local-powerpc8xx-dcbz

Gbp-Pq: Topic powerpc
Gbp-Pq: Name local-powerpc8xx-dcbz.diff

diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
index ce2281cf118e533a175f50dacfc20ae07ec10f58..4d809a896853bc66b61dfcfcd3afbe464477bd6d 100644 (file)
--- a/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
@@ -16,5 +16,21 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#ifndef __powerpc64__
+/* We have to detect 8xx processors, which have buggy dcbz implementations
+ * that cannot report page faults correctly. That requires reading SPR,
+ * which is a privileged operation.  Fortunately 2.2.18 and later emulates
+ * PowerPC mfspr reads from the PVR register.  */
+#define DL_PLATFORM_AUXV \
+  {                                                                    \
+    unsigned pvr = 0;                                                  \
+    asm ("mfspr %0, 287" : "=r" (pvr));                                        \
+    if ((pvr & 0xffff0000) == 0x00500000)                              \
+      GLRO(dl_cache_line_size) = 0;                                    \
+    else                                                               \
+      GLRO(dl_cache_line_size) = auxv_values[AT_DCACHEBSIZE];          \
+  }
+#else
 #define DL_PLATFORM_AUXV \
   GLRO(dl_cache_line_size) = auxv_values[AT_DCACHEBSIZE];
+#endif