+/*
+ * Enable MMU to use DCache as DRAM.
+ *
+ * This is useful on PXA25x and PXA26x in early bootstages, where there is no
+ * other possible memory available to hold stack.
+ */
+#ifdef CONFIG_CPU_PXA25X
+.macro CPWAIT reg
+ mrc p15, 0, \reg, c2, c0, 0
+ mov \reg, \reg
+ sub pc, pc, #4
+.endm
+lock_cache_for_stack:
+ /* Domain access -- enable for all CPs */
+ ldr r0, =0x0000ffff
+ mcr p15, 0, r0, c3, c0, 0
+
+ /* Point TTBR to MMU table */
+ ldr r0, =mmutable
+ mcr p15, 0, r0, c2, c0, 0
+
+ /* Kick in MMU, ICache, DCache, BTB */
+ mrc p15, 0, r0, c1, c0, 0
+ bic r0, #0x1b00
+ bic r0, #0x0087
+ orr r0, #0x1800
+ orr r0, #0x0005
+ mcr p15, 0, r0, c1, c0, 0
+ CPWAIT r0
+
+ /* Unlock Icache, Dcache */
+ mcr p15, 0, r0, c9, c1, 1
+ mcr p15, 0, r0, c9, c2, 1
+
+ /* Flush Icache, Dcache, BTB */
+ mcr p15, 0, r0, c7, c7, 0
+
+ /* Unlock I-TLB, D-TLB */
+ mcr p15, 0, r0, c10, c4, 1
+ mcr p15, 0, r0, c10, c8, 1
+
+ /* Flush TLB */
+ mcr p15, 0, r0, c8, c7, 0
+
+ /* Allocate 4096 bytes of Dcache as RAM */
+
+ /* Drain pending loads and stores */
+ mcr p15, 0, r0, c7, c10, 4
+
+ mov r4, #0x00
+ mov r5, #0x00
+ mov r2, #0x01
+ mcr p15, 0, r0, c9, c2, 0
+ CPWAIT r0
+
+ /* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
+ mov r0, #128
+ ldr r1, =0xfffff000
+
+alloc:
+ mcr p15, 0, r1, c7, c2, 5
+ /* Drain pending loads and stores */
+ mcr p15, 0, r0, c7, c10, 4
+ strd r4, [r1], #8
+ strd r4, [r1], #8
+ strd r4, [r1], #8
+ strd r4, [r1], #8
+ subs r0, #0x01
+ bne alloc
+ /* Drain pending loads and stores */
+ mcr p15, 0, r0, c7, c10, 4
+ mov r2, #0x00
+ mcr p15, 0, r2, c9, c2, 0
+ CPWAIT r0