From 17d6dc8ff098cc8c57941c82f7702804302b1ea1 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Tue, 18 Apr 2006 17:19:52 -0700 Subject: [PATCH] [PATCH] PCI: Ignore pre-set 64-bit BARs on 32-bit platforms [pci] Ignore pre-set 64-bit BARs on 32-bit platforms Currently, Linux always rejects a device which has a pre-set 64-bit address on a 32-bit platform. On systems which do not do PCI initialization in firmware, this causes some devices which don't correctly power up with all BARs zero to fail. This patch makes the kernel automatically zero out such an address (thus treating it as if it had not been set at all, meaning it will assign an address if necessary). I have done this only for devices, not bridges. It seems potentially hazardous to do for bridges. Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman --- drivers/pci/probe.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index a10ed9dab2..5c4924c27f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -180,25 +180,31 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) res->flags |= pci_calc_resource_flags(l); if ((l & (PCI_BASE_ADDRESS_SPACE | PCI_BASE_ADDRESS_MEM_TYPE_MASK)) == (PCI_BASE_ADDRESS_SPACE_MEMORY | PCI_BASE_ADDRESS_MEM_TYPE_64)) { - pci_read_config_dword(dev, reg+4, &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); + szhi = pci_size(lhi, szhi, 0xffffffff); next++; #if BITS_PER_LONG == 64 - res->start |= ((unsigned long) l) << 32; + res->start |= ((unsigned long) lhi) << 32; res->end = res->start + sz; - pci_write_config_dword(dev, reg+4, ~0); - pci_read_config_dword(dev, reg+4, &sz); - pci_write_config_dword(dev, reg+4, l); - sz = pci_size(l, sz, 0xffffffff); - if (sz) { + if (szhi) { /* This BAR needs > 4GB? Wow. */ - res->end |= (unsigned long)sz<<32; + res->end |= (unsigned long)szhi<<32; } #else - if (l) { - printk(KERN_ERR "PCI: Unable to handle 64-bit address for device %s\n", pci_name(dev)); + if (szhi) { + printk(KERN_ERR "PCI: Unable to handle 64-bit BAR for device %s\n", pci_name(dev)); res->start = 0; res->flags = 0; - continue; + } else if (l) { + /* 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 } -- 2.39.5