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authorGreentime Hu2018-04-30 15:02:27 +0800
committerGreentime Hu2018-05-23 13:26:22 +0800
commitabb90a24eade1f612324de0e6920041ef64795cb (patch)
tree67f24bc5d0c844db9c5d3f4c8aabe9d66e464273 /arch/nds32
parent8769c223491a7fbb345021e7004cbdffe024eaf8 (diff)
nds32: To fix a cache inconsistency issue by setting correct cacheability of NTC
The nds32 architecture will use physical memory when interrupt or exception comes and it will use the setting of NTC0-4. The original implementation didn't consider the DRAM start address may start from 1GB, 2GB or 3GB to cause this issue. It will write the data to DRAM if it is running in physical address however kernel will read the data with virtaul address through data cache. In this case, the data of DRAM is latest. This fix will set the correct cacheability to let kernel write/read the latest data in cache instead of DRAM. Signed-off-by: Greentime Hu <greentime@andestech.com>
Diffstat (limited to 'arch/nds32')
-rw-r--r--arch/nds32/include/asm/bitfield.h1
-rw-r--r--arch/nds32/kernel/head.S28
2 files changed, 24 insertions, 5 deletions
diff --git a/arch/nds32/include/asm/bitfield.h b/arch/nds32/include/asm/bitfield.h
index 28b7d797fd59..8e84fc385b94 100644
--- a/arch/nds32/include/asm/bitfield.h
+++ b/arch/nds32/include/asm/bitfield.h
@@ -396,6 +396,7 @@
#define MMU_CTL_D8KB 1
#define MMU_CTL_UNA ( 0x1 << MMU_CTL_offUNA )
+#define MMU_CTL_CACHEABLE_NON 0
#define MMU_CTL_CACHEABLE_WB 2
#define MMU_CTL_CACHEABLE_WT 3
diff --git a/arch/nds32/kernel/head.S b/arch/nds32/kernel/head.S
index 71f57bd70f3b..c5fdae174ced 100644
--- a/arch/nds32/kernel/head.S
+++ b/arch/nds32/kernel/head.S
@@ -57,14 +57,32 @@ _nodtb:
isb
mtsr $r4, $L1_PPTB ! load page table pointer\n"
-/* set NTC0 cacheable/writeback, mutliple page size in use */
+#ifdef CONFIG_CPU_DCACHE_DISABLE
+ #define MMU_CTL_NTCC MMU_CTL_CACHEABLE_NON
+#else
+ #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+ #define MMU_CTL_NTCC MMU_CTL_CACHEABLE_WT
+ #else
+ #define MMU_CTL_NTCC MMU_CTL_CACHEABLE_WB
+ #endif
+#endif
+
+/* set NTC cacheability, mutliple page size in use */
mfsr $r3, $MMU_CTL
- li $r0, #~MMU_CTL_mskNTC0
- and $r3, $r3, $r0
+#if CONFIG_MEMORY_START >= 0xc0000000
+ ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC3)
+#elif CONFIG_MEMORY_START >= 0x80000000
+ ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC2)
+#elif CONFIG_MEMORY_START >= 0x40000000
+ ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC1)
+#else
+ ori $r3, $r3, (MMU_CTL_NTCC << MMU_CTL_offNTC0)
+#endif
+
#ifdef CONFIG_ANDES_PAGE_SIZE_4KB
- ori $r3, $r3, #(MMU_CTL_mskMPZIU|(MMU_CTL_CACHEABLE_WB << MMU_CTL_offNTC0))
+ ori $r3, $r3, #(MMU_CTL_mskMPZIU)
#else
- ori $r3, $r3, #(MMU_CTL_mskMPZIU|(MMU_CTL_CACHEABLE_WB << MMU_CTL_offNTC0)|MMU_CTL_D8KB)
+ ori $r3, $r3, #(MMU_CTL_mskMPZIU|MMU_CTL_D8KB)
#endif
#ifdef CONFIG_HW_SUPPORT_UNALIGNMENT_ACCESS
li $r0, #MMU_CTL_UNA