/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 1997, Stefan Esser <se@freebsd.org>
* Copyright (c) 2000, Michael Smith <msmith@freebsd.org>
* Copyright (c) 2000, BSDi
* 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.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/pci_cfgreg.h>
static uint32_t pci_docfgregread(int bus, int slot, int func, int reg,
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);
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);
SYSCTL_DECL(_hw_pci);
/*
* For amd64 we assume that type 1 I/O port-based access always works.
* If an ACPI MCFG table exists, pcie_cfgregopen() will be called to
* switch to memory-mapped access.
*/
int cfgmech = CFGMECH_1;
static vm_offset_t pcie_base;
static int pcie_minbus, pcie_maxbus;
static uint32_t pcie_badslots;
static struct mtx pcicfg_mtx;
MTX_SYSINIT(pcicfg_mtx, &pcicfg_mtx, "pcicfg_mtx", MTX_SPIN);
static int mcfg_enable = 1;
SYSCTL_INT(_hw_pci, OID_AUTO, mcfg, CTLFLAG_RDTUN, &mcfg_enable, 0,
"Enable support for PCI-e memory mapped config access");
int
pci_cfgregopen(void)
{
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
*/
u_int32_t
pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
{
uint32_t line;
/*
* 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 the rest of the PCI code recognizes as
* as an invalid IRQ.
*/
if (reg == PCIR_INTLINE && bytes == 1) {
line = pci_docfgregread(bus, slot, func, PCIR_INTLINE, 1);
if (line == 0 || line >= 128)
line = 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, (1U << 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;
mtx_lock_spin(&pcicfg_mtx);
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();
}
mtx_unlock_spin(&pcicfg_mtx);
return (data);
}
static void
pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
{
int port;
mtx_lock_spin(&pcicfg_mtx);
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();
}
mtx_unlock_spin(&pcicfg_mtx);
}
int
pcie_cfgregopen(uint64_t base, uint8_t minbus, uint8_t maxbus)
{
uint32_t val1, val2;
int slot;
if (!mcfg_enable)
return (0);
if (minbus != 0)
return (0);
if (bootverbose)
printf("PCIe: Memory Mapped configuration base @ 0x%lx\n",
base);
/* XXX: We should make sure this really fits into the direct map. */
pcie_base = (vm_offset_t)pmap_mapdev_pciecfg(base, (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) {
for (slot = 0; slot <= PCI_SLOTMAX; slot++) {
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)))
/*
* AMD BIOS And Kernel Developer's Guides for CPU families starting with 10h
* have a requirement that all accesses to the memory mapped PCI configuration
* space are done using AX class of registers.
* Since other vendors do not currently have any contradicting requirements
* the AMD access pattern is applied universally.
*/
static int
pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg,
unsigned bytes)
{
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:
__asm("movl %1, %0" : "=a" (data)
: "m" (*(volatile uint32_t *)va));
break;
case 2:
__asm("movzwl %1, %0" : "=a" (data)
: "m" (*(volatile uint16_t *)va));
break;
case 1:
__asm("movzbl %1, %0" : "=a" (data)
: "m" (*(volatile uint8_t *)va));
break;
}
return (data);
}
static void
pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data,
unsigned bytes)
{
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:
__asm("movl %1, %0" : "=m" (*(volatile uint32_t *)va)
: "a" (data));
break;
case 2:
__asm("movw %1, %0" : "=m" (*(volatile uint16_t *)va)
: "a" ((uint16_t)data));
break;
case 1:
__asm("movb %1, %0" : "=m" (*(volatile uint8_t *)va)
: "a" ((uint8_t)data));
break;
}
}
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