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>
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 4566683..ef12c0e 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -48,17 +48,36 @@
*/
__HEAD
+ .begin no-absolute-literals
+
ENTRY(_start)
- _j 2f
+ /* Preserve the pointer to the boot parameter list in EXCSAVE_1 */
+ wsr a2, excsave1
+ _j _SetupMMU
+
.align 4
-1: .word _startup
-2: l32r a0, 1b
+ .literal_position
+.Lstartup:
+ .word _startup
+
+ .align 4
+ .global _SetupMMU
+_SetupMMU:
+ Offset = _SetupMMU - _start
+
+#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+ initialize_mmu
+#endif
+ .end no-absolute-literals
+
+ l32r a0, .Lstartup
jx a0
ENDPROC(_start)
- .section .init.text, "ax"
+ __INIT
+ .literal_position
ENTRY(_startup)
@@ -67,10 +86,6 @@
movi a0, LOCKLEVEL
wsr a0, ps
- /* Preserve the pointer to the boot parameter list in EXCSAVE_1 */
-
- wsr a2, excsave1
-
/* Start with a fresh windowbase and windowstart. */
movi a1, 1
@@ -158,8 +173,6 @@
isync
- initialize_mmu
-
/* Unpack data sections
*
* The linker script used to build the Linux kernel image
@@ -207,6 +220,10 @@
___flush_dcache_all a2 a3
#endif
+ memw
+ isync
+ ___invalidate_icache_all a2 a3
+ isync
/* Setup stack and enable window exceptions (keep irqs disabled) */