xtensa: add MMU v3 support

MMUv3 comes out of reset with identity vaddr -> paddr mapping in the TLB
way 6:

Way 6 (512 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0x00000000  0x00000000  0x01  0x03 RWX Bypass
        0x20000000  0x20000000  0x01  0x03 RWX Bypass
        0x40000000  0x40000000  0x01  0x03 RWX Bypass
        0x60000000  0x60000000  0x01  0x03 RWX Bypass
        0x80000000  0x80000000  0x01  0x03 RWX Bypass
        0xa0000000  0xa0000000  0x01  0x03 RWX Bypass
        0xc0000000  0xc0000000  0x01  0x03 RWX Bypass
        0xe0000000  0xe0000000  0x01  0x03 RWX Bypass

This patch adds remapping code at the reset vector or at the kernel
_start (depending on CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) that
reconfigures MMUv3 as MMUv2:

Way 5 (128 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0xd0000000  0x00000000  0x01  0x07 RWX WB
        0xd8000000  0x00000000  0x01  0x03 RWX Bypass
Way 6 (256 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0xe0000000  0xf0000000  0x01  0x07 RWX WB
        0xf0000000  0xf0000000  0x01  0x03 RWX Bypass

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 32 insertions, 16 deletions

diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index 14695240536..21acd11b5df 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -18,6 +18,7 @@
 #include <asm/page.h>
 #include <asm/thread_info.h>
 
+#include <asm/vectors.h>
 #include <variant/core.h>
 #include <platform/hardware.h>
 OUTPUT_ARCH(xtensa)
@@ -30,7 +31,7 @@ jiffies = jiffies_64;
 #endif
 
 #ifndef KERNELOFFSET
-#define KERNELOFFSET 0xd0001000
+#define KERNELOFFSET 0xd0003000
 #endif
 
 /* Note: In the following macros, it would be nice to specify only the
@@ -185,16 +186,16 @@ SECTIONS
 
   SECTION_VECTOR (_WindowVectors_text,
 		  .WindowVectors.text,
-		  XCHAL_WINDOW_VECTORS_VADDR, 4,
+		  WINDOW_VECTORS_VADDR, 4,
 		  .dummy)
   SECTION_VECTOR (_DebugInterruptVector_literal,
 		  .DebugInterruptVector.literal,
-		  XCHAL_DEBUG_VECTOR_VADDR - 4,
+		  DEBUG_VECTOR_VADDR - 4,
 		  SIZEOF(.WindowVectors.text),
 		  .WindowVectors.text)
   SECTION_VECTOR (_DebugInterruptVector_text,
 		  .DebugInterruptVector.text,
-		  XCHAL_DEBUG_VECTOR_VADDR,
+		  DEBUG_VECTOR_VADDR,
 		  4,
 		  .DebugInterruptVector.literal)
 #undef LAST
@@ -202,7 +203,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 2
   SECTION_VECTOR (_Level2InterruptVector_text,
 		  .Level2InterruptVector.text,
-		  XCHAL_INTLEVEL2_VECTOR_VADDR,
+		  INTLEVEL2_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level2InterruptVector.text
@@ -210,7 +211,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 3
   SECTION_VECTOR (_Level3InterruptVector_text,
 		  .Level3InterruptVector.text,
-		  XCHAL_INTLEVEL3_VECTOR_VADDR,
+		  INTLEVEL3_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level3InterruptVector.text
@@ -218,7 +219,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 4
   SECTION_VECTOR (_Level4InterruptVector_text,
 		  .Level4InterruptVector.text,
-		  XCHAL_INTLEVEL4_VECTOR_VADDR,
+		  INTLEVEL4_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level4InterruptVector.text
@@ -226,7 +227,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 5
   SECTION_VECTOR (_Level5InterruptVector_text,
 		  .Level5InterruptVector.text,
-		  XCHAL_INTLEVEL5_VECTOR_VADDR,
+		  INTLEVEL5_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level5InterruptVector.text
@@ -234,39 +235,39 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 6
   SECTION_VECTOR (_Level6InterruptVector_text,
 		  .Level6InterruptVector.text,
-		  XCHAL_INTLEVEL6_VECTOR_VADDR,
+		  INTLEVEL6_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level6InterruptVector.text
 #endif
   SECTION_VECTOR (_KernelExceptionVector_literal,
 		  .KernelExceptionVector.literal,
-		  XCHAL_KERNEL_VECTOR_VADDR - 4,
+		  KERNEL_VECTOR_VADDR - 4,
 		  SIZEOF(LAST), LAST)
 #undef LAST
   SECTION_VECTOR (_KernelExceptionVector_text,
 		  .KernelExceptionVector.text,
-		  XCHAL_KERNEL_VECTOR_VADDR,
+		  KERNEL_VECTOR_VADDR,
 		  4,
 		  .KernelExceptionVector.literal)
   SECTION_VECTOR (_UserExceptionVector_literal,
 		  .UserExceptionVector.literal,
-		  XCHAL_USER_VECTOR_VADDR - 4,
+		  USER_VECTOR_VADDR - 4,
 		  SIZEOF(.KernelExceptionVector.text),
 		  .KernelExceptionVector.text)
   SECTION_VECTOR (_UserExceptionVector_text,
 		  .UserExceptionVector.text,
-		  XCHAL_USER_VECTOR_VADDR,
+		  USER_VECTOR_VADDR,
 		  4,
 		  .UserExceptionVector.literal)
   SECTION_VECTOR (_DoubleExceptionVector_literal,
 		  .DoubleExceptionVector.literal,
-		  XCHAL_DOUBLEEXC_VECTOR_VADDR - 16,
+		  DOUBLEEXC_VECTOR_VADDR - 16,
 		  SIZEOF(.UserExceptionVector.text),
 		  .UserExceptionVector.text)
   SECTION_VECTOR (_DoubleExceptionVector_text,
 		  .DoubleExceptionVector.text,
-		  XCHAL_DOUBLEEXC_VECTOR_VADDR,
+		  DOUBLEEXC_VECTOR_VADDR,
 		  32,
 		  .DoubleExceptionVector.literal)
 
@@ -284,11 +285,26 @@ SECTIONS
   . = ALIGN(0x10);
   .bootstrap : { *(.bootstrap.literal .bootstrap.text .bootstrap.data) }
 
-  .ResetVector.text XCHAL_RESET_VECTOR_VADDR :
+  .ResetVector.text RESET_VECTOR_VADDR :
   {
     *(.ResetVector.text)
   }
 
+
+  /*
+   * This is a remapped copy of the Secondary Reset Vector Code.
+   * It keeps gdb in sync with the PC after switching
+   * to the temporary mapping used while setting up
+   * the V2 MMU mappings for Linux.
+   *
+   * Only debug information about this section is put in the kernel image.
+   */
+  .SecondaryResetVector.remapped_text 0x46000000 (INFO):
+  {
+	*(.SecondaryResetVector.remapped_text)
+  }
+
+
   .xt.lit : { *(.xt.lit) }
   .xt.prop : { *(.xt.prop) }