[src/trunk]: src/sys/external/bsd/drm2/i915drm Tweak i915 gen6_gtt_init calcu...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/948e06819c2f
branches:  trunk
changeset: 329197:948e06819c2f
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed May 14 15:58:24 2014 +0000

description:
Tweak i915 gen6_gtt_init calculations for clarity.

diffstat:

 sys/external/bsd/drm2/i915drm/i915_gem_gtt.c |  62 +++++++++++++++------------
 1 files changed, 35 insertions(+), 27 deletions(-)

diffs (111 lines):

diff -r a761bac730a3 -r 948e06819c2f sys/external/bsd/drm2/i915drm/i915_gem_gtt.c
--- a/sys/external/bsd/drm2/i915drm/i915_gem_gtt.c      Wed May 14 14:59:14 2014 +0000
+++ b/sys/external/bsd/drm2/i915drm/i915_gem_gtt.c      Wed May 14 15:58:24 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: i915_gem_gtt.c,v 1.5 2014/05/02 14:36:10 riastradh Exp $       */
+/*     $NetBSD: i915_gem_gtt.c,v 1.6 2014/05/14 15:58:24 riastradh Exp $       */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i915_gem_gtt.c,v 1.5 2014/05/02 14:36:10 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i915_gem_gtt.c,v 1.6 2014/05/14 15:58:24 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -565,13 +565,13 @@
        struct drm_i915_private *const dev_priv = dev->dev_private;
        struct pci_attach_args *const pa = &dev->pdev->pd_pa;
        struct intel_gtt *gtt = dev_priv->mm.gtt;
+       bus_addr_t gtt_addr;
+       bus_size_t gtt_size;
        uint16_t snb_gmch_ctl, ggms, gms;
        int ret;
 
        gtt->do_idle_maps = false;
 
-       gtt->gma_bus_addr = dev->bus_maps[2].bm_base;
-
        snb_gmch_ctl = pci_conf_read(pa->pa_pc, pa->pa_tag, SNB_GMCH_CTRL);
 
        /* GMS: Graphics Mode Select.  */
@@ -586,36 +586,45 @@
                gtt->stolen_size = sizes[gms] << 20;
        }
 
-       /* GGMS: GTT Graphics Memory Size.  */
+       /* GGMS: GTT Graphics Memory Size, in megabytes.  */
        ggms = __SHIFTOUT(snb_gmch_ctl, SNB_GMCH_GGMS);
+       CTASSERT(SNB_GMCH_GGMS_MASK <= (INT_MAX >> 20));
        gtt->gtt_total_entries = (ggms << 20) / sizeof(gtt_pte_t);
 
+       /* Linux sez:  For GEN6+ the PTEs for the ggtt live at 2MB + BAR0 */
+       gtt_addr = (2<<20);
+       gtt_size = (gtt->gtt_total_entries * sizeof(gtt_pte_t));
+       if ((gtt_addr > (__type_max(bus_addr_t) - dev->bus_maps[0].bm_base)) ||
+           (gtt_size > (__type_max(bus_addr_t) -
+               (dev->bus_maps[0].bm_base + gtt_addr)))) {
+               DRM_ERROR("GTT doesn't fit in BAR0:"
+                   " base 0x%"PRIxMAX
+                   " size 0x%"PRIxMAX","
+                   " gtt_addr 0x%"PRIxMAX""
+                   " gtt_total_entries 0x%"PRIxMAX"\n",
+                   (uintmax_t)dev->bus_maps[0].bm_base,
+                   (uintmax_t)dev->bus_maps[0].bm_size,
+                   (uintmax_t)gtt_addr,
+                   (uintmax_t)gtt->gtt_total_entries);
+               ret = -ENODEV;
+               goto fail0;
+       }
+
+       if (bus_space_map(dev->bst, (dev->bus_maps[0].bm_base + gtt_addr),
+               gtt_size, 0, &gtt->gtt_bsh)) {
+               DRM_ERROR("unable to map GTT\n");
+               ret = -ENODEV;
+               goto fail0;
+       }
+
+       gtt->gma_bus_addr = dev->bus_maps[2].bm_base;
        gtt->gtt_mappable_entries = (dev->bus_maps[2].bm_size >> PAGE_SHIFT);
        if (((gtt->gtt_mappable_entries >> 8) < 64) ||
            (gtt->gtt_total_entries < gtt->gtt_mappable_entries)) {
                DRM_ERROR("unknown GMADR entries: %d\n",
                    gtt->gtt_mappable_entries);
                ret = -ENXIO;
-               goto fail0;
-       }
-
-       /* Linux sez:  For GEN6+ the PTEs for the ggtt live at 2MB + BAR0 */
-       if (dev->bus_maps[0].bm_size < (gtt->gtt_total_entries *
-               sizeof(gtt_pte_t))) {
-               DRM_ERROR("BAR0 too small for GTT: 0x%"PRIxMAX" < 0x%"PRIxMAX
-                   "\n",
-                   (uintmax_t)dev->bus_maps[0].bm_size,
-                   (uintmax_t)(gtt->gtt_total_entries * sizeof(gtt_pte_t)));
-               ret = -ENODEV;
-               goto fail0;
-       }
-       if (bus_space_map(dev->bst, (dev->bus_maps[0].bm_base + (2<<20)),
-               (gtt->gtt_total_entries * sizeof(gtt_pte_t)),
-               0,
-               &gtt->gtt_bsh)) {
-               DRM_ERROR("unable to map GTT\n");
-               ret = -ENODEV;
-               goto fail0;
+               goto fail1;
        }
 
        ret = i915_gem_gtt_init_scratch_page(gtt, dev->dmat);
@@ -627,8 +636,7 @@
 
 fail2: __unused
        i915_gem_gtt_fini_scratch_page(gtt, dev->dmat);
-fail1: bus_space_unmap(dev->bst, gtt->gtt_bsh,
-           (gtt->gtt_total_entries * sizeof(gtt_pte_t)));
+fail1: bus_space_unmap(dev->bst, gtt->gtt_bsh, gtt_size);
 fail0: return ret;
 }