* Handle resources of PCI devices. If the world were perfect, we could
	84	* just allocate all the resource regions and do nothing more. It isn't.
	85	* On the other hand, we cannot just re-allocate all devices, as it would
	86	* require us to know lots of host bridge internals. So we attempt to
	87	* keep as much of the original configuration as possible, but tweak it
	88	* when it's found to be wrong.
	89	*
	90	* Known BIOS problems we have to work around:
	91	* - I/O or memory regions not configured
	92	* - regions configured, but not enabled in the command register
	93	* - bogus I/O addresses above 64K used
	94	* - expansion ROMs left enabled (this may sound harmless, but given
	95	* the fact the PCI specs explicitly allow address decoders to be
	96	* shared between expansion ROMs and other resource regions, it's
	97	* at least dangerous)
	98	*
	99	* Our solution:
	100	* (1) Allocate resources for all buses behind PCI-to-PCI bridges.
	101	* This gives us fixed barriers on where we can allocate.
	102	* (2) Allocate resources for all enabled devices. If there is
	103	* a collision, just mark the resource as unallocated. Also
	104	* disable expansion ROMs during this step.
	105	* (3) Try to allocate resources for disabled devices. If the
	106	* resources were assigned correctly, everything goes well,
	107	* if they weren't, they won't disturb allocation of other
	108	* resources.
	109	* (4) Assign new addresses to resources which were either
	110	* not configured at all or misconfigured. If explicitly
	111	* requested by the user, configure expansion ROM address
	112	* as well.
	113	*/
	114
	115	static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
	116	{
	117	struct pci_bus *bus;
	118	struct pci_dev *dev;
	119	int idx;
a76117df	120	struct resource *r;
1da177e4 LT	121
	122	/* Depth-First Search on bus tree */
	123	list_for_each_entry(bus, bus_list, node) {
	124	if ((dev = bus->self)) {
7edab2f0 RD	125	for (idx = PCI_BRIDGE_RESOURCES;
7edab2f0 RD	126	idx < PCI_NUM_RESOURCES; idx++) {
1da177e4	127	r = &dev->resource[idx];
299de034	128	if (!r->flags)
1da177e4	129	continue;
a76117df MW	130	if (!r->start \|\|
a76117df MW	131	pci_claim_resource(dev, idx) < 0) {
104bafcf	132	dev_info(&dev->dev, "BAR %d: can't allocate resource\n", idx);
7edab2f0 RD	133	/*
	134	* Something is wrong with the region.
	135	* Invalidate the resource to prevent
	136	* child resource allocations in this
	137	* range.
	138	*/
299de034 IK	139	r->flags = 0;
299de034 IK	140	}
1da177e4 LT	141	}
	142	}
	143	pcibios_allocate_bus_resources(&bus->children);
	144	}
	145	}
	146
	147	static void __init pcibios_allocate_resources(int pass)
	148	{
	149	struct pci_dev *dev = NULL;
	150	int idx, disabled;
	151	u16 command;
a76117df	152	struct resource *r;
1da177e4 LT	153
	154	for_each_pci_dev(dev) {
	155	pci_read_config_word(dev, PCI_COMMAND, &command);
7edab2f0	156	for (idx = 0; idx < PCI_ROM_RESOURCE; idx++) {
1da177e4 LT	157	r = &dev->resource[idx];
	158	if (r->parent) /* Already allocated */
	159	continue;
	160	if (!r->start) /* Address not assigned at all */
	161	continue;
	162	if (r->flags & IORESOURCE_IO)
	163	disabled = !(command & PCI_COMMAND_IO);
	164	else
	165	disabled = !(command & PCI_COMMAND_MEMORY);
	166	if (pass == disabled) {
011fec74	167	dev_dbg(&dev->dev, "resource %#08llx-%#08llx (f=%lx, d=%d, p=%d)\n",
12c0b20f BH	168	(unsigned long long) r->start,
	169	(unsigned long long) r->end,
	170	r->flags, disabled, pass);
a76117df	171	if (pci_claim_resource(dev, idx) < 0) {
104bafcf	172	dev_info(&dev->dev, "BAR %d: can't allocate resource\n", idx);
1da177e4 LT	173	/* We'll assign a new address later */
	174	r->end -= r->start;
	175	r->start = 0;
	176	}
	177	}
	178	}
	179	if (!pass) {
	180	r = &dev->resource[PCI_ROM_RESOURCE];
	181	if (r->flags & IORESOURCE_ROM_ENABLE) {
7edab2f0 RD	182	/* Turn the ROM off, leave the resource region,
7edab2f0 RD	183	* but keep it unregistered. */
1da177e4	184	u32 reg;
12c0b20f	185	dev_dbg(&dev->dev, "disabling ROM\n");
1da177e4	186	r->flags &= ~IORESOURCE_ROM_ENABLE;
7edab2f0 RD	187	pci_read_config_dword(dev,
	188	dev->rom_base_reg, &reg);
	189	pci_write_config_dword(dev, dev->rom_base_reg,
	190	reg & ~PCI_ROM_ADDRESS_ENABLE);
1da177e4 LT	191	}
	192	}
	193	}
	194	}
	195
	196	static int __init pcibios_assign_resources(void)
	197	{
	198	struct pci_dev *dev = NULL;
a76117df	199	struct resource *r;
1da177e4	200
81d4af13	201	if (!(pci_probe & PCI_ASSIGN_ROMS)) {
7edab2f0 RD	202	/*
	203	* Try to use BIOS settings for ROMs, otherwise let
	204	* pci_assign_unassigned_resources() allocate the new
	205	* addresses.
	206	*/
81d4af13	207	for_each_pci_dev(dev) {
1da177e4	208	r = &dev->resource[PCI_ROM_RESOURCE];
81d4af13 IK	209	if (!r->flags \|\| !r->start)
81d4af13 IK	210	continue;
a76117df	211	if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
81d4af13 IK	212	r->end -= r->start;
	213	r->start = 0;
	214	}
1da177e4 LT	215	}
1da177e4 LT	216	}
81d4af13 IK	217
	218	pci_assign_unassigned_resources();
	219
1da177e4 LT	220	return 0;
	221	}
	222
	223	void __init pcibios_resource_survey(void)
	224	{
	225	DBG("PCI: Allocating resources\n");
	226	pcibios_allocate_bus_resources(&pci_root_buses);
	227	pcibios_allocate_resources(0);
	228	pcibios_allocate_resources(1);
a5444d15 IM	229
a5444d15 IM	230	e820_reserve_resources_late();
857fdc53 YL	231	/*
	232	* Insert the IO APIC resources after PCI initialization has
	233	* occured to handle IO APICS that are mapped in on a BAR in
	234	* PCI space, but before trying to assign unassigned pci res.
	235	*/
	236	ioapic_insert_resources();
1da177e4 LT	237	}
	238
	239	/**
	240	* called in fs_initcall (one below subsys_initcall),
	241	* give a chance for motherboard reserve resources
	242	*/
	243	fs_initcall(pcibios_assign_resources);
	244
0e94ecd0 YL	245	void __weak x86_pci_root_bus_res_quirks(struct pci_bus *b)
	246	{
	247	}
	248
1da177e4 LT	249	/*
	250	* If we set up a device for bus mastering, we need to check the latency
	251	* timer as certain crappy BIOSes forget to set it properly.
	252	*/
	253	unsigned int pcibios_max_latency = 255;
	254
	255	void pcibios_set_master(struct pci_dev *dev)
	256	{
	257	u8 lat;
	258	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
	259	if (lat < 16)
	260	lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
	261	else if (lat > pcibios_max_latency)
	262	lat = pcibios_max_latency;
	263	else
	264	return;
12c0b20f	265	dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat);
1da177e4 LT	266	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
	267	}
	268
f0f37e2f	269	static const struct vm_operations_struct pci_mmap_ops = {
7ae8ed50	270	.access = generic_access_phys,
03d72aa1	271	};
03d72aa1	272
1da177e4 LT	273	int pci_mmap_page_range(struct pci_dev dev, struct vm_area_struct vma,
	274	enum pci_mmap_state mmap_state, int write_combine)
	275	{
	276	unsigned long prot;
	277
	278	/* I/O space cannot be accessed via normal processor loads and
	279	* stores on this platform.
	280	*/
	281	if (mmap_state == pci_mmap_io)
	282	return -EINVAL;
	283
1da177e4	284	prot = pgprot_val(vma->vm_page_prot);
499f8f84	285	if (pat_enabled && write_combine)
03d72aa1	286	prot \|= _PAGE_CACHE_WC;
499f8f84	287	else if (pat_enabled \|\| boot_cpu_data.x86 > 3)
de33c442 SS	288	/*
	289	* ioremap() and ioremap_nocache() defaults to UC MINUS for now.
	290	* To avoid attribute conflicts, request UC MINUS here
	291	* aswell.
	292	*/
	293	prot \|= _PAGE_CACHE_UC_MINUS;
03d72aa1	294
1da177e4 LT	295	vma->vm_page_prot = __pgprot(prot);
1da177e4 LT	296
346d3882 MT	297	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
	298	vma->vm_end - vma->vm_start,
	299	vma->vm_page_prot))
1da177e4 LT	300	return -EAGAIN;
1da177e4 LT	301
03d72aa1	302	vma->vm_ops = &pci_mmap_ops;
03d72aa1	303
1da177e4 LT	304	return 0;
1da177e4 LT	305	}