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authorVineet Gupta <vgupta@synopsys.com>2019-03-21 17:19:37 -0700
committerVineet Gupta <vgupta@synopsys.com>2019-04-02 12:03:07 -0700
commit99bd5fcc505d65ea9c60619202f0b2d926eabbe9 (patch)
tree95d214f8089b046d9920753b06720a55d3d0f73b /arch/arc/mm
parent79a3aaa7b82e3106be97842dedfd8429248896e6 (diff)
ARC: PAE40: don't panic and instead turn off hw ioc
HSDK currently panics when built for HIGHMEM/ARC_HAS_PAE40 because ioc is enabled with default which doesn't work for the 2 non contiguous memory nodes. So get PAE working by disabling ioc instead. Tested with !PAE40 by forcing @ioc_enable=0 and running the glibc testsuite over ssh Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/mm')
-rw-r--r--arch/arc/mm/cache.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 4135abec3fb0..63e6e6504699 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -113,10 +113,24 @@ static void read_decode_cache_bcr_arcv2(int cpu)
}
READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
- if (cbcr.c)
+ if (cbcr.c) {
ioc_exists = 1;
- else
+
+ /*
+ * As for today we don't support both IOC and ZONE_HIGHMEM enabled
+ * simultaneously. This happens because as of today IOC aperture covers
+ * only ZONE_NORMAL (low mem) and any dma transactions outside this
+ * region won't be HW coherent.
+ * If we want to use both IOC and ZONE_HIGHMEM we can use
+ * bounce_buffer to handle dma transactions to HIGHMEM.
+ * Also it is possible to modify dma_direct cache ops or increase IOC
+ * aperture size if we are planning to use HIGHMEM without PAE.
+ */
+ if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled())
+ ioc_enable = 0;
+ } else {
ioc_enable = 0;
+ }
/* HS 2.0 didn't have AUX_VOL */
if (cpuinfo_arc700[cpu].core.family > 0x51) {
@@ -1158,19 +1172,6 @@ noinline void __init arc_ioc_setup(void)
if (!ioc_enable)
return;
- /*
- * As for today we don't support both IOC and ZONE_HIGHMEM enabled
- * simultaneously. This happens because as of today IOC aperture covers
- * only ZONE_NORMAL (low mem) and any dma transactions outside this
- * region won't be HW coherent.
- * If we want to use both IOC and ZONE_HIGHMEM we can use
- * bounce_buffer to handle dma transactions to HIGHMEM.
- * Also it is possible to modify dma_direct cache ops or increase IOC
- * aperture size if we are planning to use HIGHMEM without PAE.
- */
- if (IS_ENABLED(CONFIG_HIGHMEM))
- panic("IOC and HIGHMEM can't be used simultaneously");
-
/* Flush + invalidate + disable L1 dcache */
__dc_disable();