1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2015 Russell King 4 * 5 * This assembly is required to safely remap the physical address space 6 * for Keystone 2 7 */ 8 #include <linux/linkage.h> 9 #include <linux/pgtable.h> 10 #include <asm/asm-offsets.h> 11 #include <asm/cp15.h> 12 #include <asm/memory.h> 13 14 .section ".idmap.text", "ax" 15 16 #define L1_ORDER 3 17 #define L2_ORDER 3 18 19 ENTRY(lpae_pgtables_remap_asm) 20 stmfd sp!, {r4-r8, lr} 21 22 mrc p15, 0, r8, c1, c0, 0 @ read control reg 23 bic ip, r8, #CR_M @ disable caches and MMU 24 mcr p15, 0, ip, c1, c0, 0 25 dsb 26 isb 27 28 /* Update level 2 entries covering the kernel */ 29 ldr r6, =(_end - 1) 30 add r7, r2, #0x1000 31 add r6, r7, r6, lsr #SECTION_SHIFT - L2_ORDER 32 add r7, r7, #PAGE_OFFSET >> (SECTION_SHIFT - L2_ORDER) 33 1: ldrd r4, r5, [r7] 34 adds r4, r4, r0 35 adc r5, r5, r1 36 strd r4, r5, [r7], #1 << L2_ORDER 37 cmp r7, r6 38 bls 1b 39 40 /* Update level 2 entries for the boot data */ 41 add r7, r2, #0x1000 42 movw r3, #FDT_FIXED_BASE >> (SECTION_SHIFT - L2_ORDER) 43 add r7, r7, r3 44 ldrd r4, r5, [r7] 45 adds r4, r4, r0 46 adc r5, r5, r1 47 strd r4, r5, [r7], #1 << L2_ORDER 48 ldrd r4, r5, [r7] 49 adds r4, r4, r0 50 adc r5, r5, r1 51 strd r4, r5, [r7] 52 53 /* Update level 1 entries */ 54 mov r6, #4 55 mov r7, r2 56 2: ldrd r4, r5, [r7] 57 adds r4, r4, r0 58 adc r5, r5, r1 59 strd r4, r5, [r7], #1 << L1_ORDER 60 subs r6, r6, #1 61 bne 2b 62 63 mrrc p15, 0, r4, r5, c2 @ read TTBR0 64 adds r4, r4, r0 @ update physical address 65 adc r5, r5, r1 66 mcrr p15, 0, r4, r5, c2 @ write back TTBR0 67 mrrc p15, 1, r4, r5, c2 @ read TTBR1 68 adds r4, r4, r0 @ update physical address 69 adc r5, r5, r1 70 mcrr p15, 1, r4, r5, c2 @ write back TTBR1 71 72 dsb 73 74 mov ip, #0 75 mcr p15, 0, ip, c7, c5, 0 @ I+BTB cache invalidate 76 mcr p15, 0, ip, c8, c7, 0 @ local_flush_tlb_all() 77 dsb 78 isb 79 80 mcr p15, 0, r8, c1, c0, 0 @ re-enable MMU 81 dsb 82 isb 83 84 ldmfd sp!, {r4-r8, pc} 85 ENDPROC(lpae_pgtables_remap_asm) 86