From 3320ad994afb2c44ad34b3b34c3c5cf0da297331 Mon Sep 17 00:00:00 2001 From: dean gaudet Date: Fri, 10 Aug 2007 22:30:59 +0200 Subject: [PATCH] x86: Work around mmio config space quirk on AMD Fam10h Some broken devices have been discovered to require %al/%ax/%eax registers for MMIO config space accesses. Modify mmconfig.c to use these registers explicitly (rather than modify the global readb/writeb/etc inlines). AK: also changed i386 to always use eax AK: moved change to extended space probing to different patch AK: reworked with inlines according to Linus' requirements. AK: improve comments. Signed-off-by: dean gaudet Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/pci/mmconfig.c | 14 ++++++------- arch/i386/pci/pci.h | 43 ++++++++++++++++++++++++++++++++++++++ arch/x86_64/pci/mmconfig.c | 12 +++++------ 3 files changed, 55 insertions(+), 14 deletions(-) diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c index bb1afd9e589d..0d46b7a88b3b 100644 --- a/arch/i386/pci/mmconfig.c +++ b/arch/i386/pci/mmconfig.c @@ -82,16 +82,15 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus, switch (len) { case 1: - *value = readb(mmcfg_virt_addr + reg); + *value = mmio_config_readb(mmcfg_virt_addr + reg); break; case 2: - *value = readw(mmcfg_virt_addr + reg); + *value = mmio_config_readw(mmcfg_virt_addr + reg); break; case 4: - *value = readl(mmcfg_virt_addr + reg); + *value = mmio_config_readl(mmcfg_virt_addr + reg); break; } - spin_unlock_irqrestore(&pci_config_lock, flags); return 0; @@ -116,16 +115,15 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, switch (len) { case 1: - writeb(value, mmcfg_virt_addr + reg); + mmio_config_writeb(mmcfg_virt_addr, value); break; case 2: - writew(value, mmcfg_virt_addr + reg); + mmio_config_writew(mmcfg_virt_addr, value); break; case 4: - writel(value, mmcfg_virt_addr + reg); + mmio_config_writel(mmcfg_virt_addr, value); break; } - spin_unlock_irqrestore(&pci_config_lock, flags); return 0; diff --git a/arch/i386/pci/pci.h b/arch/i386/pci/pci.h index e58bae2076ad..8c66f275756f 100644 --- a/arch/i386/pci/pci.h +++ b/arch/i386/pci/pci.h @@ -104,3 +104,46 @@ extern DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS); extern int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus, unsigned int devfn); extern int __init pci_mmcfg_arch_init(void); + +/* + * AMD Fam10h CPUs are buggy, and cannot access MMIO config space + * on their northbrige except through the * %eax register. As such, you MUST + * NOT use normal IOMEM accesses, you need to only use the magic mmio-config + * accessor functions. + * In fact just use pci_config_*, nothing else please. + */ +static inline unsigned char mmio_config_readb(void __iomem *pos) +{ + u8 val; + asm volatile("movb (%1),%%al" : "=a" (val) : "r" (pos)); + return val; +} + +static inline unsigned short mmio_config_readw(void __iomem *pos) +{ + u16 val; + asm volatile("movw (%1),%%ax" : "=a" (val) : "r" (pos)); + return val; +} + +static inline unsigned int mmio_config_readl(void __iomem *pos) +{ + u32 val; + asm volatile("movl (%1),%%eax" : "=a" (val) : "r" (pos)); + return val; +} + +static inline void mmio_config_writeb(void __iomem *pos, u8 val) +{ + asm volatile("movb %%al,(%1)" :: "a" (val), "r" (pos) : "memory"); +} + +static inline void mmio_config_writew(void __iomem *pos, u16 val) +{ + asm volatile("movw %%ax,(%1)" :: "a" (val), "r" (pos) : "memory"); +} + +static inline void mmio_config_writel(void __iomem *pos, u32 val) +{ + asm volatile("movl %%eax,(%1)" :: "a" (val), "r" (pos) : "memory"); +} diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c index 65d82736987e..4095e4d66a1d 100644 --- a/arch/x86_64/pci/mmconfig.c +++ b/arch/x86_64/pci/mmconfig.c @@ -66,13 +66,13 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus, switch (len) { case 1: - *value = readb(addr + reg); + *value = mmio_config_readb(addr + reg); break; case 2: - *value = readw(addr + reg); + *value = mmio_config_readw(addr + reg); break; case 4: - *value = readl(addr + reg); + *value = mmio_config_readl(addr + reg); break; } @@ -94,13 +94,13 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus, switch (len) { case 1: - writeb(value, addr + reg); + mmio_config_writeb(addr + reg, value); break; case 2: - writew(value, addr + reg); + mmio_config_writew(addr + reg, value); break; case 4: - writel(value, addr + reg); + mmio_config_writel(addr + reg, value); break; } -- 2.20.1