Commit f7195824 authored by David Woodhouse's avatar David Woodhouse Committed by Bjorn Helgaas

PCI: Add pci_mmap_resource_range() and use it for ARM64

Starting to leave behind the legacy of the pci_mmap_page_range() interface
which takes "user-visible" BAR addresses.  This takes just the resource and
offset.

For now, both APIs coexist and depending on the platform, one is
implemented as a wrapper around the other.
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent f66e2258
...@@ -113,9 +113,13 @@ Supporting PCI access on new platforms ...@@ -113,9 +113,13 @@ Supporting PCI access on new platforms
-------------------------------------- --------------------------------------
In order to support PCI resource mapping as described above, Linux platform In order to support PCI resource mapping as described above, Linux platform
code must define HAVE_PCI_MMAP and provide a pci_mmap_page_range function. code should ideally define ARCH_GENERIC_PCI_MMAP_RESOURCE and use the generic
Platforms are free to only support subsets of the mmap functionality, but implementation of that functionality. To support the historical interface of
useful return codes should be provided. mmap() through files in /proc/bus/pci, platforms may also set HAVE_PCI_MMAP.
Alternatively, platforms which set HAVE_PCI_MMAP may provide their own
implementation of pci_mmap_page_range() instead of defining
ARCH_GENERIC_PCI_MMAP_RESOURCE.
Platforms which support write-combining maps of PCI resources must define Platforms which support write-combining maps of PCI resources must define
arch_can_pci_mmap_wc() which shall evaluate to non-zero at runtime when arch_can_pci_mmap_wc() which shall evaluate to non-zero at runtime when
......
...@@ -22,6 +22,8 @@ ...@@ -22,6 +22,8 @@
*/ */
#define PCI_DMA_BUS_IS_PHYS (0) #define PCI_DMA_BUS_IS_PHYS (0)
#define ARCH_GENERIC_PCI_MMAP_RESOURCE 1
extern int isa_dma_bridge_buggy; extern int isa_dma_bridge_buggy;
#ifdef CONFIG_PCI #ifdef CONFIG_PCI
......
...@@ -4,7 +4,7 @@ ...@@ -4,7 +4,7 @@
obj-y += access.o bus.o probe.o host-bridge.o remove.o pci.o \ obj-y += access.o bus.o probe.o host-bridge.o remove.o pci.o \
pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \ pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
irq.o vpd.o setup-bus.o vc.o irq.o vpd.o setup-bus.o vc.o mmap.o
obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_SYSFS) += slot.o obj-$(CONFIG_SYSFS) += slot.o
......
/*
* mmap.c — generic PCI resource mmap helper
*
* Copyright © 2017 Amazon.com, Inc. or its affiliates.
*
* Author: David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>
#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
/*
* Modern setup: generic pci_mmap_resource_range(), and implement the legacy
* pci_mmap_page_range() (if needed) as a wrapper round it.
*/
#ifdef HAVE_PCI_MMAP
int pci_mmap_page_range(struct pci_dev *pdev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
resource_size_t start, end;
pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
/* Adjust vm_pgoff to be the offset within the resource */
vma->vm_pgoff -= start >> PAGE_SHIFT;
return pci_mmap_resource_range(pdev, bar, vma, mmap_state,
write_combine);
}
#endif
static const struct vm_operations_struct pci_phys_vm_ops = {
#ifdef CONFIG_HAVE_IOREMAP_PROT
.access = generic_access_phys,
#endif
};
int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
unsigned long size;
if (mmap_state == pci_mmap_io)
return -EINVAL;
size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
if (vma->vm_pgoff + vma_pages(vma) > size)
return -EINVAL;
if (write_combine)
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
else
vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
vma->vm_ops = &pci_phys_vm_ops;
return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
#elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */
/*
* Legacy setup: Impement pci_mmap_resource_range() as a wrapper around
* the architecture's pci_mmap_page_range(), converting to "user visible"
* addresses as necessary.
*/
int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
resource_size_t start, end;
/*
* pci_mmap_page_range() expects the same kind of entry as coming
* from /proc/bus/pci/ which is a "user visible" value. If this is
* different from the resource itself, arch will do necessary fixup.
*/
pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
vma->vm_pgoff += start >> PAGE_SHIFT;
return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine);
}
#endif
...@@ -980,7 +980,7 @@ void pci_remove_legacy_files(struct pci_bus *b) ...@@ -980,7 +980,7 @@ void pci_remove_legacy_files(struct pci_bus *b)
} }
#endif /* HAVE_PCI_LEGACY */ #endif /* HAVE_PCI_LEGACY */
#ifdef HAVE_PCI_MMAP #if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma, int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
enum pci_mmap_api mmap_api) enum pci_mmap_api mmap_api)
...@@ -1019,7 +1019,6 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, ...@@ -1019,7 +1019,6 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
int bar = (unsigned long)attr->private; int bar = (unsigned long)attr->private;
enum pci_mmap_state mmap_type; enum pci_mmap_state mmap_type;
resource_size_t start, end;
struct resource *res = &pdev->resource[bar]; struct resource *res = &pdev->resource[bar];
if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start)) if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
...@@ -1033,15 +1032,9 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, ...@@ -1033,15 +1032,9 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
(u64)pci_resource_len(pdev, bar)); (u64)pci_resource_len(pdev, bar));
return -EINVAL; return -EINVAL;
} }
/* pci_mmap_page_range() expects the same kind of entry as coming
* from /proc/bus/pci/ which is a "user visible" value. If this is
* different from the resource itself, arch will do necessary fixup.
*/
pci_resource_to_user(pdev, bar, res, &start, &end);
vma->vm_pgoff += start >> PAGE_SHIFT;
mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io; mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
return pci_mmap_page_range(pdev, bar, vma, mmap_type, write_combine);
return pci_mmap_resource_range(pdev, bar, vma, mmap_type, write_combine);
} }
static int pci_mmap_resource_uc(struct file *filp, struct kobject *kobj, static int pci_mmap_resource_uc(struct file *filp, struct kobject *kobj,
......
...@@ -21,14 +21,14 @@ void pci_create_firmware_label_files(struct pci_dev *pdev); ...@@ -21,14 +21,14 @@ void pci_create_firmware_label_files(struct pci_dev *pdev);
void pci_remove_firmware_label_files(struct pci_dev *pdev); void pci_remove_firmware_label_files(struct pci_dev *pdev);
#endif #endif
void pci_cleanup_rom(struct pci_dev *dev); void pci_cleanup_rom(struct pci_dev *dev);
#ifdef HAVE_PCI_MMAP
enum pci_mmap_api { enum pci_mmap_api {
PCI_MMAP_SYSFS, /* mmap on /sys/bus/pci/devices/<BDF>/resource<N> */ PCI_MMAP_SYSFS, /* mmap on /sys/bus/pci/devices/<BDF>/resource<N> */
PCI_MMAP_PROCFS /* mmap on /proc/bus/pci/<BDF> */ PCI_MMAP_PROCFS /* mmap on /proc/bus/pci/<BDF> */
}; };
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai, int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
enum pci_mmap_api mmap_api); enum pci_mmap_api mmap_api);
#endif
int pci_probe_reset_function(struct pci_dev *dev); int pci_probe_reset_function(struct pci_dev *dev);
/** /**
......
...@@ -1626,10 +1626,21 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; } ...@@ -1626,10 +1626,21 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; }
#include <asm/pci.h> #include <asm/pci.h>
/* Map a range of PCI memory or I/O space for a device into user space. /* These two functions provide almost identical functionality. Depennding
* Architectures provide this function if they set HAVE_PCI_MMAP, and * on the architecture, one will be implemented as a wrapper around the
* it accepts the 'write_combine' argument when arch_can_pci_mmap_wc() * other (in drivers/pci/mmap.c).
* evaluates to nonzero. */ *
* pci_mmap_resource_range() maps a specific BAR, and vm->vm_pgoff
* is expected to be an offset within that region.
*
* pci_mmap_page_range() is the legacy architecture-specific interface,
* which accepts a "user visible" resource address converted by
* pci_resource_to_user(), as used in the legacy mmap() interface in
* /proc/bus/pci/.
*/
int pci_mmap_resource_range(struct pci_dev *dev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
int pci_mmap_page_range(struct pci_dev *pdev, int bar, int pci_mmap_page_range(struct pci_dev *pdev, int bar,
struct vm_area_struct *vma, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine); enum pci_mmap_state mmap_state, int write_combine);
......
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