diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/pci/mmconfig.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/pci/mmconfig.c')
-rw-r--r-- | arch/i386/pci/mmconfig.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c new file mode 100644 index 00000000000..021a50aa51f --- /dev/null +++ b/arch/i386/pci/mmconfig.c @@ -0,0 +1,122 @@ +/* + * Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx> + * Copyright (C) 2004 Intel Corp. + * + * This code is released under the GNU General Public License version 2. + */ + +/* + * mmconfig.c - Low-level direct PCI config space access via MMCONFIG + */ + +#include <linux/pci.h> +#include <linux/init.h> +#include "pci.h" + +/* The physical address of the MMCONFIG aperture. Set from ACPI tables. */ +u32 pci_mmcfg_base_addr; + +#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; + +/* + * Functions for accessing PCI configuration space with MMCONFIG accesses + */ + +static inline void pci_exp_set_dev_base(int bus, int devfn) +{ + u32 dev_base = pci_mmcfg_base_addr | (bus << 20) | (devfn << 12); + if (dev_base != mmcfg_last_accessed_device) { + mmcfg_last_accessed_device = dev_base; + 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; + + if (!value || (bus > 255) || (devfn > 255) || (reg > 4095)) + return -EINVAL; + + spin_lock_irqsave(&pci_config_lock, flags); + + pci_exp_set_dev_base(bus, devfn); + + switch (len) { + case 1: + *value = readb(mmcfg_virt_addr + reg); + break; + case 2: + *value = readw(mmcfg_virt_addr + reg); + break; + case 4: + *value = readl(mmcfg_virt_addr + reg); + break; + } + + spin_unlock_irqrestore(&pci_config_lock, flags); + + 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; + + if ((bus > 255) || (devfn > 255) || (reg > 4095)) + return -EINVAL; + + spin_lock_irqsave(&pci_config_lock, flags); + + pci_exp_set_dev_base(bus, devfn); + + switch (len) { + case 1: + writeb(value, mmcfg_virt_addr + reg); + break; + case 2: + writew(value, mmcfg_virt_addr + reg); + break; + case 4: + writel(value, mmcfg_virt_addr + reg); + break; + } + + spin_unlock_irqrestore(&pci_config_lock, flags); + + return 0; +} + +static struct pci_raw_ops pci_mmcfg = { + .read = pci_mmcfg_read, + .write = pci_mmcfg_write, +}; + +static int __init pci_mmcfg_init(void) +{ + if ((pci_probe & PCI_PROBE_MMCONF) == 0) + goto out; + if (!pci_mmcfg_base_addr) + goto out; + + /* Kludge for now. Don't use mmconfig on AMD systems because + those have some busses where mmconfig doesn't work, + and we don't parse ACPI MCFG well enough to handle that. + Remove when proper handling is added. */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) + goto out; + + printk(KERN_INFO "PCI: Using MMCONFIG\n"); + raw_pci_ops = &pci_mmcfg; + pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; + + out: + return 0; +} + +arch_initcall(pci_mmcfg_init); |