From: Arnd Bergmann <arnd@xxxxxxxx>
The main feature of the sparc specific implementation of
pci_mmap_resource_range() is that it allows mapping the entire PCI
I/O space for a PCI host bridge using the /proc/bus/pci interface on a
bridge device.
The generic implementation cannot do this, but it also appears that this
got broken for sparc by commit 9eff02e2042f ("PCI: check mmap range of
/proc/bus/pci files too"), which enforces that each address is part of
a BAR for kernels after 2.6.28.
Remove it all, assuming that the corresponding user space code has
already been changed to access /dev/ioport instead a long time ago.
The pci_iobar_pfn() function needs to be added to make it possible
to map I/O resources. This is adapted from the powerpc version.
Link: https://lore.kernel.org/lkml/1519887203.622.3.camel@xxxxxxxxxxxxx/t/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
It's quite possible that I missed something important, but it
appears that David Miller was thinking of the pre-2.6.28 behavior
that was already broken when David Woodhouse sent his series.
---
arch/sparc/include/asm/pci.h | 1 +
arch/sparc/kernel/pci.c | 154 +----------------------------------
2 files changed, 5 insertions(+), 150 deletions(-)
diff --git a/arch/sparc/include/asm/pci.h b/arch/sparc/include/asm/pci.h
index 4deddf430e5d..dff90dce6cb7 100644
--- a/arch/sparc/include/asm/pci.h
+++ b/arch/sparc/include/asm/pci.h
@@ -37,6 +37,7 @@ static inline int pci_proc_domain(struct pci_bus *bus)
#define HAVE_PCI_MMAP
#define arch_can_pci_mmap_io() 1
#define HAVE_ARCH_PCI_GET_UNMAPPED_AREA
+#define ARCH_GENERIC_PCI_MMAP_RESOURCE
#define get_pci_unmapped_area get_fb_unmapped_area
#endif /* CONFIG_SPARC64 */
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index f580db840bf7..cb1ef25116e9 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -751,161 +751,15 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
}
/* Platform support for /proc/bus/pci/X/Y mmap()s. */
-
-/* If the user uses a host-bridge as the PCI device, he may use
- * this to perform a raw mmap() of the I/O or MEM space behind
- * that controller.
- *
- * This can be useful for execution of x86 PCI bios initialization code
- * on a PCI card, like the xfree86 int10 stuff does.
- */
-static int __pci_mmap_make_offset_bus(struct pci_dev *pdev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state)
+int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
{
struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
- unsigned long space_size, user_offset, user_size;
-
- if (mmap_state == pci_mmap_io) {
- space_size = resource_size(&pbm->io_space);
- } else {
- space_size = resource_size(&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;
+ resource_size_t ioaddr = pci_resource_start(pdev, bar);
- if (user_offset >= space_size ||
- (user_offset + user_size) > space_size)
+ if (!pbm)
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;
-}
-
-/* Adjust vm_pgoff of VMA such that it is the physical page offset
- * corresponding to the 32-bit pci bus offset for DEV requested by the user.
- *
- * Basically, the user finds the base address for his device which he wishes
- * to mmap. They read the 32-bit value from the config space base register,
- * add whatever PAGE_SIZE multiple offset they wish, and feed this into the
- * offset parameter of mmap on /proc/bus/pci/XXX for that device.
- *
- * Returns negative error code on failure, zero on success.
- */
-static int __pci_mmap_make_offset(struct pci_dev *pdev,
- struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state)
-{
- unsigned long user_paddr, user_size;
- int i, err;
-
- /* First compute the physical address in vma->vm_pgoff,
- * making sure the user offset is within range in the
- * appropriate PCI space.
- */
- err = __pci_mmap_make_offset_bus(pdev, vma, mmap_state);
- if (err)
- return err;
-
- /* If this is a mapping on a host bridge, any address
- * is OK.
- */
- if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
- return err;
-
- /* Otherwise make sure it's in the range for one of the
- * device's resources.
- */
- user_paddr = vma->vm_pgoff << PAGE_SHIFT;
- user_size = vma->vm_end - vma->vm_start;
-
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- struct resource *rp = &pdev->resource[i];
- resource_size_t aligned_end;
-
- /* Active? */
- if (!rp->flags)
- continue;
-
- /* Same type? */
- if (i == PCI_ROM_RESOURCE) {
- if (mmap_state != pci_mmap_mem)
- continue;
- } else {
- if ((mmap_state == pci_mmap_io &&
- (rp->flags & IORESOURCE_IO) == 0) ||
- (mmap_state == pci_mmap_mem &&
- (rp->flags & IORESOURCE_MEM) == 0))
- continue;
- }
-
- /* Align the resource end to the next page address.
- * PAGE_SIZE intentionally added instead of (PAGE_SIZE - 1),
- * because actually we need the address of the next byte
- * after rp->end.
- */
- aligned_end = (rp->end + PAGE_SIZE) & PAGE_MASK;
-
- if ((rp->start <= user_paddr) &&
- (user_paddr + user_size) <= aligned_end)
- break;
- }
-
- if (i > PCI_ROM_RESOURCE)
- return -EINVAL;
-
- return 0;
-}
-
-/* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
- * device mapping.
- */
-static void __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state)
-{
- /* Our io_remap_pfn_range takes care of this, do nothing. */
-}
-
-/* Perform the actual remap of the pages for a PCI device mapping, as appropriate
- * for this architecture. The region in the process to map is described by vm_start
- * and vm_end members of VMA, the BAR relative address is found in vm_pgoff.
- * The pci device structure is provided so that architectures may make mapping
- * decisions on a per-device or per-bus basis.
- *
- * Returns a negative error code on failure, zero on success.
- */
-int pci_mmap_resource_range(struct pci_dev *dev, int bar,
- struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine)
-{
- int ret;
- resource_size_t start, end;
-
- /* convert per-BAR address to PCI bus address */
- pci_resource_to_user(dev, bar, &dev->resource[bar], &start, &end);
- vma->vm_pgoff += start >> PAGE_SHIFT;
-
- ret = __pci_mmap_make_offset(dev, vma, mmap_state);
- if (ret < 0)
- return ret;
-
- __pci_mmap_set_pgprot(dev, vma, mmap_state);
-
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- ret = io_remap_pfn_range(vma, vma->vm_start,
- vma->vm_pgoff,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
- if (ret)
- return ret;
+ vma->vm_pgoff += (ioaddr + pbm->io_space.start) >> PAGE_SHIFT;
return 0;
}
--
2.29.2
