From 7fc986d8a9727e5d40da3c2c1c343da6142e82a9 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 19 Nov 2014 14:30:32 -0700 Subject: [PATCH] PCI: Support 64-bit bridge windows if we have 64-bit dma_addr_t Aaron reported that a 32-bit x86 kernel with Physical Address Extension (PAE) support complains about bridge prefetchable memory windows above 4GB: pci_bus 0000:00: root bus resource [mem 0x380000000000-0x383fffffffff] ... pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] pci 0000:00:02.2: PCI bridge to [bus 03-04] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] pci 0000:00:02.2: can't handle 64-bit address space for bridge In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits. Previously we used "unsigned long" to hold the bridge window address. But this is a bus address, so we should use dma_addr_t instead. Use dma_addr_t to hold the bridge window base and limit. The question of whether the CPU can actually *address* the window is separate and depends on what the physical address space of the CPU is and whether the host bridge does any address translation. [bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma Tested-by: Aaron Ma Signed-off-by: Yinghai Lu Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.14+ --- drivers/pci/probe.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6244b1834dfe..c8ca98c2b480 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -407,15 +407,16 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child) { struct pci_dev *dev = child->self; u16 mem_base_lo, mem_limit_lo; - unsigned long base, limit; + u64 base64, limit64; + dma_addr_t base, limit; struct pci_bus_region region; struct resource *res; res = child->resource[2]; pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo); pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo); - base = ((unsigned long) mem_base_lo & PCI_PREF_RANGE_MASK) << 16; - limit = ((unsigned long) mem_limit_lo & PCI_PREF_RANGE_MASK) << 16; + base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16; + limit64 = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16; if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { u32 mem_base_hi, mem_limit_hi; @@ -429,17 +430,20 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child) * this, just assume they are not being used. */ if (mem_base_hi <= mem_limit_hi) { -#if BITS_PER_LONG == 64 - base |= ((unsigned long) mem_base_hi) << 32; - limit |= ((unsigned long) mem_limit_hi) << 32; -#else - if (mem_base_hi || mem_limit_hi) { - dev_err(&dev->dev, "can't handle 64-bit address space for bridge\n"); - return; - } -#endif + base64 |= (u64) mem_base_hi << 32; + limit64 |= (u64) mem_limit_hi << 32; } } + + base = (dma_addr_t) base64; + limit = (dma_addr_t) limit64; + + if (base != base64) { + dev_err(&dev->dev, "can't handle bridge window above 4GB (bus address %#010llx)\n", + (unsigned long long) base64); + return; + } + if (base <= limit) { res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH; -- 2.20.1