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-rw-r--r--arch/xtensa/include/asm/initialize_mmu.h107
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/initialize_mmu.h b/arch/xtensa/include/asm/initialize_mmu.h
index e1f8ba4..722553f 100644
--- a/arch/xtensa/include/asm/initialize_mmu.h
+++ b/arch/xtensa/include/asm/initialize_mmu.h
@@ -23,6 +23,9 @@
#ifndef _XTENSA_INITIALIZE_MMU_H
#define _XTENSA_INITIALIZE_MMU_H
+#include <asm/pgtable.h>
+#include <asm/vectors.h>
+
#ifdef __ASSEMBLY__
#define XTENSA_HWVERSION_RC_2009_0 230000
@@ -48,6 +51,110 @@
* (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0)
*/
+#if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
+/*
+ * Have MMU v3
+ */
+
+#if !XCHAL_HAVE_VECBASE
+# error "MMU v3 requires reloc vectors"
+#endif
+
+ movi a1, 0
+ _call0 1f
+ _j 2f
+
+ .align 4
+1: movi a2, 0x10000000
+ movi a3, 0x18000000
+ add a2, a2, a0
+9: bgeu a2, a3, 9b /* PC is out of the expected range */
+
+ /* Step 1: invalidate mapping at 0x40000000..0x5FFFFFFF. */
+
+ movi a2, 0x40000006
+ idtlb a2
+ iitlb a2
+ isync
+
+ /* Step 2: map 0x40000000..0x47FFFFFF to paddr containing this code
+ * and jump to the new mapping.
+ */
+#define CA_BYPASS (_PAGE_CA_BYPASS | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
+#define CA_WRITEBACK (_PAGE_CA_WB | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
+
+ srli a3, a0, 27
+ slli a3, a3, 27
+ addi a3, a3, CA_BYPASS
+ addi a7, a2, -1
+ wdtlb a3, a7
+ witlb a3, a7
+ isync
+
+ slli a4, a0, 5
+ srli a4, a4, 5
+ addi a5, a2, -6
+ add a4, a4, a5
+ jx a4
+
+ /* Step 3: unmap everything other than current area.
+ * Start at 0x60000000, wrap around, and end with 0x20000000
+ */
+2: movi a4, 0x20000000
+ add a5, a2, a4
+3: idtlb a5
+ iitlb a5
+ add a5, a5, a4
+ bne a5, a2, 3b
+
+ /* Step 4: Setup MMU with the old V2 mappings. */
+ movi a6, 0x01000000
+ wsr a6, ITLBCFG
+ wsr a6, DTLBCFG
+ isync
+
+ movi a5, 0xd0000005
+ movi a4, CA_WRITEBACK
+ wdtlb a4, a5
+ witlb a4, a5
+
+ movi a5, 0xd8000005
+ movi a4, CA_BYPASS
+ wdtlb a4, a5
+ witlb a4, a5
+
+ movi a5, 0xe0000006
+ movi a4, 0xf0000000 + CA_WRITEBACK
+ wdtlb a4, a5
+ witlb a4, a5
+
+ movi a5, 0xf0000006
+ movi a4, 0xf0000000 + CA_BYPASS
+ wdtlb a4, a5
+ witlb a4, a5
+
+ isync
+
+ /* Jump to self, using MMU v2 mappings. */
+ movi a4, 1f
+ jx a4
+
+1:
+ movi a2, VECBASE_RESET_VADDR
+ wsr a2, vecbase
+
+ /* Step 5: remove temporary mapping. */
+ idtlb a7
+ iitlb a7
+ isync
+
+ movi a0, 0
+ wsr a0, ptevaddr
+ rsync
+
+#endif /* defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU &&
+ XCHAL_HAVE_SPANNING_WAY */
+
.endm
#endif /*__ASSEMBLY__*/
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