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From: Yinghai Lu <yinghai@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	David Miller <davem@davemloft.net>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Wei Yang <weiyang@linux.vnet.ibm.com>, TJ <linux@iam.tj>,
	Yijing Wang <wangyijing@huawei.com>,
	Khalid Aziz <khalid.aziz@oracle.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource
Date: Wed, 27 Apr 2016 21:55:45 -0700	[thread overview]
Message-ID: <CAE9FiQWQ2ke3_P4Qhj+ON7pMiVCx4myhVNVaSYO4vYAL_P4njg@mail.gmail.com> (raw)
In-Reply-To: <20160422204920.GA17215@localhost>

On Fri, Apr 22, 2016 at 1:49 PM, Bjorn Helgaas <helgaas@kernel.org> wrote:
> [+cc Ben, Michael]
> I'm kind of confused here.  There are two ways to mmap PCI BARs:
>
>   /proc/bus/pci/00/02.0 (proc_bus_pci_mmap()):
>     all BARs in one file; MEM/IO determined by ioctl()
>     mmap offset is a CPU physical address in the PCI resource
>
>   /sys/devices/pci0000:00/0000:00:02.0/resource0 (pci_mmap_resource()):
>     one file per BAR; MEM/IO determined by BAR type
>     mmap offset is between 0 and BAR size
>
> Both proc_bus_pci_mmap() and pci_mmap_resource() validate the
> requested area with pci_mmap_fits() before calling pci_mmap_page_range().
>
> In the proc_bus_pci_mmap() path, the offset in vma->vm_pgoff must be
> within the pdev->resource[], so the user must be supplying a CPU
> physical address (not an address obtained from pci_resource_to_user()).
> That vma->vm_pgoff is passed unchanged to pci_mmap_page_range().
>
> In the pci_mmap_resource() path, vma->vm_pgoff must be between 0 and
> the BAR size.  Then we add in the pci_resource_to_user() information
> before passing it to pci_mmap_page_range().  The comment in
> pci_mmap_resource() says pci_mmap_page_range() expects a "user
> visible" address, but I don't really believe that based on how
> proc_bus_pci_mmap() works.
>
> Do both proc_bus_pci_mmap() and pci_mmap_resource() work on sparc?
> It looks like they call pci_mmap_page_range() with different
> assumptions, so I don't see how they can both work.

for sysfs path: in pci_mmap_resource
        pci_resource_to_user(pdev, i, res, &start, &end);
        vma->vm_pgoff += start >> PAGE_SHIFT;
     then call pci_mmap_page_range()

the fit checking in pci_mmap_fits(),
        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)

so proc fs assume resource_start for vm_pgoff ?

but current pci_mmap_page_range want to use bus address
start aka BAR value.

and we have

        /* 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.
         */

so we need to fix pci_mmap_fits(), please check if it is ok, will
submit it as separated one.

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index d319a9c..3768c6a 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -969,15 +969,20 @@ void pci_remove_legacy_files(struct pci_bus *b)
 int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
                  enum pci_mmap_api mmap_api)
 {
-       unsigned long nr, start, size, pci_start;
+       unsigned long nr, start, size;
+       resource_size_t pci_start = 0, pci_end;

        if (pci_resource_len(pdev, resno) == 0)
                return 0;
        nr = vma_pages(vma);
        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 (mmap_api == PCI_MMAP_PROCFS) {
+               struct resource *res = &pdev->resource[resno];
+
+               pci_resource_to_user(pdev, resno, res, &pci_start, &pci_end);
+               pci_start >>= PAGE_SHIFT;
+       }
        if (start >= pci_start && start < pci_start + size &&
                        start + nr <= pci_start + size)
                return 1;

  reply	other threads:[~2016-04-28  4:55 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-08  0:15 [PATCH v11 00/60] PCI: Resource allocation cleanup for v4.7 Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 01/60] PCI: Fix iomem_is_exclusive() checking in pci_mmap_resource() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 02/60] alpha/PCI: Only check iomem_is_exclusive() for IORESOURCE_MEM, not IORESOURCE_IO Yinghai Lu
2016-04-25 21:01   ` Bjorn Helgaas
2016-04-08  0:15 ` [PATCH v11 03/60] PCI: Add pci_find_bus_resource() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource Yinghai Lu
2016-04-22 20:49   ` Bjorn Helgaas
2016-04-28  4:55     ` Yinghai Lu [this message]
2016-04-28 13:56       ` Bjorn Helgaas
2016-04-29  7:19         ` Yinghai Lu
2016-05-03 22:52           ` Yinghai Lu
2016-05-04  0:37             ` Benjamin Herrenschmidt
2016-05-04  1:25               ` Bjorn Helgaas
2016-05-04  5:08                 ` Yinghai Lu
2016-05-04  5:52                   ` Yinghai Lu
2016-05-04 15:17                     ` Bjorn Helgaas
2016-05-04 18:46                       ` Yinghai Lu
2016-05-05  0:25                         ` Yinghai Lu
2016-05-05 15:53                           ` Yinghai Lu
2016-05-05 22:02                             ` Benjamin Herrenschmidt
2016-05-06  0:56                               ` Yinghai Lu
2016-05-06  4:18                                 ` Yinghai Lu
2016-05-06 18:26                             ` Bjorn Helgaas
2016-05-10  6:18                               ` Yinghai Lu
2016-05-04  4:17               ` David Miller
2016-04-08  0:15 ` [PATCH v11 05/60] sparc/PCI: Reserve legacy mmio after PCI mmio Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 06/60] sparc/PCI: Add IORESOURCE_MEM_64 for 64-bit resource in OF parsing Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 07/60] sparc/PCI: Keep resource idx order with bridge register number Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 08/60] PCI: Kill wrong quirk about M7101 Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 09/60] powerpc/PCI: Keep resource idx order with bridge register number Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 10/60] powerpc/PCI: Add IORESOURCE_MEM_64 for 64-bit resource in OF parsing Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 11/60] OF/PCI: Add IORESOURCE_MEM_64 for 64-bit resource Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 12/60] PCI: Check pref compatible bit for mem64 resource of PCIe device Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 13/60] PCI: Only treat non-pref mmio64 as pref if all bridges have MEM_64 Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 14/60] PCI: Add has_mem64 for struct host_bridge Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 15/60] PCI: Only treat non-pref mmio64 as pref if host bridge has mmio64 Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 16/60] PCI: Restore pref MMIO allocation logic for host bridge without mmio64 Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 17/60] PCI: Don't release fixed resource for realloc Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 18/60] PCI: Claim fixed resource during remove/rescan path Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 19/60] PCI: Set resource to FIXED for LSI devices Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 20/60] PCI: Separate realloc list checking after allocation Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 21/60] PCI: Treat optional as required in first try for bridge rescan Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 22/60] PCI: Get new realloc size for bridge for last try Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 23/60] PCI: Don't release sibling bridge resources during hotplug Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 24/60] PCI: Cleanup res_to_dev_res() printout Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 25/60] PCI: Reuse res_to_dev_res() in reassign_resources_sorted() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 26/60] PCI: Use correct align for optional only resources during sorting Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 27/60] PCI: Optimize bus min_align/size calculation during sizing Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 28/60] PCI: Optimize bus align/size calculation for optional " Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 29/60] PCI: Don't add too much optional size for hotplug bridge MMIO Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 30/60] PCI: Reorder resources list for required/optional resources Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 31/60] PCI: Remove duplicated code for resource sorting Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 32/60] PCI: Rename pdev_sort_resources() to pdev_assign_resources_prepare() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 33/60] PCI: Treat ROM resource as optional during realloc Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 34/60] PCI: Add debug printout during releasing partial assigned resources Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 35/60] PCI: Simplify res reference using in __assign_resources_sorted() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 36/60] PCI: Add __add_to_list() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 37/60] PCI: Cache window alignment value during bus sizing Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 38/60] PCI: Check if resource is allocated before trying to assign one Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 39/60] PCI: Separate out save_resources()/restore_resources() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 40/60] PCI: Move comment to pci_need_to_release() Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 41/60] PCI: Separate required+optional assigning to another function Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 42/60] PCI: Skip required+optional if there is no optional Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 43/60] PCI: Move saved required resource list out of required+optional assigning Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 44/60] PCI: Add alt_size ressource allocation support Yinghai Lu
2016-04-08  0:56   ` Linus Torvalds
2016-04-08  5:50     ` Yinghai Lu
2016-04-08  6:24     ` Benjamin Herrenschmidt
2016-04-08  0:15 ` [PATCH v11 45/60] PCI: Add support for more than two alt_size entries under same bridge Yinghai Lu
2016-04-08  0:15 ` [PATCH v11 46/60] PCI: Fix size calculation with old_size on rescan path Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 47/60] PCI: Don't add too much optional size for hotplug bridge io Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 48/60] PCI: Move ISA io port align out of calculate_iosize() Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 49/60] PCI: Don't add too much io port for hotplug bridge with old size Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 50/60] PCI: Unify calculate_size() for io port and MMIO Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 51/60] PCI: Allow bridge optional only io port resource required size to be 0 Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 52/60] PCI: Unify skip_ioresource_align() Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 53/60] PCI: Kill macro checking for bus io port sizing Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 54/60] resources: Make allocate_resource() return best fit resource Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 55/60] PCI, x86: Allocate from high in available window for MMIO Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 56/60] PCI: Add debug print out for min_align and alt_size Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 57/60] PCI, x86: Add pci=assign_pref_bars to reallocate pref BARs Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 58/60] PCI: Introduce resource_disabled() Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 59/60] PCI: Don't set flags to 0 when assign resource fail Yinghai Lu
2016-04-08  0:16 ` [PATCH v11 60/60] PCI: Only try to assign io port only for root bus that support it Yinghai Lu
2016-04-08  0:51 ` [PATCH v11 00/60] PCI: Resource allocation cleanup for v4.7 Linus Torvalds
2016-04-09  5:29   ` Yinghai Lu

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