[U-Boot] [PATCH 2/6] omap: Set appropriate cache configuration for LPAE and non-LAPE cases

Keerthy
2016-09-14T05:13:29Z

Cache configuration methods is different for LPAE and non-LPAE cases.
Hence the bits and the interpretaion is different for two cases.
In case of non-LPAE mode short descriptor format is used and we need
to set Cache and Buffer bits.

In the case of LPAE the cache configuration happens via MAIR0 lookup.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
arch/arm/cpu/armv7/omap-common/omap-cache.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap-common/omap-cache.c b/arch/arm/cpu/armv7/omap-common/omap-cache.c
index ee89f1f..b37163a 100644
--- a/arch/arm/cpu/armv7/omap-common/omap-cache.c
+++ b/arch/arm/cpu/armv7/omap-common/omap-cache.c
@@ -17,7 +17,28 @@

DECLARE_GLOBAL_DATA_PTR;

-#define ARMV7_DCACHE_WRITEBACK 0xe
+/*
+ * Without LPAE short descriptors are used
+ * Set C - Cache Bit3
+ * Set B - Buffer Bit2
+ * The last 2 bits set to 0b10
+ * Do Not set XN bit4
+ * So value is 0xe
+ *
+ * With LPAE cache configuration happens via MAIR0 register
+ * AttrIndx value is 0x3 for picking byte3 for MAIR0 which has 0xFF.
+ * 0xFF maps to Cache writeback with Read and Write Allocate set
+ * The bits[1:0] should have the value 0b01 for the first level
+ * descriptor.
+ * So the value is 0xd
+ */
+
+#ifdef CONFIG_ARMV7_LPAE
+#define ARMV7_DCACHE_POLICY DCACHE_WRITEALLOC
+#else
+#define ARMV7_DCACHE_POLICY DCACHE_WRITEBACK & ~TTB_SECT_XN_MASK
+#endif
+
#define ARMV7_DOMAIN_CLIENT 1
#define ARMV7_DOMAIN_MASK (0x3 << 0)

@@ -38,7 +59,7 @@ void dram_bank_mmu_setup(int bank)

debug("%s: bank: %d\n", __func__, bank);
for (i = start; i < end; i++)
- set_section_dcache(i, ARMV7_DCACHE_WRITEBACK);
+ set_section_dcache(i, ARMV7_DCACHE_POLICY);
}

void arm_init_domains(void)
--
1.9.1