[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915 Avoid bus_space_read/wri...

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

details:   https://anonhg.NetBSD.org/src/rev/9ceafc084a74
branches:  trunk
changeset: 330789:9ceafc084a74
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Jul 21 20:01:18 2014 +0000

description:
Avoid bus_space_read/write_8 on i386.

Would be nice if there were a clearer way to detect it than _LP64,
and if its absence caused a compile error instead of a link error.

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/i915_gem_gtt.c |  42 ++++++++++++++++++---
 1 files changed, 36 insertions(+), 6 deletions(-)

diffs (70 lines):

diff -r 72a09520f20d -r 9ceafc084a74 sys/external/bsd/drm2/dist/drm/i915/i915_gem_gtt.c
--- a/sys/external/bsd/drm2/dist/drm/i915/i915_gem_gtt.c        Mon Jul 21 14:23:43 2014 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/i915_gem_gtt.c        Mon Jul 21 20:01:18 2014 +0000
@@ -2029,7 +2029,38 @@
 #endif
 }
 
-#ifndef __NetBSD__
+#ifdef __NetBSD__
+static inline uint64_t
+gen8_get_pte(bus_space_tag_t bst, bus_space_handle_t bsh, unsigned i)
+{
+       CTASSERT(_BYTE_ORDER == _LITTLE_ENDIAN); /* x86 */
+       CTASSERT(sizeof(gen8_gtt_pte_t) == 8);
+#ifdef _LP64                   /* XXX How to detect bus_space_read_8?  */
+       return bus_space_read_8(bst, bsh, 8*i);
+#else
+       /*
+        * XXX I'm not sure this case can actually happen in practice:
+        * 32-bit gen8 chipsets?
+        */
+       return bus_space_read_4(bst, bsh, 8*i) |
+           ((uint64_t)bus_space_read_4(bst, bsh, 8*i + 4) << 32);
+#endif
+}
+
+static inline void
+gen8_set_pte(bus_space_tag_t bst, bus_space_handle_t bsh, unsigned i,
+    gen8_gtt_pte_t pte)
+{
+       CTASSERT(_BYTE_ORDER == _LITTLE_ENDIAN); /* x86 */
+       CTASSERT(sizeof(gen8_gtt_pte_t) == 8);
+#ifdef _LP64                   /* XXX How to detect bus_space_write_8?  */
+       bus_space_write_8(bst, bsh, 8*i, pte);
+#else
+       bus_space_write_4(bst, bsh, 8*i, (uint32_t)pte);
+       bus_space_write_4(bst, bsh, 8*i + 4, (uint32_t)(pte >> 32));
+#endif
+}
+#else
 static inline void gen8_set_pte(void __iomem *addr, gen8_gtt_pte_t pte)
 {
 #ifdef writeq
@@ -2055,13 +2086,12 @@
        KASSERT(0 < dmamap->dm_nsegs);
        for (i = 0; i < dmamap->dm_nsegs; i++) {
                KASSERT(dmamap->dm_segs[i].ds_len == PAGE_SIZE);
-               CTASSERT(sizeof(gen8_gtt_pte_t) == 8);
-               bus_space_write_8(bst, bsh, 8*(first_entry + i),
+               gen8_set_pte(bst, bsh, first_entry + i,
                    gen8_pte_encode(dmamap->dm_segs[i].ds_addr, level, true));
        }
        if (0 < i) {
                /* Posting read.  */
-               WARN_ON(bus_space_read_8(bst, bsh, 8*(first_entry + i - 1))
+               WARN_ON(gen8_get_pte(bst, bsh, (first_entry + i - 1))
                    != gen8_pte_encode(dmamap->dm_segs[i - 1].ds_addr, level,
                        true));
        }
@@ -2212,8 +2242,8 @@
 #ifdef __NetBSD__
        CTASSERT(sizeof(gen8_gtt_pte_t) == 8);
        for (i = 0; i < num_entries; i++)
-               bus_space_write_8(bst, bsh, 8*(first_entry + i), scratch_pte);
-       (void)bus_space_read_8(bst, bsh, 8*first_entry);
+               gen8_set_pte(bst, bsh, first_entry + i, scratch_pte);
+       (void)gen8_get_pte(bst, bsh, first_entry);
 #else
        for (i = 0; i < num_entries; i++)
                gen8_set_pte(&gtt_base[i], scratch_pte);