security/vboot: Remove struct vboot_working_data

After CB:36808, CB:36844 and CB:36845, all fields except buffer_offset
were removed from struct vboot_working_data. Since buffer_offset is used
to record the offset of the workbuf relative to the whole structure, it
is no longer needed.

This patch removes the structure, and renames vboot_get_working_data()
to vboot_get_workbuf().

BRANCH=none
BUG=chromium:1021452
TEST=emerge-nami coreboot

Change-Id: I304a5e4236f13b1aecd64b88ca5c8fbc1526e592
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37231
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Joel Kitching <kitching@google.com>

src/lib/coreboot_table.c

@@ -221,20 +221,18 @@ static void lb_vbnv(struct lb_header *header)
 static void lb_vboot_workbuf(struct lb_header *header)
 {
 	struct lb_range *vbwb;
-	struct vboot_working_data *wd = vboot_get_working_data();
+	void *wb = vboot_get_workbuf();
 
 	vbwb = (struct lb_range *)lb_new_record(header);
 	vbwb->tag = LB_TAG_VBOOT_WORKBUF;
 	vbwb->size = sizeof(*vbwb);
-	vbwb->range_start = (uintptr_t)wd + wd->buffer_offset;
+	vbwb->range_start = (uintptr_t)wb;
 	/*
 	 * TODO(chromium:1021452): Since cbmem size of vboot workbuf is now
 	 * always a known value, we hardcode the value of range_size here.
-	 * Ultimately we'll want to move this to add_cbmem_pointers() below,
-	 * but we'll have to get rid of the vboot_working_data struct first.
+	 * Ultimately we'll want to move this to add_cbmem_pointers() below.
 	 */
-	vbwb->range_size = VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE -
-		wd->buffer_offset;
+	vbwb->range_size = VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE;
 }
 
 __weak uint32_t board_id(void) { return UNDEFINED_STRAPPING_ID; }

src/security/vboot/common.c

@@ -27,57 +27,42 @@
 
 static struct vb2_context *vboot_ctx;
 
-struct vboot_working_data *vboot_get_working_data(void)
+void *vboot_get_workbuf(void)
 {
-	struct vboot_working_data *wd = NULL;
+	void *wb = NULL;
 
 	if (cbmem_possibly_online())
-		wd = cbmem_find(CBMEM_ID_VBOOT_WORKBUF);
+		wb = cbmem_find(CBMEM_ID_VBOOT_WORKBUF);
 
-	if (wd == NULL && CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) &&
+	if (wb == NULL && CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) &&
 	    preram_symbols_available())
-		wd = (struct vboot_working_data *)_vboot2_work;
+		wb = _vboot2_work;
 
-	assert(wd != NULL);
+	assert(wb != NULL);
 
-	return wd;
-}
-
-static inline void *vboot_get_workbuf(struct vboot_working_data *wd)
-{
-	return (void *)((uintptr_t)wd + wd->buffer_offset);
+	return wb;
 }
 
 struct vb2_context *vboot_get_context(void)
 {
-	struct vboot_working_data *wd;
+	void *wb;
 
 	/* Return if context has already been initialized/restored. */
 	if (vboot_ctx)
 		return vboot_ctx;
 
-	wd = vboot_get_working_data();
+	wb = vboot_get_workbuf();
 
 	/* Restore context from a previous stage. */
 	if (vboot_logic_executed()) {
-		assert(vb2api_reinit(vboot_get_workbuf(wd),
-				     &vboot_ctx) == VB2_SUCCESS);
+		assert(vb2api_reinit(wb, &vboot_ctx) == VB2_SUCCESS);
 		return vboot_ctx;
 	}
 
 	assert(verification_should_run());
 
-	/*
-	 * vboot prefers 16-byte alignment. This takes away 16 bytes
-	 * from the VBOOT2_WORK region, but the vboot devs said that's okay.
-	 */
-	memset(wd, 0, sizeof(*wd));
-	wd->buffer_offset = ALIGN_UP(sizeof(*wd), 16);
-
 	/* Initialize vb2_shared_data and friends. */
-	assert(vb2api_init(vboot_get_workbuf(wd),
-			   VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE -
-			   wd->buffer_offset,
+	assert(vb2api_init(wb, VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE,
 			   &vboot_ctx) == VB2_SUCCESS);
 
 	return vboot_ctx;
@@ -96,35 +81,19 @@ int vboot_locate_firmware(const struct vb2_context *ctx,
 	return fmap_locate_area_as_rdev(name, fw);
 }
 
-#if CONFIG(VBOOT_STARTS_IN_BOOTBLOCK)
-/*
- * For platforms that do not employ VBOOT_STARTS_IN_ROMSTAGE, vboot
- * verification occurs before CBMEM is brought online, using pre-RAM.
- * In order to make vboot data structures available downstream, copy
- * vboot_working_data from SRAM/CAR into CBMEM.
- */
-static void vboot_migrate_cbmem(int unused)
-{
-	const size_t cbmem_size = VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE;
-	struct vboot_working_data *wd_preram =
-		(struct vboot_working_data *)_vboot2_work;
-	struct vboot_working_data *wd_cbmem =
-		cbmem_add(CBMEM_ID_VBOOT_WORKBUF, cbmem_size);
-	assert(wd_cbmem != NULL);
-	memcpy(wd_cbmem, wd_preram, sizeof(struct vboot_working_data));
-	vb2api_relocate(vboot_get_workbuf(wd_cbmem),
-			vboot_get_workbuf(wd_preram),
-			cbmem_size - wd_cbmem->buffer_offset,
-			&vboot_ctx);
-}
-ROMSTAGE_CBMEM_INIT_HOOK(vboot_migrate_cbmem)
-#else
 static void vboot_setup_cbmem(int unused)
 {
-	struct vboot_working_data *wd_cbmem =
-		cbmem_add(CBMEM_ID_VBOOT_WORKBUF,
-			  VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE);
-	assert(wd_cbmem != NULL);
+	const size_t cbmem_size = VB2_KERNEL_WORKBUF_RECOMMENDED_SIZE;
+	void *wb_cbmem = cbmem_add(CBMEM_ID_VBOOT_WORKBUF, cbmem_size);
+	assert(wb_cbmem != NULL);
+	/*
+	 * For platforms where VBOOT_STARTS_IN_BOOTBLOCK, vboot verification
+	 * occurs before CBMEM is brought online, using pre-RAM. In order to
+	 * make vboot data structures available downstream, copy vboot workbuf
+	 * from SRAM/CAR into CBMEM.
+	 */
+	if (CONFIG(VBOOT_STARTS_IN_BOOTBLOCK))
+		assert(vb2api_relocate(wb_cbmem, _vboot2_work, cbmem_size,
+				       &vboot_ctx) == VB2_SUCCESS);
 }
 ROMSTAGE_CBMEM_INIT_HOOK(vboot_setup_cbmem)
-#endif

src/security/vboot/misc.h

@@ -22,22 +22,10 @@
 struct vb2_context;
 struct vb2_shared_data;
 
-/*
- * Stores vboot-related information.  selected_region is used by verstage to
- * store the location of the selected slot.  buffer is used by vboot to store
- * its work buffer.  vb2_context is contained within this work buffer, and is
- * accessible via vboot_get_context() declared below.
- * Keep the struct CPU architecture agnostic as it crosses stage boundaries.
- */
-struct vboot_working_data {
-	/* offset of the buffer from the start of this struct */
-	uint16_t buffer_offset;
-};
-
 /*
  * Source: security/vboot/common.c
  */
-struct vboot_working_data *vboot_get_working_data(void);
+void *vboot_get_workbuf(void);
 struct vb2_context *vboot_get_context(void);
 
 /*