Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161997AbaKOA00 (ORCPT ); Fri, 14 Nov 2014 19:26:26 -0500 Received: from mail-ig0-f170.google.com ([209.85.213.170]:40276 "EHLO mail-ig0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161621AbaKOA0Y (ORCPT ); Fri, 14 Nov 2014 19:26:24 -0500 Date: Fri, 14 Nov 2014 17:26:18 -0700 From: Bjorn Helgaas To: Yinghai Lu Cc: Andrew Morton , "H. Peter Anvin" , Ingo Molnar , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: Don't reject 64bit mmio on 32bit/PAE mode Message-ID: <20141115002618.GA4280@google.com> References: <1415937550-14469-1-git-send-email-yinghai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415937550-14469-1-git-send-email-yinghai@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 13, 2014 at 07:59:10PM -0800, Yinghai Lu wrote: > Aaron reported 32bit/PAE mode, has problem with 64bit resource. > > [ 6.610012] pci 0000:03:00.0: reg 0x10: [mem 0x383fffc00000-0x383fffdfffff 64bit pref] > [ 6.622195] pci 0000:03:00.0: reg 0x20: [mem 0x383fffe04000-0x383fffe07fff 64bit pref] > [ 6.656112] pci 0000:03:00.1: reg 0x10: [mem 0x383fffa00000-0x383fffbfffff 64bit pref] > [ 6.668293] pci 0000:03:00.1: reg 0x20: [mem 0x383fffe00000-0x383fffe03fff 64bit pref] > [ 6.702055] pci 0000:00:02.2: PCI bridge to [bus 03-04] > [ 6.706434] pci 0000:00:02.2: bridge window [io 0x1000-0x1fff] > [ 6.711783] pci 0000:00:02.2: bridge window [mem 0x91900000-0x91cfffff] > [ 6.717906] pci 0000:00:02.2: can't handle 64-bit address space for bridge > > So the kernel reject 64bit mmio on pci pref bridge that is assigned by > firmware. > > When 32bit PAE is enabled, we could support 64bit mmio. > but BITS_PER_LONG==64 checking could reject firmware assigned mmio that > is above 4G. On x86 32bit always has BITS_PER_LONG equal to 32. > > We could use CONFIG_ARCH_DMA_ADDR_T_64BIT or dma_addr_t size checking instead. > Use dma_addr_t size checking to avoid using MARCO. > > Also need to change to use dma_addr_t instead of unsigned long > for base/limit to avoid overflow. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 > Reported-by: Aaron Ma > Tested-by: Aaron Ma > Signed-off-by: Yinghai Lu Applied to for-linus for v3.18, thanks! > --- > drivers/pci/probe.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > Index: linux-2.6/drivers/pci/probe.c > =================================================================== > --- linux-2.6.orig/drivers/pci/probe.c > +++ linux-2.6/drivers/pci/probe.c > @@ -406,15 +406,15 @@ static void pci_read_bridge_mmio_pref(st > { > struct pci_dev *dev = child->self; > u16 mem_base_lo, mem_limit_lo; > - unsigned long base, limit; > + 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; > + base = ((dma_addr_t) mem_base_lo & PCI_PREF_RANGE_MASK) << 16; > + limit = ((dma_addr_t) 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; > @@ -428,15 +428,15 @@ static void pci_read_bridge_mmio_pref(st > * 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; > + if (sizeof(dma_addr_t) < 8) { > + if (mem_base_hi || mem_limit_hi) { > + dev_err(&dev->dev, "can't handle 64-bit address space for bridge\n"); > + return; > + } > + } else { > + base |= ((dma_addr_t) mem_base_hi) << 32; > + limit |= ((dma_addr_t) mem_limit_hi) << 32; > } > -#endif > } > } > if (base <= limit) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/