Linux-libre 4.2-gnu

1 files changed, 88 insertions, 0 deletions

diff --git a/arch/arm/mm/pv-fixup-asm.S b/arch/arm/mm/pv-fixup-asm.S
new file mode 100644
index 000000000..1867f3e43
--- /dev/null
+++ b/arch/arm/mm/pv-fixup-asm.S
@@ -0,0 +1,88 @@
+/*
+ *  Copyright (C) 2015 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This assembly is required to safely remap the physical address space
+ * for Keystone 2
+ */
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/cp15.h>
+#include <asm/memory.h>
+#include <asm/pgtable.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, [r7]
+	adds	r4, r4, r0
+	adc	r5, r5, r1
+	strd	r4, [r7], #1 << L2_ORDER
+	cmp	r7, r6
+	bls	1b
+
+	/* Update level 2 entries for the boot data */
+	add	r7, r2, #0x1000
+	add	r7, r7, r3, lsr #SECTION_SHIFT - L2_ORDER
+	bic	r7, r7, #(1 << L2_ORDER) - 1
+	ldrd	r4, [r7]
+	adds	r4, r4, r0
+	adc	r5, r5, r1
+	strd	r4, [r7], #1 << L2_ORDER
+	ldrd	r4, [r7]
+	adds	r4, r4, r0
+	adc	r5, r5, r1
+	strd	r4, [r7]
+
+	/* Update level 1 entries */
+	mov	r6, #4
+	mov	r7, r2
+2:	ldrd	r4, [r7]
+	adds	r4, r4, r0
+	adc	r5, r5, r1
+	strd	r4, [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)