[PATCH v6 1/5] drm/i915: Use kernel_write() in shmem object create

[陈涛涛 Taotao Chen]

From: Taotao Chen <chentao...@didiglobal.com>

Replace the write_begin/write_end loop in
i915_gem_object_create_shmem_from_data() with call to kernel_write().

This function initializes shmem-backed GEM objects. kernel_write()
simplifies the code by removing manual folio handling.

Part of a series refactoring address_space_operations write_begin and
write_end callbacks to use struct kiocb for passing write context and
flags.

Signed-off-by: Taotao Chen <chentao...@didiglobal.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 33 +++++++----------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c 
b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 19a3eb82dc6a..1e8f66ac48ca 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -637,9 +637,8 @@ i915_gem_object_create_shmem_from_data(struct 
drm_i915_private *i915,
 {
        struct drm_i915_gem_object *obj;
        struct file *file;
-       const struct address_space_operations *aops;
-       loff_t pos;
-       int err;
+       loff_t pos = 0;
+       ssize_t err;
 
        GEM_WARN_ON(IS_DGFX(i915));
        obj = i915_gem_object_create_shmem(i915, round_up(size, PAGE_SIZE));
@@ -649,29 +648,15 @@ i915_gem_object_create_shmem_from_data(struct 
drm_i915_private *i915,
        GEM_BUG_ON(obj->write_domain != I915_GEM_DOMAIN_CPU);
 
        file = obj->base.filp;
-       aops = file->f_mapping->a_ops;
-       pos = 0;
-       do {
-               unsigned int len = min_t(typeof(size), size, PAGE_SIZE);
-               struct folio *folio;
-               void *fsdata;
-
-               err = aops->write_begin(file, file->f_mapping, pos, len,
-                                       &folio, &fsdata);
-               if (err < 0)
-                       goto fail;
+       err = kernel_write(file, data, size, &pos);
 
-               memcpy_to_folio(folio, offset_in_folio(folio, pos), data, len);
+       if (err < 0)
+               goto fail;
 
-               err = aops->write_end(file, file->f_mapping, pos, len, len,
-                                     folio, fsdata);
-               if (err < 0)
-                       goto fail;
-
-               size -= len;
-               data += len;
-               pos += len;
-       } while (size);
+       if (err != size) {
+               err = -EIO;
+               goto fail;
+       }
 
        return obj;
 
-- 
2.34.1