drm/i915/gvt: Refine find_bb_size()

Returns the error code if something is wrong and the size of batch buffer
is passed through the pointer.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
index cd2681a..3355eb4 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
+++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
@@ -1594,23 +1594,23 @@ static int batch_buffer_needs_scan(struct parser_exec_state *s)
        return 1;
 }
 
-static int find_bb_size(struct parser_exec_state *s)
+static int find_bb_size(struct parser_exec_state *s, unsigned long *bb_size)
 {
        unsigned long gma = 0;
        struct cmd_info *info;
-       int bb_size = 0;
        uint32_t cmd_len = 0;
-       bool met_bb_end = false;
+       bool bb_end = false;
        struct intel_vgpu *vgpu = s->vgpu;
        u32 cmd;
 
+       *bb_size = 0;
+
        /* get the start gm address of the batch buffer */
        gma = get_gma_bb_from_cmd(s, 1);
        if (gma == INTEL_GVT_INVALID_ADDR)
                return -EFAULT;
 
        cmd = cmd_val(s, 0);
-
        info = get_cmd_info(s->vgpu->gvt, cmd, s->ring_id);
        if (info == NULL) {
                gvt_vgpu_err("unknown cmd 0x%x, opcode=0x%x\n",
@@ -1629,20 +1629,18 @@ static int find_bb_size(struct parser_exec_state *s)
                }
 
                if (info->opcode == OP_MI_BATCH_BUFFER_END) {
-                       met_bb_end = true;
+                       bb_end = true;
                } else if (info->opcode == OP_MI_BATCH_BUFFER_START) {
-                       if (BATCH_BUFFER_2ND_LEVEL_BIT(cmd) == 0) {
+                       if (BATCH_BUFFER_2ND_LEVEL_BIT(cmd) == 0)
                                /* chained batch buffer */
-                               met_bb_end = true;
-                       }
+                               bb_end = true;
                }
                cmd_len = get_cmd_length(info, cmd) << 2;
-               bb_size += cmd_len;
+               *bb_size += cmd_len;
                gma += cmd_len;
+       } while (!bb_end);
 
-       } while (!met_bb_end);
-
-       return bb_size;
+       return 0;
 }
 
 static int perform_bb_shadow(struct parser_exec_state *s)
@@ -1650,7 +1648,7 @@ static int perform_bb_shadow(struct parser_exec_state *s)
        struct intel_shadow_bb_entry *entry_obj;
        struct intel_vgpu *vgpu = s->vgpu;
        unsigned long gma = 0;
-       int bb_size;
+       unsigned long bb_size;
        void *dst = NULL;
        int ret = 0;
 
@@ -1660,9 +1658,9 @@ static int perform_bb_shadow(struct parser_exec_state *s)
                return -EFAULT;
 
        /* get the size of the batch buffer */
-       bb_size = find_bb_size(s);
-       if (bb_size < 0)
-               return bb_size;
+       ret = find_bb_size(s, &bb_size);
+       if (ret)
+               return ret;
 
        /* allocate shadow batch buffer */
        entry_obj = kmalloc(sizeof(*entry_obj), GFP_KERNEL);