MIPS: mm: c-r4k: Detect instruction cache aliases
The *Aptiv cores can use the CONF7/IAR bit to detect if the core
has hardware support to remove instruction cache aliasing.
This also defines the CONF7/AR bit in order to avoid using
the '16' magic number.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6499/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index bbc3dd4..0c74617 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -653,6 +653,9 @@
#define MIPS_CONF7_RPS (_ULCAST_(1) << 2)
+#define MIPS_CONF7_IAR (_ULCAST_(1) << 10)
+#define MIPS_CONF7_AR (_ULCAST_(1) << 16)
+
/* EntryHI bit definition */
#define MIPS_ENTRYHI_EHINV (_ULCAST_(1) << 10)
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index c14259e..8f1d549 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1117,9 +1117,14 @@
case CPU_PROAPTIV:
if (current_cpu_type() == CPU_74K)
alias_74k_erratum(c);
- if ((read_c0_config7() & (1 << 16))) {
- /* effectively physically indexed dcache,
- thus no virtual aliases. */
+ if (!(read_c0_config7() & MIPS_CONF7_IAR) &&
+ (c->icache.waysize > PAGE_SIZE))
+ c->icache.flags |= MIPS_CACHE_ALIASES;
+ if (read_c0_config7() & MIPS_CONF7_AR) {
+ /*
+ * Effectively physically indexed dcache,
+ * thus no virtual aliases.
+ */
c->dcache.flags |= MIPS_CACHE_PINDEX;
break;
}