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-rw-r--r--arch/arm/mm/pv-fixup-asm.S85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/arm/mm/pv-fixup-asm.S b/arch/arm/mm/pv-fixup-asm.S
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index 000000000..5c5e19520
--- /dev/null
+++ b/arch/arm/mm/pv-fixup-asm.S
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2015 Russell King
+ *
+ * This assembly is required to safely remap the physical address space
+ * for Keystone 2
+ */
+#include <linux/linkage.h>
+#include <linux/pgtable.h>
+#include <asm/asm-offsets.h>
+#include <asm/cp15.h>
+#include <asm/memory.h>
+
+ .section ".idmap.text", "ax"
+
+#define L1_ORDER 3
+#define L2_ORDER 3
+
+ENTRY(lpae_pgtables_remap_asm)
+ stmfd sp!, {r4-r8, lr}
+
+ mrc p15, 0, r8, c1, c0, 0 @ read control reg
+ bic ip, r8, #CR_M @ disable caches and MMU
+ mcr p15, 0, ip, c1, c0, 0
+ dsb
+ isb
+
+ /* Update level 2 entries covering the kernel */
+ ldr r6, =(_end - 1)
+ add r7, r2, #0x1000
+ add r6, r7, r6, lsr #SECTION_SHIFT - L2_ORDER
+ add r7, r7, #PAGE_OFFSET >> (SECTION_SHIFT - L2_ORDER)
+1: ldrd r4, r5, [r7]
+ adds r4, r4, r0
+ adc r5, r5, r1
+ strd r4, r5, [r7], #1 << L2_ORDER
+ cmp r7, r6
+ bls 1b
+
+ /* Update level 2 entries for the boot data */
+ add r7, r2, #0x1000
+ movw r3, #FDT_FIXED_BASE >> (SECTION_SHIFT - L2_ORDER)
+ add r7, r7, r3
+ ldrd r4, r5, [r7]
+ adds r4, r4, r0
+ adc r5, r5, r1
+ strd r4, r5, [r7], #1 << L2_ORDER
+ ldrd r4, r5, [r7]
+ adds r4, r4, r0
+ adc r5, r5, r1
+ strd r4, r5, [r7]
+
+ /* Update level 1 entries */
+ mov r6, #4
+ mov r7, r2
+2: ldrd r4, r5, [r7]
+ adds r4, r4, r0
+ adc r5, r5, r1
+ strd r4, r5, [r7], #1 << L1_ORDER
+ subs r6, r6, #1
+ bne 2b
+
+ mrrc p15, 0, r4, r5, c2 @ read TTBR0
+ adds r4, r4, r0 @ update physical address
+ adc r5, r5, r1
+ mcrr p15, 0, r4, r5, c2 @ write back TTBR0
+ mrrc p15, 1, r4, r5, c2 @ read TTBR1
+ adds r4, r4, r0 @ update physical address
+ adc r5, r5, r1
+ mcrr p15, 1, r4, r5, c2 @ write back TTBR1
+
+ dsb
+
+ mov ip, #0
+ mcr p15, 0, ip, c7, c5, 0 @ I+BTB cache invalidate
+ mcr p15, 0, ip, c8, c7, 0 @ local_flush_tlb_all()
+ dsb
+ isb
+
+ mcr p15, 0, r8, c1, c0, 0 @ re-enable MMU
+ dsb
+ isb
+
+ ldmfd sp!, {r4-r8, pc}
+ENDPROC(lpae_pgtables_remap_asm)