diff options
author | Zhao Liu <zhao1.liu@intel.com> | 2023-12-03 16:29:45 +0300 |
---|---|---|
committer | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2023-12-15 12:34:30 +0300 |
commit | 55a6e46180cb8b36fb1076501b569bfd42df1644 (patch) | |
tree | c0113fe76e92fe63965221596c6b5f2039f29f5f /drivers/gpu/drm/i915 | |
parent | b1c51b0e2e7cb98f643a801c50f8ad76ebc36450 (diff) | |
download | linux-55a6e46180cb8b36fb1076501b569bfd42df1644.tar.xz |
drm/i915: Use memcpy_from_page() in gt/uc/intel_uc_fw.c
The use of kmap_atomic() is being deprecated in favor of
kmap_local_page()[1], and this patch converts the call from
kmap_atomic() to kmap_local_page().
The main difference between atomic and local mappings is that local
mappings doesn't disable page faults or preemption (the preemption is
disabled for !PREEMPT_RT case, otherwise it only disables migration).
With kmap_local_page(), we can avoid the often unwanted side effect of
unnecessary page faults or preemption disables.
In drm/i915/gt/uc/intel_us_fw.c, the function intel_uc_fw_copy_rsa()
just use the mapping to do memory copy so it doesn't need to disable
pagefaults and preemption for mapping. Thus the local mapping without
atomic context (not disable pagefaults / preemption) is enough.
Therefore, intel_uc_fw_copy_rsa() is a function where the use of
memcpy_from_page() with kmap_local_page() in place of memcpy() with
kmap_atomic() is correctly suited.
Convert the calls of memcpy() with kmap_atomic() / kunmap_atomic() to
memcpy_from_page() which uses local mapping to copy.
[1]: https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/T/#u
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231203132947.2328805-8-zhao1.liu@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915')
-rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c index 362639162ed6..756093eaf2ad 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c @@ -1343,16 +1343,13 @@ size_t intel_uc_fw_copy_rsa(struct intel_uc_fw *uc_fw, void *dst, u32 max_len) for_each_sgt_page(page, iter, uc_fw->obj->mm.pages) { u32 len = min_t(u32, size, PAGE_SIZE - offset); - void *vaddr; if (idx > 0) { idx--; continue; } - vaddr = kmap_atomic(page); - memcpy(dst, vaddr + offset, len); - kunmap_atomic(vaddr); + memcpy_from_page(dst, page, offset, len); offset = 0; dst += len; |