[net-next-2.6.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..
 */
resource_size_t
pcibios_align_resource(void *data, const struct resource *res,
			resource_size_t size, resource_size_t align)
{
	struct pci_dev *dev = data;
	resource_size_t start = res->start;

	if (res->flags & IORESOURCE_IO) {
		if (skip_isa_ioresource_align(dev))
			return start;
		if (start & 0x300)
			start = (start + 0x3ff) & ~0x3ff;
	} else if (res->flags & IORESOURCE_MEM) {
		if (start < BIOS_END)
			start = BIOS_END;
	}
	return 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)
 *	- bad resource sizes or overlaps with other regions
 *
 *  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) {
					/*
					 * Something is wrong with the region.
					 * Invalidate the resource to prevent
					 * child resource allocations in this
					 * range.
					 */
					r->start = r->end = 0;
					r->flags = 0;
				}
			}
		}
		pcibios_allocate_bus_resources(&bus->children);
	}
}

struct pci_check_idx_range {
	int start;
	int end;
};

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

	struct pci_check_idx_range idx_range[] = {
		{ PCI_STD_RESOURCES, PCI_STD_RESOURCE_END },
#ifdef CONFIG_PCI_IOV
		{ PCI_IOV_RESOURCES, PCI_IOV_RESOURCE_END },
#endif
	};

	for_each_pci_dev(dev) {
		pci_read_config_word(dev, PCI_COMMAND, &command);
		for (i = 0; i < ARRAY_SIZE(idx_range); i++)
		for (idx = idx_range[i].start; idx <= idx_range[i].end; 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,
					"BAR %d: reserving %pr (d=%d, p=%d)\n",
					idx, r, disabled, pass);
				if (pci_claim_resource(dev, idx) < 0) {
					/* 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 %pR\n", r);
				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);

/*
 *  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);

	/*
 	 * Return error if pat is not enabled and write_combine is requested.
 	 * Caller can followup with UC MINUS request and add a WC mtrr if there
 	 * is a free mtrr slot.
 	 */
	if (!pat_enabled && write_combine)
		return -EINVAL;

	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	*/
b26b2d49	63	resource_size_t
3b7a17fc	64	pcibios_align_resource(void data, const struct resource res,
e31dd6e4	65	resource_size_t size, resource_size_t align)
1da177e4	66	{
036fff4c	67	struct pci_dev *dev = data;
b26b2d49	68	resource_size_t start = res->start;
036fff4c	69
1da177e4	70	if (res->flags & IORESOURCE_IO) {
036fff4c	71	if (skip_isa_ioresource_align(dev))
b26b2d49 DB	72	return start;
b26b2d49 DB	73	if (start & 0x300)
1da177e4	74	start = (start + 0x3ff) & ~0x3ff;
55051feb BH	75	} else if (res->flags & IORESOURCE_MEM) {
	76	if (start < BIOS_END)
	77	start = BIOS_END;
1da177e4	78	}
b26b2d49	79	return start;
1da177e4	80	}
6c00a61e	81	EXPORT_SYMBOL(pcibios_align_resource);
1da177e4 LT	82
	83	/*
	84	* Handle resources of PCI devices. If the world were perfect, we could
	85	* just allocate all the resource regions and do nothing more. It isn't.
	86	* On the other hand, we cannot just re-allocate all devices, as it would
	87	* require us to know lots of host bridge internals. So we attempt to
	88	* keep as much of the original configuration as possible, but tweak it
	89	* when it's found to be wrong.
	90	*
	91	* Known BIOS problems we have to work around:
	92	* - I/O or memory regions not configured
	93	* - regions configured, but not enabled in the command register
	94	* - bogus I/O addresses above 64K used
	95	* - expansion ROMs left enabled (this may sound harmless, but given
	96	* the fact the PCI specs explicitly allow address decoders to be
	97	* shared between expansion ROMs and other resource regions, it's
	98	* at least dangerous)
837c4ef1	99	* - bad resource sizes or overlaps with other regions
1da177e4 LT	100	*
	101	* Our solution:
	102	* (1) Allocate resources for all buses behind PCI-to-PCI bridges.
	103	* This gives us fixed barriers on where we can allocate.
	104	* (2) Allocate resources for all enabled devices. If there is
	105	* a collision, just mark the resource as unallocated. Also
	106	* disable expansion ROMs during this step.
	107	* (3) Try to allocate resources for disabled devices. If the
	108	* resources were assigned correctly, everything goes well,
	109	* if they weren't, they won't disturb allocation of other
	110	* resources.
	111	* (4) Assign new addresses to resources which were either
	112	* not configured at all or misconfigured. If explicitly
	113	* requested by the user, configure expansion ROM address
	114	* as well.
	115	*/
	116
	117	static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
	118	{
	119	struct pci_bus *bus;
	120	struct pci_dev *dev;
	121	int idx;
a76117df	122	struct resource *r;
1da177e4 LT	123
	124	/* Depth-First Search on bus tree */
	125	list_for_each_entry(bus, bus_list, node) {
	126	if ((dev = bus->self)) {
7edab2f0 RD	127	for (idx = PCI_BRIDGE_RESOURCES;
7edab2f0 RD	128	idx < PCI_NUM_RESOURCES; idx++) {
1da177e4	129	r = &dev->resource[idx];
299de034	130	if (!r->flags)
1da177e4	131	continue;
a76117df MW	132	if (!r->start \|\|
a76117df MW	133	pci_claim_resource(dev, idx) < 0) {
7edab2f0 RD	134	/*
	135	* Something is wrong with the region.
	136	* Invalidate the resource to prevent
	137	* child resource allocations in this
	138	* range.
	139	*/
837c4ef1	140	r->start = r->end = 0;
299de034 IK	141	r->flags = 0;
299de034 IK	142	}
1da177e4 LT	143	}
	144	}
	145	pcibios_allocate_bus_resources(&bus->children);
	146	}
	147	}
	148
575939cf YL	149	struct pci_check_idx_range {
	150	int start;
	151	int end;
	152	};
	153
1da177e4 LT	154	static void __init pcibios_allocate_resources(int pass)
	155	{
	156	struct pci_dev *dev = NULL;
575939cf	157	int idx, disabled, i;
1da177e4	158	u16 command;
a76117df	159	struct resource *r;
1da177e4	160
575939cf YL	161	struct pci_check_idx_range idx_range[] = {
	162	{ PCI_STD_RESOURCES, PCI_STD_RESOURCE_END },
	163	#ifdef CONFIG_PCI_IOV
	164	{ PCI_IOV_RESOURCES, PCI_IOV_RESOURCE_END },
	165	#endif
	166	};
	167
1da177e4 LT	168	for_each_pci_dev(dev) {
1da177e4 LT	169	pci_read_config_word(dev, PCI_COMMAND, &command);
575939cf YL	170	for (i = 0; i < ARRAY_SIZE(idx_range); i++)
575939cf YL	171	for (idx = idx_range[i].start; idx <= idx_range[i].end; idx++) {
1da177e4 LT	172	r = &dev->resource[idx];
	173	if (r->parent) /* Already allocated */
	174	continue;
	175	if (!r->start) /* Address not assigned at all */
	176	continue;
	177	if (r->flags & IORESOURCE_IO)
	178	disabled = !(command & PCI_COMMAND_IO);
	179	else
	180	disabled = !(command & PCI_COMMAND_MEMORY);
	181	if (pass == disabled) {
c7dabef8	182	dev_dbg(&dev->dev,
865df576	183	"BAR %d: reserving %pr (d=%d, p=%d)\n",
c7dabef8	184	idx, r, disabled, pass);
a76117df	185	if (pci_claim_resource(dev, idx) < 0) {
1da177e4 LT	186	/* We'll assign a new address later */
	187	r->end -= r->start;
	188	r->start = 0;
	189	}
	190	}
	191	}
	192	if (!pass) {
	193	r = &dev->resource[PCI_ROM_RESOURCE];
	194	if (r->flags & IORESOURCE_ROM_ENABLE) {
7edab2f0 RD	195	/* Turn the ROM off, leave the resource region,
7edab2f0 RD	196	* but keep it unregistered. */
1da177e4	197	u32 reg;
c7dabef8	198	dev_dbg(&dev->dev, "disabling ROM %pR\n", r);
1da177e4	199	r->flags &= ~IORESOURCE_ROM_ENABLE;
7edab2f0 RD	200	pci_read_config_dword(dev,
	201	dev->rom_base_reg, &reg);
	202	pci_write_config_dword(dev, dev->rom_base_reg,
	203	reg & ~PCI_ROM_ADDRESS_ENABLE);
1da177e4 LT	204	}
	205	}
	206	}
	207	}
	208
	209	static int __init pcibios_assign_resources(void)
	210	{
	211	struct pci_dev *dev = NULL;
a76117df	212	struct resource *r;
1da177e4	213
81d4af13	214	if (!(pci_probe & PCI_ASSIGN_ROMS)) {
7edab2f0 RD	215	/*
	216	* Try to use BIOS settings for ROMs, otherwise let
	217	* pci_assign_unassigned_resources() allocate the new
	218	* addresses.
	219	*/
81d4af13	220	for_each_pci_dev(dev) {
1da177e4	221	r = &dev->resource[PCI_ROM_RESOURCE];
81d4af13 IK	222	if (!r->flags \|\| !r->start)
81d4af13 IK	223	continue;
a76117df	224	if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
81d4af13 IK	225	r->end -= r->start;
	226	r->start = 0;
	227	}
1da177e4 LT	228	}
1da177e4 LT	229	}
81d4af13 IK	230
	231	pci_assign_unassigned_resources();
	232
1da177e4 LT	233	return 0;
	234	}
	235
	236	void __init pcibios_resource_survey(void)
	237	{
	238	DBG("PCI: Allocating resources\n");
	239	pcibios_allocate_bus_resources(&pci_root_buses);
	240	pcibios_allocate_resources(0);
	241	pcibios_allocate_resources(1);
a5444d15 IM	242
a5444d15 IM	243	e820_reserve_resources_late();
857fdc53 YL	244	/*
	245	* Insert the IO APIC resources after PCI initialization has
	246	* occured to handle IO APICS that are mapped in on a BAR in
	247	* PCI space, but before trying to assign unassigned pci res.
	248	*/
	249	ioapic_insert_resources();
1da177e4 LT	250	}
	251
	252	/**
	253	* called in fs_initcall (one below subsys_initcall),
	254	* give a chance for motherboard reserve resources
	255	*/
	256	fs_initcall(pcibios_assign_resources);
	257
1da177e4 LT	258	/*
	259	* If we set up a device for bus mastering, we need to check the latency
	260	* timer as certain crappy BIOSes forget to set it properly.
	261	*/
	262	unsigned int pcibios_max_latency = 255;
	263
	264	void pcibios_set_master(struct pci_dev *dev)
	265	{
	266	u8 lat;
	267	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
	268	if (lat < 16)
	269	lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
	270	else if (lat > pcibios_max_latency)
	271	lat = pcibios_max_latency;
	272	else
	273	return;
12c0b20f	274	dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat);
1da177e4 LT	275	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
	276	}
	277
f0f37e2f	278	static const struct vm_operations_struct pci_mmap_ops = {
7ae8ed50	279	.access = generic_access_phys,
03d72aa1	280	};
03d72aa1	281
1da177e4 LT	282	int pci_mmap_page_range(struct pci_dev dev, struct vm_area_struct vma,
	283	enum pci_mmap_state mmap_state, int write_combine)
	284	{
	285	unsigned long prot;
	286
	287	/* I/O space cannot be accessed via normal processor loads and
	288	* stores on this platform.
	289	*/
	290	if (mmap_state == pci_mmap_io)
	291	return -EINVAL;
	292
1da177e4	293	prot = pgprot_val(vma->vm_page_prot);
2992e545 SS	294
	295	/*
	296	* Return error if pat is not enabled and write_combine is requested.
	297	* Caller can followup with UC MINUS request and add a WC mtrr if there
	298	* is a free mtrr slot.
	299	*/
	300	if (!pat_enabled && write_combine)
	301	return -EINVAL;
	302
499f8f84	303	if (pat_enabled && write_combine)
03d72aa1	304	prot \|= _PAGE_CACHE_WC;
499f8f84	305	else if (pat_enabled \|\| boot_cpu_data.x86 > 3)
de33c442 SS	306	/*
	307	* ioremap() and ioremap_nocache() defaults to UC MINUS for now.
	308	* To avoid attribute conflicts, request UC MINUS here
	309	* aswell.
	310	*/
	311	prot \|= _PAGE_CACHE_UC_MINUS;
03d72aa1	312
1da177e4 LT	313	vma->vm_page_prot = __pgprot(prot);
1da177e4 LT	314
346d3882 MT	315	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
	316	vma->vm_end - vma->vm_start,
	317	vma->vm_page_prot))
1da177e4 LT	318	return -EAGAIN;
1da177e4 LT	319
03d72aa1	320	vma->vm_ops = &pci_mmap_ops;
03d72aa1	321
1da177e4 LT	322	return 0;
1da177e4 LT	323	}