diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2013-05-29 04:22:21 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-01-21 06:58:49 +0100 |
| commit | eb29d8d2aad70636ea23810b4868693673d630d5 (patch) | |
| tree | f62b6c19f812b6f731dc90b3ae9989822b3749e6 /lib/pci_iomap.c | |
| parent | mn10300: drop dead code (diff) | |
| download | linux-eb29d8d2aad70636ea23810b4868693673d630d5.tar.xz linux-eb29d8d2aad70636ea23810b4868693673d630d5.zip | |
pci: add pci_iomap_range
Virtio drivers should map the part of the BAR they need, not necessarily
all of it.
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'lib/pci_iomap.c')
| -rw-r--r-- | lib/pci_iomap.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c index 0d83ea8a9605..bcce5f149310 100644 --- a/lib/pci_iomap.c +++ b/lib/pci_iomap.c @@ -10,10 +10,11 @@ #ifdef CONFIG_PCI /** - * pci_iomap - create a virtual mapping cookie for a PCI BAR + * pci_iomap_range - create a virtual mapping cookie for a PCI BAR * @dev: PCI device that owns the BAR * @bar: BAR number - * @maxlen: length of the memory to map + * @offset: map memory at the given offset in BAR + * @maxlen: max length of the memory to map * * Using this function you will get a __iomem address to your device BAR. * You can access it using ioread*() and iowrite*(). These functions hide @@ -21,16 +22,21 @@ * you expect from them in the correct way. * * @maxlen specifies the maximum length to map. If you want to get access to - * the complete BAR without checking for its length first, pass %0 here. + * the complete BAR from offset to the end, pass %0 here. * */ -void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) +void __iomem *pci_iomap_range(struct pci_dev *dev, + int bar, + unsigned long offset, + unsigned long maxlen) { resource_size_t start = pci_resource_start(dev, bar); resource_size_t len = pci_resource_len(dev, bar); unsigned long flags = pci_resource_flags(dev, bar); - if (!len || !start) + if (len <= offset || !start) return NULL; + len -= offset; + start += offset; if (maxlen && len > maxlen) len = maxlen; if (flags & IORESOURCE_IO) @@ -43,6 +49,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) /* What? */ return NULL; } +EXPORT_SYMBOL(pci_iomap_range); +/** + * pci_iomap - create a virtual mapping cookie for a PCI BAR + * @dev: PCI device that owns the BAR + * @bar: BAR number + * @maxlen: length of the memory to map + * + * Using this function you will get a __iomem address to your device BAR. + * You can access it using ioread*() and iowrite*(). These functions hide + * the details if this is a MMIO or PIO address space and will just do what + * you expect from them in the correct way. + * + * @maxlen specifies the maximum length to map. If you want to get access to + * the complete BAR without checking for its length first, pass %0 here. + * */ +void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) +{ + return pci_iomap_range(dev, bar, 0, maxlen); +} EXPORT_SYMBOL(pci_iomap); #endif /* CONFIG_PCI */ |