From 0fee6f111f8e2e967192d983dede083fcd781b79 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Tue, 23 Jun 2015 21:30:38 +0200 Subject: PCI: rework BAR size calculation The probe code now does a much better job at detecting bad BARs. Also make sure to preserve any previous content of the BAR registers if we don't relocate them. Signed-off-by: Lucas Stach Signed-off-by: Sascha Hauer --- drivers/pci/pci.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3a0e7a5f4e..1e4590706d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -129,10 +129,24 @@ static struct pci_dev *alloc_pci_dev(void) return dev; } +static u32 pci_size(u32 base, u32 maxbase, u32 mask) +{ + u32 size = maxbase & mask; + if (!size) + return 0; + + size = (size & ~(size-1)) - 1; + + if (base == maxbase && ((base | size) & mask) != mask) + return 0; + + return size + 1; +} + + static void setup_device(struct pci_dev *dev, int max_bar) { - int bar, size; - u32 mask; + int bar; u8 cmd; pci_read_config_byte(dev, PCI_COMMAND, &cmd); @@ -141,9 +155,12 @@ static void setup_device(struct pci_dev *dev, int max_bar) for (bar = 0; bar < max_bar; bar++) { resource_size_t last_addr; + u32 orig, mask, size; + pci_read_config_dword(dev, PCI_BASE_ADDRESS_0 + bar * 4, &orig); pci_write_config_dword(dev, PCI_BASE_ADDRESS_0 + bar * 4, 0xfffffffe); pci_read_config_dword(dev, PCI_BASE_ADDRESS_0 + bar * 4, &mask); + pci_write_config_dword(dev, PCI_BASE_ADDRESS_0 + bar * 4, orig); if (mask == 0 || mask == 0xffffffff) { pr_debug("pbar%d set bad mask\n", bar); @@ -151,7 +168,11 @@ static void setup_device(struct pci_dev *dev, int max_bar) } if (mask & 0x01) { /* IO */ - size = ((~(mask & 0xfffffffe)) & 0xffff) + 1; + size = pci_size(orig, mask, 0xfffffffe); + if (!size) { + pr_debug("pbar%d bad IO mask\n", bar); + continue; + } pr_debug("pbar%d: mask=%08x io %d bytes\n", bar, mask, size); if (last_io + size > dev->bus->resource[PCI_BUS_RESOURCE_IO]->end) { @@ -164,7 +185,11 @@ static void setup_device(struct pci_dev *dev, int max_bar) last_io += size; } else if ((mask & PCI_BASE_ADDRESS_MEM_PREFETCH) && last_mem_pref) /* prefetchable MEM */ { - size = (~(mask & 0xfffffff0)) + 1; + size = pci_size(orig, mask, 0xfffffff0); + if (!size) { + pr_debug("pbar%d bad P-MEM mask\n", bar); + continue; + } pr_debug("pbar%d: mask=%08x P memory %d bytes\n", bar, mask, size); if (last_mem_pref + size > @@ -178,7 +203,11 @@ static void setup_device(struct pci_dev *dev, int max_bar) last_addr = last_mem_pref; last_mem_pref += size; } else { /* non-prefetch MEM */ - size = (~(mask & 0xfffffff0)) + 1; + size = pci_size(orig, mask, 0xfffffff0); + if (!size) { + pr_debug("pbar%d bad NP-MEM mask\n", bar); + continue; + } pr_debug("pbar%d: mask=%08x NP memory %d bytes\n", bar, mask, size); if (last_mem + size > -- cgit v1.2.3