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SubjectRe: [PATCH v11 04/60] sparc/PCI: Use correct offset for bus address to resource
From
On Fri, Apr 29, 2016 at 12:19 AM, Yinghai Lu <yinghai@kernel.org> wrote:
> On Thu, Apr 28, 2016 at 6:56 AM, Bjorn Helgaas <helgaas@kernel.org> wrote:
>>
>> 1) The sysfs path uses offsets between 0 and BAR size. This path
>> should work identically on all arches. "User" addresses are not
>> involved, so it doesn't make sense that this path calls
>> pci_resource_to_user() from pci_mmap_resource().
>>
>> 2) The procfs path uses offsets of resource values (CPU physical
>> addresses) on most architectures. If some arches use something else,
>> e.g., "user" addresses, the grunge of dealing with them should be in
>> this path, i.e., in proc_bus_pci_mmap(). This implies that
>> pci_mmap_page_range() should deal with CPU physical addresses, not bus
>> addresses, and proc_bus_pci_mmap() should perform any necessary
>> translation.

Please check if following is what you want.

BenH and DavidM,
Are you ok to let /proc/bus/pci/devices to expose resource value instead of
BAR value?
powerpc already expose MMIO as resource value, but still keep IO as BAR value?

Or can we just dump /proc/bus/pci support from now?

Thanks

Yinghai


Subject: [RFC PATCH] PCI: Expose resource value in /proc/bus/pci/devices

Some arch where cpu address (resource value) is not same as pci bus address
(BAR value in pci BAR registers), include sparc, powerpc, microblaze.

Orignally in /proc/bus/pci/devices is exposing device BAR value aka is
user value. later in 396a1a5832 ("[POWERPC] Fix mmap of PCI resource with
hack for X"), in will change to use resource start instead.

Also 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. remove those non uniformed pci_resource_to_user.
2. in proc path: proc_bus_pci_mmap==>pci_mmap_fits/pci_mmap_page_range
all use resource start instead.
3. in sysfs path: pci_mmap_resource will just offset with resource start.
4. all pci_mmap_page_range will all have vma->vm_pgoff with in resource range
instead of BAR value.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
arch/microblaze/include/asm/pci.h | 5 ---
arch/microblaze/pci/pci-common.c | 53 ++------------------------------------
arch/mips/include/asm/pci.h | 12 --------
arch/powerpc/include/asm/pci.h | 5 ---
arch/powerpc/kernel/pci-common.c | 53 ++------------------------------------
arch/sparc/include/asm/pci_64.h | 5 ---
arch/sparc/kernel/pci.c | 43 ++++++------------------------
arch/xtensa/kernel/pci.c | 11 ++-----
drivers/pci/pci-sysfs.c | 13 ++-------
drivers/pci/proc.c | 16 ++++-------
include/linux/pci.h | 15 ----------
kernel/trace/trace_mmiotrace.c | 21 +++++----------
12 files changed, 37 insertions(+), 215 deletions(-)

Index: linux-2.6/arch/microblaze/include/asm/pci.h
===================================================================
--- linux-2.6.orig/arch/microblaze/include/asm/pci.h
+++ linux-2.6/arch/microblaze/include/asm/pci.h
@@ -81,11 +81,6 @@ extern pgprot_t pci_phys_mem_access_prot
unsigned long size,
pgprot_t prot);

-#define HAVE_ARCH_PCI_RESOURCE_TO_USER
-extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc,
- resource_size_t *start, resource_size_t *end);
-
extern void pcibios_setup_bus_devices(struct pci_bus *bus);
extern void pcibios_setup_bus_self(struct pci_bus *bus);

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;
}

@@ -467,45 +461,6 @@ int pci_mmap_legacy_page_range(struct pc
vma->vm_page_prot);
}

-void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc,
- resource_size_t *start, resource_size_t *end)
-{
- struct pci_controller *hose = pci_bus_to_host(dev->bus);
- resource_size_t offset = 0;
-
- if (hose == NULL)
- return;
-
- if (rsrc->flags & IORESOURCE_IO)
- offset = (unsigned long)hose->io_base_virt - _IO_BASE;
-
- /* We pass a fully fixed up address to userland for MMIO instead of
- * a BAR value because X is lame and expects to be able to use that
- * to pass to /dev/mem !
- *
- * That means that we'll have potentially 64 bits values where some
- * userland apps only expect 32 (like X itself since it thinks only
- * Sparc has 64 bits MMIO) but if we don't do that, we break it on
- * 32 bits CHRPs :-(
- *
- * 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().
- *
- * BenH.
- */
-#if 0
- else if (rsrc->flags & IORESOURCE_MEM)
- offset = hose->pci_mem_offset;
-#endif
-
- *start = rsrc->start - offset;
- *end = rsrc->end - offset;
-}
-
/**
* pci_process_bridge_OF_ranges - Parse PCI bridge resources from device tree
* @hose: newly allocated pci_controller to be setup
Index: linux-2.6/arch/mips/include/asm/pci.h
===================================================================
--- linux-2.6.orig/arch/mips/include/asm/pci.h
+++ linux-2.6/arch/mips/include/asm/pci.h
@@ -80,18 +80,6 @@ extern void pcibios_set_master(struct pc
extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);

-#define HAVE_ARCH_PCI_RESOURCE_TO_USER
-
-static inline void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc, resource_size_t *start,
- resource_size_t *end)
-{
- phys_addr_t size = resource_size(rsrc);
-
- *start = fixup_bigphys_addr(rsrc->start, size);
- *end = rsrc->start + size;
-}
-
/*
* Dynamic DMA mapping stuff.
* MIPS has everything mapped statically.
Index: linux-2.6/arch/powerpc/include/asm/pci.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/pci.h
+++ linux-2.6/arch/powerpc/include/asm/pci.h
@@ -135,11 +135,6 @@ extern pgprot_t pci_phys_mem_access_prot
unsigned long size,
pgprot_t prot);

-#define HAVE_ARCH_PCI_RESOURCE_TO_USER
-extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc,
- resource_size_t *start, resource_size_t *end);
-
extern resource_size_t pcibios_io_space_offset(struct pci_controller *hose);
extern void pcibios_setup_bus_devices(struct pci_bus *bus);
extern void pcibios_setup_bus_self(struct pci_bus *bus);
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;
}

@@ -606,45 +600,6 @@ int pci_mmap_legacy_page_range(struct pc
vma->vm_page_prot);
}

-void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc,
- resource_size_t *start, resource_size_t *end)
-{
- struct pci_controller *hose = pci_bus_to_host(dev->bus);
- resource_size_t offset = 0;
-
- if (hose == NULL)
- return;
-
- if (rsrc->flags & IORESOURCE_IO)
- offset = (unsigned long)hose->io_base_virt - _IO_BASE;
-
- /* We pass a fully fixed up address to userland for MMIO instead of
- * a BAR value because X is lame and expects to be able to use that
- * to pass to /dev/mem !
- *
- * That means that we'll have potentially 64 bits values where some
- * userland apps only expect 32 (like X itself since it thinks only
- * Sparc has 64 bits MMIO) but if we don't do that, we break it on
- * 32 bits CHRPs :-(
- *
- * 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().
- *
- * BenH.
- */
-#if 0
- else if (rsrc->flags & IORESOURCE_MEM)
- offset = hose->pci_mem_offset;
-#endif
-
- *start = rsrc->start - offset;
- *end = rsrc->end - offset;
-}
-
/**
* pci_process_bridge_OF_ranges - Parse PCI bridge resources from device tree
* @hose: newly allocated pci_controller to be setup
Index: linux-2.6/arch/sparc/include/asm/pci_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/pci_64.h
+++ linux-2.6/arch/sparc/include/asm/pci_64.h
@@ -53,11 +53,6 @@ static inline int pci_get_legacy_ide_irq
{
return PCI_IRQ_NONE;
}
-
-#define HAVE_ARCH_PCI_RESOURCE_TO_USER
-void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc,
- resource_size_t *start, resource_size_t *end);
#endif /* __KERNEL__ */

#endif /* __SPARC64_PCI_H */
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;
}

@@ -982,22 +973,6 @@ int pci64_dma_supported(struct pci_dev *
return (device_mask & dma_addr_mask) == dma_addr_mask;
}

-void pci_resource_to_user(const struct pci_dev *pdev, int bar,
- const struct resource *rp, resource_size_t *start,
- resource_size_t *end)
-{
- struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
- unsigned long offset;
-
- if (rp->flags & IORESOURCE_IO)
- offset = pbm->io_space.start;
- else
- offset = pbm->mem_space.start;
-
- *start = rp->start - offset;
- *end = rp->end - offset;
-}
-
void pcibios_set_master(struct pci_dev *dev)
{
/* No special bus mastering setup handling */
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
@@ -143,10 +143,9 @@ static ssize_t resource_show(struct devi

for (i = 0; i < max; i++) {
struct resource *res = &pci_dev->resource[i];
- pci_resource_to_user(pci_dev, i, res, &start, &end);
str += sprintf(str, "0x%016llx 0x%016llx 0x%016llx\n",
- (unsigned long long)start,
- (unsigned long long)end,
+ (unsigned long long)res->start,
+ (unsigned long long)res->end,
(unsigned long long)res->flags);
}
return (str - buf);
@@ -999,7 +998,6 @@ 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 +1018,7 @@ 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
@@ -343,20 +343,16 @@ static int show_device(struct seq_file *
dev->irq);

/* only print standard and ROM resources to preserve compatibility */
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- resource_size_t start, end;
- pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+ for (i = 0; i <= PCI_ROM_RESOURCE; i++)
seq_printf(m, "\t%16llx",
- (unsigned long long)(start |
+ (unsigned long long)(dev->resource[i].start |
(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
- }
- for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
- resource_size_t start, end;
- pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+
+ for (i = 0; i <= PCI_ROM_RESOURCE; i++)
seq_printf(m, "\t%16llx",
dev->resource[i].start < dev->resource[i].end ?
- (unsigned long long)(end - start) + 1 : 0);
- }
+ (unsigned long long)resource_size(&dev->resource[i]) : 0);
+
seq_putc(m, '\t');
if (drv)
seq_printf(m, "%s", drv->name);
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -1545,21 +1545,6 @@ static inline const char *pci_name(const
return dev_name(&pdev->dev);
}

-
-/* Some archs don't want to expose struct resource to userland as-is
- * in sysfs and /proc
- */
-#ifndef HAVE_ARCH_PCI_RESOURCE_TO_USER
-static inline void pci_resource_to_user(const struct pci_dev *dev, int bar,
- const struct resource *rsrc, resource_size_t *start,
- resource_size_t *end)
-{
- *start = rsrc->start;
- *end = rsrc->end;
-}
-#endif /* HAVE_ARCH_PCI_RESOURCE_TO_USER */
-
-
/*
* The world is not perfect and supplies us with broken PCI devices.
* For at least a part of these bugs we need a work-around, so both
Index: linux-2.6/kernel/trace/trace_mmiotrace.c
===================================================================
--- linux-2.6.orig/kernel/trace/trace_mmiotrace.c
+++ linux-2.6/kernel/trace/trace_mmiotrace.c
@@ -62,29 +62,22 @@ static void mmio_trace_start(struct trac
static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
{
int i;
- resource_size_t start, end;
const struct pci_driver *drv = pci_dev_driver(dev);

trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
dev->bus->number, dev->devfn,
dev->vendor, dev->device, dev->irq);
- /*
- * XXX: is pci_resource_to_user() appropriate, since we are
- * supposed to interpret the __ioremap() phys_addr argument based on
- * these printed values?
- */
- for (i = 0; i < 7; i++) {
- pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+
+ for (i = 0; i < 7; i++)
trace_seq_printf(s, " %llx",
- (unsigned long long)(start |
+ (unsigned long long)(dev->resource[i].start |
(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
- }
- for (i = 0; i < 7; i++) {
- pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
+
+ for (i = 0; i < 7; i++)
trace_seq_printf(s, " %llx",
dev->resource[i].start < dev->resource[i].end ?
- (unsigned long long)(end - start) + 1 : 0);
- }
+ (unsigned long long)resource_size(&dev->resource[i]) : 0);
+
if (drv)
trace_seq_printf(s, " %s\n", drv->name);
else
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