[dragonfly.git] / sys / bus / pci / x86_64 / pci_cfgreg.c

/*-
 * Copyright (c) 1997, Stefan Esser <se@kfreebsd.org>
 * Copyright (c) 2000, Michael Smith <msmith@kfreebsd.org>
 * Copyright (c) 2000, BSDi
 * Copyright (c) 2004, Scott Long <scottl@kfreebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD: src/sys/i386/pci/pci_cfgreg.c,v 1.124.2.3 2009/05/04 21:04:29 jhb
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/thread2.h>
#include <sys/spinlock.h>
#include <sys/spinlock2.h>
#include <sys/queue.h>
#include <bus/pci/pcivar.h>
#include <bus/pci/pcireg.h>
#include "pci_cfgreg.h"
#include <machine/pc/bios.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <machine/pmap.h>

enum {
	CFGMECH_NONE = 0,
	CFGMECH_1,
	CFGMECH_PCIE,
};

static vm_offset_t pcie_base;
static int pcie_minbus, pcie_maxbus;
static uint32_t pcie_badslots;
static int cfgmech;
static struct spinlock pcicfg_spin;

static int mcfg_enable = 1;
TUNABLE_INT("hw.pci.mcfg", &mcfg_enable);

static uint32_t	pci_docfgregread(int bus, int slot, int func, int reg, int bytes);

static int	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
static void	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data,
		    int bytes);

static int	pciereg_cfgread(int bus, unsigned slot, unsigned func,
                   unsigned reg, unsigned bytes);
static void	pciereg_cfgwrite(int bus, unsigned slot, unsigned func,
                   unsigned reg, int data, unsigned bytes);

/* 
 * Initialise access to PCI configuration space 
 */
int
pci_cfgregopen(void)
{
	static int inited = 0;
	uint64_t pciebar;
	uint16_t vid, did;

	if (!inited) {
		inited = 1;
		spin_init(&pcicfg_spin);
	}

	if (cfgmech != CFGMECH_NONE)
		return 1;
	cfgmech = CFGMECH_1;

	/*
	 * Grope around in the PCI config space to see if this is a
	 * chipset that is capable of doing memory-mapped config cycles.
	 * This also implies that it can do PCIe extended config cycles.
	 */

	/* Check for supported chipsets */
	vid = pci_cfgregread(0, 0, 0, PCIR_VENDOR, 2);
	did = pci_cfgregread(0, 0, 0, PCIR_DEVICE, 2);
	switch (vid) {
	case 0x8086:
		switch (did) {
		case 0x3590:
		case 0x3592:
			/* Intel 7520 or 7320 */
			pciebar = pci_cfgregread(0, 0, 0, 0xce, 2) << 16;
			pcie_cfgregopen(pciebar, 0, 255);
			break;
		case 0x2580:
		case 0x2584:
		case 0x2590:
			/* Intel 915, 925, or 915GM */
			pciebar = pci_cfgregread(0, 0, 0, 0x48, 4);
			pcie_cfgregopen(pciebar, 0, 255);
			break;
		}
	}
	return 1;
}

static uint32_t
pci_docfgregread(int bus, int slot, int func, int reg, int bytes)
{
	if (cfgmech == CFGMECH_PCIE &&
	    (bus >= pcie_minbus && bus <= pcie_maxbus) &&
	    (bus != 0 || !(1 << slot & pcie_badslots)))
		return pciereg_cfgread(bus, slot, func, reg, bytes);
	else
		return pcireg_cfgread(bus, slot, func, reg, bytes);
}

/* 
 * Read configuration space register
 */
uint32_t
pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
{
	/*
	 * Some BIOS writers seem to want to ignore the spec and put
	 * 0 in the intline rather than 255 to indicate none.  Some use
	 * numbers in the range 128-254 to indicate something strange and
	 * apparently undocumented anywhere.  Assume these are completely
	 * bogus and map them to 255, which means "none".
	 */
	if (reg == PCIR_INTLINE && bytes == 1) {
		uint32_t line;

		line = pci_docfgregread(bus, slot, func, PCIR_INTLINE, 1);
		if (line == 0 || line >= 128)
			return (PCI_INVALID_IRQ);
		return line;
	}
	return pci_docfgregread(bus, slot, func, reg, bytes);
}

/* 
 * Write configuration space register 
 */
void
pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
{
	if (cfgmech == CFGMECH_PCIE &&
	    (bus >= pcie_minbus && bus <= pcie_maxbus) &&
	    (bus != 0 || !(1 << slot & pcie_badslots)))
		pciereg_cfgwrite(bus, slot, func, reg, data, bytes);
	else
		pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
}

/* 
 * Configuration space access using direct register operations
 */

/* enable configuration space accesses and return data port address */
static int
pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
{
	int dataport = 0;

	if (bus <= PCI_BUSMAX &&
	    slot <= PCI_SLOTMAX &&
	    func <= PCI_FUNCMAX &&
	    (unsigned)reg <= PCI_REGMAX &&
	    bytes != 3 &&
	    (unsigned)bytes <= 4 &&
	    (reg & (bytes - 1)) == 0) {
		outl(CONF1_ADDR_PORT, (1 << 31) | (bus << 16) | (slot << 11) |
		    (func << 8) | (reg & ~0x03));
		dataport = CONF1_DATA_PORT + (reg & 0x03);
	}
	return dataport;
}

/* disable configuration space accesses */
static void
pci_cfgdisable(void)
{
	/*
	 * Do nothing.  Writing a 0 to the address port can apparently
	 * confuse some bridges and cause spurious access failures.
	 */
}

static int
pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
{
	int data = -1;
	int port;

	spin_lock(&pcicfg_spin);
	port = pci_cfgenable(bus, slot, func, reg, bytes);
	if (port != 0) {
		switch (bytes) {
		case 1:
			data = inb(port);
			break;
		case 2:
			data = inw(port);
			break;
		case 4:
			data = inl(port);
			break;
		}
		pci_cfgdisable();
	}
	spin_unlock(&pcicfg_spin);
	return data;
}

static void
pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
{
	int port;

	spin_lock(&pcicfg_spin);
	port = pci_cfgenable(bus, slot, func, reg, bytes);
	if (port != 0) {
		switch (bytes) {
		case 1:
			outb(port, data);
			break;
		case 2:
			outw(port, data);
			break;
		case 4:
			outl(port, data);
			break;
		}
		pci_cfgdisable();
	}
	spin_unlock(&pcicfg_spin);
}

int
pcie_cfgregopen(uint64_t base, uint8_t minbus, uint8_t maxbus)
{
	if (bootverbose) {
		kprintf("PCIe: Memory Mapped configuration base @ 0x%jx, "
		        "bus [%d, %d]\n", (uintmax_t)base, minbus, maxbus);
	}

	if (!mcfg_enable)
		return 0;

	if (minbus != 0)
		return 0;

	if (bootverbose)
		kprintf("PCIe: Using Memory Mapped configuration\n");

	pcie_base = (vm_offset_t)pmap_mapdev_uncacheable(base,
	    ((unsigned)maxbus + 1) << 20);
	pcie_minbus = minbus;
	pcie_maxbus = maxbus;
	cfgmech = CFGMECH_PCIE;

	/*
	 * On some AMD systems, some of the devices on bus 0 are
	 * inaccessible using memory-mapped PCI config access.  Walk
	 * bus 0 looking for such devices.  For these devices, we will
	 * fall back to using type 1 config access instead.
	 */
	if (pci_cfgregopen() != 0) {
		int slot;

		for (slot = 0; slot <= PCI_SLOTMAX; slot++) {
			uint32_t val1, val2;

			val1 = pcireg_cfgread(0, slot, 0, 0, 4);
			if (val1 == 0xffffffff)
				continue;

			val2 = pciereg_cfgread(0, slot, 0, 0, 4);
			if (val2 != val1)
				pcie_badslots |= (1 << slot);
		}
	}
	return 1;
}

#define PCIE_VADDR(base, reg, bus, slot, func) \
	((base) + \
	 ((((bus) & 0xff) << 20) | \
	  (((slot) & 0x1f) << 15) | \
	  (((func) & 0x7) << 12) | \
	  ((reg) & 0xfff)))

static int
pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg,
    unsigned bytes)
{
	volatile vm_offset_t va;
	int data = -1;

	if (bus < pcie_minbus || bus > pcie_maxbus || slot > PCI_SLOTMAX ||
	    func > PCI_FUNCMAX || reg > PCIE_REGMAX)
		return -1;

	va = PCIE_VADDR(pcie_base, reg, bus, slot, func);

	switch (bytes) {
	case 4:
		data = *(volatile uint32_t *)(va);
		break;
	case 2:
		data = *(volatile uint16_t *)(va);
		break;
	case 1:
		data = *(volatile uint8_t *)(va);
		break;
	}
	return data;
}

static void
pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data,
    unsigned bytes)
{
	volatile vm_offset_t va;

	if (bus < pcie_minbus || bus > pcie_maxbus || slot > PCI_SLOTMAX ||
	    func > PCI_FUNCMAX || reg > PCIE_REGMAX)
		return;

	va = PCIE_VADDR(pcie_base, reg, bus, slot, func);

	switch (bytes) {
	case 4:
		*(volatile uint32_t *)(va) = data;
		break;
	case 2:
		*(volatile uint16_t *)(va) = data;
		break;
	case 1:
		*(volatile uint8_t *)(va) = data;
		break;
	}
}
Commit	Line	Data
2ac05e91 SZ	1	/*-
	2	* Copyright (c) 1997, Stefan Esser <se@kfreebsd.org>
	3	* Copyright (c) 2000, Michael Smith <msmith@kfreebsd.org>
	4	* Copyright (c) 2000, BSDi
	5	* Copyright (c) 2004, Scott Long <scottl@kfreebsd.org>
	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice unmodified, this list of conditions, and the following
	13	* disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in the
	16	* documentation and/or other materials provided with the distribution.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	28	*
4ea06a72	29	* $FreeBSD: src/sys/i386/pci/pci_cfgreg.c,v 1.124.2.3 2009/05/04 21:04:29 jhb
2ac05e91 SZ	30	*/
	31
	32	#include <sys/param.h>
	33	#include <sys/systm.h>
	34	#include <sys/bus.h>
4ea06a72	35	#include <sys/kernel.h>
2ac05e91 SZ	36	#include <sys/lock.h>
	37	#include <sys/malloc.h>
	38	#include <sys/thread2.h>
	39	#include <sys/spinlock.h>
	40	#include <sys/spinlock2.h>
	41	#include <sys/queue.h>
	42	#include <bus/pci/pcivar.h>
	43	#include <bus/pci/pcireg.h>
	44	#include "pci_cfgreg.h"
	45	#include <machine/pc/bios.h>
2ac05e91 SZ	46
	47	#include <vm/vm.h>
	48	#include <vm/vm_param.h>
	49	#include <vm/vm_kern.h>
	50	#include <vm/vm_extern.h>
	51	#include <vm/pmap.h>
	52	#include <machine/pmap.h>
	53
2ac05e91 SZ	54	enum {
	55	CFGMECH_NONE = 0,
	56	CFGMECH_1,
2ac05e91 SZ	57	CFGMECH_PCIE,
	58	};
	59
926777f6	60	static vm_offset_t pcie_base;
4ea06a72 AP	61	static int pcie_minbus, pcie_maxbus;
4ea06a72 AP	62	static uint32_t pcie_badslots;
2ac05e91	63	static int cfgmech;
926777f6	64	static struct spinlock pcicfg_spin;
2ac05e91	65
aaa57655	66	static int mcfg_enable = 1;
4ea06a72 AP	67	TUNABLE_INT("hw.pci.mcfg", &mcfg_enable);
	68
	69	static uint32_t pci_docfgregread(int bus, int slot, int func, int reg, int bytes);
926777f6	70
2ac05e91	71	static int pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
926777f6 SZ	72	static void pcireg_cfgwrite(int bus, int slot, int func, int reg, int data,
926777f6 SZ	73	int bytes);
2ac05e91	74
4ea06a72 AP	75	static int pciereg_cfgread(int bus, unsigned slot, unsigned func,
	76	unsigned reg, unsigned bytes);
	77	static void pciereg_cfgwrite(int bus, unsigned slot, unsigned func,
	78	unsigned reg, int data, unsigned bytes);
	79
2ac05e91 SZ	80	/*
	81	* Initialise access to PCI configuration space
	82	*/
	83	int
	84	pci_cfgregopen(void)
	85	{
926777f6 SZ	86	static int inited = 0;
	87	uint64_t pciebar;
	88	uint16_t vid, did;
2ac05e91	89
926777f6 SZ	90	if (!inited) {
	91	inited = 1;
	92	spin_init(&pcicfg_spin);
	93	}
2ac05e91	94
926777f6 SZ	95	if (cfgmech != CFGMECH_NONE)
	96	return 1;
	97	cfgmech = CFGMECH_1;
4ea06a72	98
2ac05e91 SZ	99	/*
	100	* Grope around in the PCI config space to see if this is a
	101	* chipset that is capable of doing memory-mapped config cycles.
	102	* This also implies that it can do PCIe extended config cycles.
	103	*/
	104
	105	/* Check for supported chipsets */
926777f6 SZ	106	vid = pci_cfgregread(0, 0, 0, PCIR_VENDOR, 2);
	107	did = pci_cfgregread(0, 0, 0, PCIR_DEVICE, 2);
	108	switch (vid) {
	109	case 0x8086:
	110	switch (did) {
	111	case 0x3590:
	112	case 0x3592:
	113	/* Intel 7520 or 7320 */
	114	pciebar = pci_cfgregread(0, 0, 0, 0xce, 2) << 16;
	115	pcie_cfgregopen(pciebar, 0, 255);
	116	break;
	117	case 0x2580:
	118	case 0x2584:
	119	case 0x2590:
	120	/* Intel 915, 925, or 915GM */
	121	pciebar = pci_cfgregread(0, 0, 0, 0x48, 4);
	122	pcie_cfgregopen(pciebar, 0, 255);
	123	break;
	124	}
	125	}
	126	return 1;
2ac05e91 SZ	127	}
2ac05e91 SZ	128
4ea06a72 AP	129	static uint32_t
	130	pci_docfgregread(int bus, int slot, int func, int reg, int bytes)
	131	{
926777f6 SZ	132	if (cfgmech == CFGMECH_PCIE &&
	133	(bus >= pcie_minbus && bus <= pcie_maxbus) &&
	134	(bus != 0 \|\| !(1 << slot & pcie_badslots)))
	135	return pciereg_cfgread(bus, slot, func, reg, bytes);
	136	else
	137	return pcireg_cfgread(bus, slot, func, reg, bytes);
4ea06a72 AP	138	}
4ea06a72 AP	139
2ac05e91 SZ	140	/*
	141	* Read configuration space register
	142	*/
926777f6	143	uint32_t
2ac05e91 SZ	144	pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
2ac05e91 SZ	145	{
2ac05e91	146	/*
2ac05e91	147	* Some BIOS writers seem to want to ignore the spec and put
926777f6 SZ	148	* 0 in the intline rather than 255 to indicate none. Some use
	149	* numbers in the range 128-254 to indicate something strange and
	150	* apparently undocumented anywhere. Assume these are completely
	151	* bogus and map them to 255, which means "none".
2ac05e91 SZ	152	*/
2ac05e91 SZ	153	if (reg == PCIR_INTLINE && bytes == 1) {
926777f6 SZ	154	uint32_t line;
926777f6 SZ	155
4ea06a72	156	line = pci_docfgregread(bus, slot, func, PCIR_INTLINE, 1);
926777f6 SZ	157	if (line == 0 \|\| line >= 128)
	158	return (PCI_INVALID_IRQ);
	159	return line;
2ac05e91	160	}
926777f6	161	return pci_docfgregread(bus, slot, func, reg, bytes);
2ac05e91 SZ	162	}
	163
	164	/*
	165	* Write configuration space register
	166	*/
	167	void
	168	pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
	169	{
4ea06a72 AP	170	if (cfgmech == CFGMECH_PCIE &&
	171	(bus >= pcie_minbus && bus <= pcie_maxbus) &&
	172	(bus != 0 \|\| !(1 << slot & pcie_badslots)))
	173	pciereg_cfgwrite(bus, slot, func, reg, data, bytes);
	174	else
	175	pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
2ac05e91 SZ	176	}
	177
	178	/*
	179	* Configuration space access using direct register operations
	180	*/
	181
	182	/* enable configuration space accesses and return data port address */
	183	static int
	184	pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
	185	{
	186	int dataport = 0;
	187
926777f6 SZ	188	if (bus <= PCI_BUSMAX &&
	189	slot <= PCI_SLOTMAX &&
	190	func <= PCI_FUNCMAX &&
	191	(unsigned)reg <= PCI_REGMAX &&
	192	bytes != 3 &&
	193	(unsigned)bytes <= 4 &&
	194	(reg & (bytes - 1)) == 0) {
	195	outl(CONF1_ADDR_PORT, (1 << 31) \| (bus << 16) \| (slot << 11) \|
	196	(func << 8) \| (reg & ~0x03));
	197	dataport = CONF1_DATA_PORT + (reg & 0x03);
2ac05e91	198	}
926777f6	199	return dataport;
2ac05e91 SZ	200	}
	201
	202	/* disable configuration space accesses */
	203	static void
	204	pci_cfgdisable(void)
	205	{
926777f6 SZ	206	/*
	207	* Do nothing. Writing a 0 to the address port can apparently
	208	* confuse some bridges and cause spurious access failures.
	209	*/
2ac05e91 SZ	210	}
	211
	212	static int
	213	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
	214	{
	215	int data = -1;
	216	int port;
	217
926777f6	218	spin_lock(&pcicfg_spin);
2ac05e91 SZ	219	port = pci_cfgenable(bus, slot, func, reg, bytes);
	220	if (port != 0) {
	221	switch (bytes) {
	222	case 1:
	223	data = inb(port);
	224	break;
	225	case 2:
	226	data = inw(port);
	227	break;
	228	case 4:
	229	data = inl(port);
	230	break;
	231	}
	232	pci_cfgdisable();
	233	}
926777f6 SZ	234	spin_unlock(&pcicfg_spin);
926777f6 SZ	235	return data;
2ac05e91 SZ	236	}
	237
	238	static void
	239	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
	240	{
	241	int port;
	242
926777f6	243	spin_lock(&pcicfg_spin);
2ac05e91 SZ	244	port = pci_cfgenable(bus, slot, func, reg, bytes);
	245	if (port != 0) {
	246	switch (bytes) {
	247	case 1:
	248	outb(port, data);
	249	break;
	250	case 2:
	251	outw(port, data);
	252	break;
	253	case 4:
	254	outl(port, data);
	255	break;
	256	}
	257	pci_cfgdisable();
	258	}
926777f6	259	spin_unlock(&pcicfg_spin);
2ac05e91 SZ	260	}
2ac05e91 SZ	261
4ea06a72 AP	262	int
4ea06a72 AP	263	pcie_cfgregopen(uint64_t base, uint8_t minbus, uint8_t maxbus)
2ac05e91	264	{
f018bb2e SZ	265	if (bootverbose) {
	266	kprintf("PCIe: Memory Mapped configuration base @ 0x%jx, "
	267	"bus [%d, %d]\n", (uintmax_t)base, minbus, maxbus);
	268	}
	269
4ea06a72	270	if (!mcfg_enable)
926777f6	271	return 0;
4ea06a72 AP	272
4ea06a72 AP	273	if (minbus != 0)
926777f6	274	return 0;
2ac05e91	275
aaa57655 SZ	276	if (bootverbose)
	277	kprintf("PCIe: Using Memory Mapped configuration\n");
	278
926777f6 SZ	279	pcie_base = (vm_offset_t)pmap_mapdev_uncacheable(base,
926777f6 SZ	280	((unsigned)maxbus + 1) << 20);
4ea06a72 AP	281	pcie_minbus = minbus;
4ea06a72 AP	282	pcie_maxbus = maxbus;
2ac05e91	283	cfgmech = CFGMECH_PCIE;
4ea06a72 AP	284
	285	/*
	286	* On some AMD systems, some of the devices on bus 0 are
	287	* inaccessible using memory-mapped PCI config access. Walk
	288	* bus 0 looking for such devices. For these devices, we will
	289	* fall back to using type 1 config access instead.
	290	*/
	291	if (pci_cfgregopen() != 0) {
926777f6 SZ	292	int slot;
	293
	294	for (slot = 0; slot <= PCI_SLOTMAX; slot++) {
	295	uint32_t val1, val2;
	296
4ea06a72 AP	297	val1 = pcireg_cfgread(0, slot, 0, 0, 4);
	298	if (val1 == 0xffffffff)
	299	continue;
	300
	301	val2 = pciereg_cfgread(0, slot, 0, 0, 4);
	302	if (val2 != val1)
	303	pcie_badslots \|= (1 << slot);
	304	}
	305	}
926777f6	306	return 1;
2ac05e91 SZ	307	}
2ac05e91 SZ	308
926777f6 SZ	309	#define PCIE_VADDR(base, reg, bus, slot, func) \
	310	((base) + \
	311	((((bus) & 0xff) << 20) \| \
	312	(((slot) & 0x1f) << 15) \| \
	313	(((func) & 0x7) << 12) \| \
	314	((reg) & 0xfff)))
2ac05e91 SZ	315
2ac05e91 SZ	316	static int
4ea06a72	317	pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg,
926777f6	318	unsigned bytes)
2ac05e91	319	{
2ac05e91	320	volatile vm_offset_t va;
4ea06a72 AP	321	int data = -1;
4ea06a72 AP	322
926777f6 SZ	323	if (bus < pcie_minbus \|\| bus > pcie_maxbus \|\| slot > PCI_SLOTMAX \|\|
	324	func > PCI_FUNCMAX \|\| reg > PCIE_REGMAX)
	325	return -1;
2ac05e91	326
926777f6	327	va = PCIE_VADDR(pcie_base, reg, bus, slot, func);
2ac05e91 SZ	328
	329	switch (bytes) {
	330	case 4:
	331	data = (volatile uint32_t )(va);
	332	break;
	333	case 2:
	334	data = (volatile uint16_t )(va);
	335	break;
	336	case 1:
	337	data = (volatile uint8_t )(va);
	338	break;
2ac05e91	339	}
926777f6	340	return data;
2ac05e91 SZ	341	}
	342
	343	static void
926777f6 SZ	344	pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data,
926777f6 SZ	345	unsigned bytes)
2ac05e91	346	{
2ac05e91	347	volatile vm_offset_t va;
2ac05e91	348
926777f6 SZ	349	if (bus < pcie_minbus \|\| bus > pcie_maxbus \|\| slot > PCI_SLOTMAX \|\|
	350	func > PCI_FUNCMAX \|\| reg > PCIE_REGMAX)
	351	return;
	352
	353	va = PCIE_VADDR(pcie_base, reg, bus, slot, func);
2ac05e91 SZ	354
	355	switch (bytes) {
	356	case 4:
	357	(volatile uint32_t )(va) = data;
	358	break;
	359	case 2:
	360	(volatile uint16_t )(va) = data;
	361	break;
	362	case 1:
	363	(volatile uint8_t )(va) = data;
	364	break;
2ac05e91	365	}
2ac05e91	366	}