diff options
author | Jiri Kosina <jkosina@suse.cz> | 2021-06-30 09:02:28 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2021-06-30 09:02:28 +0200 |
commit | 5a94296bc02ac616336da7b5332b86d2ca8827f0 (patch) | |
tree | d13c4e7db2b4b01adb87fbf2ea5bafd2dc920b2f /mm/io-mapping.c | |
parent | 3b770932eefb7c0c6319d332023efee87eb12913 (diff) | |
parent | 24a31ea94922d391a96a9dd0a9a830de65423817 (diff) |
Merge branch 'for-5.14/amd-sfh' into for-linus
- support for Renoir and Cezanne SoCs
- support for Ambient Light Sensor
- support for Human Presence Detection sensor
all from Basavaraj Natikar
Diffstat (limited to 'mm/io-mapping.c')
-rw-r--r-- | mm/io-mapping.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/mm/io-mapping.c b/mm/io-mapping.c new file mode 100644 index 0000000000000..01b3627999304 --- /dev/null +++ b/mm/io-mapping.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/mm.h> +#include <linux/io-mapping.h> + +/** + * io_mapping_map_user - remap an I/O mapping to userspace + * @iomap: the source io_mapping + * @vma: user vma to map to + * @addr: target user address to start at + * @pfn: physical address of kernel memory + * @size: size of map area + * + * Note: this is only safe if the mm semaphore is held when called. + */ +int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, + unsigned long addr, unsigned long pfn, unsigned long size) +{ + vm_flags_t expected_flags = VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; + + if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags)) + return -EINVAL; + + /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ + return remap_pfn_range_notrack(vma, addr, pfn, size, + __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | + (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK))); +} +EXPORT_SYMBOL_GPL(io_mapping_map_user); |