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/direct.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/direct.c')
-rw-r--r-- | arch/i386/pci/direct.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/arch/i386/pci/direct.c b/arch/i386/pci/direct.c new file mode 100644 index 00000000000..30b7e9b4f6a --- /dev/null +++ b/arch/i386/pci/direct.c @@ -0,0 +1,289 @@ +/* + * direct.c - Low-level direct PCI config space access + */ + +#include <linux/pci.h> +#include <linux/init.h> +#include "pci.h" + +/* + * Functions for accessing PCI configuration space with type 1 accesses + */ + +#define PCI_CONF1_ADDRESS(bus, devfn, reg) \ + (0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3)) + +static int pci_conf1_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 > 255)) + return -EINVAL; + + spin_lock_irqsave(&pci_config_lock, flags); + + outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8); + + switch (len) { + case 1: + *value = inb(0xCFC + (reg & 3)); + break; + case 2: + *value = inw(0xCFC + (reg & 2)); + break; + case 4: + *value = inl(0xCFC); + break; + } + + spin_unlock_irqrestore(&pci_config_lock, flags); + + return 0; +} + +static int pci_conf1_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 > 255)) + return -EINVAL; + + spin_lock_irqsave(&pci_config_lock, flags); + + outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8); + + switch (len) { + case 1: + outb((u8)value, 0xCFC + (reg & 3)); + break; + case 2: + outw((u16)value, 0xCFC + (reg & 2)); + break; + case 4: + outl((u32)value, 0xCFC); + break; + } + + spin_unlock_irqrestore(&pci_config_lock, flags); + + return 0; +} + +#undef PCI_CONF1_ADDRESS + +struct pci_raw_ops pci_direct_conf1 = { + .read = pci_conf1_read, + .write = pci_conf1_write, +}; + + +/* + * Functions for accessing PCI configuration space with type 2 accesses + */ + +#define PCI_CONF2_ADDRESS(dev, reg) (u16)(0xC000 | (dev << 8) | reg) + +static int pci_conf2_read(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, u32 *value) +{ + unsigned long flags; + int dev, fn; + + if (!value || (bus > 255) || (devfn > 255) || (reg > 255)) + return -EINVAL; + + dev = PCI_SLOT(devfn); + fn = PCI_FUNC(devfn); + + if (dev & 0x10) + return PCIBIOS_DEVICE_NOT_FOUND; + + spin_lock_irqsave(&pci_config_lock, flags); + + outb((u8)(0xF0 | (fn << 1)), 0xCF8); + outb((u8)bus, 0xCFA); + + switch (len) { + case 1: + *value = inb(PCI_CONF2_ADDRESS(dev, reg)); + break; + case 2: + *value = inw(PCI_CONF2_ADDRESS(dev, reg)); + break; + case 4: + *value = inl(PCI_CONF2_ADDRESS(dev, reg)); + break; + } + + outb(0, 0xCF8); + + spin_unlock_irqrestore(&pci_config_lock, flags); + + return 0; +} + +static int pci_conf2_write(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, u32 value) +{ + unsigned long flags; + int dev, fn; + + if ((bus > 255) || (devfn > 255) || (reg > 255)) + return -EINVAL; + + dev = PCI_SLOT(devfn); + fn = PCI_FUNC(devfn); + + if (dev & 0x10) + return PCIBIOS_DEVICE_NOT_FOUND; + + spin_lock_irqsave(&pci_config_lock, flags); + + outb((u8)(0xF0 | (fn << 1)), 0xCF8); + outb((u8)bus, 0xCFA); + + switch (len) { + case 1: + outb((u8)value, PCI_CONF2_ADDRESS(dev, reg)); + break; + case 2: + outw((u16)value, PCI_CONF2_ADDRESS(dev, reg)); + break; + case 4: + outl((u32)value, PCI_CONF2_ADDRESS(dev, reg)); + break; + } + + outb(0, 0xCF8); + + spin_unlock_irqrestore(&pci_config_lock, flags); + + return 0; +} + +#undef PCI_CONF2_ADDRESS + +static struct pci_raw_ops pci_direct_conf2 = { + .read = pci_conf2_read, + .write = pci_conf2_write, +}; + + +/* + * Before we decide to use direct hardware access mechanisms, we try to do some + * trivial checks to ensure it at least _seems_ to be working -- we just test + * whether bus 00 contains a host bridge (this is similar to checking + * techniques used in XFree86, but ours should be more reliable since we + * attempt to make use of direct access hints provided by the PCI BIOS). + * + * This should be close to trivial, but it isn't, because there are buggy + * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID. + */ +static int __init pci_sanity_check(struct pci_raw_ops *o) +{ + u32 x = 0; + int devfn; + + if (pci_probe & PCI_NO_CHECKS) + return 1; + + for (devfn = 0; devfn < 0x100; devfn++) { + if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x)) + continue; + if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA) + return 1; + + if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x)) + continue; + if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ) + return 1; + } + + DBG("PCI: Sanity check failed\n"); + return 0; +} + +static int __init pci_check_type1(void) +{ + unsigned long flags; + unsigned int tmp; + int works = 0; + + local_irq_save(flags); + + outb(0x01, 0xCFB); + tmp = inl(0xCF8); + outl(0x80000000, 0xCF8); + if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) { + works = 1; + } + outl(tmp, 0xCF8); + local_irq_restore(flags); + + return works; +} + +static int __init pci_check_type2(void) +{ + unsigned long flags; + int works = 0; + + local_irq_save(flags); + + outb(0x00, 0xCFB); + outb(0x00, 0xCF8); + outb(0x00, 0xCFA); + if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 && + pci_sanity_check(&pci_direct_conf2)) { + works = 1; + } + + local_irq_restore(flags); + + return works; +} + +static int __init pci_direct_init(void) +{ + struct resource *region, *region2; + + if ((pci_probe & PCI_PROBE_CONF1) == 0) + goto type2; + region = request_region(0xCF8, 8, "PCI conf1"); + if (!region) + goto type2; + + if (pci_check_type1()) { + printk(KERN_INFO "PCI: Using configuration type 1\n"); + raw_pci_ops = &pci_direct_conf1; + return 0; + } + release_resource(region); + + type2: + if ((pci_probe & PCI_PROBE_CONF2) == 0) + goto out; + region = request_region(0xCF8, 4, "PCI conf2"); + if (!region) + goto out; + region2 = request_region(0xC000, 0x1000, "PCI conf2"); + if (!region2) + goto fail2; + + if (pci_check_type2()) { + printk(KERN_INFO "PCI: Using configuration type 2\n"); + raw_pci_ops = &pci_direct_conf2; + return 0; + } + + release_resource(region2); + fail2: + release_resource(region); + + out: + return 0; +} + +arch_initcall(pci_direct_init); |