From: Matthew Wilcox Date: Mon, 28 Jul 2008 17:38:59 +0000 (-0400) Subject: PCI: rewrite PCI BAR reading code X-Git-Tag: v2.6.27-rc1~3^2~10 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ac665c63dcac8fcec534a1d224ecbb8b867ad59;p=linux-2.6 PCI: rewrite PCI BAR reading code Factor out the code to read one BAR from the loop in pci_read_bases into a new function, __pci_read_base. The new code is slightly more readable, better commented and removes the ifdef. Signed-off-by: Matthew Wilcox Signed-off-by: Jesse Barnes --- diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b1724cf31b..3b690c3512 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -163,12 +163,9 @@ static inline unsigned int pci_calc_resource_flags(unsigned int flags) return IORESOURCE_MEM; } -/* - * Find the extent of a PCI decode.. - */ -static u32 pci_size(u32 base, u32 maxbase, u32 mask) +static u64 pci_size(u64 base, u64 maxbase, u64 mask) { - u32 size = mask & maxbase; /* Find the significant bits */ + u64 size = mask & maxbase; /* Find the significant bits */ if (!size) return 0; @@ -184,135 +181,142 @@ static u32 pci_size(u32 base, u32 maxbase, u32 mask) return size; } -static u64 pci_size64(u64 base, u64 maxbase, u64 mask) -{ - u64 size = mask & maxbase; /* Find the significant bits */ - if (!size) - return 0; +enum pci_bar_type { + pci_bar_unknown, /* Standard PCI BAR probe */ + pci_bar_io, /* An io port BAR */ + pci_bar_mem32, /* A 32-bit memory BAR */ + pci_bar_mem64, /* A 64-bit memory BAR */ +}; - /* Get the lowest of them to find the decode size, and - from that the extent. */ - size = (size & ~(size-1)) - 1; +static inline enum pci_bar_type decode_bar(struct resource *res, u32 bar) +{ + if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { + res->flags = bar & ~PCI_BASE_ADDRESS_IO_MASK; + return pci_bar_io; + } - /* base == maxbase can be valid only if the BAR has - already been programmed with all 1s. */ - if (base == maxbase && ((base | size) & mask) != mask) - return 0; + res->flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK; - return size; + if (res->flags == PCI_BASE_ADDRESS_MEM_TYPE_64) + return pci_bar_mem64; + return pci_bar_mem32; } -static inline int is_64bit_memory(u32 mask) +/* + * If the type is not unknown, we assume that the lowest bit is 'enable'. + * Returns 1 if the BAR was 64-bit and 0 if it was 32-bit. + */ +static int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, + struct resource *res, unsigned int pos) { - if ((mask & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) == - (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) - return 1; - return 0; -} + u32 l, sz, mask; -static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) -{ - unsigned int pos, reg, next; - u32 l, sz; - struct resource *res; + mask = type ? ~PCI_ROM_ADDRESS_ENABLE : ~0; - for(pos=0; posname = pci_name(dev); - next = pos+1; - res = &dev->resource[pos]; - res->name = pci_name(dev); - reg = PCI_BASE_ADDRESS_0 + (pos << 2); - pci_read_config_dword(dev, reg, &l); - pci_write_config_dword(dev, reg, ~0); - pci_read_config_dword(dev, reg, &sz); - pci_write_config_dword(dev, reg, l); - if (!sz || sz == 0xffffffff) - continue; - if (l == 0xffffffff) - l = 0; - raw_sz = sz; - if ((l & PCI_BASE_ADDRESS_SPACE) == - PCI_BASE_ADDRESS_SPACE_MEMORY) { - sz = pci_size(l, sz, (u32)PCI_BASE_ADDRESS_MEM_MASK); - /* - * For 64bit prefetchable memory sz could be 0, if the - * real size is bigger than 4G, so we need to check - * szhi for that. - */ - if (!is_64bit_memory(l) && !sz) - continue; - res->start = l & PCI_BASE_ADDRESS_MEM_MASK; - res->flags |= l & ~PCI_BASE_ADDRESS_MEM_MASK; + pci_read_config_dword(dev, pos, &l); + pci_write_config_dword(dev, pos, mask); + pci_read_config_dword(dev, pos, &sz); + pci_write_config_dword(dev, pos, l); + + /* + * All bits set in sz means the device isn't working properly. + * If the BAR isn't implemented, all bits must be 0. If it's a + * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit + * 1 must be clear. + */ + if (!sz || sz == 0xffffffff) + goto fail; + + /* + * I don't know how l can have all bits set. Copied from old code. + * Maybe it fixes a bug on some ancient platform. + */ + if (l == 0xffffffff) + l = 0; + + if (type == pci_bar_unknown) { + type = decode_bar(res, l); + res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN; + if (type == pci_bar_io) { + l &= PCI_BASE_ADDRESS_IO_MASK; + mask = PCI_BASE_ADDRESS_IO_MASK & 0xffff; } else { - sz = pci_size(l, sz, PCI_BASE_ADDRESS_IO_MASK & 0xffff); - if (!sz) - continue; - res->start = l & PCI_BASE_ADDRESS_IO_MASK; - res->flags |= l & ~PCI_BASE_ADDRESS_IO_MASK; + l &= PCI_BASE_ADDRESS_MEM_MASK; + mask = (u32)PCI_BASE_ADDRESS_MEM_MASK; } - res->end = res->start + (unsigned long) sz; - res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN; - if (is_64bit_memory(l)) { - u32 szhi, lhi; - - pci_read_config_dword(dev, reg+4, &lhi); - pci_write_config_dword(dev, reg+4, ~0); - pci_read_config_dword(dev, reg+4, &szhi); - pci_write_config_dword(dev, reg+4, lhi); - sz64 = ((u64)szhi << 32) | raw_sz; - l64 = ((u64)lhi << 32) | l; - sz64 = pci_size64(l64, sz64, PCI_BASE_ADDRESS_MEM_MASK); - next++; -#if BITS_PER_LONG == 64 - if (!sz64) { - res->start = 0; - res->end = 0; - res->flags = 0; - continue; - } - res->start = l64 & PCI_BASE_ADDRESS_MEM_MASK; - res->end = res->start + sz64; -#else - if (sz64 > 0x100000000ULL) { - dev_err(&dev->dev, "BAR %d: can't handle 64-bit" - " BAR\n", pos); - res->start = 0; - res->flags = 0; - } else if (lhi) { - /* 64-bit wide address, treat as disabled */ - pci_write_config_dword(dev, reg, - l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK); - pci_write_config_dword(dev, reg+4, 0); - res->start = 0; - res->end = sz; - } -#endif + } else { + res->flags |= (l & IORESOURCE_ROM_ENABLE); + l &= PCI_ROM_ADDRESS_MASK; + mask = (u32)PCI_ROM_ADDRESS_MASK; + } + + if (type == pci_bar_mem64) { + u64 l64 = l; + u64 sz64 = sz; + u64 mask64 = mask | (u64)~0 << 32; + + pci_read_config_dword(dev, pos + 4, &l); + pci_write_config_dword(dev, pos + 4, ~0); + pci_read_config_dword(dev, pos + 4, &sz); + pci_write_config_dword(dev, pos + 4, l); + + l64 |= ((u64)l << 32); + sz64 |= ((u64)sz << 32); + + sz64 = pci_size(l64, sz64, mask64); + + if (!sz64) + goto fail; + + if ((BITS_PER_LONG < 64) && (sz64 > 0x100000000ULL)) { + dev_err(&dev->dev, "can't handle 64-bit BAR\n"); + goto fail; + } else if ((BITS_PER_LONG < 64) && l) { + /* Address above 32-bit boundary; disable the BAR */ + pci_write_config_dword(dev, pos, 0); + pci_write_config_dword(dev, pos + 4, 0); + res->start = 0; + res->end = sz64; + } else { + res->start = l64; + res->end = l64 + sz64; } + } else { + sz = pci_size(l, sz, mask); + + if (!sz) + goto fail; + + res->start = l; + res->end = l + sz; } + + out: + return (type == pci_bar_mem64) ? 1 : 0; + fail: + res->flags = 0; + goto out; +} + +static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) +{ + unsigned int pos, reg; + + for (pos = 0; pos < howmany; pos++) { + struct resource *res = &dev->resource[pos]; + reg = PCI_BASE_ADDRESS_0 + (pos << 2); + pos += __pci_read_base(dev, pci_bar_unknown, res, reg); + } + if (rom) { + struct resource *res = &dev->resource[PCI_ROM_RESOURCE]; dev->rom_base_reg = rom; - res = &dev->resource[PCI_ROM_RESOURCE]; - res->name = pci_name(dev); - pci_read_config_dword(dev, rom, &l); - pci_write_config_dword(dev, rom, ~PCI_ROM_ADDRESS_ENABLE); - pci_read_config_dword(dev, rom, &sz); - pci_write_config_dword(dev, rom, l); - if (l == 0xffffffff) - l = 0; - if (sz && sz != 0xffffffff) { - sz = pci_size(l, sz, (u32)PCI_ROM_ADDRESS_MASK); - if (sz) { - res->flags = (l & IORESOURCE_ROM_ENABLE) | - IORESOURCE_MEM | IORESOURCE_PREFETCH | - IORESOURCE_READONLY | IORESOURCE_CACHEABLE | - IORESOURCE_SIZEALIGN; - res->start = l & PCI_ROM_ADDRESS_MASK; - res->end = res->start + (unsigned long) sz; - } - } + res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH | + IORESOURCE_READONLY | IORESOURCE_CACHEABLE | + IORESOURCE_SIZEALIGN; + __pci_read_base(dev, pci_bar_mem32, res, rom); } }