157 lines
3.4 KiB
C
157 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
|
|
* Copyright (C) 2004 Intel Corp.
|
|
*/
|
|
|
|
/*
|
|
* mmconfig.c - Low-level direct PCI config space access via MMCONFIG
|
|
*/
|
|
|
|
#include <linux/pci.h>
|
|
#include <linux/init.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <asm/e820/api.h>
|
|
#include <asm/pci_x86.h>
|
|
|
|
/* Assume systems with more busses have correct MCFG */
|
|
#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
|
|
|
|
/* The base address of the last MMCONFIG device accessed */
|
|
static u32 mmcfg_last_accessed_device;
|
|
static int mmcfg_last_accessed_cpu;
|
|
|
|
/*
|
|
* Functions for accessing PCI configuration space with MMCONFIG accesses
|
|
*/
|
|
static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
|
|
{
|
|
struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
|
|
|
|
if (cfg)
|
|
return cfg->address;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is always called under pci_config_lock
|
|
*/
|
|
static void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
|
|
{
|
|
u32 dev_base = base | PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12);
|
|
int cpu = smp_processor_id();
|
|
if (dev_base != mmcfg_last_accessed_device ||
|
|
cpu != mmcfg_last_accessed_cpu) {
|
|
mmcfg_last_accessed_device = dev_base;
|
|
mmcfg_last_accessed_cpu = cpu;
|
|
set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
|
|
}
|
|
}
|
|
|
|
static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
|
|
unsigned int devfn, int reg, int len, u32 *value)
|
|
{
|
|
unsigned long flags;
|
|
u32 base;
|
|
|
|
if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
|
|
err: *value = -1;
|
|
return -EINVAL;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
base = get_base_addr(seg, bus, devfn);
|
|
if (!base) {
|
|
rcu_read_unlock();
|
|
goto err;
|
|
}
|
|
|
|
raw_spin_lock_irqsave(&pci_config_lock, flags);
|
|
|
|
pci_exp_set_dev_base(base, bus, devfn);
|
|
|
|
switch (len) {
|
|
case 1:
|
|
*value = mmio_config_readb(mmcfg_virt_addr + reg);
|
|
break;
|
|
case 2:
|
|
*value = mmio_config_readw(mmcfg_virt_addr + reg);
|
|
break;
|
|
case 4:
|
|
*value = mmio_config_readl(mmcfg_virt_addr + reg);
|
|
break;
|
|
}
|
|
raw_spin_unlock_irqrestore(&pci_config_lock, flags);
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
|
|
unsigned int devfn, int reg, int len, u32 value)
|
|
{
|
|
unsigned long flags;
|
|
u32 base;
|
|
|
|
if ((bus > 255) || (devfn > 255) || (reg > 4095))
|
|
return -EINVAL;
|
|
|
|
rcu_read_lock();
|
|
base = get_base_addr(seg, bus, devfn);
|
|
if (!base) {
|
|
rcu_read_unlock();
|
|
return -EINVAL;
|
|
}
|
|
|
|
raw_spin_lock_irqsave(&pci_config_lock, flags);
|
|
|
|
pci_exp_set_dev_base(base, bus, devfn);
|
|
|
|
switch (len) {
|
|
case 1:
|
|
mmio_config_writeb(mmcfg_virt_addr + reg, value);
|
|
break;
|
|
case 2:
|
|
mmio_config_writew(mmcfg_virt_addr + reg, value);
|
|
break;
|
|
case 4:
|
|
mmio_config_writel(mmcfg_virt_addr + reg, value);
|
|
break;
|
|
}
|
|
raw_spin_unlock_irqrestore(&pci_config_lock, flags);
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct pci_raw_ops pci_mmcfg = {
|
|
.read = pci_mmcfg_read,
|
|
.write = pci_mmcfg_write,
|
|
};
|
|
|
|
int __init pci_mmcfg_arch_init(void)
|
|
{
|
|
printk(KERN_INFO "PCI: Using MMCONFIG for extended config space\n");
|
|
raw_pci_ext_ops = &pci_mmcfg;
|
|
return 1;
|
|
}
|
|
|
|
void __init pci_mmcfg_arch_free(void)
|
|
{
|
|
}
|
|
|
|
int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* Invalidate the cached mmcfg map entry. */
|
|
raw_spin_lock_irqsave(&pci_config_lock, flags);
|
|
mmcfg_last_accessed_device = 0;
|
|
raw_spin_unlock_irqrestore(&pci_config_lock, flags);
|
|
}
|