From: Keir Fraser Date: Fri, 14 Aug 2009 09:54:33 +0000 (+0100) Subject: PCI x86: always use conf1 to access config space below 256 bytes X-Git-Tag: xen-3.4.2~16 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=02551dbd02428255912aac6e30f9a6e9ce5fa02f;p=legacy%2Flinux-2.6.18-xen.git PCI x86: always use conf1 to access config space below 256 bytes Back-ported to 2.6.18.8 by Simon Horman Signed-off-by: Ivan Kokshaysky Signed-off-by: Matthew Wilcox Signed-off-by: Linus Torvalds Signed-off-by: Simon Horman --- diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c index 972180f7..445052a7 100644 --- a/arch/i386/pci/mmconfig.c +++ b/arch/i386/pci/mmconfig.c @@ -19,16 +19,11 @@ #define MMCONFIG_APER_MIN (2 * 1024*1024) #define MMCONFIG_APER_MAX (256 * 1024*1024) -/* Assume systems with more busses have correct MCFG */ -#define MAX_CHECK_BUS 16 - #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 DECLARE_BITMAP(fallback_slots, MAX_CHECK_BUS*32); - /* * Functions for accessing PCI configuration space with MMCONFIG accesses */ @@ -37,10 +32,6 @@ static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn) int cfg_num = -1; struct acpi_table_mcfg_config *cfg; - if (seg == 0 && bus < MAX_CHECK_BUS && - test_bit(PCI_SLOT(devfn) + 32*bus, fallback_slots)) - return 0; - while (1) { ++cfg_num; if (cfg_num >= pci_mmcfg_config_num) { @@ -83,13 +74,16 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus, u32 base; if ((bus > 255) || (devfn > 255) || (reg > 4095)) { - *value = -1; +err: *value = -1; return -EINVAL; } + if (reg < 256) + return pci_conf1_read(seg,bus,devfn,reg,len,value); + base = get_base_addr(seg, bus, devfn); if (!base) - return pci_conf1_read(seg,bus,devfn,reg,len,value); + goto err; spin_lock_irqsave(&pci_config_lock, flags); @@ -121,9 +115,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, if ((bus > 255) || (devfn > 255) || (reg > 4095)) return -EINVAL; + if (reg < 256) + return pci_conf1_write(seg,bus,devfn,reg,len,value); + base = get_base_addr(seg, bus, devfn); if (!base) - return pci_conf1_write(seg,bus,devfn,reg,len,value); + return -EINVAL; spin_lock_irqsave(&pci_config_lock, flags); @@ -151,42 +148,6 @@ static struct pci_raw_ops pci_mmcfg = { .write = pci_mmcfg_write, }; -/* K8 systems have some devices (typically in the builtin northbridge) - that are only accessible using type1 - Normally this can be expressed in the MCFG by not listing them - and assigning suitable _SEGs, but this isn't implemented in some BIOS. - Instead try to discover all devices on bus 0 that are unreachable using MM - and fallback for them. */ -static __init void unreachable_devices(void) -{ - int i, k; - unsigned long flags; - - for (k = 0; k < MAX_CHECK_BUS; k++) { - for (i = 0; i < 32; i++) { - u32 val1; - u32 addr; - - pci_conf1_read(0, k, PCI_DEVFN(i, 0), 0, 4, &val1); - if (val1 == 0xffffffff) - continue; - - /* Locking probably not needed, but safer */ - spin_lock_irqsave(&pci_config_lock, flags); - addr = get_base_addr(0, k, PCI_DEVFN(i, 0)); - if (addr != 0) - pci_exp_set_dev_base(addr, k, PCI_DEVFN(i, 0)); - if (addr == 0 || - readl((u32 __iomem *)mmcfg_virt_addr) != val1) { - set_bit(i + 32*k, fallback_slots); - printk(KERN_NOTICE - "PCI: No mmconfig possible on %x:%x\n", k, i); - } - spin_unlock_irqrestore(&pci_config_lock, flags); - } - } -} - void __init pci_mmcfg_init(void) { if ((pci_probe & PCI_PROBE_MMCONF) == 0) @@ -210,6 +171,4 @@ void __init pci_mmcfg_init(void) printk(KERN_INFO "PCI: Using MMCONFIG\n"); raw_pci_ops = &pci_mmcfg; pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; - - unreachable_devices(); } diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c index 7a7b66a2..a939652b 100644 --- a/arch/x86_64/pci/mmconfig.c +++ b/arch/x86_64/pci/mmconfig.c @@ -17,12 +17,6 @@ #define MMCONFIG_APER_MIN (2 * 1024*1024) #define MMCONFIG_APER_MAX (256 * 1024*1024) -/* Verify the first 16 busses. We assume that systems with more busses - get MCFG right. */ -#define MAX_CHECK_BUS 16 - -static DECLARE_BITMAP(fallback_slots, 32*MAX_CHECK_BUS); - /* Static virtual mapping of the MMCONFIG aperture */ struct mmcfg_virt { struct acpi_table_mcfg_config *cfg; @@ -87,9 +81,6 @@ static char __iomem *get_virt(unsigned int seg, unsigned bus) static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) { char __iomem *addr; - if (seg == 0 && bus < MAX_CHECK_BUS && - test_bit(32*bus + PCI_SLOT(devfn), fallback_slots)) - return NULL; addr = get_virt(seg, bus); if (!addr) return NULL; @@ -103,13 +94,16 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus, /* Why do we have this when nobody checks it. How about a BUG()!? -AK */ if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) { - *value = -1; +err: *value = -1; return -EINVAL; } + if (reg < 256) + return pci_conf1_read(seg,bus,devfn,reg,len,value); + addr = pci_dev_base(seg, bus, devfn); if (!addr) - return pci_conf1_read(seg,bus,devfn,reg,len,value); + goto err; switch (len) { case 1: @@ -135,9 +129,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) return -EINVAL; + if (reg < 256) + return pci_conf1_write(seg,bus,devfn,reg,len,value); + addr = pci_dev_base(seg, bus, devfn); if (!addr) - return pci_conf1_write(seg,bus,devfn,reg,len,value); + return -EINVAL; switch (len) { case 1: @@ -159,35 +156,6 @@ static struct pci_raw_ops pci_mmcfg = { .write = pci_mmcfg_write, }; -/* K8 systems have some devices (typically in the builtin northbridge) - that are only accessible using type1 - Normally this can be expressed in the MCFG by not listing them - and assigning suitable _SEGs, but this isn't implemented in some BIOS. - Instead try to discover all devices on bus 0 that are unreachable using MM - and fallback for them. */ -static __init void unreachable_devices(void) -{ - int i, k; - /* Use the max bus number from ACPI here? */ - for (k = 0; k < MAX_CHECK_BUS; k++) { - for (i = 0; i < 32; i++) { - u32 val1; - char __iomem *addr; - - pci_conf1_read(0, k, PCI_DEVFN(i,0), 0, 4, &val1); - if (val1 == 0xffffffff) - continue; - addr = pci_dev_base(0, k, PCI_DEVFN(i, 0)); - if (addr == NULL|| readl(addr) != val1) { - set_bit(i + 32*k, fallback_slots); - printk(KERN_NOTICE - "PCI: No mmconfig possible on device %x:%x\n", - k, i); - } - } - } -} - void __init pci_mmcfg_init(void) { int i; @@ -226,8 +194,6 @@ void __init pci_mmcfg_init(void) } } - unreachable_devices(); - raw_pci_ops = &pci_mmcfg; pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; }