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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/x86_64/pci/mmconfig.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
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/x86_64/pci/mmconfig.c')
-rw-r--r-- | arch/x86_64/pci/mmconfig.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c new file mode 100644 index 0000000..b693c23 --- /dev/null +++ b/arch/x86_64/pci/mmconfig.c @@ -0,0 +1,104 @@ +/* + * mmconfig.c - Low-level direct PCI config space access via MMCONFIG + * + * This is an 64bit optimized version that always keeps the full mmconfig + * space mapped. This allows lockless config space operation. + */ + +#include <linux/pci.h> +#include <linux/init.h> +#include "pci.h" + +#define MMCONFIG_APER_SIZE (256*1024*1024) + +/* The physical address of the MMCONFIG aperture. Set from ACPI tables. */ +u32 pci_mmcfg_base_addr; + +/* Static virtual mapping of the MMCONFIG aperture */ +char *pci_mmcfg_virt; + +static inline char *pci_dev_base(unsigned int bus, unsigned int devfn) +{ + return pci_mmcfg_virt + ((bus << 20) | (devfn << 12)); +} + +static int pci_mmcfg_read(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, u32 *value) +{ + char *addr = pci_dev_base(bus, devfn); + + if (unlikely(!value || (bus > 255) || (devfn > 255) || (reg > 4095))) + return -EINVAL; + + switch (len) { + case 1: + *value = readb(addr + reg); + break; + case 2: + *value = readw(addr + reg); + break; + case 4: + *value = readl(addr + reg); + break; + } + + return 0; +} + +static int pci_mmcfg_write(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, u32 value) +{ + char *addr = pci_dev_base(bus,devfn); + + if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) + return -EINVAL; + + switch (len) { + case 1: + writeb(value, addr + reg); + break; + case 2: + writew(value, addr + reg); + break; + case 4: + writel(value, addr + reg); + break; + } + + 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) + return 0; + if (!pci_mmcfg_base_addr) + return 0; + + /* 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) + return 0; + + /* RED-PEN i386 doesn't do _nocache right now */ + pci_mmcfg_virt = ioremap_nocache(pci_mmcfg_base_addr, MMCONFIG_APER_SIZE); + if (!pci_mmcfg_virt) { + printk("PCI: Cannot map mmconfig aperture\n"); + return 0; + } + + printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_base_addr); + raw_pci_ops = &pci_mmcfg; + pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; + + return 0; +} + +arch_initcall(pci_mmcfg_init); |