From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757171AbcEDFwh (ORCPT ); Wed, 4 May 2016 01:52:37 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:35737 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756994AbcEDFwe (ORCPT ); Wed, 4 May 2016 01:52:34 -0400 MIME-Version: 1.0 In-Reply-To: References: <1460074573-7481-1-git-send-email-yinghai@kernel.org> <1460074573-7481-5-git-send-email-yinghai@kernel.org> <20160422204920.GA17215@localhost> <20160428135607.GA12470@localhost> <1462322260.30470.76.camel@kernel.crashing.org> <20160504012531.GB17170@localhost> Date: Tue, 3 May 2016 22:52:33 -0700 X-Google-Sender-Auth: GgAniCOM22AJ1FyjkOt9cHbBB_M Message-ID: Subject: Re: [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource From: Yinghai Lu To: Bjorn Helgaas Cc: Benjamin Herrenschmidt , Bjorn Helgaas , David Miller , Linus Torvalds , Wei Yang , TJ , Yijing Wang , Khalid Aziz , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List , Michael Ellerman Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 3, 2016 at 10:08 PM, Yinghai Lu wrote: > On Tue, May 3, 2016 at 6:25 PM, Bjorn Helgaas wrote: >> I did not propose changing any user-visible ABI. To recap what I did >> propose: > > I want to avoid introduce one strange pci_user_to_resource. > >> >> - The sysfs path uses offsets between 0 and BAR size on all arches. >> It uses pci_resource_to_user() today, but I think it should not. >> >> - The procfs path uses offsets of resource values (CPU physical >> addresses) on most architectures, but uses something else, e.g., >> BAR values, on others. pci_resource_to_user() does this >> translation. The procfs path does not use pci_resource_to_user() >> today, but I think it should. > > current powerpc pci_resource_to_user is strange: > it will return resource start for io mem. > but will return BAR (?) start for io port. > > sparc pci_resource_to_user does return BAR value for iomem. > >> >> - This implies that pci_mmap_page_range() should deal with resource >> values (CPU physical addresses), and proc_bus_pci_mmap() should do >> any necessary arch-specific translation from BAR values to >> resource values. > > so will need one different version pci_user_to_resource. > and can not use pcibios_bus_to_resource directly, and will be another mess. looks like we can avoid that pci_user_to_resource() via trying out. Please check it: Subject: [RFC PATCH] PCI: Let pci_mmap_page_range() take resource addr Some arch where cpu address (resource value) is not same as pci bus address (BAR value in pci BAR registers), include sparc, powerpc, microblaze. In 8c05cd08a7 ("PCI: fix offset check for sysfs mmapped files"), try to check exposed value with resource start/end in proc mmap path. | start = vma->vm_pgoff; | size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1; | pci_start = (mmap_api == PCI_MMAP_PROCFS) ? | pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0; | if (start >= pci_start && start < pci_start + size && | start + nr <= pci_start + size) That would break sparc that exposed value is still BAR value. According to Bjorn, we could just pass resource addr instead of BAR. In the patch: 1. in proc path: proc_bus_pci_mmap, try convert back to resource before calling pci_mmap_page_range 2. in sysfs path: pci_mmap_resource will just offset with resource start. 3. all pci_mmap_page_range will all have vma->vm_pgoff with in resource range instead of BAR value. Signed-off-by: Yinghai Lu --- arch/microblaze/pci/pci-common.c | 14 ++++---------- arch/powerpc/kernel/pci-common.c | 14 ++++---------- arch/sparc/kernel/pci.c | 27 +++++++++------------------ arch/xtensa/kernel/pci.c | 11 ++++------- drivers/pci/pci-sysfs.c | 8 +------- drivers/pci/proc.c | 13 +++++++++++++ 6 files changed, 35 insertions(+), 52 deletions(-) Index: linux-2.6/arch/microblaze/pci/pci-common.c =================================================================== --- linux-2.6.orig/arch/microblaze/pci/pci-common.c +++ linux-2.6/arch/microblaze/pci/pci-common.c @@ -169,23 +169,16 @@ static struct resource *__pci_mmap_make_ enum pci_mmap_state mmap_state) { struct pci_controller *hose = pci_bus_to_host(dev->bus); - unsigned long io_offset = 0; int i, res_bit; if (!hose) return NULL; /* should never happen */ /* If memory, add on the PCI bridge address offset */ - if (mmap_state == pci_mmap_mem) { -#if 0 /* See comment in pci_resource_to_user() for why this is disabled */ - *offset += hose->pci_mem_offset; -#endif + if (mmap_state == pci_mmap_mem) res_bit = IORESOURCE_MEM; - } else { - io_offset = (unsigned long)hose->io_base_virt - _IO_BASE; - *offset += io_offset; + else res_bit = IORESOURCE_IO; - } /* * Check that the offset requested corresponds to one of the @@ -209,7 +202,8 @@ static struct resource *__pci_mmap_make_ /* found it! construct the final physical address */ if (mmap_state == pci_mmap_io) - *offset += hose->io_base_phys - io_offset; + *offset += hose->io_base_phys - + ((unsigned long)hose->io_base_virt - _IO_BASE); return rp; } Index: linux-2.6/arch/powerpc/kernel/pci-common.c =================================================================== --- linux-2.6.orig/arch/powerpc/kernel/pci-common.c +++ linux-2.6/arch/powerpc/kernel/pci-common.c @@ -308,23 +308,16 @@ static struct resource *__pci_mmap_make_ enum pci_mmap_state mmap_state) { struct pci_controller *hose = pci_bus_to_host(dev->bus); - unsigned long io_offset = 0; int i, res_bit; if (hose == NULL) return NULL; /* should never happen */ /* If memory, add on the PCI bridge address offset */ - if (mmap_state == pci_mmap_mem) { -#if 0 /* See comment in pci_resource_to_user() for why this is disabled */ - *offset += hose->pci_mem_offset; -#endif + if (mmap_state == pci_mmap_mem) res_bit = IORESOURCE_MEM; - } else { - io_offset = (unsigned long)hose->io_base_virt - _IO_BASE; - *offset += io_offset; + else res_bit = IORESOURCE_IO; - } /* * Check that the offset requested corresponds to one of the @@ -348,7 +341,8 @@ static struct resource *__pci_mmap_make_ /* found it! construct the final physical address */ if (mmap_state == pci_mmap_io) - *offset += hose->io_base_phys - io_offset; + *offset += hose->io_base_phys - + ((unsigned long)hose->io_base_virt - _IO_BASE); return rp; } Index: linux-2.6/arch/sparc/kernel/pci.c =================================================================== --- linux-2.6.orig/arch/sparc/kernel/pci.c +++ linux-2.6/arch/sparc/kernel/pci.c @@ -743,30 +743,21 @@ static int __pci_mmap_make_offset_bus(st enum pci_mmap_state mmap_state) { struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller; - unsigned long space_size, user_offset, user_size; + unsigned long start, end; + struct resource *res; - if (mmap_state == pci_mmap_io) { - space_size = resource_size(&pbm->io_space); - } else { - space_size = resource_size(&pbm->mem_space); - } + if (mmap_state == pci_mmap_io) + res = &pbm->io_space; + else + res = &pbm->mem_space; /* Make sure the request is in range. */ - user_offset = vma->vm_pgoff << PAGE_SHIFT; - user_size = vma->vm_end - vma->vm_start; + start = vma->vm_pgoff << PAGE_SHIFT; + end = vma->vm_end - vma->vm_start + start - 1; - if (user_offset >= space_size || - (user_offset + user_size) > space_size) + if (!((res->start <= start) && (res->end >= end))) return -EINVAL; - if (mmap_state == pci_mmap_io) { - vma->vm_pgoff = (pbm->io_space.start + - user_offset) >> PAGE_SHIFT; - } else { - vma->vm_pgoff = (pbm->mem_space.start + - user_offset) >> PAGE_SHIFT; - } - return 0; } Index: linux-2.6/arch/xtensa/kernel/pci.c =================================================================== --- linux-2.6.orig/arch/xtensa/kernel/pci.c +++ linux-2.6/arch/xtensa/kernel/pci.c @@ -288,20 +288,16 @@ __pci_mmap_make_offset(struct pci_dev *d { struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata; unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; - unsigned long io_offset = 0; int i, res_bit; if (pci_ctrl == 0) return -EINVAL; /* should never happen */ /* If memory, add on the PCI bridge address offset */ - if (mmap_state == pci_mmap_mem) { + if (mmap_state == pci_mmap_mem) res_bit = IORESOURCE_MEM; - } else { - io_offset = (unsigned long)pci_ctrl->io_space.base; - offset += io_offset; + else res_bit = IORESOURCE_IO; - } /* * Check that the offset requested corresponds to one of the @@ -325,7 +321,8 @@ __pci_mmap_make_offset(struct pci_dev *d /* found it! construct the final physical address */ if (mmap_state == pci_mmap_io) - offset += pci_ctrl->io_space.start - io_offset; + offset += pci_ctrl->io_space.start - + pci_ctrl->io_space.base; vma->vm_pgoff = offset >> PAGE_SHIFT; return 0; } Index: linux-2.6/drivers/pci/pci-sysfs.c =================================================================== --- linux-2.6.orig/drivers/pci/pci-sysfs.c +++ linux-2.6/drivers/pci/pci-sysfs.c @@ -999,7 +999,6 @@ static int pci_mmap_resource(struct kobj struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); struct resource *res = attr->private; enum pci_mmap_state mmap_type; - resource_size_t start, end; int i; for (i = 0; i < PCI_ROM_RESOURCE; i++) @@ -1020,12 +1019,7 @@ static int pci_mmap_resource(struct kobj return -EINVAL; } - /* pci_mmap_page_range() expects the same kind of entry as coming - * from /proc/bus/pci/ which is a "user visible" value. If this is - * different from the resource itself, arch will do necessary fixup. - */ - pci_resource_to_user(pdev, i, res, &start, &end); - vma->vm_pgoff += start >> PAGE_SHIFT; + vma->vm_pgoff += res->start >> PAGE_SHIFT; mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io; return pci_mmap_page_range(pdev, vma, mmap_type, write_combine); } Index: linux-2.6/drivers/pci/proc.c =================================================================== --- linux-2.6.orig/drivers/pci/proc.c +++ linux-2.6/drivers/pci/proc.c @@ -231,13 +231,26 @@ static int proc_bus_pci_mmap(struct file { struct pci_dev *dev = PDE_DATA(file_inode(file)); struct pci_filp_private *fpriv = file->private_data; + resource_size_t start, end, offset; + struct resource *res; int i, ret; if (!capable(CAP_SYS_RAWIO)) return -EPERM; + offset = vma->vm_pgoff << PAGE_SHIFT; + /* Make sure the caller is mapping a real resource for this device */ for (i = 0; i < PCI_ROM_RESOURCE; i++) { + res = &dev->resource[i]; + if (!res->flags) + continue; + + pci_resource_to_user(dev, i, res, &start, &end); + if (!(offset >= start && offset <= end)) + continue; + + vma->vm_pgoff = (res->start + (offset - start)) >> PAGE_SHIFT; if (pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS)) break; }