[PATCH v4 00/24] PCI: Convert all dynamic sysfs attributes to static

[PATCH v4 00/24] PCI: Convert all dynamic sysfs attributes to static

[Krzysztof Wilczyński]

Hello,

This series converts every dynamically allocated PCI sysfs attribute to
a static const definition.  After the full series, pci_sysfs_init() and
sysfs_initialized are gone, and every sysfs file is created by the
driver model at device_add() time.

Currently, the PCI resource files (resourceN, resourceN_wc) and the
legacy bus files (legacy_io, legacy_mem) are created dynamically
from two unsynchronised paths:

Path A: late_initcall

  pci_sysfs_init                        (late_initcall)
    sysfs_initialized = 1
    for_each_pci_dev
      pci_create_sysfs_dev_files
        sysfs_create_bin_file           (resourceN, resourceN_wc)
    pci_find_next_bus
      pci_create_legacy_files
        sysfs_create_bin_file           (legacy_io, legacy_mem)

Path B: device registration / hotplug

  pci_bus_add_devices
    pci_bus_add_device
      pci_create_sysfs_dev_files
        if (!sysfs_initialized) return  <- only guard
        sysfs_create_bin_file           (resourceN, resourceN_wc)

On most ACPI systems this does not race because PCI enumeration
completes at subsys_initcall time, before pci_sysfs_init() runs:

  subsys_initcall (level 4):
    acpi_pci_root_add
      pci_bus_add_device
        pci_create_sysfs_dev_files
          if (!sysfs_initialized)          <- not yet set
            return -EACCES

  late_initcall (level 7):
    pci_sysfs_init
      sysfs_initialized = 1
      for_each_pci_dev
        pci_create_sysfs_dev_files         <- creates the files, no race

On Devicetree platforms the host controller is a platform driver that
probes via the driver model, often on a workqueue, and overlaps with the
late_initcall:

  CPU 0 (late_initcall)                CPU 1 (driver probe)
  ---------------------------          ----------------------------
  pci_sysfs_init()
    sysfs_initialized = 1
    for_each_pci_dev(pdev)             pci_bus_add_device(pdev)
      pci_create_sysfs_dev_files()       pci_create_sysfs_dev_files()
        sysfs_create_bin_file()            sysfs_create_bin_file()
                                             -> "duplicate filename"

The same happens on ACPI when probing is asynchronous (hv_pci on
Azure, RISC-V with ACPI).

The duplicate causes sysfs_create_bin_file() to fail with -EEXIST.
pci_create_resource_files() then calls pci_remove_resource_files() in
its error unwind, tearing down files the other thread created and
still references through pdev->res_attr[].  This has caused kernel
panics on i.MX6 and boot failures on other platforms.

Several different fixes have been proposed over the years: reordering
the sysfs_initialized assignment, adding locks, checking
pci_dev_is_added(), setting pdev->res_attr[] to NULL after kfree
(which only prevents a double-free on the teardown path, not the
error unwind removing the other thread's files).  None would address the
root cause.

This has been reported a few times:

  - https://lore.kernel.org/linux-pci/20250702155112.40124-1-heshuan@bytedance.com/
  - https://lore.kernel.org/linux-pci/b51519d6-ce45-4b6d-8135-c70169bd110e@h-partners.com/
  - https://lore.kernel.org/linux-pci/1702093576-30405-1-git-send-email-ssengar@linux.microsoft.com/
  - https://lore.kernel.org/linux-pci/SY0P300MB04687548090B73E40AF97D8897B82@SY0P300MB0468.AUSP300.PROD.OUTLOOK.COM/
  - https://lore.kernel.org/linux-pci/20230105174736.GA1154719@bhelgaas/
  - https://lore.kernel.org/linux-pci/m3eebg9puj.fsf@t19.piap.pl/
  - https://lore.kernel.org/linux-pci/20200716110423.xtfyb3n6tn5ixedh@pali/
  - https://lore.kernel.org/linux-pci/1366196798-15929-1-git-send-email-artem.savkov@gmail.com/
  - https://bugzilla.kernel.org/show_bug.cgi?id=215515
  - https://bugzilla.kernel.org/show_bug.cgi?id=216888

With static attributes the driver model creates sysfs entries once per
device at device_add() time, under the device lock, eliminating the
late_initcall iteration and the race along with it.

	Krzysztof

---
Changes in v4:
  https://lore.kernel.org/linux-pci/20260410055040.39233-1-kwilczynski@kernel.org/

   - Added new Reviewed-by tags.
   - Added pci_resource_is_io() and pci_resource_is_mem() helpers
     for resource type checks, replacing the open-coded bitwise
     flag tests in pci_mmap_resource(), pci_resource_io(), and
     Alpha's pci_mmap_resource(), as per Ilpo Järvinen's
     suggestion.
   - Split the __pci_mmap_fits() cleanup into two patches.  An
     overflow fix for zero-length BARs, which now includes a
     Fixes: tag referencing the original Alpha PCI sysfs commit,
     and the WARN macro removal is a separate cleanup as per Ilpo
     Järvinen's suggestion.
   - Added a missing Fixes: tag to the Alpha lockdown check,
     referencing the commit that added the check to the generic
     path but missed Alpha's implementation.
   - Added PCI_LEGACY_IO_SIZE and PCI_LEGACY_MEM_SIZE macros to
     replace the raw literals used for legacy address space sizes.
     These are used in both Alpha's pci_mmap_legacy_page_range()
     and the static legacy attribute definitions, as per Ilpo
     Järvinen's suggestion.
   - Replaced sysfs_update_groups() in the BAR resize path with
     sysfs_remove_groups() before the resize and sysfs_create_groups()
     after, restoring the original teardown before BAR resize
     ordering.  This was reported by Sashiko, see:
     https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=7
   - Defined pci_dev_resource_attr_groups as a NULL macro when
     HAVE_PCI_MMAP and ARCH_GENERIC_PCI_MMAP_RESOURCE are both
     absent, so the resize path compiles unconditionally without
     #ifdef guards in the function body.  This was reported by
     Sashiko, see:
     https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=7
   - Moved the pci_legacy_has_sparse() prototype into the patch
     that introduces the function, alongside the existing
     pci_adjust_legacy_attr() declaration, to fix a bisection
     issue where Alpha would warn on -Wmissing-prototypes.
     This was reported by Sashiko, see:
     https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=18

Changes in v3:
  https://lore.kernel.org/linux-pci/20210910202623.2293708-1-kw@linux.com/

  - Updated for modern kernel releases and expanded scope.  The
    v2 only covered the generic resource files.  This version
    also converts Alpha's sparse/dense resource files and the
    legacy bus attributes, removing pci_sysfs_init() entirely.
  - Split the single macro definition into three distinct ones
    (per I/O, UC, and WC), to make sure that each carries only
    the callbacks its resource type needs.
  - Updated to use the new .bin_size callback, as the attributes
    are const, to replace using a->size directly, which was not
    ideal.  This required changes to pci_llseek_resource(), to
    ensure that it would work for device and bus-level attributes.
  - Updated the __resource_resize_store() to include CAP_SYS_ADMIN
    capabilities check.
  - Added the security_locked_down() check to Alpha's
    pci_mmap_resource(), to align with other architectures.

Changes in v2:
  https://lore.kernel.org/linux-pci/20210825212255.878043-1-kw@linux.com/

  - Refactored code so that the macros, helpers and internal
    functions can be used to correctly leverage the read(),
    write() and mmap() callbacks rather than to use the
    .is_bin_visible() callback to set up sysfs objects
    internals as this is not supported.
  - Refactored some if-statements to check for a resource
    flag first, and then call either arch_can_pci_mmap_io()
    or arch_can_pci_mmap_wc(), plus store result of testing
    for IORESOURCE_MEM and IORESOURCE_PREFETCH flags into
    a boolean variable, as per Bjorn Helgaas' suggestion.
  - Renamed pci_read_resource_io() and pci_write_resource_io()
    callbacks so that these are not specifically tied to I/O
    BARs read() and write() operations also as per Bjorn
    Helgaas' suggestion.
  - Updated style for code handling bitwise operations to
    match the style that is preferred as per Bjorn Helgaas'
    suggestion.
  - Updated commit messages adding more details about the
    implementation as requested by Bjorn Helgaas.

Krzysztof Wilczyński (24):
  PCI/sysfs: Use PCI resource accessor macros
  PCI: Add pci_resource_is_io() and pci_resource_is_mem() helpers
  PCI/sysfs: Only allow supported resource types in I/O and MMIO helpers
  PCI/sysfs: Use BAR length in pci_llseek_resource() when attr->size is
    zero
  PCI/sysfs: Add CAP_SYS_ADMIN check to __resource_resize_store()
  PCI/sysfs: Add static PCI resource attribute macros
  PCI/sysfs: Convert PCI resource files to static attributes
  PCI/sysfs: Convert __resource_resize_store() to use static attributes
  PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()
  PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope
  alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
  alpha/PCI: Use BAR index in sysfs attr->private instead of resource
    pointer
  alpha/PCI: Use PCI resource accessor macros
  alpha/PCI: Clean up pci_mmap_resource()
  alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs
  alpha/PCI: Remove WARN from __pci_mmap_fits()
  alpha/PCI: Add static PCI resource attribute macros
  alpha/PCI: Convert resource files to static attributes
  PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()
  PCI: Add macros for legacy I/O and memory address space sizes
  alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()
  PCI/sysfs: Add __weak pci_legacy_has_sparse() helper
  PCI/sysfs: Convert legacy I/O and memory attributes to static
    definitions
  PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()

 arch/alpha/include/asm/pci.h   |  13 +-
 arch/alpha/kernel/pci-sysfs.c  | 373 +++++++++++----------
 arch/powerpc/include/asm/pci.h |   2 -
 drivers/pci/bus.c              |   1 -
 drivers/pci/pci-sysfs.c        | 575 +++++++++++++++++++--------------
 drivers/pci/pci.h              |  16 +-
 drivers/pci/probe.c            |   6 -
 drivers/pci/remove.c           |   3 -
 include/linux/pci.h            |  39 ++-
 9 files changed, 578 insertions(+), 450 deletions(-)

-- 
2.53.0

[PATCH v4 01/24] PCI/sysfs: Use PCI resource accessor macros

[Krzysztof Wilczyński]

Replace direct pdev->resource[] accesses with pci_resource_n(),
and pdev->resource[].flags accesses with pci_resource_flags().

No functional changes intended.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 16eaaf749ba9..ad3c17f86c7f 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -177,7 +177,7 @@ static ssize_t resource_show(struct device *dev, struct device_attribute *attr,
 		max = PCI_BRIDGE_RESOURCES;
 
 	for (i = 0; i < max; i++) {
-		struct resource *res =  &pci_dev->resource[i];
+		struct resource *res = pci_resource_n(pci_dev, i);
 		struct resource zerores = {};
 
 		/* For backwards compatibility */
@@ -715,7 +715,7 @@ static ssize_t boot_vga_show(struct device *dev, struct device_attribute *attr,
 		return sysfs_emit(buf, "%u\n", (pdev == vga_dev));
 
 	return sysfs_emit(buf, "%u\n",
-			  !!(pdev->resource[PCI_ROM_RESOURCE].flags &
+			  !!(pci_resource_flags(pdev, PCI_ROM_RESOURCE) &
 			     IORESOURCE_ROM_SHADOW));
 }
 static DEVICE_ATTR_RO(boot_vga);
@@ -1108,7 +1108,7 @@ static int pci_mmap_resource(struct kobject *kobj, const struct bin_attribute *a
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 	int bar = (unsigned long)attr->private;
 	enum pci_mmap_state mmap_type;
-	struct resource *res = &pdev->resource[bar];
+	struct resource *res = pci_resource_n(pdev, bar);
 	int ret;
 
 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
@@ -1312,7 +1312,7 @@ static int pci_create_resource_files(struct pci_dev *pdev)
 		retval = pci_create_attr(pdev, i, 0);
 		/* for prefetchable resources, create a WC mappable file */
 		if (!retval && arch_can_pci_mmap_wc() &&
-		    pdev->resource[i].flags & IORESOURCE_PREFETCH)
+		    pci_resource_flags(pdev, i) & IORESOURCE_PREFETCH)
 			retval = pci_create_attr(pdev, i, 1);
 		if (retval) {
 			pci_remove_resource_files(pdev);
-- 
2.53.0

[PATCH v4 02/24] PCI: Add pci_resource_is_io() and pci_resource_is_mem() helpers

[Krzysztof Wilczyński]

Add helpers to check whether a PCI resource is of I/O port or
memory type.  These replace the open-coded pci_resource_flags()
with IORESOURCE_IO and IORESOURCE_MEM pattern used across the
tree.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 include/linux/pci.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 1c270f1d5123..05aceb7f1f37 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2295,6 +2295,31 @@ int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma);
 	CONCATENATE(__pci_dev_for_each_res, COUNT_ARGS(__VA_ARGS__)) 	\
 		    (dev, res, __VA_ARGS__)
 
+/**
+ * pci_resource_is_io - check if a PCI resource is of I/O port type.
+ * @dev: PCI device to check.
+ * @resno: The resource number (BAR index) to check.
+ *
+ * Returns true if the resource type is I/O port.
+ */
+static inline bool pci_resource_is_io(const struct pci_dev *dev, int resno)
+{
+	return resource_type(pci_resource_n(dev, resno)) == IORESOURCE_IO;
+}
+
+/**
+ * pci_resource_is_mem - check if a PCI resource is of memory type.
+ * @dev: PCI device to check.
+ * @resno: The resource number (BAR index) to check.
+ *
+ * Returns true if the resource type is memory, including
+ * prefetchable memory.
+ */
+static inline bool pci_resource_is_mem(const struct pci_dev *dev, int resno)
+{
+	return resource_type(pci_resource_n(dev, resno)) == IORESOURCE_MEM;
+}
+
 /*
  * Similar to the helpers above, these manipulate per-pci_dev
  * driver-specific data.  They are really just a wrapper around
-- 
2.53.0

[PATCH v4 03/24] PCI/sysfs: Only allow supported resource types in I/O and MMIO helpers

[Krzysztof Wilczyński]

Currently, when the sysfs attributes for PCI resources are added
dynamically, the resource access callbacks are only set when the
underlying BAR type matches, using .read and .write for IORESOURCE_IO,
and .mmap for IORESOURCE_MEM or IORESOURCE_IO with arch_can_pci_mmap_io()
support.  As such, when the callback is not set, the operation inherently
fails.

After the conversion to static attributes, visibility callbacks will
control which resource files appear for each BAR, but the callbacks
themselves will always be set.

Thus, add a type check to pci_resource_io() and pci_mmap_resource()
to return -EIO for an unsupported resource type.

Use the new pci_resource_is_io() and pci_resource_is_mem() helpers
for the type checks, replacing the open-coded bitwise flag tests and
also drop the local struct resource pointer in pci_mmap_resource().

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index ad3c17f86c7f..6783c6168445 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1108,20 +1108,24 @@ static int pci_mmap_resource(struct kobject *kobj, const struct bin_attribute *a
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 	int bar = (unsigned long)attr->private;
 	enum pci_mmap_state mmap_type;
-	struct resource *res = pci_resource_n(pdev, bar);
 	int ret;
 
 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
 	if (ret)
 		return ret;
 
-	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
+	if (!pci_resource_is_mem(pdev, bar) &&
+	    !(pci_resource_is_io(pdev, bar) && arch_can_pci_mmap_io()))
+		return -EIO;
+
+	if (pci_resource_is_mem(pdev, bar) &&
+	    iomem_is_exclusive(pci_resource_start(pdev, bar)))
 		return -EINVAL;
 
 	if (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS))
 		return -EINVAL;
 
-	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
+	mmap_type = pci_resource_is_mem(pdev, bar) ? pci_mmap_mem : pci_mmap_io;
 
 	return pci_mmap_resource_range(pdev, bar, vma, mmap_type, write_combine);
 }
@@ -1149,6 +1153,9 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
 	int bar = (unsigned long)attr->private;
 	unsigned long port = off;
 
+	if (!pci_resource_is_io(pdev, bar))
+		return -EIO;
+
 	port += pci_resource_start(pdev, bar);
 
 	if (port > pci_resource_end(pdev, bar))
-- 
2.53.0

[PATCH v4 04/24] PCI/sysfs: Use BAR length in pci_llseek_resource() when attr->size is zero

[Krzysztof Wilczyński]

Both legacy and resource attributes set .f_mapping = iomem_get_mapping,
so the default generic_file_llseek() would consult iomem_inode for the
file size, which knows nothing about the attribute.  That is why this
custom llseek callback exists.

Currently, the legacy and resource attributes have .size set at creation
time, as such, using the attr->size is sufficient.  However, the upcoming
static resource attributes will have .size == 0 set, since they are const,
and the .bin_size callback will be used to provide the real size to kernfs
instead.

Thus, update pci_llseek_resource() to derive the file size from the
BAR using pci_resource_len() instead of reading the attr->size directly.

The custom pci_llseek_resource() helper has been added in commit
24de09c16f97 ("PCI: Implement custom llseek for sysfs resource
entries").

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 6783c6168445..73a9ae9d289b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -909,11 +909,21 @@ static const struct attribute_group pci_dev_config_attr_group = {
  */
 static __maybe_unused loff_t
 pci_llseek_resource(struct file *filep,
-		    struct kobject *kobj __always_unused,
+		    struct kobject *kobj,
 		    const struct bin_attribute *attr,
 		    loff_t offset, int whence)
 {
-	return fixed_size_llseek(filep, offset, whence, attr->size);
+	struct pci_dev *pdev;
+	int bar;
+
+	if (attr->size)
+		return fixed_size_llseek(filep, offset, whence, attr->size);
+
+	pdev = to_pci_dev(kobj_to_dev(kobj));
+	bar = (unsigned long)attr->private;
+
+	return fixed_size_llseek(filep, offset, whence,
+				 pci_resource_len(pdev, bar));
 }
 
 #ifdef HAVE_PCI_LEGACY
-- 
2.53.0

[PATCH v4 05/24] PCI/sysfs: Add CAP_SYS_ADMIN check to __resource_resize_store()

[Krzysztof Wilczyński]

Currently, the __resource_resize_store() allows writing to the
resourceN_resize sysfs attribute to change a BAR's size without
checking for capabilities, currently relying only on the file
access check.

Resizing a BAR modifies PCI device configuration and can disrupt
active drivers.  After the upcoming conversion to static attributes,
it will also trigger resource file updates via sysfs_update_groups().

Thus, add a CAP_SYS_ADMIN check to prevent unprivileged users from
performing BAR resize operations.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 73a9ae9d289b..4f95b336cc34 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1619,6 +1619,9 @@ static ssize_t __resource_resize_store(struct device *dev, int n,
 	int ret;
 	u16 cmd;
 
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
 	if (kstrtoul(buf, 0, &size) < 0)
 		return -EINVAL;
 
-- 
2.53.0

[PATCH v4 06/24] PCI/sysfs: Add static PCI resource attribute macros

[Krzysztof Wilczyński]

Add three macros for declaring static binary attributes for PCI
resource files:

  - pci_dev_resource_io_attr(), for I/O BAR resources (read/write)
  - pci_dev_resource_uc_attr(), for memory BAR resources (mmap uncached)
  - pci_dev_resource_wc_attr(), for write-combine resources (mmap WC)

Each macro only sets the callbacks its resource type needs.  The I/O
macro conditionally includes mmap support via __PCI_RESOURCE_IO_MMAP_ATTRS
on architectures where arch_can_pci_mmap_io() is true at compile time
(such as PowerPC, SPARC, and Xtensa).

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 4f95b336cc34..ca0074674acc 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1220,6 +1220,47 @@ static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj,
 	return pci_resource_io(filp, kobj, attr, buf, off, count, true);
 }
 
+/*
+ * generic_file_llseek() consults f_mapping->host to determine
+ * the file size. As iomem_inode knows nothing about the
+ * attribute, it's not going to work, so override it as well.
+ */
+#if arch_can_pci_mmap_io()
+# define __PCI_RESOURCE_IO_MMAP_ATTRS		\
+	.f_mapping = iomem_get_mapping,		\
+	.llseek = pci_llseek_resource,		\
+	.mmap = pci_mmap_resource_uc,
+#else
+# define __PCI_RESOURCE_IO_MMAP_ATTRS
+#endif
+
+#define pci_dev_resource_io_attr(_bar)					\
+static const struct bin_attribute dev_resource##_bar##_io_attr = {	\
+	.attr = { .name = "resource" __stringify(_bar), .mode = 0600 },	\
+	.private = (void *)(unsigned long)(_bar),			\
+	.read = pci_read_resource,					\
+	.write = pci_write_resource,					\
+	__PCI_RESOURCE_IO_MMAP_ATTRS					\
+}
+
+#define pci_dev_resource_uc_attr(_bar)					\
+static const struct bin_attribute dev_resource##_bar##_uc_attr = {	\
+	.attr = { .name = "resource" __stringify(_bar), .mode = 0600 },	\
+	.private = (void *)(unsigned long)(_bar),			\
+	.f_mapping = iomem_get_mapping,					\
+	.llseek = pci_llseek_resource,					\
+	.mmap = pci_mmap_resource_uc,					\
+}
+
+#define pci_dev_resource_wc_attr(_bar)						\
+static const struct bin_attribute dev_resource##_bar##_wc_attr = {		\
+	.attr = { .name = "resource" __stringify(_bar) "_wc", .mode = 0600 },	\
+	.private = (void *)(unsigned long)(_bar),				\
+	.f_mapping = iomem_get_mapping,						\
+	.llseek = pci_llseek_resource,						\
+	.mmap = pci_mmap_resource_wc,						\
+}
+
 /**
  * pci_remove_resource_files - cleanup resource files
  * @pdev: dev to cleanup
-- 
2.53.0

[PATCH v4 07/24] PCI/sysfs: Convert PCI resource files to static attributes

[Krzysztof Wilczyński]

Currently, the PCI resource files (resourceN, resourceN_wc) are
dynamically created by pci_create_sysfs_dev_files(), called from
both pci_bus_add_device() and the pci_sysfs_init() late_initcall,
with only a sysfs_initialized flag for synchronisation.  This has
caused "duplicate filename" warnings and boot panics when both
paths race on the same device.

This is especially likely on Devicetree-based platforms, where the
PCI host controllers are platform drivers that probe via the driver
model, which can happen during or after the late_initcall.  As such,
pci_bus_add_device() and pci_sysfs_init() are more likely to overlap.

Thus, convert to static const attributes with three attribute groups
(I/O, UC, WC), each with an .is_bin_visible callback that checks
resource flags, BAR length, and non_mappable_bars.  A .bin_size
callback provides pci_resource_len() to the kernfs node for correct
stat and lseek behaviour.

As part of this conversion:

  - Rename pci_read_resource_io() and pci_write_resource_io() to
    pci_read_resource() and pci_write_resource() since the callbacks
    are no longer I/O-specific in the static attribute context.

  - Remove pci_create_resource_files(), pci_remove_resource_files(),
    and pci_create_attr() which are no longer needed.

  - Move the __weak stubs outside the #if guard so they remain
    available for callers converted in subsequent commits.

Platforms that do not define the HAVE_PCI_MMAP macro or the
ARCH_GENERIC_PCI_MMAP_RESOURCE macro, such as Alpha architecture,
continue using their platform-specific resource file creation.

For reference, the dynamic creation dates back to the pre-Git era:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/drivers/pci/pci-sysfs.c?id=42298be0eeb5ae98453b3374c36161b05a46c5dc

The write-combine support was added in commit 45aec1ae72fc ("x86: PAT
export resource_wc in pci sysfs").

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 242 +++++++++++++++++++++-------------------
 include/linux/pci.h     |   2 -
 2 files changed, 127 insertions(+), 117 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index ca0074674acc..2922905ff070 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1200,14 +1200,14 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
 #endif
 }
 
-static ssize_t pci_read_resource_io(struct file *filp, struct kobject *kobj,
+static ssize_t pci_read_resource(struct file *filp, struct kobject *kobj,
 				    const struct bin_attribute *attr, char *buf,
 				    loff_t off, size_t count)
 {
 	return pci_resource_io(filp, kobj, attr, buf, off, count, false);
 }
 
-static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj,
+static ssize_t pci_write_resource(struct file *filp, struct kobject *kobj,
 				     const struct bin_attribute *attr, char *buf,
 				     loff_t off, size_t count)
 {
@@ -1261,129 +1261,136 @@ static const struct bin_attribute dev_resource##_bar##_wc_attr = {		\
 	.mmap = pci_mmap_resource_wc,						\
 }
 
-/**
- * pci_remove_resource_files - cleanup resource files
- * @pdev: dev to cleanup
- *
- * If we created resource files for @pdev, remove them from sysfs and
- * free their resources.
- */
-static void pci_remove_resource_files(struct pci_dev *pdev)
+static inline umode_t
+__pci_resource_attr_is_visible(struct kobject *kobj,
+			       const struct bin_attribute *a,
+			       int bar, bool write_combine,
+			       unsigned long flags)
 {
-	int i;
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 
-	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
-		struct bin_attribute *res_attr;
-
-		res_attr = pdev->res_attr[i];
-		if (res_attr) {
-			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
-			kfree(res_attr);
-		}
-
-		res_attr = pdev->res_attr_wc[i];
-		if (res_attr) {
-			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
-			kfree(res_attr);
-		}
-	}
-}
-
-static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
-{
-	/* allocate attribute structure, piggyback attribute name */
-	int name_len = write_combine ? 13 : 10;
-	struct bin_attribute *res_attr;
-	char *res_attr_name;
-	int retval;
-
-	res_attr = kzalloc(sizeof(*res_attr) + name_len, GFP_ATOMIC);
-	if (!res_attr)
-		return -ENOMEM;
-
-	res_attr_name = (char *)(res_attr + 1);
-
-	sysfs_bin_attr_init(res_attr);
-	if (write_combine) {
-		sprintf(res_attr_name, "resource%d_wc", num);
-		res_attr->mmap = pci_mmap_resource_wc;
-	} else {
-		sprintf(res_attr_name, "resource%d", num);
-		if (pci_resource_flags(pdev, num) & IORESOURCE_IO) {
-			res_attr->read = pci_read_resource_io;
-			res_attr->write = pci_write_resource_io;
-			if (arch_can_pci_mmap_io())
-				res_attr->mmap = pci_mmap_resource_uc;
-		} else {
-			res_attr->mmap = pci_mmap_resource_uc;
-		}
-	}
-	if (res_attr->mmap) {
-		res_attr->f_mapping = iomem_get_mapping;
-		/*
-		 * generic_file_llseek() consults f_mapping->host to determine
-		 * the file size. As iomem_inode knows nothing about the
-		 * attribute, it's not going to work, so override it as well.
-		 */
-		res_attr->llseek = pci_llseek_resource;
-	}
-	res_attr->attr.name = res_attr_name;
-	res_attr->attr.mode = 0600;
-	res_attr->size = pci_resource_len(pdev, num);
-	res_attr->private = (void *)(unsigned long)num;
-	retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
-	if (retval) {
-		kfree(res_attr);
-		return retval;
-	}
-
-	if (write_combine)
-		pdev->res_attr_wc[num] = res_attr;
-	else
-		pdev->res_attr[num] = res_attr;
-
-	return 0;
-}
-
-/**
- * pci_create_resource_files - create resource files in sysfs for @dev
- * @pdev: dev in question
- *
- * Walk the resources in @pdev creating files for each resource available.
- */
-static int pci_create_resource_files(struct pci_dev *pdev)
-{
-	int i;
-	int retval;
-
-	/* Skip devices with non-mappable BARs */
 	if (pdev->non_mappable_bars)
 		return 0;
 
-	/* Expose the PCI resources from this device as files */
-	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
+	if (!pci_resource_len(pdev, bar))
+		return 0;
 
-		/* skip empty resources */
-		if (!pci_resource_len(pdev, i))
-			continue;
+	if ((pci_resource_flags(pdev, bar) & flags) != flags)
+		return 0;
 
-		retval = pci_create_attr(pdev, i, 0);
-		/* for prefetchable resources, create a WC mappable file */
-		if (!retval && arch_can_pci_mmap_wc() &&
-		    pci_resource_flags(pdev, i) & IORESOURCE_PREFETCH)
-			retval = pci_create_attr(pdev, i, 1);
-		if (retval) {
-			pci_remove_resource_files(pdev);
-			return retval;
-		}
-	}
-	return 0;
+	if (write_combine && !arch_can_pci_mmap_wc())
+		return 0;
+
+	return a->attr.mode;
 }
-#else /* !(defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)) */
-int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
-void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }
+
+static umode_t pci_dev_resource_io_is_visible(struct kobject *kobj,
+					      const struct bin_attribute *a,
+					      int n)
+{
+	return __pci_resource_attr_is_visible(kobj, a, n, false,
+					      IORESOURCE_IO);
+}
+
+static umode_t pci_dev_resource_uc_is_visible(struct kobject *kobj,
+					      const struct bin_attribute *a,
+					      int n)
+{
+	return __pci_resource_attr_is_visible(kobj, a, n, false,
+					      IORESOURCE_MEM);
+}
+
+static umode_t pci_dev_resource_wc_is_visible(struct kobject *kobj,
+					      const struct bin_attribute *a,
+					      int n)
+{
+	return __pci_resource_attr_is_visible(kobj, a, n, true,
+					      IORESOURCE_MEM | IORESOURCE_PREFETCH);
+}
+
+static size_t pci_dev_resource_bin_size(struct kobject *kobj,
+					const struct bin_attribute *a,
+					int n)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+	return pci_resource_len(pdev, n);
+}
+
+pci_dev_resource_io_attr(0);
+pci_dev_resource_io_attr(1);
+pci_dev_resource_io_attr(2);
+pci_dev_resource_io_attr(3);
+pci_dev_resource_io_attr(4);
+pci_dev_resource_io_attr(5);
+
+pci_dev_resource_uc_attr(0);
+pci_dev_resource_uc_attr(1);
+pci_dev_resource_uc_attr(2);
+pci_dev_resource_uc_attr(3);
+pci_dev_resource_uc_attr(4);
+pci_dev_resource_uc_attr(5);
+
+pci_dev_resource_wc_attr(0);
+pci_dev_resource_wc_attr(1);
+pci_dev_resource_wc_attr(2);
+pci_dev_resource_wc_attr(3);
+pci_dev_resource_wc_attr(4);
+pci_dev_resource_wc_attr(5);
+
+static const struct bin_attribute *const pci_dev_resource_io_attrs[] = {
+	&dev_resource0_io_attr,
+	&dev_resource1_io_attr,
+	&dev_resource2_io_attr,
+	&dev_resource3_io_attr,
+	&dev_resource4_io_attr,
+	&dev_resource5_io_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_dev_resource_uc_attrs[] = {
+	&dev_resource0_uc_attr,
+	&dev_resource1_uc_attr,
+	&dev_resource2_uc_attr,
+	&dev_resource3_uc_attr,
+	&dev_resource4_uc_attr,
+	&dev_resource5_uc_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_dev_resource_wc_attrs[] = {
+	&dev_resource0_wc_attr,
+	&dev_resource1_wc_attr,
+	&dev_resource2_wc_attr,
+	&dev_resource3_wc_attr,
+	&dev_resource4_wc_attr,
+	&dev_resource5_wc_attr,
+	NULL,
+};
+
+static const struct attribute_group pci_dev_resource_io_attr_group = {
+	.bin_attrs = pci_dev_resource_io_attrs,
+	.is_bin_visible = pci_dev_resource_io_is_visible,
+	.bin_size = pci_dev_resource_bin_size,
+};
+
+static const struct attribute_group pci_dev_resource_uc_attr_group = {
+	.bin_attrs = pci_dev_resource_uc_attrs,
+	.is_bin_visible = pci_dev_resource_uc_is_visible,
+	.bin_size = pci_dev_resource_bin_size,
+};
+
+static const struct attribute_group pci_dev_resource_wc_attr_group = {
+	.bin_attrs = pci_dev_resource_wc_attrs,
+	.is_bin_visible = pci_dev_resource_wc_is_visible,
+	.bin_size = pci_dev_resource_bin_size,
+};
+
 #endif
 
+int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
+void __weak pci_remove_resource_files(struct pci_dev *dev) { }
+
 /**
  * pci_write_rom - used to enable access to the PCI ROM display
  * @filp: sysfs file
@@ -1861,6 +1868,11 @@ static const struct attribute_group pci_dev_group = {
 
 const struct attribute_group *pci_dev_groups[] = {
 	&pci_dev_group,
+#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
+	&pci_dev_resource_io_attr_group,
+	&pci_dev_resource_uc_attr_group,
+	&pci_dev_resource_wc_attr_group,
+#endif
 	&pci_dev_config_attr_group,
 	&pci_dev_rom_attr_group,
 	&pci_dev_reset_attr_group,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 05aceb7f1f37..9c0782899ef9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2526,10 +2526,8 @@ int pcibios_alloc_irq(struct pci_dev *dev);
 void pcibios_free_irq(struct pci_dev *dev);
 resource_size_t pcibios_default_alignment(void);
 
-#if !defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
 extern int pci_create_resource_files(struct pci_dev *dev);
 extern void pci_remove_resource_files(struct pci_dev *dev);
-#endif
 
 #if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_MCFG)
 void __init pci_mmcfg_early_init(void);
-- 
2.53.0

[PATCH v4 08/24] PCI/sysfs: Convert __resource_resize_store() to use static attributes

[Krzysztof Wilczyński]

Currently, __resource_resize_store() calls pci_remove_resource_files()
and pci_create_resource_files() to tear down and recreate resource
files after a BAR resize.

Replace these with sysfs_remove_groups() before the resize and
sysfs_create_groups() after, which re-evaluates visibility and
runs the .bin_size callback for the static resource attribute
groups.  Also, add a warning if pci_resize_resource() fails to
expose potential failures.

For architectures without HAVE_PCI_MMAP or ARCH_GENERIC_PCI_MMAP_RESOURCE,
define pci_dev_resource_attr_groups as NULL so the resize path compiles
unconditionally and sysfs_remove_groups() and sysfs_create_groups() become
no-ops.

While at it, rename the resource_resize_is_visible() to
resource_resize_attr_is_visible() and the corresponding group variable
to align with the naming convention used by the resource attribute
groups.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 2922905ff070..c0925bdc9ecd 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1386,6 +1386,14 @@ static const struct attribute_group pci_dev_resource_wc_attr_group = {
 	.bin_size = pci_dev_resource_bin_size,
 };
 
+static const struct attribute_group *pci_dev_resource_attr_groups[] = {
+	&pci_dev_resource_io_attr_group,
+	&pci_dev_resource_uc_attr_group,
+	&pci_dev_resource_wc_attr_group,
+	NULL,
+};
+#else
+#define pci_dev_resource_attr_groups NULL
 #endif
 
 int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
@@ -1692,14 +1700,17 @@ static ssize_t __resource_resize_store(struct device *dev, int n,
 	pci_write_config_word(pdev, PCI_COMMAND,
 			      cmd & ~PCI_COMMAND_MEMORY);
 
-	pci_remove_resource_files(pdev);
+	sysfs_remove_groups(&pdev->dev.kobj, pci_dev_resource_attr_groups);
 
 	ret = pci_resize_resource(pdev, n, size, 0);
+	if (ret)
+		pci_warn(pdev, "Failed to resize BAR %d: %pe\n",
+			 n, ERR_PTR(ret));
 
 	pci_assign_unassigned_bus_resources(bus);
 
-	if (pci_create_resource_files(pdev))
-		pci_warn(pdev, "Failed to recreate resource files after BAR resizing\n");
+	if (sysfs_create_groups(&pdev->dev.kobj, pci_dev_resource_attr_groups))
+		pci_warn(pdev, "Failed to recreate resource groups after BAR resizing\n");
 
 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
 pm_put:
@@ -1742,7 +1753,7 @@ static struct attribute *resource_resize_attrs[] = {
 	NULL,
 };
 
-static umode_t resource_resize_is_visible(struct kobject *kobj,
+static umode_t resource_resize_attr_is_visible(struct kobject *kobj,
 					  struct attribute *a, int n)
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
@@ -1750,9 +1761,9 @@ static umode_t resource_resize_is_visible(struct kobject *kobj,
 	return pci_rebar_get_current_size(pdev, n) < 0 ? 0 : a->mode;
 }
 
-static const struct attribute_group pci_dev_resource_resize_group = {
+static const struct attribute_group pci_dev_resource_resize_attr_group = {
 	.attrs = resource_resize_attrs,
-	.is_visible = resource_resize_is_visible,
+	.is_visible = resource_resize_attr_is_visible,
 };
 
 int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
@@ -1873,6 +1884,7 @@ const struct attribute_group *pci_dev_groups[] = {
 	&pci_dev_resource_uc_attr_group,
 	&pci_dev_resource_wc_attr_group,
 #endif
+	&pci_dev_resource_resize_attr_group,
 	&pci_dev_config_attr_group,
 	&pci_dev_rom_attr_group,
 	&pci_dev_reset_attr_group,
@@ -1884,7 +1896,6 @@ const struct attribute_group *pci_dev_groups[] = {
 #ifdef CONFIG_ACPI
 	&pci_dev_acpi_attr_group,
 #endif
-	&pci_dev_resource_resize_group,
 	ARCH_PCI_DEV_GROUPS
 	NULL,
 };
-- 
2.53.0

[PATCH v4 09/24] PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()

[Krzysztof Wilczyński]

On platforms with HAVE_PCI_MMAP or ARCH_GENERIC_PCI_MMAP_RESOURCE,
resource files are now handled by static attribute groups registered
via pci_dev_groups[].

Thus, the pci_create_sysfs_dev_files() and pci_remove_sysfs_dev_files()
can now be stubbed out, as the dynamic resource file creation is no
longer needed.

Also, simplify pci_sysfs_init() on these platforms to only iterate
buses for legacy attributes creation, skipping the per-device loop.

Move the __weak stubs for pci_create_resource_files() and
pci_remove_resource_files() into the #else branch since only platforms
without HAVE_PCI_MMAP (such as Alpha architecture) still need them.
Guard the res_attr[] and res_attr_wc[] fields in struct pci_dev the
same way.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 15 ++++++++++++---
 include/linux/pci.h     |  4 ++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index c0925bdc9ecd..517efb6d71cc 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1394,10 +1394,9 @@ static const struct attribute_group *pci_dev_resource_attr_groups[] = {
 };
 #else
 #define pci_dev_resource_attr_groups NULL
-#endif
-
 int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
 void __weak pci_remove_resource_files(struct pci_dev *dev) { }
+#endif
 
 /**
  * pci_write_rom - used to enable access to the PCI ROM display
@@ -1766,6 +1765,10 @@ static const struct attribute_group pci_dev_resource_resize_attr_group = {
 	.is_visible = resource_resize_attr_is_visible,
 };
 
+#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
+int pci_create_sysfs_dev_files(struct pci_dev *pdev) { return 0; }
+void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
+#else
 int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
 {
 	if (!sysfs_initialized)
@@ -1787,9 +1790,15 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 
 	pci_remove_resource_files(pdev);
 }
+#endif
 
 static int __init pci_sysfs_init(void)
 {
+#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
+	struct pci_bus *pbus = NULL;
+
+	sysfs_initialized = 1;
+#else
 	struct pci_dev *pdev = NULL;
 	struct pci_bus *pbus = NULL;
 	int retval;
@@ -1802,7 +1811,7 @@ static int __init pci_sysfs_init(void)
 			return retval;
 		}
 	}
-
+#endif
 	while ((pbus = pci_find_next_bus(pbus)))
 		pci_create_legacy_files(pbus);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9c0782899ef9..30aeb8e02b7b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -507,8 +507,10 @@ struct pci_dev {
 	spinlock_t	pcie_cap_lock;		/* Protects RMW ops in capability accessors */
 	u32		saved_config_space[16]; /* Config space saved at suspend time */
 	struct hlist_head saved_cap_space;
+#if !defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
 	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
 	struct bin_attribute *res_attr_wc[DEVICE_COUNT_RESOURCE]; /* sysfs file for WC mapping of resources */
+#endif
 
 #ifdef CONFIG_HOTPLUG_PCI_PCIE
 	unsigned int	broken_cmd_compl:1;	/* No compl for some cmds */
@@ -2526,8 +2528,10 @@ int pcibios_alloc_irq(struct pci_dev *dev);
 void pcibios_free_irq(struct pci_dev *dev);
 resource_size_t pcibios_default_alignment(void);
 
+#if !defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
 extern int pci_create_resource_files(struct pci_dev *dev);
 extern void pci_remove_resource_files(struct pci_dev *dev);
+#endif
 
 #if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_MCFG)
 void __init pci_mmcfg_early_init(void);
-- 
2.53.0

[PATCH v4 10/24] PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope

[Krzysztof Wilczyński]

Currently, pci_sysfs_init() and sysfs_initialized compile
unconditionally, even on platforms where static attribute
groups handle all resource file creation.

Thus, place them behind a new HAVE_PCI_SYSFS_INIT macro,
especially as the late_initcall is only needed when:

  - HAVE_PCI_LEGACY is set, to iterate buses and create legacy
    I/O and memory files.

  - Neither HAVE_PCI_MMAP nor ARCH_GENERIC_PCI_MMAP_RESOURCE is
    set, to iterate devices and create resource files via the
    __weak pci_create_resource_files() stub override (this is
    how the Alpha architecture handles this currently).

On most systems both conditions are false and the entire
late_initcall compiles away.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 517efb6d71cc..d22bc5c48bc0 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -37,7 +37,14 @@
 #define ARCH_PCI_DEV_GROUPS
 #endif
 
+#if defined(HAVE_PCI_LEGACY) || \
+	!defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
+#define HAVE_PCI_SYSFS_INIT
+#endif
+
+#ifdef HAVE_PCI_SYSFS_INIT
 static int sysfs_initialized;	/* = 0 */
+#endif
 
 /* show configuration fields */
 #define pci_config_attr(field, format_string)				\
@@ -1792,6 +1799,7 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 }
 #endif
 
+#ifdef HAVE_PCI_SYSFS_INIT
 static int __init pci_sysfs_init(void)
 {
 #if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
@@ -1818,6 +1826,7 @@ static int __init pci_sysfs_init(void)
 	return 0;
 }
 late_initcall(pci_sysfs_init);
+#endif
 
 static struct attribute *pci_dev_dev_attrs[] = {
 	&dev_attr_boot_vga.attr,
-- 
2.53.0

[PATCH v4 11/24] alpha/PCI: Add security_locked_down() check to pci_mmap_resource()

[Krzysztof Wilczyński]

Currently, Alpha's pci_mmap_resource() does not check
security_locked_down(LOCKDOWN_PCI_ACCESS) before allowing
userspace to mmap PCI BARs.

The generic version has had this check since commit eb627e17727e
("PCI: Lock down BAR access when the kernel is locked down") to
prevent DMA attacks when the kernel is locked down.

Add the same check to Alpha's pci_mmap_resource().

Fixes: eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 3048758304b5..2324720c3e83 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/security.h>
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
@@ -71,7 +72,11 @@ static int pci_mmap_resource(struct kobject *kobj,
 	struct resource *res = attr->private;
 	enum pci_mmap_state mmap_type;
 	struct pci_bus_region bar;
-	int i;
+	int i, ret;
+
+	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < PCI_STD_NUM_BARS; i++)
 		if (res == &pdev->resource[i])
-- 
2.53.0

[PATCH v4 12/24] alpha/PCI: Use BAR index in sysfs attr->private instead of resource pointer

[Krzysztof Wilczyński]

Currently, Alpha's pci_create_one_attr() stores a resource pointer in
attr->private, and pci_mmap_resource() loops through all BARs to find
the matching index.

Thus, store the BAR index directly in attr->private and retrieve the
resource via pci_resource_n().  This eliminates the loop and aligns
with the convention used by the generic PCI sysfs code.

While at it, add parentheses around the bitwise flag test in
pci_mmap_resource() to make the precedence explicit, and to
match the preferred style.

The PCI core change was first added in the commit dca40b186b75 ("PCI:
Use BAR index in sysfs attr->private instead of resource pointer").

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 2324720c3e83..c84867ce31f5 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -69,25 +69,20 @@ static int pci_mmap_resource(struct kobject *kobj,
 			     struct vm_area_struct *vma, int sparse)
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
-	struct resource *res = attr->private;
+	int barno = (unsigned long)attr->private;
+	struct resource *res = pci_resource_n(pdev, barno);
 	enum pci_mmap_state mmap_type;
 	struct pci_bus_region bar;
-	int i, ret;
+	int ret;
 
 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < PCI_STD_NUM_BARS; i++)
-		if (res == &pdev->resource[i])
-			break;
-	if (i >= PCI_STD_NUM_BARS)
-		return -ENODEV;
-
-	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
+	if ((res->flags & IORESOURCE_MEM) && iomem_is_exclusive(res->start))
 		return -EINVAL;
 
-	if (!__pci_mmap_fits(pdev, i, vma, sparse))
+	if (!__pci_mmap_fits(pdev, barno, vma, sparse))
 		return -EINVAL;
 
 	pcibios_resource_to_bus(pdev->bus, &bar, res);
@@ -170,7 +165,7 @@ static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,
 	res_attr->attr.name = name;
 	res_attr->attr.mode = S_IRUSR | S_IWUSR;
 	res_attr->size = sparse ? size << 5 : size;
-	res_attr->private = &pdev->resource[num];
+	res_attr->private = (void *)(unsigned long)num;
 	return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
 }
 
-- 
2.53.0

[PATCH v4 13/24] alpha/PCI: Use PCI resource accessor macros

[Krzysztof Wilczyński]

Replace direct pdev->resource[] accesses with pci_resource_n(),
and pdev->resource[].flags accesses with pci_resource_flags().

No functional changes intended.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index c84867ce31f5..7aac5e76dcd6 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -141,7 +141,7 @@ static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
 	long dense_offset;
 	unsigned long sparse_size;
 
-	pcibios_resource_to_bus(pdev->bus, &bar, &pdev->resource[num]);
+	pcibios_resource_to_bus(pdev->bus, &bar, pci_resource_n(pdev, num));
 
 	/* All core logic chips have 4G sparse address space, except
 	   CIA which has 16G (see xxx_SPARSE_MEM and xxx_DENSE_MEM
@@ -181,7 +181,7 @@ static int pci_create_attr(struct pci_dev *pdev, int num)
 	suffix = "";	/* Assume bwx machine, normal resourceN files. */
 	nlen1 = 10;
 
-	if (pdev->resource[num].flags & IORESOURCE_MEM) {
+	if (pci_resource_flags(pdev, num) & IORESOURCE_MEM) {
 		sparse_base = hose->sparse_mem_base;
 		dense_base = hose->dense_mem_base;
 		if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {
-- 
2.53.0

[PATCH v4 14/24] alpha/PCI: Clean up pci_mmap_resource()

[Krzysztof Wilczyński]

Replace open-coded res->flags type checks with new pci_resource_is_mem()
and pci_resource_start() helpers.  Move the pci_resource_n() call into
pcibios_resource_to_bus() and drop the local struct resource pointer.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 7aac5e76dcd6..6c011dab326d 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -70,7 +70,6 @@ static int pci_mmap_resource(struct kobject *kobj,
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 	int barno = (unsigned long)attr->private;
-	struct resource *res = pci_resource_n(pdev, barno);
 	enum pci_mmap_state mmap_type;
 	struct pci_bus_region bar;
 	int ret;
@@ -79,15 +78,16 @@ static int pci_mmap_resource(struct kobject *kobj,
 	if (ret)
 		return ret;
 
-	if ((res->flags & IORESOURCE_MEM) && iomem_is_exclusive(res->start))
+	if (pci_resource_is_mem(pdev, barno) &&
+	    iomem_is_exclusive(pci_resource_start(pdev, barno)))
 		return -EINVAL;
 
 	if (!__pci_mmap_fits(pdev, barno, vma, sparse))
 		return -EINVAL;
 
-	pcibios_resource_to_bus(pdev->bus, &bar, res);
+	pcibios_resource_to_bus(pdev->bus, &bar, pci_resource_n(pdev, barno));
 	vma->vm_pgoff += bar.start >> (PAGE_SHIFT - (sparse ? 5 : 0));
-	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
+	mmap_type = pci_resource_is_mem(pdev, barno) ? pci_mmap_mem : pci_mmap_io;
 
 	return hose_mmap_page_range(pdev->sysdata, vma, mmap_type, sparse);
 }
-- 
2.53.0

[PATCH v4 15/24] alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs

[Krzysztof Wilczyński]

Currently, __pci_mmap_fits() computes the BAR size using
pci_resource_len() - 1, which wraps to a large value when the
BAR length is zero, causing the bounds check to incorrectly
succeed.

Thus, add an early return for empty resources.

Fixes: 10a0ef39fbd1 ("PCI/alpha: pci sysfs resources")
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 6c011dab326d..2748000a7486 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -37,12 +37,16 @@ static int hose_mmap_page_range(struct pci_controller *hose,
 static int __pci_mmap_fits(struct pci_dev *pdev, int num,
 			   struct vm_area_struct *vma, int sparse)
 {
+	resource_size_t len = pci_resource_len(pdev, num);
 	unsigned long nr, start, size;
 	int shift = sparse ? 5 : 0;
 
+	if (!len)
+		return 0;
+
 	nr = vma_pages(vma);
 	start = vma->vm_pgoff;
-	size = ((pci_resource_len(pdev, num) - 1) >> (PAGE_SHIFT - shift)) + 1;
+	size = ((len - 1) >> (PAGE_SHIFT - shift)) + 1;
 
 	if (start < size && size - start >= nr)
 		return 1;
-- 
2.53.0

[PATCH v4 16/24] alpha/PCI: Remove WARN from __pci_mmap_fits()

[Krzysztof Wilczyński]

Remove the WARN() that fires when userspace attempts to mmap beyond
the BAR bounds.  The check still returns 0 to reject the mapping,
but the warning is excessive for normal operation.

A similar warning was removed from the PCI core in the commit
3b519e4ea618 ("PCI: fix size checks for mmap() on /proc/bus/pci files").

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 2748000a7486..c136603ddf2c 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -48,13 +48,7 @@ static int __pci_mmap_fits(struct pci_dev *pdev, int num,
 	start = vma->vm_pgoff;
 	size = ((len - 1) >> (PAGE_SHIFT - shift)) + 1;
 
-	if (start < size && size - start >= nr)
-		return 1;
-	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "
-		"(size 0x%08lx)\n",
-		current->comm, sparse ? " sparse" : "", start, start + nr,
-		pci_name(pdev), num, size);
-	return 0;
+	return start < size && size - start >= nr;
 }
 
 /**
-- 
2.53.0

[PATCH v4 17/24] alpha/PCI: Add static PCI resource attribute macros

[Krzysztof Wilczyński]

Add macros for declaring static binary attributes for Alpha's PCI
resource files:

  - pci_dev_resource_attr(),        for dense/BWX systems (mmap dense)
  - pci_dev_resource_sparse_attr(), for sparse systems (mmap sparse)
  - pci_dev_resource_dense_attr(),  for dense companion files (mmap dense)

Each macro creates a const bin_attribute with the BAR index stored in
the .private property and the appropriate .mmap callback.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index c136603ddf2c..824e514c4adb 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -104,6 +104,26 @@ static int pci_mmap_resource_dense(struct file *filp, struct kobject *kobj,
 	return pci_mmap_resource(kobj, attr, vma, 0);
 }
 
+#define __pci_dev_resource_attr(_bar, _name, _suffix, _mmap)		\
+static const struct bin_attribute					\
+pci_dev_resource##_bar##_suffix##_attr = {				\
+	.attr = { .name = __stringify(_name), .mode = 0600 },		\
+	.private = (void *)(unsigned long)(_bar),			\
+	.mmap = (_mmap),						\
+}
+
+#define pci_dev_resource_attr(_bar)					\
+	__pci_dev_resource_attr(_bar, resource##_bar,,			\
+			    pci_mmap_resource_dense)
+
+#define pci_dev_resource_sparse_attr(_bar)				\
+	__pci_dev_resource_attr(_bar, resource##_bar##_sparse, _sparse,	\
+			    pci_mmap_resource_sparse)
+
+#define pci_dev_resource_dense_attr(_bar)				\
+	__pci_dev_resource_attr(_bar, resource##_bar##_dense, _dense,	\
+			    pci_mmap_resource_dense)
+
 /**
  * pci_remove_resource_files - cleanup resource files
  * @pdev: pci_dev to cleanup
-- 
2.53.0

[PATCH v4 18/24] alpha/PCI: Convert resource files to static attributes

[Krzysztof Wilczyński]

Currently, Alpha's PCI resource files (resourceN, resourceN_sparse,
resourceN_dense) are dynamically created by pci_create_resource_files(),
which overrides the generic __weak implementation.  The current code
allocates bin_attributes at runtime and manages them via the res_attr[]
and res_attr_wc[] fields in struct pci_dev.

Thus, convert to static const attributes with three attribute groups
(plain, sparse, dense), each with an .is_bin_visible callback that
checks resource length, has_sparse(), and sparse_mem_mmap_fits().  A
.bin_size callback provides the resource size to the kernfs node, with
the sparse variant shifting by 5 bits for byte-level addressing.

Register the groups via ARCH_PCI_DEV_GROUPS so the driver model handles
creation and removal automatically.

Use the new pci_resource_is_mem() helper for the type check, replacing
the open-coded bitwise flag test.

Finally, remove pci_create_resource_files(), pci_remove_resource_files(),
pci_create_attr(), and pci_create_one_attr() which are no longer needed.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/include/asm/pci.h  |   9 ++
 arch/alpha/kernel/pci-sysfs.c | 291 +++++++++++++++++++---------------
 2 files changed, 172 insertions(+), 128 deletions(-)

diff --git a/arch/alpha/include/asm/pci.h b/arch/alpha/include/asm/pci.h
index 6c04fcbdc8ed..ef19295f2e33 100644
--- a/arch/alpha/include/asm/pci.h
+++ b/arch/alpha/include/asm/pci.h
@@ -88,4 +88,13 @@ extern void pci_adjust_legacy_attr(struct pci_bus *bus,
 				   enum pci_mmap_state mmap_type);
 #define HAVE_PCI_LEGACY	1
 
+extern const struct attribute_group pci_dev_resource_attr_group;
+extern const struct attribute_group pci_dev_resource_sparse_attr_group;
+extern const struct attribute_group pci_dev_resource_dense_attr_group;
+
+#define ARCH_PCI_DEV_GROUPS		\
+	&pci_dev_resource_attr_group,	\
+	&pci_dev_resource_sparse_attr_group,	\
+	&pci_dev_resource_dense_attr_group,
+
 #endif /* __ALPHA_PCI_H */
diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 824e514c4adb..2e9693e5abe1 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -12,8 +12,6 @@
 
 #include <linux/sched.h>
 #include <linux/security.h>
-#include <linux/stat.h>
-#include <linux/slab.h>
 #include <linux/pci.h>
 
 static int hose_mmap_page_range(struct pci_controller *hose,
@@ -124,34 +122,6 @@ pci_dev_resource##_bar##_suffix##_attr = {				\
 	__pci_dev_resource_attr(_bar, resource##_bar##_dense, _dense,	\
 			    pci_mmap_resource_dense)
 
-/**
- * pci_remove_resource_files - cleanup resource files
- * @pdev: pci_dev to cleanup
- *
- * If we created resource files for @dev, remove them from sysfs and
- * free their resources.
- */
-void pci_remove_resource_files(struct pci_dev *pdev)
-{
-	int i;
-
-	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
-		struct bin_attribute *res_attr;
-
-		res_attr = pdev->res_attr[i];
-		if (res_attr) {
-			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
-			kfree(res_attr);
-		}
-
-		res_attr = pdev->res_attr_wc[i];
-		if (res_attr) {
-			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
-			kfree(res_attr);
-		}
-	}
-}
-
 static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
 {
 	struct pci_bus_region bar;
@@ -171,104 +141,6 @@ static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
 	return bar.end < sparse_size;
 }
 
-static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,
-			       char *suffix, struct bin_attribute *res_attr,
-			       unsigned long sparse)
-{
-	size_t size = pci_resource_len(pdev, num);
-
-	sprintf(name, "resource%d%s", num, suffix);
-	res_attr->mmap = sparse ? pci_mmap_resource_sparse :
-				  pci_mmap_resource_dense;
-	res_attr->attr.name = name;
-	res_attr->attr.mode = S_IRUSR | S_IWUSR;
-	res_attr->size = sparse ? size << 5 : size;
-	res_attr->private = (void *)(unsigned long)num;
-	return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
-}
-
-static int pci_create_attr(struct pci_dev *pdev, int num)
-{
-	/* allocate attribute structure, piggyback attribute name */
-	int retval, nlen1, nlen2 = 0, res_count = 1;
-	unsigned long sparse_base, dense_base;
-	struct bin_attribute *attr;
-	struct pci_controller *hose = pdev->sysdata;
-	char *suffix, *attr_name;
-
-	suffix = "";	/* Assume bwx machine, normal resourceN files. */
-	nlen1 = 10;
-
-	if (pci_resource_flags(pdev, num) & IORESOURCE_MEM) {
-		sparse_base = hose->sparse_mem_base;
-		dense_base = hose->dense_mem_base;
-		if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {
-			sparse_base = 0;
-			suffix = "_dense";
-			nlen1 = 16;	/* resourceN_dense */
-		}
-	} else {
-		sparse_base = hose->sparse_io_base;
-		dense_base = hose->dense_io_base;
-	}
-
-	if (sparse_base) {
-		suffix = "_sparse";
-		nlen1 = 17;
-		if (dense_base) {
-			nlen2 = 16;	/* resourceN_dense */
-			res_count = 2;
-		}
-	}
-
-	attr = kzalloc(sizeof(*attr) * res_count + nlen1 + nlen2, GFP_ATOMIC);
-	if (!attr)
-		return -ENOMEM;
-
-	/* Create bwx, sparse or single dense file */
-	attr_name = (char *)(attr + res_count);
-	pdev->res_attr[num] = attr;
-	retval = pci_create_one_attr(pdev, num, attr_name, suffix, attr,
-				     sparse_base);
-	if (retval || res_count == 1)
-		return retval;
-
-	/* Create dense file */
-	attr_name += nlen1;
-	attr++;
-	pdev->res_attr_wc[num] = attr;
-	return pci_create_one_attr(pdev, num, attr_name, "_dense", attr, 0);
-}
-
-/**
- * pci_create_resource_files - create resource files in sysfs for @pdev
- * @pdev: pci_dev in question
- *
- * Walk the resources in @dev creating files for each resource available.
- *
- * Return: %0 on success, or negative error code
- */
-int pci_create_resource_files(struct pci_dev *pdev)
-{
-	int i;
-	int retval;
-
-	/* Expose the PCI resources from this device as files */
-	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
-
-		/* skip empty resources */
-		if (!pci_resource_len(pdev, i))
-			continue;
-
-		retval = pci_create_attr(pdev, i);
-		if (retval) {
-			pci_remove_resource_files(pdev);
-			return retval;
-		}
-	}
-	return 0;
-}
-
 /* Legacy I/O bus mapping stuff. */
 
 static int __legacy_mmap_fits(struct pci_controller *hose,
@@ -388,3 +260,166 @@ int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
 	}
 	return -EINVAL;
 }
+
+pci_dev_resource_attr(0);
+pci_dev_resource_attr(1);
+pci_dev_resource_attr(2);
+pci_dev_resource_attr(3);
+pci_dev_resource_attr(4);
+pci_dev_resource_attr(5);
+
+pci_dev_resource_sparse_attr(0);
+pci_dev_resource_sparse_attr(1);
+pci_dev_resource_sparse_attr(2);
+pci_dev_resource_sparse_attr(3);
+pci_dev_resource_sparse_attr(4);
+pci_dev_resource_sparse_attr(5);
+
+pci_dev_resource_dense_attr(0);
+pci_dev_resource_dense_attr(1);
+pci_dev_resource_dense_attr(2);
+pci_dev_resource_dense_attr(3);
+pci_dev_resource_dense_attr(4);
+pci_dev_resource_dense_attr(5);
+
+static inline enum pci_mmap_state pci_bar_mmap_type(struct pci_dev *pdev,
+						    int bar)
+{
+	return pci_resource_is_mem(pdev, bar) ? pci_mmap_mem : pci_mmap_io;
+}
+
+static inline umode_t __pci_dev_resource_is_visible(struct kobject *kobj,
+						    const struct bin_attribute *a,
+						    int bar)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+	if (!pci_resource_len(pdev, bar))
+		return 0;
+
+	return a->attr.mode;
+}
+
+static umode_t pci_dev_resource_is_visible(struct kobject *kobj,
+					   const struct bin_attribute *a,
+					   int bar)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+	struct pci_controller *hose = pdev->sysdata;
+
+	if (has_sparse(hose, pci_bar_mmap_type(pdev, bar)))
+		return 0;
+
+	return __pci_dev_resource_is_visible(kobj, a, bar);
+}
+
+static umode_t pci_dev_resource_sparse_is_visible(struct kobject *kobj,
+						  const struct bin_attribute *a,
+						  int bar)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+	struct pci_controller *hose = pdev->sysdata;
+	enum pci_mmap_state type = pci_bar_mmap_type(pdev, bar);
+
+	if (!has_sparse(hose, type))
+		return 0;
+
+	if (type == pci_mmap_mem && !sparse_mem_mmap_fits(pdev, bar))
+		return 0;
+
+	return __pci_dev_resource_is_visible(kobj, a, bar);
+}
+
+static umode_t pci_dev_resource_dense_is_visible(struct kobject *kobj,
+						 const struct bin_attribute *a,
+						 int bar)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+	struct pci_controller *hose = pdev->sysdata;
+	enum pci_mmap_state type = pci_bar_mmap_type(pdev, bar);
+	unsigned long dense_base;
+
+	if (!has_sparse(hose, type))
+		return 0;
+
+	if (type == pci_mmap_mem && !sparse_mem_mmap_fits(pdev, bar))
+		return __pci_dev_resource_is_visible(kobj, a, bar);
+
+	dense_base = (type == pci_mmap_mem) ? hose->dense_mem_base :
+					      hose->dense_io_base;
+	if (!dense_base)
+		return 0;
+
+	return __pci_dev_resource_is_visible(kobj, a, bar);
+}
+
+static inline size_t __pci_dev_resource_bin_size(struct kobject *kobj,
+						 int bar, bool sparse)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+	size_t size = pci_resource_len(pdev, bar);
+
+	return sparse ? size << 5 : size;
+}
+
+static size_t pci_dev_resource_bin_size(struct kobject *kobj,
+					const struct bin_attribute *a,
+					int bar)
+{
+	return __pci_dev_resource_bin_size(kobj, bar, false);
+}
+
+static size_t pci_dev_resource_sparse_bin_size(struct kobject *kobj,
+					       const struct bin_attribute *a,
+					       int bar)
+{
+	return __pci_dev_resource_bin_size(kobj, bar, true);
+}
+
+static const struct bin_attribute *const pci_dev_resource_attrs[] = {
+	&pci_dev_resource0_attr,
+	&pci_dev_resource1_attr,
+	&pci_dev_resource2_attr,
+	&pci_dev_resource3_attr,
+	&pci_dev_resource4_attr,
+	&pci_dev_resource5_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_dev_resource_sparse_attrs[] = {
+	&pci_dev_resource0_sparse_attr,
+	&pci_dev_resource1_sparse_attr,
+	&pci_dev_resource2_sparse_attr,
+	&pci_dev_resource3_sparse_attr,
+	&pci_dev_resource4_sparse_attr,
+	&pci_dev_resource5_sparse_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_dev_resource_dense_attrs[] = {
+	&pci_dev_resource0_dense_attr,
+	&pci_dev_resource1_dense_attr,
+	&pci_dev_resource2_dense_attr,
+	&pci_dev_resource3_dense_attr,
+	&pci_dev_resource4_dense_attr,
+	&pci_dev_resource5_dense_attr,
+	NULL,
+};
+
+const struct attribute_group pci_dev_resource_attr_group = {
+	.bin_attrs = pci_dev_resource_attrs,
+	.is_bin_visible = pci_dev_resource_is_visible,
+	.bin_size = pci_dev_resource_bin_size,
+};
+
+const struct attribute_group pci_dev_resource_sparse_attr_group = {
+	.bin_attrs = pci_dev_resource_sparse_attrs,
+	.is_bin_visible = pci_dev_resource_sparse_is_visible,
+	.bin_size = pci_dev_resource_sparse_bin_size,
+};
+
+const struct attribute_group pci_dev_resource_dense_attr_group = {
+	.bin_attrs = pci_dev_resource_dense_attrs,
+	.is_bin_visible = pci_dev_resource_dense_is_visible,
+	.bin_size = pci_dev_resource_bin_size,
+};
-- 
2.53.0

[PATCH v4 19/24] PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()

[Krzysztof Wilczyński]

Currently, pci_create_sysfs_dev_files() and pci_remove_sysfs_dev_files()
are no-op stubs.  With both the generic and Alpha resource files now
handled by static attribute groups, no platform needs dynamic per-device
sysfs file creation.

Thus, remove both functions, their declarations, and the call sites in
pci_bus_add_device() and pci_stop_bus_device().

Remove __weak pci_create_resource_files() and pci_remove_resource_files()
stubs and their declarations in pci.h, as no architecture overrides them
anymore.

Remove the res_attr[] and res_attr_wc[] fields from struct pci_dev
which were used to track dynamically allocated resource attributes.

Finally, simplify pci_sysfs_init() to only handle legacy file creation
under HAVE_PCI_LEGACY, removing the per-device loop and the
HAVE_PCI_SYSFS_INIT helper added earlier.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/bus.c       |  1 -
 drivers/pci/pci-sysfs.c | 52 ++---------------------------------------
 drivers/pci/pci.h       |  4 ----
 drivers/pci/remove.c    |  1 -
 include/linux/pci.h     |  9 -------
 5 files changed, 2 insertions(+), 65 deletions(-)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 6c1ad1f542d9..655ed53436d3 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -354,7 +354,6 @@ void pci_bus_add_device(struct pci_dev *dev)
 	pci_fixup_device(pci_fixup_final, dev);
 	if (pci_is_bridge(dev))
 		of_pci_make_dev_node(dev);
-	pci_create_sysfs_dev_files(dev);
 	pci_proc_attach_device(dev);
 	pci_bridge_d3_update(dev);
 
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index d22bc5c48bc0..3a7bbb00ca60 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -37,12 +37,7 @@
 #define ARCH_PCI_DEV_GROUPS
 #endif
 
-#if defined(HAVE_PCI_LEGACY) || \
-	!defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
-#define HAVE_PCI_SYSFS_INIT
-#endif
-
-#ifdef HAVE_PCI_SYSFS_INIT
+#ifdef HAVE_PCI_LEGACY
 static int sysfs_initialized;	/* = 0 */
 #endif
 
@@ -1401,8 +1396,6 @@ static const struct attribute_group *pci_dev_resource_attr_groups[] = {
 };
 #else
 #define pci_dev_resource_attr_groups NULL
-int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
-void __weak pci_remove_resource_files(struct pci_dev *dev) { }
 #endif
 
 /**
@@ -1772,54 +1765,13 @@ static const struct attribute_group pci_dev_resource_resize_attr_group = {
 	.is_visible = resource_resize_attr_is_visible,
 };
 
-#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
-int pci_create_sysfs_dev_files(struct pci_dev *pdev) { return 0; }
-void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
-#else
-int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
-{
-	if (!sysfs_initialized)
-		return -EACCES;
-
-	return pci_create_resource_files(pdev);
-}
-
-/**
- * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
- * @pdev: device whose entries we should free
- *
- * Cleanup when @pdev is removed from sysfs.
- */
-void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
-{
-	if (!sysfs_initialized)
-		return;
-
-	pci_remove_resource_files(pdev);
-}
-#endif
-
-#ifdef HAVE_PCI_SYSFS_INIT
+#ifdef HAVE_PCI_LEGACY
 static int __init pci_sysfs_init(void)
 {
-#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
 	struct pci_bus *pbus = NULL;
 
 	sysfs_initialized = 1;
-#else
-	struct pci_dev *pdev = NULL;
-	struct pci_bus *pbus = NULL;
-	int retval;
 
-	sysfs_initialized = 1;
-	for_each_pci_dev(pdev) {
-		retval = pci_create_sysfs_dev_files(pdev);
-		if (retval) {
-			pci_dev_put(pdev);
-			return retval;
-		}
-	}
-#endif
 	while ((pbus = pci_find_next_bus(pbus)))
 		pci_create_legacy_files(pbus);
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 13d998fbacce..1bf165595583 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -391,16 +391,12 @@ static inline int pci_no_d1d2(struct pci_dev *dev)
 }
 
 #ifdef CONFIG_SYSFS
-int pci_create_sysfs_dev_files(struct pci_dev *pdev);
-void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
 extern const struct attribute_group *pci_dev_groups[];
 extern const struct attribute_group *pci_dev_attr_groups[];
 extern const struct attribute_group *pcibus_groups[];
 extern const struct attribute_group *pci_bus_groups[];
 extern const struct attribute_group pci_doe_sysfs_group;
 #else
-static inline int pci_create_sysfs_dev_files(struct pci_dev *pdev) { return 0; }
-static inline void pci_remove_sysfs_dev_files(struct pci_dev *pdev) { }
 #define pci_dev_groups NULL
 #define pci_dev_attr_groups NULL
 #define pcibus_groups NULL
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index e9d519993853..6e796dbc5b29 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -26,7 +26,6 @@ static void pci_stop_dev(struct pci_dev *dev)
 
 	device_release_driver(&dev->dev);
 	pci_proc_detach_device(dev);
-	pci_remove_sysfs_dev_files(dev);
 	of_pci_remove_node(dev);
 }
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 30aeb8e02b7b..f6f55005f82d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -507,10 +507,6 @@ struct pci_dev {
 	spinlock_t	pcie_cap_lock;		/* Protects RMW ops in capability accessors */
 	u32		saved_config_space[16]; /* Config space saved at suspend time */
 	struct hlist_head saved_cap_space;
-#if !defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
-	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
-	struct bin_attribute *res_attr_wc[DEVICE_COUNT_RESOURCE]; /* sysfs file for WC mapping of resources */
-#endif
 
 #ifdef CONFIG_HOTPLUG_PCI_PCIE
 	unsigned int	broken_cmd_compl:1;	/* No compl for some cmds */
@@ -2528,11 +2524,6 @@ int pcibios_alloc_irq(struct pci_dev *dev);
 void pcibios_free_irq(struct pci_dev *dev);
 resource_size_t pcibios_default_alignment(void);
 
-#if !defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
-extern int pci_create_resource_files(struct pci_dev *dev);
-extern void pci_remove_resource_files(struct pci_dev *dev);
-#endif
-
 #if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_MCFG)
 void __init pci_mmcfg_early_init(void);
 void __init pci_mmcfg_late_init(void);
-- 
2.53.0

[PATCH v4 20/24] PCI: Add macros for legacy I/O and memory address space sizes

[Krzysztof Wilczyński]

Add defines for the standard PCI legacy address space sizes,
replacing the raw literals used by the legacy sysfs attributes.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 include/linux/pci.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/pci.h b/include/linux/pci.h
index f6f55005f82d..6b630bac8c08 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -27,6 +27,7 @@
 #include <linux/mod_devicetable.h>
 
 #include <linux/types.h>
+#include <linux/sizes.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/list.h>
@@ -1167,6 +1168,10 @@ enum {
 /* These external functions are only available when PCI support is enabled */
 #ifdef CONFIG_PCI
 
+/* PCI legacy I/O port and memory address space sizes. */
+#define PCI_LEGACY_IO_SIZE	(SZ_64K - 1)
+#define PCI_LEGACY_MEM_SIZE	SZ_1M
+
 extern unsigned int pci_flags;
 
 static inline void pci_set_flags(int flags) { pci_flags = flags; }
-- 
2.53.0

[PATCH v4 21/24] alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()

[Krzysztof Wilczyński]

Currently, pci_mmap_legacy_page_range() reads the legacy resource
size from bus->legacy_mem->size or bus->legacy_io->size.  This
couples the mmap bounds check to the struct pci_bus fields that
will be removed when legacy attributes are converted to static
definitions.

Compute the size directly using PCI_LEGACY_MEM_SIZE (0x100000) and
PCI_LEGACY_IO_SIZE (0xffff) macros, and shift by 5 bits for sparse
systems.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/kernel/pci-sysfs.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 2e9693e5abe1..a9dea147528d 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -180,8 +180,11 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
 	int sparse = has_sparse(hose, mmap_type);
 	unsigned long res_size;
 
-	res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
-						 bus->legacy_io->size;
+	res_size = (mmap_type == pci_mmap_mem) ? PCI_LEGACY_MEM_SIZE : \
+						 PCI_LEGACY_IO_SIZE;
+	if (sparse)
+		res_size <<= 5;
+
 	if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
 		return -EINVAL;
 
-- 
2.53.0

[PATCH v4 22/24] PCI/sysfs: Add __weak pci_legacy_has_sparse() helper

[Krzysztof Wilczyński]

Currently, Alpha's sparse/dense legacy attribute handling is done via
pci_adjust_legacy_attr(), which updates dynamically allocated attributes
at runtime.  The upcoming conversion to static attributes needs a way
to determine sparse support at visibility check time.

Add a __weak pci_legacy_has_sparse() that returns false by default.
Alpha overrides it to check has_sparse() on the bus host controller.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/include/asm/pci.h  | 2 ++
 arch/alpha/kernel/pci-sysfs.c | 7 +++++++
 drivers/pci/pci-sysfs.c       | 6 ++++++
 drivers/pci/pci.h             | 4 ++++
 4 files changed, 19 insertions(+)

diff --git a/arch/alpha/include/asm/pci.h b/arch/alpha/include/asm/pci.h
index ef19295f2e33..95de7ffd59e8 100644
--- a/arch/alpha/include/asm/pci.h
+++ b/arch/alpha/include/asm/pci.h
@@ -86,6 +86,8 @@ extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
 				      enum pci_mmap_state mmap_state);
 extern void pci_adjust_legacy_attr(struct pci_bus *bus,
 				   enum pci_mmap_state mmap_type);
+extern bool pci_legacy_has_sparse(struct pci_bus *bus,
+				  enum pci_mmap_state type);
 #define HAVE_PCI_LEGACY	1
 
 extern const struct attribute_group pci_dev_resource_attr_group;
diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index a9dea147528d..ea51f6b20458 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -191,6 +191,13 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
 	return hose_mmap_page_range(hose, vma, mmap_type, sparse);
 }
 
+bool pci_legacy_has_sparse(struct pci_bus *bus, enum pci_mmap_state type)
+{
+	struct pci_controller *hose = bus->sysdata;
+
+	return has_sparse(hose, type);
+}
+
 /**
  * pci_adjust_legacy_attr - adjustment of legacy file attributes
  * @bus: bus to create files under
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 3a7bbb00ca60..ce004b349594 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1019,6 +1019,12 @@ static int pci_mmap_legacy_io(struct file *filp, struct kobject *kobj,
 	return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
 }
 
+bool __weak pci_legacy_has_sparse(struct pci_bus *bus,
+				  enum pci_mmap_state type)
+{
+	return false;
+}
+
 /**
  * pci_adjust_legacy_attr - adjustment of legacy file attributes
  * @b: bus to create files under
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 1bf165595583..f52caf7e4d13 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -390,6 +390,10 @@ static inline int pci_no_d1d2(struct pci_dev *dev)
 
 }
 
+#ifdef HAVE_PCI_LEGACY
+bool pci_legacy_has_sparse(struct pci_bus *bus, enum pci_mmap_state type);
+#endif
+
 #ifdef CONFIG_SYSFS
 extern const struct attribute_group *pci_dev_groups[];
 extern const struct attribute_group *pci_dev_attr_groups[];
-- 
2.53.0

[PATCH v4 23/24] PCI/sysfs: Convert legacy I/O and memory attributes to static definitions

[Krzysztof Wilczyński]

Currently, legacy_io and legacy_mem are dynamically allocated and
created by pci_create_legacy_files(), with pci_adjust_legacy_attr()
updating the attributes at runtime on Alpha to rename them and shift
the size for sparse addressing.

Convert to four static const attributes (legacy_io, legacy_io_sparse,
legacy_mem, legacy_mem_sparse) with is_bin_visible() callbacks that
use pci_legacy_has_sparse() to select the appropriate variant per bus.
The sizes are compile-time constants and .size is set directly on
each attribute.

Register the groups in pcibus_groups[] under a HAVE_PCI_LEGACY guard
so the driver model handles creation and removal automatically.

Stub out pci_create_legacy_files() and pci_remove_legacy_files() as
the dynamic creation is no longer needed.  Remove the __weak
pci_adjust_legacy_attr(), Alpha's override, and its declaration from
both Alpha and PowerPC asm/pci.h headers.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 arch/alpha/include/asm/pci.h   |   2 -
 arch/alpha/kernel/pci-sysfs.c  |  24 ----
 arch/powerpc/include/asm/pci.h |   2 -
 drivers/pci/pci-sysfs.c        | 200 ++++++++++++++++++++-------------
 4 files changed, 120 insertions(+), 108 deletions(-)

diff --git a/arch/alpha/include/asm/pci.h b/arch/alpha/include/asm/pci.h
index 95de7ffd59e8..ad5d1391e1fa 100644
--- a/arch/alpha/include/asm/pci.h
+++ b/arch/alpha/include/asm/pci.h
@@ -84,8 +84,6 @@ extern int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val,
 extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
 				      struct vm_area_struct *vma,
 				      enum pci_mmap_state mmap_state);
-extern void pci_adjust_legacy_attr(struct pci_bus *bus,
-				   enum pci_mmap_state mmap_type);
 extern bool pci_legacy_has_sparse(struct pci_bus *bus,
 				  enum pci_mmap_state type);
 #define HAVE_PCI_LEGACY	1
diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index ea51f6b20458..7f052e05cbae 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -198,30 +198,6 @@ bool pci_legacy_has_sparse(struct pci_bus *bus, enum pci_mmap_state type)
 	return has_sparse(hose, type);
 }
 
-/**
- * pci_adjust_legacy_attr - adjustment of legacy file attributes
- * @bus: bus to create files under
- * @mmap_type: I/O port or memory
- *
- * Adjust file name and size for sparse mappings.
- */
-void pci_adjust_legacy_attr(struct pci_bus *bus, enum pci_mmap_state mmap_type)
-{
-	struct pci_controller *hose = bus->sysdata;
-
-	if (!has_sparse(hose, mmap_type))
-		return;
-
-	if (mmap_type == pci_mmap_mem) {
-		bus->legacy_mem->attr.name = "legacy_mem_sparse";
-		bus->legacy_mem->size <<= 5;
-	} else {
-		bus->legacy_io->attr.name = "legacy_io_sparse";
-		bus->legacy_io->size <<= 5;
-	}
-	return;
-}
-
 /* Legacy I/O bus read/write functions */
 int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
 {
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 46a9c4491ed0..72f286e74786 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -82,8 +82,6 @@ extern int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val,
 extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
 				      struct vm_area_struct *vma,
 				      enum pci_mmap_state mmap_state);
-extern void pci_adjust_legacy_attr(struct pci_bus *bus,
-				   enum pci_mmap_state mmap_type);
 #define HAVE_PCI_LEGACY	1
 
 extern void pcibios_claim_one_bus(struct pci_bus *b);
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index ce004b349594..c81d3964cfa4 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -702,11 +702,6 @@ static const struct attribute_group pcibus_group = {
 	.attrs = pcibus_attrs,
 };
 
-const struct attribute_group *pcibus_groups[] = {
-	&pcibus_group,
-	NULL,
-};
-
 static ssize_t boot_vga_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
@@ -1025,91 +1020,136 @@ bool __weak pci_legacy_has_sparse(struct pci_bus *bus,
 	return false;
 }
 
-/**
- * pci_adjust_legacy_attr - adjustment of legacy file attributes
- * @b: bus to create files under
- * @mmap_type: I/O port or memory
- *
- * Stub implementation. Can be overridden by arch if necessary.
- */
-void __weak pci_adjust_legacy_attr(struct pci_bus *b,
-				   enum pci_mmap_state mmap_type)
+static inline umode_t __pci_legacy_is_visible(struct kobject *kobj,
+					      const struct bin_attribute *a,
+					      enum pci_mmap_state type,
+					      bool sparse)
 {
+	struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));
+
+	if (pci_legacy_has_sparse(bus, type) != sparse)
+		return 0;
+
+	return a->attr.mode;
 }
 
-/**
- * pci_create_legacy_files - create legacy I/O port and memory files
- * @b: bus to create files under
- *
- * Some platforms allow access to legacy I/O port and ISA memory space on
- * a per-bus basis.  This routine creates the files and ties them into
- * their associated read, write and mmap files from pci-sysfs.c
- *
- * On error unwind, but don't propagate the error to the caller
- * as it is ok to set up the PCI bus without these files.
- */
-void pci_create_legacy_files(struct pci_bus *b)
+static umode_t pci_legacy_io_is_visible(struct kobject *kobj,
+					const struct bin_attribute *a, int n)
 {
-	int error;
-
-	if (!sysfs_initialized)
-		return;
-
-	b->legacy_io = kzalloc_objs(struct bin_attribute, 2, GFP_ATOMIC);
-	if (!b->legacy_io)
-		goto kzalloc_err;
-
-	sysfs_bin_attr_init(b->legacy_io);
-	b->legacy_io->attr.name = "legacy_io";
-	b->legacy_io->size = 0xffff;
-	b->legacy_io->attr.mode = 0600;
-	b->legacy_io->read = pci_read_legacy_io;
-	b->legacy_io->write = pci_write_legacy_io;
-	/* See pci_create_attr() for motivation */
-	b->legacy_io->llseek = pci_llseek_resource;
-	b->legacy_io->mmap = pci_mmap_legacy_io;
-	b->legacy_io->f_mapping = iomem_get_mapping;
-	pci_adjust_legacy_attr(b, pci_mmap_io);
-	error = device_create_bin_file(&b->dev, b->legacy_io);
-	if (error)
-		goto legacy_io_err;
-
-	/* Allocated above after the legacy_io struct */
-	b->legacy_mem = b->legacy_io + 1;
-	sysfs_bin_attr_init(b->legacy_mem);
-	b->legacy_mem->attr.name = "legacy_mem";
-	b->legacy_mem->size = 1024*1024;
-	b->legacy_mem->attr.mode = 0600;
-	b->legacy_mem->mmap = pci_mmap_legacy_mem;
-	/* See pci_create_attr() for motivation */
-	b->legacy_mem->llseek = pci_llseek_resource;
-	b->legacy_mem->f_mapping = iomem_get_mapping;
-	pci_adjust_legacy_attr(b, pci_mmap_mem);
-	error = device_create_bin_file(&b->dev, b->legacy_mem);
-	if (error)
-		goto legacy_mem_err;
-
-	return;
-
-legacy_mem_err:
-	device_remove_bin_file(&b->dev, b->legacy_io);
-legacy_io_err:
-	kfree(b->legacy_io);
-	b->legacy_io = NULL;
-kzalloc_err:
-	dev_warn(&b->dev, "could not create legacy I/O port and ISA memory resources in sysfs\n");
+	return __pci_legacy_is_visible(kobj, a, pci_mmap_io, false);
 }
 
-void pci_remove_legacy_files(struct pci_bus *b)
+static umode_t pci_legacy_io_sparse_is_visible(struct kobject *kobj,
+					       const struct bin_attribute *a,
+					       int n)
 {
-	if (b->legacy_io) {
-		device_remove_bin_file(&b->dev, b->legacy_io);
-		device_remove_bin_file(&b->dev, b->legacy_mem);
-		kfree(b->legacy_io); /* both are allocated here */
-	}
+	return __pci_legacy_is_visible(kobj, a, pci_mmap_io, true);
 }
+
+static umode_t pci_legacy_mem_is_visible(struct kobject *kobj,
+					 const struct bin_attribute *a, int n)
+{
+	return __pci_legacy_is_visible(kobj, a, pci_mmap_mem, false);
+}
+
+static umode_t pci_legacy_mem_sparse_is_visible(struct kobject *kobj,
+						const struct bin_attribute *a,
+						int n)
+{
+	return __pci_legacy_is_visible(kobj, a, pci_mmap_mem, true);
+}
+
+static const struct bin_attribute pci_legacy_io_attr = {
+	.attr = { .name = "legacy_io", .mode = 0600 },
+	.size = PCI_LEGACY_IO_SIZE,
+	.read = pci_read_legacy_io,
+	.write = pci_write_legacy_io,
+	.mmap = pci_mmap_legacy_io,
+	.llseek = pci_llseek_resource,
+	.f_mapping = iomem_get_mapping,
+};
+
+static const struct bin_attribute pci_legacy_io_sparse_attr = {
+	.attr = { .name = "legacy_io_sparse", .mode = 0600 },
+	.size = PCI_LEGACY_IO_SIZE << 5,
+	.read = pci_read_legacy_io,
+	.write = pci_write_legacy_io,
+	.mmap = pci_mmap_legacy_io,
+	.llseek = pci_llseek_resource,
+	.f_mapping = iomem_get_mapping,
+};
+
+static const struct bin_attribute pci_legacy_mem_attr = {
+	.attr = { .name = "legacy_mem", .mode = 0600 },
+	.size = PCI_LEGACY_MEM_SIZE,
+	.mmap = pci_mmap_legacy_mem,
+	.llseek = pci_llseek_resource,
+	.f_mapping = iomem_get_mapping,
+};
+
+static const struct bin_attribute pci_legacy_mem_sparse_attr = {
+	.attr = { .name = "legacy_mem_sparse", .mode = 0600 },
+	.size = PCI_LEGACY_MEM_SIZE << 5,
+	.mmap = pci_mmap_legacy_mem,
+	.llseek = pci_llseek_resource,
+	.f_mapping = iomem_get_mapping,
+};
+
+static const struct bin_attribute *const pci_legacy_io_attrs[] = {
+	&pci_legacy_io_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_legacy_io_sparse_attrs[] = {
+	&pci_legacy_io_sparse_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_legacy_mem_attrs[] = {
+	&pci_legacy_mem_attr,
+	NULL,
+};
+
+static const struct bin_attribute *const pci_legacy_mem_sparse_attrs[] = {
+	&pci_legacy_mem_sparse_attr,
+	NULL,
+};
+
+static const struct attribute_group pci_legacy_io_group = {
+	.bin_attrs = pci_legacy_io_attrs,
+	.is_bin_visible = pci_legacy_io_is_visible,
+};
+
+static const struct attribute_group pci_legacy_io_sparse_group = {
+	.bin_attrs = pci_legacy_io_sparse_attrs,
+	.is_bin_visible = pci_legacy_io_sparse_is_visible,
+};
+
+static const struct attribute_group pci_legacy_mem_group = {
+	.bin_attrs = pci_legacy_mem_attrs,
+	.is_bin_visible = pci_legacy_mem_is_visible,
+};
+
+static const struct attribute_group pci_legacy_mem_sparse_group = {
+	.bin_attrs = pci_legacy_mem_sparse_attrs,
+	.is_bin_visible = pci_legacy_mem_sparse_is_visible,
+};
+
+void pci_create_legacy_files(struct pci_bus *b) { }
+void pci_remove_legacy_files(struct pci_bus *b) { }
 #endif /* HAVE_PCI_LEGACY */
 
+const struct attribute_group *pcibus_groups[] = {
+	&pcibus_group,
+#ifdef HAVE_PCI_LEGACY
+	&pci_legacy_io_group,
+	&pci_legacy_io_sparse_group,
+	&pci_legacy_mem_group,
+	&pci_legacy_mem_sparse_group,
+#endif
+	NULL,
+};
+
 #if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
 /**
  * pci_mmap_resource - map a PCI resource into user memory space
-- 
2.53.0

[PATCH v4 24/24] PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()

[Krzysztof Wilczyński]

Currently, pci_create_legacy_files() and pci_remove_legacy_files() are
no-op stubs.  With legacy attributes now handled by static groups
registered via pcibus_groups[], no call site needs them.

Remove both functions, their declarations, and the call sites in
pci_register_host_bridge(), pci_alloc_child_bus(), and pci_remove_bus().

Remove the pci_sysfs_init() late_initcall and sysfs_initialized.  The
late_initcall originally existed to create all the dynamic PCI sysfs
files, but with both resource and legacy attributes now handled by
static groups, it is no longer needed.

Remove the legacy_io and legacy_mem fields from struct pci_bus which
were used to track the dynamically allocated legacy attributes.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
 drivers/pci/pci-sysfs.c | 21 ---------------------
 drivers/pci/pci.h       |  8 --------
 drivers/pci/probe.c     |  6 ------
 drivers/pci/remove.c    |  2 --
 include/linux/pci.h     |  2 --
 5 files changed, 39 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index c81d3964cfa4..b167e32d55ac 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -37,10 +37,6 @@
 #define ARCH_PCI_DEV_GROUPS
 #endif
 
-#ifdef HAVE_PCI_LEGACY
-static int sysfs_initialized;	/* = 0 */
-#endif
-
 /* show configuration fields */
 #define pci_config_attr(field, format_string)				\
 static ssize_t								\
@@ -1135,8 +1131,6 @@ static const struct attribute_group pci_legacy_mem_sparse_group = {
 	.is_bin_visible = pci_legacy_mem_sparse_is_visible,
 };
 
-void pci_create_legacy_files(struct pci_bus *b) { }
-void pci_remove_legacy_files(struct pci_bus *b) { }
 #endif /* HAVE_PCI_LEGACY */
 
 const struct attribute_group *pcibus_groups[] = {
@@ -1811,21 +1805,6 @@ static const struct attribute_group pci_dev_resource_resize_attr_group = {
 	.is_visible = resource_resize_attr_is_visible,
 };
 
-#ifdef HAVE_PCI_LEGACY
-static int __init pci_sysfs_init(void)
-{
-	struct pci_bus *pbus = NULL;
-
-	sysfs_initialized = 1;
-
-	while ((pbus = pci_find_next_bus(pbus)))
-		pci_create_legacy_files(pbus);
-
-	return 0;
-}
-late_initcall(pci_sysfs_init);
-#endif
-
 static struct attribute *pci_dev_dev_attrs[] = {
 	&dev_attr_boot_vga.attr,
 	&dev_attr_serial_number.attr,
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f52caf7e4d13..63f249d4833a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -356,14 +356,6 @@ static inline int pci_proc_detach_bus(struct pci_bus *bus) { return 0; }
 int pci_hp_add_bridge(struct pci_dev *dev);
 bool pci_hp_spurious_link_change(struct pci_dev *pdev);
 
-#if defined(CONFIG_SYSFS) && defined(HAVE_PCI_LEGACY)
-void pci_create_legacy_files(struct pci_bus *bus);
-void pci_remove_legacy_files(struct pci_bus *bus);
-#else
-static inline void pci_create_legacy_files(struct pci_bus *bus) { }
-static inline void pci_remove_legacy_files(struct pci_bus *bus) { }
-#endif
-
 /* Lock for read/write access to pci device and bus lists */
 extern struct rw_semaphore pci_bus_sem;
 extern struct mutex pci_slot_mutex;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index bccc7a4bdd79..94c52bf3a65c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1068,9 +1068,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 			dev_err(&bus->dev, "failed to add bus: %d\n", err);
 	}
 
-	/* Create legacy_io and legacy_mem files for this bus */
-	pci_create_legacy_files(bus);
-
 	if (parent)
 		dev_info(parent, "PCI host bridge to bus %s\n", name);
 	else
@@ -1276,9 +1273,6 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 			dev_err(&child->dev, "failed to add bus: %d\n", ret);
 	}
 
-	/* Create legacy_io and legacy_mem files for this bus */
-	pci_create_legacy_files(child);
-
 	return child;
 }
 
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 6e796dbc5b29..d8bffa21498a 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -65,8 +65,6 @@ void pci_remove_bus(struct pci_bus *bus)
 	list_del(&bus->node);
 	pci_bus_release_busn_res(bus);
 	up_write(&pci_bus_sem);
-	pci_remove_legacy_files(bus);
-
 	if (bus->ops->remove_bus)
 		bus->ops->remove_bus(bus);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6b630bac8c08..1859c0bf4e35 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -724,8 +724,6 @@ struct pci_bus {
 	pci_bus_flags_t bus_flags;	/* Inherited by child buses */
 	struct device		*bridge;
 	struct device		dev;
-	struct bin_attribute	*legacy_io;	/* Legacy I/O for this bus */
-	struct bin_attribute	*legacy_mem;	/* Legacy mem */
 	unsigned int		is_added:1;
 	unsigned int		unsafe_warn:1;	/* warned about RW1C config write */
 	unsigned int		flit_mode:1;	/* Link in Flit mode */
-- 
2.53.0

Re: [PATCH v4 00/24] PCI: Convert all dynamic sysfs attributes to static

[Magnus Lindholm]

On Sat, Apr 11, 2026 at 10:01 AM Krzysztof Wilczyński
<kwilczynski@kernel.org> wrote:
>
> Hello,
>
> This series converts every dynamically allocated PCI sysfs attribute to
> a static const definition.  After the full series, pci_sysfs_init() and
> sysfs_initialized are gone, and every sysfs file is created by the
> driver model at device_add() time.
>
> Currently, the PCI resource files (resourceN, resourceN_wc) and the
> legacy bus files (legacy_io, legacy_mem) are created dynamically
> from two unsynchronised paths:
>
> Path A: late_initcall
>
>   pci_sysfs_init                        (late_initcall)
>     sysfs_initialized = 1
>     for_each_pci_dev
>       pci_create_sysfs_dev_files
>         sysfs_create_bin_file           (resourceN, resourceN_wc)
>     pci_find_next_bus
>       pci_create_legacy_files
>         sysfs_create_bin_file           (legacy_io, legacy_mem)
>
> Path B: device registration / hotplug
>
>   pci_bus_add_devices
>     pci_bus_add_device
>       pci_create_sysfs_dev_files
>         if (!sysfs_initialized) return  <- only guard
>         sysfs_create_bin_file           (resourceN, resourceN_wc)
>
> On most ACPI systems this does not race because PCI enumeration
> completes at subsys_initcall time, before pci_sysfs_init() runs:
>
>   subsys_initcall (level 4):
>     acpi_pci_root_add
>       pci_bus_add_device
>         pci_create_sysfs_dev_files
>           if (!sysfs_initialized)          <- not yet set
>             return -EACCES
>
>   late_initcall (level 7):
>     pci_sysfs_init
>       sysfs_initialized = 1
>       for_each_pci_dev
>         pci_create_sysfs_dev_files         <- creates the files, no race
>
> On Devicetree platforms the host controller is a platform driver that
> probes via the driver model, often on a workqueue, and overlaps with the
> late_initcall:
>
>   CPU 0 (late_initcall)                CPU 1 (driver probe)
>   ---------------------------          ----------------------------
>   pci_sysfs_init()
>     sysfs_initialized = 1
>     for_each_pci_dev(pdev)             pci_bus_add_device(pdev)
>       pci_create_sysfs_dev_files()       pci_create_sysfs_dev_files()
>         sysfs_create_bin_file()            sysfs_create_bin_file()
>                                              -> "duplicate filename"
>
> The same happens on ACPI when probing is asynchronous (hv_pci on
> Azure, RISC-V with ACPI).
>
> The duplicate causes sysfs_create_bin_file() to fail with -EEXIST.
> pci_create_resource_files() then calls pci_remove_resource_files() in
> its error unwind, tearing down files the other thread created and
> still references through pdev->res_attr[].  This has caused kernel
> panics on i.MX6 and boot failures on other platforms.
>
> Several different fixes have been proposed over the years: reordering
> the sysfs_initialized assignment, adding locks, checking
> pci_dev_is_added(), setting pdev->res_attr[] to NULL after kfree
> (which only prevents a double-free on the teardown path, not the
> error unwind removing the other thread's files).  None would address the
> root cause.
>
> This has been reported a few times:
>
>   - https://lore.kernel.org/linux-pci/20250702155112.40124-1-heshuan@bytedance.com/
>   - https://lore.kernel.org/linux-pci/b51519d6-ce45-4b6d-8135-c70169bd110e@h-partners.com/
>   - https://lore.kernel.org/linux-pci/1702093576-30405-1-git-send-email-ssengar@linux.microsoft.com/
>   - https://lore.kernel.org/linux-pci/SY0P300MB04687548090B73E40AF97D8897B82@SY0P300MB0468.AUSP300.PROD.OUTLOOK.COM/
>   - https://lore.kernel.org/linux-pci/20230105174736.GA1154719@bhelgaas/
>   - https://lore.kernel.org/linux-pci/m3eebg9puj.fsf@t19.piap.pl/
>   - https://lore.kernel.org/linux-pci/20200716110423.xtfyb3n6tn5ixedh@pali/
>   - https://lore.kernel.org/linux-pci/1366196798-15929-1-git-send-email-artem.savkov@gmail.com/
>   - https://bugzilla.kernel.org/show_bug.cgi?id=215515
>   - https://bugzilla.kernel.org/show_bug.cgi?id=216888
>
> With static attributes the driver model creates sysfs entries once per
> device at device_add() time, under the device lock, eliminating the
> late_initcall iteration and the race along with it.
>
>         Krzysztof
>
> ---
> Changes in v4:
>   https://lore.kernel.org/linux-pci/20260410055040.39233-1-kwilczynski@kernel.org/
>
>    - Added new Reviewed-by tags.
>    - Added pci_resource_is_io() and pci_resource_is_mem() helpers
>      for resource type checks, replacing the open-coded bitwise
>      flag tests in pci_mmap_resource(), pci_resource_io(), and
>      Alpha's pci_mmap_resource(), as per Ilpo Järvinen's
>      suggestion.
>    - Split the __pci_mmap_fits() cleanup into two patches.  An
>      overflow fix for zero-length BARs, which now includes a
>      Fixes: tag referencing the original Alpha PCI sysfs commit,
>      and the WARN macro removal is a separate cleanup as per Ilpo
>      Järvinen's suggestion.
>    - Added a missing Fixes: tag to the Alpha lockdown check,
>      referencing the commit that added the check to the generic
>      path but missed Alpha's implementation.
>    - Added PCI_LEGACY_IO_SIZE and PCI_LEGACY_MEM_SIZE macros to
>      replace the raw literals used for legacy address space sizes.
>      These are used in both Alpha's pci_mmap_legacy_page_range()
>      and the static legacy attribute definitions, as per Ilpo
>      Järvinen's suggestion.
>    - Replaced sysfs_update_groups() in the BAR resize path with
>      sysfs_remove_groups() before the resize and sysfs_create_groups()
>      after, restoring the original teardown before BAR resize
>      ordering.  This was reported by Sashiko, see:
>      https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=7
>    - Defined pci_dev_resource_attr_groups as a NULL macro when
>      HAVE_PCI_MMAP and ARCH_GENERIC_PCI_MMAP_RESOURCE are both
>      absent, so the resize path compiles unconditionally without
>      #ifdef guards in the function body.  This was reported by
>      Sashiko, see:
>      https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=7
>    - Moved the pci_legacy_has_sparse() prototype into the patch
>      that introduces the function, alongside the existing
>      pci_adjust_legacy_attr() declaration, to fix a bisection
>      issue where Alpha would warn on -Wmissing-prototypes.
>      This was reported by Sashiko, see:
>      https://sashiko.dev/#/patchset/20260410055040.39233-1-kwilczynski%40kernel.org?part=18
>
> Changes in v3:
>   https://lore.kernel.org/linux-pci/20210910202623.2293708-1-kw@linux.com/
>
>   - Updated for modern kernel releases and expanded scope.  The
>     v2 only covered the generic resource files.  This version
>     also converts Alpha's sparse/dense resource files and the
>     legacy bus attributes, removing pci_sysfs_init() entirely.
>   - Split the single macro definition into three distinct ones
>     (per I/O, UC, and WC), to make sure that each carries only
>     the callbacks its resource type needs.
>   - Updated to use the new .bin_size callback, as the attributes
>     are const, to replace using a->size directly, which was not
>     ideal.  This required changes to pci_llseek_resource(), to
>     ensure that it would work for device and bus-level attributes.
>   - Updated the __resource_resize_store() to include CAP_SYS_ADMIN
>     capabilities check.
>   - Added the security_locked_down() check to Alpha's
>     pci_mmap_resource(), to align with other architectures.
>
> Changes in v2:
>   https://lore.kernel.org/linux-pci/20210825212255.878043-1-kw@linux.com/
>
>   - Refactored code so that the macros, helpers and internal
>     functions can be used to correctly leverage the read(),
>     write() and mmap() callbacks rather than to use the
>     .is_bin_visible() callback to set up sysfs objects
>     internals as this is not supported.
>   - Refactored some if-statements to check for a resource
>     flag first, and then call either arch_can_pci_mmap_io()
>     or arch_can_pci_mmap_wc(), plus store result of testing
>     for IORESOURCE_MEM and IORESOURCE_PREFETCH flags into
>     a boolean variable, as per Bjorn Helgaas' suggestion.
>   - Renamed pci_read_resource_io() and pci_write_resource_io()
>     callbacks so that these are not specifically tied to I/O
>     BARs read() and write() operations also as per Bjorn
>     Helgaas' suggestion.
>   - Updated style for code handling bitwise operations to
>     match the style that is preferred as per Bjorn Helgaas'
>     suggestion.
>   - Updated commit messages adding more details about the
>     implementation as requested by Bjorn Helgaas.
>
> Krzysztof Wilczyński (24):
>   PCI/sysfs: Use PCI resource accessor macros
>   PCI: Add pci_resource_is_io() and pci_resource_is_mem() helpers
>   PCI/sysfs: Only allow supported resource types in I/O and MMIO helpers
>   PCI/sysfs: Use BAR length in pci_llseek_resource() when attr->size is
>     zero
>   PCI/sysfs: Add CAP_SYS_ADMIN check to __resource_resize_store()
>   PCI/sysfs: Add static PCI resource attribute macros
>   PCI/sysfs: Convert PCI resource files to static attributes
>   PCI/sysfs: Convert __resource_resize_store() to use static attributes
>   PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()
>   PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope
>   alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
>   alpha/PCI: Use BAR index in sysfs attr->private instead of resource
>     pointer
>   alpha/PCI: Use PCI resource accessor macros
>   alpha/PCI: Clean up pci_mmap_resource()
>   alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs
>   alpha/PCI: Remove WARN from __pci_mmap_fits()
>   alpha/PCI: Add static PCI resource attribute macros
>   alpha/PCI: Convert resource files to static attributes
>   PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()
>   PCI: Add macros for legacy I/O and memory address space sizes
>   alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()
>   PCI/sysfs: Add __weak pci_legacy_has_sparse() helper
>   PCI/sysfs: Convert legacy I/O and memory attributes to static
>     definitions
>   PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()
>
>  arch/alpha/include/asm/pci.h   |  13 +-
>  arch/alpha/kernel/pci-sysfs.c  | 373 +++++++++++----------
>  arch/powerpc/include/asm/pci.h |   2 -
>  drivers/pci/bus.c              |   1 -
>  drivers/pci/pci-sysfs.c        | 575 +++++++++++++++++++--------------
>  drivers/pci/pci.h              |  16 +-
>  drivers/pci/probe.c            |   6 -
>  drivers/pci/remove.c           |   3 -
>  include/linux/pci.h            |  39 ++-
>  9 files changed, 578 insertions(+), 450 deletions(-)
>

Hi ,

Applied the series on an Alpha UP2000+, built and booted
successfully. PCI enumeration and device initialization looked
normal, I saw no relevant sysfs/PCI warnings in dmesg, and PCI
sysfs resource files for tested devices looked sane.

From the Alpha side, this looks good to me.

Tested-by: Magnus Lindholm <linmag7@gmail.com>
Acked-by: Magnus Lindholm <linmag7@gmail.com>