From: jsg <jsg@openbsd.org>
Date: Thu, 21 Mar 2024 05:14:35 +0000 (+0000)
Subject: add uao_read_to_iosys_map() alternative to shmem_read_to_iosys_map()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=0a503ede77f395ac19eba8770e42c9e0665a730d;p=openbsd

add uao_read_to_iosys_map() alternative to shmem_read_to_iosys_map()
---

diff --git a/sys/dev/pci/drm/i915/gt/shmem_utils.c b/sys/dev/pci/drm/i915/gt/shmem_utils.c
index a5f2ed8f652..18f598bd42d 100644
--- a/sys/dev/pci/drm/i915/gt/shmem_utils.c
+++ b/sys/dev/pci/drm/i915/gt/shmem_utils.c
@@ -249,6 +249,38 @@ static int __uao_rw(struct uvm_object *uao, loff_t off,
 	return 0;
 }
 
+int uao_read_to_iosys_map(struct uvm_object *uao, loff_t off,
+			    struct iosys_map *map, size_t map_off, size_t len)
+{
+	struct pglist plist;
+	struct vm_page *page;
+	vaddr_t pgoff = trunc_page(off);
+	size_t olen = round_page(len);
+
+	TAILQ_INIT(&plist);
+	if (uvm_obj_wire(uao, pgoff, olen, &plist))
+		return -ENOMEM;
+
+	TAILQ_FOREACH(page, &plist, pageq) {
+		unsigned int this =
+			min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
+		void *vaddr;
+
+		vaddr = kmap(page);
+		iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off),
+				    this);
+		kunmap_va(vaddr);
+
+		len -= this;
+		map_off += this;
+		off = 0;
+	}
+
+	uvm_obj_unwire(uao, pgoff, olen);
+
+	return 0;
+}
+
 int uao_read(struct uvm_object *uao, loff_t off, void *dst, size_t len)
 {
 	return __uao_rw(uao, off, dst, len, false);
diff --git a/sys/dev/pci/drm/i915/gt/shmem_utils.h b/sys/dev/pci/drm/i915/gt/shmem_utils.h
index a416139db45..dcec6346148 100644
--- a/sys/dev/pci/drm/i915/gt/shmem_utils.h
+++ b/sys/dev/pci/drm/i915/gt/shmem_utils.h
@@ -27,6 +27,8 @@ int shmem_write(struct file *file, loff_t off, void *src, size_t len);
 
 struct uvm_object *
 uao_create_from_object(struct drm_i915_gem_object *);
+int uao_read_to_iosys_map(struct uvm_object *, loff_t,
+	struct iosys_map *, size_t, size_t);
 int uao_read(struct uvm_object *, loff_t, void *, size_t);
 int uao_write(struct uvm_object *, loff_t, void *, size_t);