i965: Fix BRW_MEMZONE_LOW_4G heap size.

The STATE_BASE_ADDRESS "Size" fields can only hold 0xfffff in pages,
and 0xfffff * 4096 = 4294963200, which is 1 page shy of 4GB.

So we can't use the top page.

Fixes: 01058a55229 i965: Add virtual memory allocator infrastructure to brw_bufmgr.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.c b/src/mesa/drivers/dri/i965/brw_bufmgr.c
index 7b0ddfb64ddd804a835b99b6e5e8ef32d9a64a7f..b8795374880bcc37c69e58b0af6d06d94df0d294 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_bufmgr.c
+++ b/src/mesa/drivers/dri/i965/brw_bufmgr.c
@@ -1717,6 +1717,9 @@ brw_bufmgr_init(struct gen_device_info *devinfo, int fd)
 
    const uint64_t _4GB = 4ull << 30;
 
+   /* The STATE_BASE_ADDRESS size field can only hold 1 page shy of 4GB */
+   const uint64_t _4GB_minus_1 = _4GB - PAGE_SIZE;
+
    if (devinfo->gen >= 8 && gtt_size > _4GB) {
       bufmgr->initial_kflags |= EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
 
@@ -1726,7 +1729,7 @@ brw_bufmgr_init(struct gen_device_info *devinfo, int fd)
          bufmgr->initial_kflags |= EXEC_OBJECT_PINNED;
 
          util_vma_heap_init(&bufmgr->vma_allocator[BRW_MEMZONE_LOW_4G],
-                            PAGE_SIZE, _4GB);
+                            PAGE_SIZE, _4GB_minus_1);
          util_vma_heap_init(&bufmgr->vma_allocator[BRW_MEMZONE_OTHER],
                             1 * _4GB, gtt_size - 1 * _4GB);
       } else if (devinfo->gen >= 10) {