ARM: 7062/1: cache: detect PIPT I-cache using CTR
The Cache Type Register L1Ip field identifies I-caches with a PIPT
policy using the encoding 11b.
This patch extends the cache policy parsing to identify PIPT I-caches
correctly and prevent them from being treated as VIPT aliasing in cases
where they are sufficiently large.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 93e39a3..3fe93f7 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -265,6 +265,10 @@
int aliasing_icache;
unsigned int id_reg, num_sets, line_size;
+ /* PIPT caches never alias. */
+ if (icache_is_pipt())
+ return 0;
+
/* arch specifies the register format */
switch (arch) {
case CPU_ARCH_ARMv7:
@@ -299,8 +303,14 @@
/* ARMv7 register format */
arch = CPU_ARCH_ARMv7;
cacheid = CACHEID_VIPT_NONALIASING;
- if ((cachetype & (3 << 14)) == 1 << 14)
+ switch (cachetype & (3 << 14)) {
+ case (1 << 14):
cacheid |= CACHEID_ASID_TAGGED;
+ break;
+ case (3 << 14):
+ cacheid |= CACHEID_PIPT;
+ break;
+ }
} else {
arch = CPU_ARCH_ARMv6;
if (cachetype & (1 << 23))
@@ -317,10 +327,11 @@
printk("CPU: %s data cache, %s instruction cache\n",
cache_is_vivt() ? "VIVT" :
cache_is_vipt_aliasing() ? "VIPT aliasing" :
- cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown",
+ cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
cache_is_vivt() ? "VIVT" :
icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
icache_is_vipt_aliasing() ? "VIPT aliasing" :
+ icache_is_pipt() ? "PIPT" :
cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
}