tests/gem_exec_parse: fix batch_len setting for cmd-crossing-page

The size of the batch buffer passed to the kernel is significantly
larger than the size of the batch buffer passed to the function. A
proposed optimization as part of the batch copy kernel series is to
use batch_len for the copy and parse operations, which leads to a
false "batch without MI_BATCH_BUFFER_END" failure for this test.

To fix this, modify the test to set batch_start_offset and batch_len
such that they define the range of actual commands in the batch,
including a few of the surrounding nops for alignment purposes.

v2: update batch_start_offset as well

Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/tests/gem_exec_parse.c b/tests/gem_exec_parse.c
index 1dc9103..e48b83a 100644 (file)
--- a/tests/gem_exec_parse.c
+++ b/tests/gem_exec_parse.c
@@ -144,16 +144,18 @@ static void exec_split_batch(int fd, uint32_t *cmds,
        struct drm_i915_gem_exec_object2 objs[1];
        uint32_t cmd_bo;
        uint32_t noop[1024] = { 0 };
+       const int alloc_size = 4096 * 2;
+       const int actual_start_offset = 4096-sizeof(uint32_t);
 
        // Allocate and fill a 2-page batch with noops
-       cmd_bo = gem_create(fd, 4096 * 2);
+       cmd_bo = gem_create(fd, alloc_size);
        gem_write(fd, cmd_bo, 0, noop, sizeof(noop));
        gem_write(fd, cmd_bo, 4096, noop, sizeof(noop));
 
        // Write the provided commands such that the first dword
        // of the command buffer is the last dword of the first
        // page (i.e. the command is split across the two pages).
-       gem_write(fd, cmd_bo, 4096-sizeof(uint32_t), cmds, size);
+       gem_write(fd, cmd_bo, actual_start_offset, cmds, size);
 
        objs[0].handle = cmd_bo;
        objs[0].relocation_count = 0;
@@ -166,8 +168,14 @@ static void exec_split_batch(int fd, uint32_t *cmds,
 
        execbuf.buffers_ptr = (uintptr_t)objs;
        execbuf.buffer_count = 1;
-       execbuf.batch_start_offset = 0;
-       execbuf.batch_len = size;
+       // NB: We want batch_start_offset and batch_len to point to the block
+       // of the actual commands (i.e. at the last dword of the first page),
+       // but have to adjust both the start offset and length to meet the
+       // kernel driver's requirements on the alignment of those fields.
+       execbuf.batch_start_offset = actual_start_offset & ~0x7;
+       execbuf.batch_len =
+               ALIGN(size + actual_start_offset - execbuf.batch_start_offset,
+                     0x8);
        execbuf.cliprects_ptr = 0;
        execbuf.num_cliprects = 0;
        execbuf.DR1 = 0;