Commit cafaf14a authored by Chris Wilson's avatar Chris Wilson

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: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: linux-mm@kvack.org
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-4-chris@chris-wilson.co.uk
parent 8678fdaf
...@@ -31,16 +31,16 @@ ...@@ -31,16 +31,16 @@
* See Documentation/io-mapping.txt * See Documentation/io-mapping.txt
*/ */
#ifdef CONFIG_HAVE_ATOMIC_IOMAP
#include <asm/iomap.h>
struct io_mapping { struct io_mapping {
resource_size_t base; resource_size_t base;
unsigned long size; unsigned long size;
pgprot_t prot; pgprot_t prot;
void __iomem *iomem;
}; };
#ifdef CONFIG_HAVE_ATOMIC_IOMAP
#include <asm/iomap.h>
/* /*
* For small address space machines, mapping large objects * For small address space machines, mapping large objects
* into the kernel virtual space isn't practical. Where * into the kernel virtual space isn't practical. Where
...@@ -49,34 +49,25 @@ struct io_mapping { ...@@ -49,34 +49,25 @@ struct io_mapping {
*/ */
static inline 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; pgprot_t prot;
iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
if (!iomap)
goto out_err;
if (iomap_create_wc(base, size, &prot)) if (iomap_create_wc(base, size, &prot))
goto out_free; return NULL;
iomap->base = base; iomap->base = base;
iomap->size = size; iomap->size = size;
iomap->prot = prot; iomap->prot = prot;
return iomap; return iomap;
out_free:
kfree(iomap);
out_err:
return NULL;
} }
static inline void static inline void
io_mapping_free(struct io_mapping *mapping) io_mapping_fini(struct io_mapping *mapping)
{ {
iomap_free(mapping->base, mapping->size); iomap_free(mapping->base, mapping->size);
kfree(mapping);
} }
/* Atomic map/unmap */ /* Atomic map/unmap */
...@@ -121,21 +112,40 @@ io_mapping_unmap(void __iomem *vaddr) ...@@ -121,21 +112,40 @@ io_mapping_unmap(void __iomem *vaddr)
#else #else
#include <linux/uaccess.h> #include <linux/uaccess.h>
#include <asm/pgtable_types.h>
/* this struct isn't actually defined anywhere */
struct io_mapping;
/* Create the io_mapping object*/ /* Create the io_mapping object*/
static inline 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)
{
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 static inline void
io_mapping_free(struct io_mapping *mapping) io_mapping_unmap(void __iomem *vaddr)
{ {
iounmap((void __force __iomem *) mapping);
} }
/* Atomic map/unmap */ /* Atomic map/unmap */
...@@ -145,30 +155,42 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping, ...@@ -145,30 +155,42 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping,
{ {
preempt_disable(); preempt_disable();
pagefault_disable(); pagefault_disable();
return ((char __force __iomem *) mapping) + offset; return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
} }
static inline void static inline void
io_mapping_unmap_atomic(void __iomem *vaddr) io_mapping_unmap_atomic(void __iomem *vaddr)
{ {
io_mapping_unmap(vaddr);
pagefault_enable(); pagefault_enable();
preempt_enable(); preempt_enable();
} }
/* Non-atomic map/unmap */ #endif /* HAVE_ATOMIC_IOMAP */
static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping, static inline struct io_mapping *
unsigned long offset, io_mapping_create_wc(resource_size_t base,
unsigned long size) 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 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 */ #endif /* _LINUX_IO_MAPPING_H */
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