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authorSergei Shtylyov <sshtylyov@ru.mvista.com>2006-05-26 19:44:54 +0400
committerRalf Baechle <ralf@linux-mips.org>2006-06-06 00:15:13 +0100
commit9370b35175ca43fad7d24bc7b391473f3becbee8 (patch)
tree4d1f3e7a0708c86da26720288711f8702b00b601 /arch/mips/mm
parentcac4bcbce0e800f2219a27b66aaeb4a33f2e3dbc (diff)
[MIPS] Save write-only Config.OD from being clobbered
Save the Config.OD bit from being clobbered by coherency_setup(). This bit, when set, fixes various errata in the early steppings of Au1x00 SOCs. Unfortunately, the bit was write-only on the most early of them. In addition, also restore the bit after a wakeup from sleep. Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
-rw-r--r--arch/mips/mm/c-r4k.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 6b3541769602..4a43924cd4fc 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1161,6 +1161,31 @@ static void __init setup_scache(void)
c->options |= MIPS_CPU_SUBSET_CACHES;
}
+void au1x00_fixup_config_od(void)
+{
+ /*
+ * c0_config.od (bit 19) was write only (and read as 0)
+ * on the early revisions of Alchemy SOCs. It disables the bus
+ * transaction overlapping and needs to be set to fix various errata.
+ */
+ switch (read_c0_prid()) {
+ case 0x00030100: /* Au1000 DA */
+ case 0x00030201: /* Au1000 HA */
+ case 0x00030202: /* Au1000 HB */
+ case 0x01030200: /* Au1500 AB */
+ /*
+ * Au1100 errata actually keeps silence about this bit, so we set it
+ * just in case for those revisions that require it to be set according
+ * to arch/mips/au1000/common/cputable.c
+ */
+ case 0x02030200: /* Au1100 AB */
+ case 0x02030201: /* Au1100 BA */
+ case 0x02030202: /* Au1100 BC */
+ set_c0_config(1 << 19);
+ break;
+ }
+}
+
static inline void coherency_setup(void)
{
change_c0_config(CONF_CM_CMASK, CONF_CM_DEFAULT);
@@ -1181,6 +1206,15 @@ static inline void coherency_setup(void)
case CPU_R4400MC:
clear_c0_config(CONF_CU);
break;
+ /*
+ * We need to catch the ealry Alchemy SOCs with
+ * the write-only co_config.od bit and set it back to one...
+ */
+ case CPU_AU1000: /* rev. DA, HA, HB */
+ case CPU_AU1100: /* rev. AB, BA, BC ?? */
+ case CPU_AU1500: /* rev. AB */
+ au1x00_fixup_config_od();
+ break;
}
}