[PATCH 07/17] pci: Use BAR index in sysfs attr->private instead of resource pointer

From: David Woodhouse
Date: Wed Mar 22 2017 - 09:25:43 EST


From: David Woodhouse <dwmw@xxxxxxxxxxxx>

We store the pointer, and then on *every* use of it we loop over the
device's resources to find out the index. That's kind of silly.

Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
drivers/pci/pci-sysfs.c | 38 ++++++++++++++------------------------
1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 07cb2fc..8a2d77b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1017,26 +1017,20 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
struct vm_area_struct *vma, int write_combine)
{
struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
- struct resource *res = attr->private;
+ int bar = (unsigned long)attr->private;
enum pci_mmap_state mmap_type;
resource_size_t start, end;
- int i;
-
- for (i = 0; i < PCI_ROM_RESOURCE; i++)
- if (res == &pdev->resource[i])
- break;
- if (i >= PCI_ROM_RESOURCE)
- return -ENODEV;
+ struct resource *res = &pdev->resource[bar];

if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
return -EINVAL;

- if (!pci_mmap_fits(pdev, i, vma, PCI_MMAP_SYSFS)) {
+ if (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS)) {
WARN(1, "process \"%s\" tried to map 0x%08lx bytes at page 0x%08lx on %s BAR %d (start 0x%16Lx, size 0x%16Lx)\n",
current->comm, vma->vm_end-vma->vm_start, vma->vm_pgoff,
- pci_name(pdev), i,
- (u64)pci_resource_start(pdev, i),
- (u64)pci_resource_len(pdev, i));
+ pci_name(pdev), bar,
+ (u64)pci_resource_start(pdev, bar),
+ (u64)pci_resource_len(pdev, bar));
return -EINVAL;
}

@@ -1044,7 +1038,7 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
* 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);
+ pci_resource_to_user(pdev, bar, res, &start, &end);
vma->vm_pgoff += 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);
@@ -1069,22 +1063,18 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
loff_t off, size_t count, bool write)
{
struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
- struct resource *res = attr->private;
+ int bar = (unsigned long)attr->private;
+ struct resource *res;
unsigned long port = off;
- int i;

- for (i = 0; i < PCI_ROM_RESOURCE; i++)
- if (res == &pdev->resource[i])
- break;
- if (i >= PCI_ROM_RESOURCE)
- return -ENODEV;
+ res = &pdev->resource[bar];

- port += pci_resource_start(pdev, i);
+ port += pci_resource_start(pdev, bar);

- if (port > pci_resource_end(pdev, i))
+ if (port > pci_resource_end(pdev, bar))
return 0;

- if (port + count - 1 > pci_resource_end(pdev, i))
+ if (port + count - 1 > pci_resource_end(pdev, bar))
return -EINVAL;

switch (count) {
@@ -1187,7 +1177,7 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
res_attr->attr.name = res_attr_name;
res_attr->attr.mode = S_IRUSR | S_IWUSR;
res_attr->size = pci_resource_len(pdev, num);
- res_attr->private = &pdev->resource[num];
+ res_attr->private = (void *)(unsigned long)num;
retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
if (retval)
kfree(res_attr);
--
2.9.3