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authorChris Wilson <chris@chris-wilson.co.uk>2016-08-19 18:54:26 +0300
committerChris Wilson <chris@chris-wilson.co.uk>2016-08-19 19:13:35 +0300
commitcafaf14a5d8f152ed3c984ecd48dee6e824446bc (patch)
tree3053466d3791ede38d33e61f34b8541bae8d3a43 /include/linux/io-mapping.h
parent8678fdaf396c3aa3732b3d98ce2241633dbc26ba (diff)
downloadlinux-cafaf14a5d8f152ed3c984ecd48dee6e824446bc.tar.xz
io-mapping: Always create a struct to hold metadata about the io-mapping
Currently, we only allocate a structure to hold metadata if we need to allocate an ioremap for every access, such as on x86-32. However, it would be useful to store basic information about the io-mapping, such as its page protection, on all platforms. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: linux-mm@kvack.org Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-4-chris@chris-wilson.co.uk
Diffstat (limited to 'include/linux/io-mapping.h')
-rw-r--r--include/linux/io-mapping.h92
1 files changed, 57 insertions, 35 deletions
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index 645ad06b5d52..b4c4b5c4216d 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -31,16 +31,16 @@
* See Documentation/io-mapping.txt
*/
-#ifdef CONFIG_HAVE_ATOMIC_IOMAP
-
-#include <asm/iomap.h>
-
struct io_mapping {
resource_size_t base;
unsigned long size;
pgprot_t prot;
+ void __iomem *iomem;
};
+#ifdef CONFIG_HAVE_ATOMIC_IOMAP
+
+#include <asm/iomap.h>
/*
* For small address space machines, mapping large objects
* into the kernel virtual space isn't practical. Where
@@ -49,34 +49,25 @@ struct io_mapping {
*/
static inline struct io_mapping *
-io_mapping_create_wc(resource_size_t base, unsigned long size)
+io_mapping_init_wc(struct io_mapping *iomap,
+ resource_size_t base,
+ unsigned long size)
{
- struct io_mapping *iomap;
pgprot_t prot;
- iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
- if (!iomap)
- goto out_err;
-
if (iomap_create_wc(base, size, &prot))
- goto out_free;
+ return NULL;
iomap->base = base;
iomap->size = size;
iomap->prot = prot;
return iomap;
-
-out_free:
- kfree(iomap);
-out_err:
- return NULL;
}
static inline void
-io_mapping_free(struct io_mapping *mapping)
+io_mapping_fini(struct io_mapping *mapping)
{
iomap_free(mapping->base, mapping->size);
- kfree(mapping);
}
/* Atomic map/unmap */
@@ -121,21 +112,40 @@ io_mapping_unmap(void __iomem *vaddr)
#else
#include <linux/uaccess.h>
-
-/* this struct isn't actually defined anywhere */
-struct io_mapping;
+#include <asm/pgtable_types.h>
/* Create the io_mapping object*/
static inline struct io_mapping *
-io_mapping_create_wc(resource_size_t base, unsigned long size)
+io_mapping_init_wc(struct io_mapping *iomap,
+ resource_size_t base,
+ unsigned long size)
+{
+ iomap->base = base;
+ iomap->size = size;
+ iomap->iomem = ioremap_wc(base, size);
+ iomap->prot = pgprot_writecombine(PAGE_KERNEL_IO);
+
+ return iomap;
+}
+
+static inline void
+io_mapping_fini(struct io_mapping *mapping)
+{
+ iounmap(mapping->iomem);
+}
+
+/* Non-atomic map/unmap */
+static inline void __iomem *
+io_mapping_map_wc(struct io_mapping *mapping,
+ unsigned long offset,
+ unsigned long size)
{
- return (struct io_mapping __force *) ioremap_wc(base, size);
+ return mapping->iomem + offset;
}
static inline void
-io_mapping_free(struct io_mapping *mapping)
+io_mapping_unmap(void __iomem *vaddr)
{
- iounmap((void __force __iomem *) mapping);
}
/* Atomic map/unmap */
@@ -145,30 +155,42 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping,
{
preempt_disable();
pagefault_disable();
- return ((char __force __iomem *) mapping) + offset;
+ return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
+ io_mapping_unmap(vaddr);
pagefault_enable();
preempt_enable();
}
-/* Non-atomic map/unmap */
-static inline void __iomem *
-io_mapping_map_wc(struct io_mapping *mapping,
- unsigned long offset,
- unsigned long size)
+#endif /* HAVE_ATOMIC_IOMAP */
+
+static inline struct io_mapping *
+io_mapping_create_wc(resource_size_t base,
+ unsigned long size)
{
- return ((char __force __iomem *) mapping) + offset;
+ struct io_mapping *iomap;
+
+ iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
+ if (!iomap)
+ return NULL;
+
+ if (!io_mapping_init_wc(iomap, base, size)) {
+ kfree(iomap);
+ return NULL;
+ }
+
+ return iomap;
}
static inline void
-io_mapping_unmap(void __iomem *vaddr)
+io_mapping_free(struct io_mapping *iomap)
{
+ io_mapping_fini(iomap);
+ kfree(iomap);
}
-#endif /* HAVE_ATOMIC_IOMAP */
-
#endif /* _LINUX_IO_MAPPING_H */