Re: [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource

From: Yinghai Lu
Date: Thu May 05 2016 - 11:53:20 EST

On Wed, May 4, 2016 at 5:25 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Wed, May 4, 2016 at 11:46 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>> On Wed, May 4, 2016 at 8:17 AM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>>> My goal is to make pci_mmap_resource() and proc_bus_pci_mmap() look
>>> very similar, e.g.,
>>>
>>> /* locate resource */
>>> pci_user_to_resource() # only in proc_bus_pci_mmap()
>>> if (!pci_mmap_fits()) {
>>> WARN(...);
>>> return -EINVAL;
>>> }
>>> pci_mmap_page_range();
>

v3, that have more change to pass *res to make powerpc prot setting simple.

Question for BenH and DavidM:

For powerpc io port, we still need extra offset from resource address
to final address.

resource_size_t offset =
((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;

+ if (mmap_state == pci_mmap_io) {
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+
+ /* hose should never be NULL */
+ offset += hose->io_base_phys -
+ ((unsigned long)hose->io_base_virt - _IO_BASE);
+ }

vma->vm_pgoff = offset >> PAGE_SHIFT;

but sparc does not need that trick.

why ?

Thanks

Yinghai


---

Subject: [RFC PATCH v3 2/2] PCI: Let pci_mmap_page_range() take resource addr

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.

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.
4. remove __pci_mmap_make_offset, as the checking is done
in pci_mmap_fits().

-v2: add pci_user_to_resource and remove __pci_mmap_make_offset
-v3: pass resource pointer with pci_mmap_page_range()

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>


---
arch/microblaze/pci/pci-common.c | 78 ++------------------------
arch/powerpc/kernel/pci-common.c | 78 ++------------------------
arch/sparc/kernel/pci.c | 117 ---------------------------------------
arch/xtensa/kernel/pci.c | 75 +++----------------------
drivers/pci/pci-sysfs.c | 23 ++++---
drivers/pci/proc.c | 57 ++++++++++++++++---
6 files changed, 88 insertions(+), 340 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
@@ -154,69 +154,6 @@ void pcibios_set_master(struct pci_dev *
*/

/*
- * 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 struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
- resource_size_t *offset,
- 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
- res_bit = IORESOURCE_MEM;
- } else {
- io_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
- *offset += io_offset;
- res_bit = IORESOURCE_IO;
- }
-
- /*
- * Check that the offset requested corresponds to one of the
- * resources of the device.
- */
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- struct resource *rp = &dev->resource[i];
- int flags = rp->flags;
-
- /* treat ROM as memory (should be already) */
- if (i == PCI_ROM_RESOURCE)
- flags |= IORESOURCE_MEM;
-
- /* Active and same type? */
- if ((flags & res_bit) == 0)
- continue;
-
- /* In the range of this resource? */
- if (*offset < (rp->start & PAGE_MASK) || *offset > rp->end)
- continue;
-
- /* found it! construct the final physical address */
- if (mmap_state == pci_mmap_io)
- *offset += hose->io_base_phys - io_offset;
- return rp;
- }
-
- return NULL;
-}
-
-/*
* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
* device mapping.
*/
@@ -308,12 +245,15 @@ int pci_mmap_page_range(struct pci_dev *
{
resource_size_t offset =
((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
- struct resource *rp;
int ret;

- rp = __pci_mmap_make_offset(dev, &offset, mmap_state);
- if (rp == NULL)
- return -EINVAL;
+ if (mmap_state == pci_mmap_io) {
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+
+ /* hose should never be NULL */
+ *offset += hose->io_base_phys -
+ ((unsigned long)hose->io_base_virt - _IO_BASE);
+ }

vma->vm_pgoff = offset >> PAGE_SHIFT;
vma->vm_page_prot = __pci_mmap_set_pgprot(dev, rp,
@@ -492,9 +432,7 @@ void pci_resource_to_user(const struct p
*
* Hopefully, the sysfs insterface is immune to that gunk. Once X
* has been fixed (and the fix spread enough), we can re-enable the
- * 2 lines below and pass down a BAR value to userland. In that case
- * we'll also have to re-enable the matching code in
- * __pci_mmap_make_offset().
+ * 2 lines below and pass down a BAR value to userland.
*
* BenH.
*/
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
@@ -293,69 +293,6 @@ static int pci_read_irq_line(struct pci_
*/

/*
- * 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 struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
- resource_size_t *offset,
- 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
- res_bit = IORESOURCE_MEM;
- } else {
- io_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
- *offset += io_offset;
- res_bit = IORESOURCE_IO;
- }
-
- /*
- * Check that the offset requested corresponds to one of the
- * resources of the device.
- */
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- struct resource *rp = &dev->resource[i];
- int flags = rp->flags;
-
- /* treat ROM as memory (should be already) */
- if (i == PCI_ROM_RESOURCE)
- flags |= IORESOURCE_MEM;
-
- /* Active and same type? */
- if ((flags & res_bit) == 0)
- continue;
-
- /* In the range of this resource? */
- if (*offset < (rp->start & PAGE_MASK) || *offset > rp->end)
- continue;
-
- /* found it! construct the final physical address */
- if (mmap_state == pci_mmap_io)
- *offset += hose->io_base_phys - io_offset;
- return rp;
- }
-
- return NULL;
-}
-
-/*
* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
* device mapping.
*/
@@ -451,12 +388,15 @@ int pci_mmap_page_range(struct pci_dev *
{
resource_size_t offset =
((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
- struct resource *rp;
int ret;

- rp = __pci_mmap_make_offset(dev, &offset, mmap_state);
- if (rp == NULL)
- return -EINVAL;
+ if (mmap_state == pci_mmap_io) {
+ struct pci_controller *hose = pci_bus_to_host(dev->bus);
+
+ /* hose should never be NULL */
+ offset += hose->io_base_phys -
+ ((unsigned long)hose->io_base_virt - _IO_BASE);
+ }

vma->vm_pgoff = offset >> PAGE_SHIFT;
vma->vm_page_prot = __pci_mmap_set_pgprot(dev, rp,
@@ -631,9 +571,7 @@ void pci_resource_to_user(const struct p
*
* Hopefully, the sysfs insterface is immune to that gunk. Once X
* has been fixed (and the fix spread enough), we can re-enable the
- * 2 lines below and pass down a BAR value to userland. In that case
- * we'll also have to re-enable the matching code in
- * __pci_mmap_make_offset().
+ * 2 lines below and pass down a BAR value to userland.
*
* BenH.
*/
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
@@ -732,119 +732,6 @@ int pcibios_enable_device(struct pci_dev

/* 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)
-{
- 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;
-
- if (user_offset >= space_size ||
- (user_offset + user_size) > space_size)
- 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.
*/
@@ -869,10 +756,6 @@ int pci_mmap_page_range(struct pci_dev *
{
int ret;

- 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);
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
@@ -272,68 +272,6 @@ pci_controller_num(struct pci_dev *dev)
*/

/*
- * 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 __inline__ int
-__pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state)
-{
- 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) {
- res_bit = IORESOURCE_MEM;
- } else {
- io_offset = (unsigned long)pci_ctrl->io_space.base;
- offset += io_offset;
- res_bit = IORESOURCE_IO;
- }
-
- /*
- * Check that the offset requested corresponds to one of the
- * resources of the device.
- */
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- struct resource *rp = &dev->resource[i];
- int flags = rp->flags;
-
- /* treat ROM as memory (should be already) */
- if (i == PCI_ROM_RESOURCE)
- flags |= IORESOURCE_MEM;
-
- /* Active and same type? */
- if ((flags & res_bit) == 0)
- continue;
-
- /* In the range of this resource? */
- if (offset < (rp->start & PAGE_MASK) || offset > rp->end)
- continue;
-
- /* found it! construct the final physical address */
- if (mmap_state == pci_mmap_io)
- offset += pci_ctrl->io_space.start - io_offset;
- vma->vm_pgoff = offset >> PAGE_SHIFT;
- return 0;
- }
-
- return -EINVAL;
-}
-
-/*
* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
* device mapping.
*/
@@ -367,11 +305,18 @@ int pci_mmap_page_range(struct pci_dev *
enum pci_mmap_state mmap_state,
int write_combine)
{
+ unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
int ret;

- ret = __pci_mmap_make_offset(dev, vma, mmap_state);
- if (ret < 0)
- return ret;
+ if (mmap_state == pci_mmap_io) {
+ struct pci_controller *pci_ctrl =
+ (struct pci_controller *)dev->sysdata;
+
+ /* pci_ctrl should never be NULL */
+ offset += pci_ctrl->io_space.start - pci_ctrl->io_space.base;
+ }
+
+ vma->vm_pgoff = offset >> PAGE_SHIFT;

__pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine);

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
@@ -967,12 +967,23 @@ void pci_remove_legacy_files(struct pci_
#ifdef HAVE_PCI_MMAP

int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_type,
enum pci_mmap_api mmap_api)
{
unsigned long nr, start, size, pci_start;
+ int flags;

if (pci_resource_len(pdev, resno) == 0)
return 0;
+
+ if (mmap_type == pci_mmap_mem)
+ flags = IORESOURCE_MEM;
+ else
+ flags = IORESOURCE_IO;
+
+ if (!(pci_resource_flags(pdev, resno) & flags))
+ return 0;
+
nr = vma_pages(vma);
start = vma->vm_pgoff;
size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
@@ -999,7 +1010,6 @@ 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++)
@@ -1011,7 +1021,8 @@ static int pci_mmap_resource(struct kobj
if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
return -EINVAL;

- if (!pci_mmap_fits(pdev, i, vma, PCI_MMAP_SYSFS)) {
+ mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
+ if (!pci_mmap_fits(pdev, i, vma, mmap_type, 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,
@@ -1020,13 +1031,7 @@ 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;
- mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
+ vma->vm_pgoff += res->start >> PAGE_SHIFT;
return pci_mmap_page_range(pdev, res, 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
@@ -227,26 +227,65 @@ static long proc_bus_pci_ioctl(struct fi
}

#ifdef HAVE_PCI_MMAP
+
+static int pci_user_to_resource(struct pci_dev *dev, resource_size_t *offset,
+ resource_size_t size, int flags)
+{
+ int i;
+
+ for (i = 0; i < PCI_ROM_RESOURCE; i++) {
+ resource_size_t start, end;
+ struct resource *res = &dev->resource[i];
+
+ if (!(res->flags & flags))
+ continue;
+
+ if (pci_resource_len(dev, i) == 0)
+ continue;
+
+ pci_resource_to_user(dev, i, res, &start, &end);
+ if (start <= *offset && (*offset + size - 1) <= end) {
+ *offset = res->start + (*offset - start);
+ return i;
+ }
+ }
+
+ return -ENODEV;
+}
+
static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
{
struct pci_dev *dev = PDE_DATA(file_inode(file));
struct pci_filp_private *fpriv = file->private_data;
- int i, ret;
+ enum pci_mmap_state mmap_type = fpriv->mmap_state;
+ resource_size_t offset, size;
+ int i, ret, flags;

if (!capable(CAP_SYS_RAWIO))
return -EPERM;

- /* Make sure the caller is mapping a real resource for this device */
- for (i = 0; i < PCI_ROM_RESOURCE; i++) {
- if (pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS))
- break;
- }
-
- if (i >= PCI_ROM_RESOURCE)
+ offset = vma->vm_pgoff << PAGE_SHIFT;
+ size = vma->vm_end - vma->vm_start;
+ if (mmap_type == pci_mmap_mem)
+ flags = IORESOURCE_MEM;
+ else
+ flags = IORESOURCE_IO;
+ i = pci_user_to_resource(dev, &offset, size, flags);
+ if (i < 0)
return -ENODEV;

+ vma->vm_pgoff = offset >> PAGE_SHIFT;
+ if (!pci_mmap_fits(dev, i, vma, mmap_type, PCI_MMAP_PROCFS)) {
+ 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(dev), i,
+ (u64)pci_resource_start(dev, i),
+ (u64)pci_resource_len(dev, i));
+ return -EINVAL;
+ }
+
ret = pci_mmap_page_range(dev, &dev->resource[i], vma,
- fpriv->mmap_state,
+ mmap_type,
fpriv->write_combine);
if (ret < 0)
return ret;