From: Michael S Tsirkin <mst@xxxxxxxxxx>
Virtio drivers should map the part of the range they need, not necessarily
all of it.
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
include/asm-generic/io.h | 4 ++++
include/asm-generic/iomap.h | 11 +++++++++++
lib/iomap.c | 41 ++++++++++++++++++++++++++++++++++++-----
3 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 9120887..3cf1787 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -286,6 +286,10 @@ static inline void writesb(const void __iomem *addr, const void *buf, int len)
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
struct pci_dev;
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
+ unsigned offset,
+ unsigned long minlen,
+ unsigned long maxlen);
static inline void pci_iounmap(struct pci_dev *dev, void __iomem *p)
{
}
diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 98dcd76..6f192d4 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -70,8 +70,19 @@ extern void ioport_unmap(void __iomem *);
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
struct pci_dev;
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
+ unsigned offset,
+ unsigned long minlen,
+ unsigned long maxlen);
extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
#else
+static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
+ unsigned offset,
+ unsigned long minlen,
+ unsigned long maxlen)
+{
+ return NULL;
+}
struct pci_dev;
static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max)
{
diff --git a/lib/iomap.c b/lib/iomap.c
index 5dbcb4b..93ae915 100644
--- a/lib/iomap.c
+++ b/lib/iomap.c
@@ -243,26 +243,37 @@ EXPORT_SYMBOL(ioport_unmap);
#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
+ * @minlen: min length of the memory to map
+ * @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
* the details if this is a MMIO or PIO address space and will just do what
* you expect from them in the correct way.
*
+ * @minlen specifies the minimum length to map. We check that BAR is
+ * large enough.
* @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 offset,
+ unsigned long minlen,
+ 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 (len < minlen)
return NULL;
if (maxlen && len > maxlen)
len = maxlen;
@@ -277,10 +288,30 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
return NULL;
}
+/**
+ * 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, 0, maxlen);
+}
+
void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
{
IO_COND(addr, /* nothing */, iounmap(addr));
}
EXPORT_SYMBOL(pci_iomap);
+EXPORT_SYMBOL(pci_iomap_range);
EXPORT_SYMBOL(pci_iounmap);
#endif /* CONFIG_PCI */
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