1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
new file mode 100644
index 000000000..402f085f3
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include <linux/iosys-map.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/shmem_fs.h>
+
+#include "gem/i915_gem_object.h"
+#include "gem/i915_gem_lmem.h"
+#include "shmem_utils.h"
+
+struct file *shmem_create_from_data(const char *name, void *data, size_t len)
+{
+	struct file *file;
+	int err;
+
+	file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);
+	if (IS_ERR(file))
+		return file;
+
+	err = shmem_write(file, 0, data, len);
+	if (err) {
+		fput(file);
+		return ERR_PTR(err);
+	}
+
+	return file;
+}
+
+struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
+{
+	struct file *file;
+	void *ptr;
+
+	if (i915_gem_object_is_shmem(obj)) {
+		file = obj->base.filp;
+		atomic_long_inc(&file->f_count);
+		return file;
+	}
+
+	ptr = i915_gem_object_pin_map_unlocked(obj, i915_gem_object_is_lmem(obj) ?
+						I915_MAP_WC : I915_MAP_WB);
+	if (IS_ERR(ptr))
+		return ERR_CAST(ptr);
+
+	file = shmem_create_from_data("", ptr, obj->base.size);
+	i915_gem_object_unpin_map(obj);
+
+	return file;
+}
+
+void *shmem_pin_map(struct file *file)
+{
+	struct page **pages;
+	size_t n_pages, i;
+	void *vaddr;
+
+	n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
+	pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+	if (!pages)
+		return NULL;
+
+	for (i = 0; i < n_pages; i++) {
+		pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,
+						       GFP_KERNEL);
+		if (IS_ERR(pages[i]))
+			goto err_page;
+	}
+
+	vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
+	if (!vaddr)
+		goto err_page;
+	mapping_set_unevictable(file->f_mapping);
+	return vaddr;
+err_page:
+	while (i--)
+		put_page(pages[i]);
+	kvfree(pages);
+	return NULL;
+}
+
+void shmem_unpin_map(struct file *file, void *ptr)
+{
+	mapping_clear_unevictable(file->f_mapping);
+	vfree(ptr);
+}
+
+static int __shmem_rw(struct file *file, loff_t off,
+		      void *ptr, size_t len,
+		      bool write)
+{
+	unsigned long pfn;
+
+	for (pfn = off >> PAGE_SHIFT; len; pfn++) {
+		unsigned int this =
+			min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
+		struct page *page;
+		void *vaddr;
+
+		page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
+						   GFP_KERNEL);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		vaddr = kmap(page);
+		if (write) {
+			memcpy(vaddr + offset_in_page(off), ptr, this);
+			set_page_dirty(page);
+		} else {
+			memcpy(ptr, vaddr + offset_in_page(off), this);
+		}
+		mark_page_accessed(page);
+		kunmap(page);
+		put_page(page);
+
+		len -= this;
+		ptr += this;
+		off = 0;
+	}
+
+	return 0;
+}
+
+int shmem_read_to_iosys_map(struct file *file, loff_t off,
+			    struct iosys_map *map, size_t map_off, size_t len)
+{
+	unsigned long pfn;
+
+	for (pfn = off >> PAGE_SHIFT; len; pfn++) {
+		unsigned int this =
+			min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
+		struct page *page;
+		void *vaddr;
+
+		page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
+						   GFP_KERNEL);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		vaddr = kmap(page);
+		iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off),
+				    this);
+		mark_page_accessed(page);
+		kunmap(page);
+		put_page(page);
+
+		len -= this;
+		map_off += this;
+		off = 0;
+	}
+
+	return 0;
+}
+
+int shmem_read(struct file *file, loff_t off, void *dst, size_t len)
+{
+	return __shmem_rw(file, off, dst, len, false);
+}
+
+int shmem_write(struct file *file, loff_t off, void *src, size_t len)
+{
+	return __shmem_rw(file, off, src, len, true);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "st_shmem_utils.c"
+#endif