linux-kernel - [PATCH v2 1/5] drm/i915: Use kernel

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Message-ID: <20250624121149.2927-2-chentaotao@didiglobal.com>
Date: Tue, 24 Jun 2025 12:12:04 +0000
From: 陈涛涛 Taotao Chen <chentaotao@...iglobal.com>
To: "tytso@....edu" <tytso@....edu>, "hch@...radead.org" <hch@...radead.org>,
	"adilger.kernel@...ger.ca" <adilger.kernel@...ger.ca>, "willy@...radead.org"
	<willy@...radead.org>, "brauner@...nel.org" <brauner@...nel.org>,
	"jani.nikula@...ux.intel.com" <jani.nikula@...ux.intel.com>,
	"rodrigo.vivi@...el.com" <rodrigo.vivi@...el.com>, "tursulin@...ulin.net"
	<tursulin@...ulin.net>, "airlied@...il.com" <airlied@...il.com>
CC: "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
	"linux-block@...r.kernel.org" <linux-block@...r.kernel.org>,
	"intel-gfx@...ts.freedesktop.org" <intel-gfx@...ts.freedesktop.org>,
	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>, "linux-doc@...r.kernel.org"
	<linux-doc@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "chentao325@...com" <chentao325@...com>,
	陈涛涛 Taotao Chen <chentaotao@...iglobal.com>
Subject: [PATCH v2 1/5] drm/i915: Use kernel_write() in shmem object create

From: Taotao Chen <chentaotao@...iglobal.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 <chentaotao@...iglobal.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 31 ++++++-----------------
 1 file changed, 8 insertions(+), 23 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..d08ade934d15 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -637,8 +637,7 @@ 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;
+	loff_t pos = 0;
 	int err;
 
 	GEM_WARN_ON(IS_DGFX(i915));
@@ -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