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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/kernel/head.S
3 *
4 * Copyright (C) 1994-2002 Russell King
Russell Kinge65f38e2005-06-18 09:33:31 +01005 * Copyright (c) 2003 ARM Limited
6 * All Rights Reserved
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Kernel startup code for all 32-bit CPUs
13 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/linkage.h>
15#include <linux/init.h>
16
17#include <asm/assembler.h>
Russell King195864c2012-01-19 10:05:41 +000018#include <asm/cp15.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <asm/domain.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/ptrace.h>
Sam Ravnborge6ae7442005-09-09 21:08:59 +020021#include <asm/asm-offsets.h>
Nicolas Pitref09b9972005-10-29 21:44:55 +010022#include <asm/memory.h>
Russell King4f7a1812005-05-05 13:11:00 +010023#include <asm/thread_info.h>
Catalin Marinase73fc882011-08-23 14:07:23 +010024#include <asm/pgtable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Rob Herring91a9fec2012-08-31 00:03:46 -050026#if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING)
27#include CONFIG_DEBUG_LL_INCLUDE
Jeremy Kerrc2933932010-07-07 11:19:48 +080028#endif
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030/*
Nicolas Pitre37d07b72005-10-29 21:44:56 +010031 * swapper_pg_dir is the virtual address of the initial page table.
Russell Kingf06b97f2006-12-11 22:29:16 +000032 * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must
33 * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect
Nicolas Pitre37d07b72005-10-29 21:44:56 +010034 * the least significant 16 bits to be 0x8000, but we could probably
Russell Kingf06b97f2006-12-11 22:29:16 +000035 * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 */
Russell King72a20e22011-01-04 19:04:00 +000037#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
Russell Kingf06b97f2006-12-11 22:29:16 +000038#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
39#error KERNEL_RAM_VADDR must start at 0xXXXX8000
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#endif
41
Catalin Marinas1b6ba462011-11-22 17:30:29 +000042#ifdef CONFIG_ARM_LPAE
43 /* LPAE requires an additional page for the PGD */
44#define PG_DIR_SIZE 0x5000
45#define PMD_ORDER 3
46#else
Catalin Marinase73fc882011-08-23 14:07:23 +010047#define PG_DIR_SIZE 0x4000
48#define PMD_ORDER 2
Catalin Marinas1b6ba462011-11-22 17:30:29 +000049#endif
Catalin Marinase73fc882011-08-23 14:07:23 +010050
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 .globl swapper_pg_dir
Catalin Marinase73fc882011-08-23 14:07:23 +010052 .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Russell King72a20e22011-01-04 19:04:00 +000054 .macro pgtbl, rd, phys
Christopher Covington2ab4e8c2014-01-21 16:25:34 +010055 add \rd, \phys, #TEXT_OFFSET
56 sub \rd, \rd, #PG_DIR_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 .endm
Nicolas Pitre37d07b72005-10-29 21:44:56 +010058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/*
60 * Kernel startup entry point.
61 * ---------------------------
62 *
63 * This is normally called from the decompressor code. The requirements
64 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
Grant Likely4c2896e2011-04-28 14:27:20 -060065 * r1 = machine nr, r2 = atags or dtb pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 *
67 * This code is mostly position independent, so if you link the kernel at
68 * 0xc0008000, you call this at __pa(0xc0008000).
69 *
70 * See linux/arch/arm/tools/mach-types for the complete list of machine
71 * numbers for r1.
72 *
73 * We're trying to keep crap to a minimum; DO NOT add any machine specific
74 * crap here - that's what the boot loader (or in extreme, well justified
75 * circumstances, zImage) is for.
76 */
Dave Martin540b5732011-07-13 15:53:30 +010077 .arm
78
Tim Abbott2abc1c52009-10-02 16:32:46 -040079 __HEAD
Linus Torvalds1da177e2005-04-16 15:20:36 -070080ENTRY(stext)
Ben Dooks97bcb0f2013-02-01 09:40:42 +000081 ARM_BE8(setend be ) @ ensure we are in BE8 mode
Dave Martin540b5732011-07-13 15:53:30 +010082
83 THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM.
84 THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
85 THUMB( .thumb ) @ switch to Thumb now.
86 THUMB(1: )
87
Dave Martin80c59da2012-02-09 08:47:17 -080088#ifdef CONFIG_ARM_VIRT_EXT
89 bl __hyp_stub_install
90#endif
91 @ ensure svc mode and all interrupts masked
92 safe_svcmode_maskall r9
93
Russell King0f44ba12006-02-24 21:04:56 +000094 mrc p15, 0, r9, c0, c0 @ get processor id
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 bl __lookup_processor_type @ r5=procinfo r9=cpuid
96 movs r10, r5 @ invalid processor (r5=0)?
Dave Martina75e5242010-11-29 19:43:28 +010097 THUMB( it eq ) @ force fixup-able long branch encoding
Russell King3c0bdac2005-11-25 15:43:22 +000098 beq __error_p @ yes, error 'p'
Russell King0eb0511d2010-11-22 12:06:28 +000099
Catalin Marinas294064f2012-01-09 12:24:47 +0100100#ifdef CONFIG_ARM_LPAE
101 mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0
102 and r3, r3, #0xf @ extract VMSA support
103 cmp r3, #5 @ long-descriptor translation table format?
104 THUMB( it lo ) @ force fixup-able long branch encoding
105 blo __error_p @ only classic page table format
106#endif
107
Russell King72a20e22011-01-04 19:04:00 +0000108#ifndef CONFIG_XIP_KERNEL
109 adr r3, 2f
110 ldmia r3, {r4, r8}
111 sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET)
112 add r8, r8, r4 @ PHYS_OFFSET
113#else
Russell Kingb713aa02013-12-10 19:21:08 +0000114 ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case
Russell King72a20e22011-01-04 19:04:00 +0000115#endif
116
Russell King0eb0511d2010-11-22 12:06:28 +0000117 /*
Grant Likely4c2896e2011-04-28 14:27:20 -0600118 * r1 = machine no, r2 = atags or dtb,
Russell King72a20e22011-01-04 19:04:00 +0000119 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
Russell King0eb0511d2010-11-22 12:06:28 +0000120 */
Bill Gatliff9d20fdd2007-05-31 22:02:22 +0100121 bl __vet_atags
Russell Kingf00ec482010-09-04 10:47:48 +0100122#ifdef CONFIG_SMP_ON_UP
123 bl __fixup_smp
124#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000125#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
126 bl __fixup_pv_table
127#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 bl __create_page_tables
129
130 /*
131 * The following calls CPU specific code in a position independent
132 * manner. See arch/arm/mm/proc-*.S for details. r10 = base of
Russell King6fc31d52011-01-12 17:50:42 +0000133 * xxx_proc_info structure selected by __lookup_processor_type
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 * above. On return, the CPU will be ready for the MMU to be
135 * turned on, and r0 will hold the CPU control register value.
136 */
Russell Kinga4ae4132010-10-04 16:22:34 +0100137 ldr r13, =__mmap_switched @ address to jump to after
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 @ mmu has been enabled
Russell King00945012010-10-04 17:56:13 +0100139 adr lr, BSYM(1f) @ return (PIC) address
Catalin Marinasd4279582011-05-26 11:22:44 +0100140 mov r8, r4 @ set TTBR1 to swapper_pg_dir
Catalin Marinasb86040a2009-07-24 12:32:54 +0100141 ARM( add pc, r10, #PROCINFO_INITFUNC )
142 THUMB( add r12, r10, #PROCINFO_INITFUNC )
143 THUMB( mov pc, r12 )
Russell King00945012010-10-04 17:56:13 +01001441: b __enable_mmu
Catalin Marinas93ed3972008-08-28 11:22:32 +0100145ENDPROC(stext)
Russell Kinga4ae4132010-10-04 16:22:34 +0100146 .ltorg
Russell King72a20e22011-01-04 19:04:00 +0000147#ifndef CONFIG_XIP_KERNEL
1482: .long .
149 .long PAGE_OFFSET
150#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
152/*
153 * Setup the initial page tables. We only setup the barest
154 * amount which are required to get the kernel running, which
155 * generally means mapping in the kernel code.
156 *
Russell King72a20e22011-01-04 19:04:00 +0000157 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 *
159 * Returns:
Russell King786f1b72010-10-04 17:51:54 +0100160 * r0, r3, r5-r7 corrupted
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400161 * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163__create_page_tables:
Russell King72a20e22011-01-04 19:04:00 +0000164 pgtbl r4, r8 @ page table address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 /*
Catalin Marinase73fc882011-08-23 14:07:23 +0100167 * Clear the swapper page table
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 */
169 mov r0, r4
170 mov r3, #0
Catalin Marinase73fc882011-08-23 14:07:23 +0100171 add r6, r0, #PG_DIR_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721: str r3, [r0], #4
173 str r3, [r0], #4
174 str r3, [r0], #4
175 str r3, [r0], #4
176 teq r0, r6
177 bne 1b
178
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000179#ifdef CONFIG_ARM_LPAE
180 /*
181 * Build the PGD table (first level) to point to the PMD table. A PGD
182 * entry is 64-bit wide.
183 */
184 mov r0, r4
185 add r3, r4, #0x1000 @ first PMD table address
186 orr r3, r3, #3 @ PGD block type
187 mov r6, #4 @ PTRS_PER_PGD
188 mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER
Will Deacond61947a2013-02-28 17:46:16 +01001891:
190#ifdef CONFIG_CPU_ENDIAN_BE8
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000191 str r7, [r0], #4 @ set top PGD entry bits
Will Deacond61947a2013-02-28 17:46:16 +0100192 str r3, [r0], #4 @ set bottom PGD entry bits
193#else
194 str r3, [r0], #4 @ set bottom PGD entry bits
195 str r7, [r0], #4 @ set top PGD entry bits
196#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000197 add r3, r3, #0x1000 @ next PMD table
198 subs r6, r6, #1
199 bne 1b
200
201 add r4, r4, #0x1000 @ point to the PMD tables
Will Deacond61947a2013-02-28 17:46:16 +0100202#ifdef CONFIG_CPU_ENDIAN_BE8
203 add r4, r4, #4 @ we only write the bottom word
204#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000205#endif
206
Russell King8799ee92006-06-29 18:24:21 +0100207 ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 /*
Russell King786f1b72010-10-04 17:51:54 +0100210 * Create identity mapping to cater for __enable_mmu.
211 * This identity mapping will be removed by paging_init().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 */
Will Deacon72662e02011-11-23 12:03:27 +0000213 adr r0, __turn_mmu_on_loc
Russell King786f1b72010-10-04 17:51:54 +0100214 ldmia r0, {r3, r5, r6}
215 sub r0, r0, r3 @ virt->phys offset
Will Deacon72662e02011-11-23 12:03:27 +0000216 add r5, r5, r0 @ phys __turn_mmu_on
217 add r6, r6, r0 @ phys __turn_mmu_on_end
Catalin Marinase73fc882011-08-23 14:07:23 +0100218 mov r5, r5, lsr #SECTION_SHIFT
219 mov r6, r6, lsr #SECTION_SHIFT
Russell King786f1b72010-10-04 17:51:54 +0100220
Catalin Marinase73fc882011-08-23 14:07:23 +01002211: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base
222 str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping
223 cmp r5, r6
224 addlo r5, r5, #1 @ next section
225 blo 1b
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 /*
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100228 * Map our RAM from the start to the end of the kernel .bss section.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 */
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100230 add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
231 ldr r6, =(_end - 1)
232 orr r3, r8, r7
233 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
2341: str r3, [r0], #1 << PMD_ORDER
235 add r3, r3, #1 << SECTION_SHIFT
236 cmp r0, r6
237 bls 1b
238
239#ifdef CONFIG_XIP_KERNEL
240 /*
241 * Map the kernel image separately as it is not located in RAM.
242 */
243#define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
Russell King786f1b72010-10-04 17:51:54 +0100244 mov r3, pc
Catalin Marinase73fc882011-08-23 14:07:23 +0100245 mov r3, r3, lsr #SECTION_SHIFT
246 orr r3, r7, r3, lsl #SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100247 add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER)
248 str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]!
249 ldr r6, =(_edata_loc - 1)
Catalin Marinase73fc882011-08-23 14:07:23 +0100250 add r0, r0, #1 << PMD_ORDER
251 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
Nicolas Pitree98ff7f2007-02-22 16:18:09 +01002521: cmp r0, r6
Catalin Marinase73fc882011-08-23 14:07:23 +0100253 add r3, r3, #1 << SECTION_SHIFT
254 strls r3, [r0], #1 << PMD_ORDER
Nicolas Pitree98ff7f2007-02-22 16:18:09 +0100255 bls 1b
Nicolas Pitreec3622d2007-02-21 15:32:28 +0100256#endif
257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 /*
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100259 * Then map boot params address in r2 if specified.
Nicolas Pitre6f16f492013-01-15 18:51:32 +0100260 * We map 2 sections in case the ATAGs/DTB crosses a section boundary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100262 mov r0, r2, lsr #SECTION_SHIFT
263 movs r0, r0, lsl #SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100264 subne r3, r0, r8
265 addne r3, r3, #PAGE_OFFSET
266 addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER)
267 orrne r6, r7, r0
Nicolas Pitre6f16f492013-01-15 18:51:32 +0100268 strne r6, [r3], #1 << PMD_ORDER
269 addne r6, r6, #1 << SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100270 strne r6, [r3]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
Paul Bolle4e1db262013-04-03 12:24:45 +0100272#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
Will Deacond61947a2013-02-28 17:46:16 +0100273 sub r4, r4, #4 @ Fixup page table pointer
274 @ for 64-bit descriptors
275#endif
276
Russell Kingc77b0422005-07-01 11:56:55 +0100277#ifdef CONFIG_DEBUG_LL
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100278#if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 /*
280 * Map in IO space for serial debugging.
281 * This allows debug messages to be output
282 * via a serial console before paging_init.
283 */
Nicolas Pitre639da5e2011-08-31 22:55:46 -0400284 addruart r7, r3, r0
Jeremy Kerrc2933932010-07-07 11:19:48 +0800285
Catalin Marinase73fc882011-08-23 14:07:23 +0100286 mov r3, r3, lsr #SECTION_SHIFT
287 mov r3, r3, lsl #PMD_ORDER
Jeremy Kerrc2933932010-07-07 11:19:48 +0800288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 add r0, r4, r3
Catalin Marinase73fc882011-08-23 14:07:23 +0100290 mov r3, r7, lsr #SECTION_SHIFT
Jeremy Kerrc2933932010-07-07 11:19:48 +0800291 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
Catalin Marinase73fc882011-08-23 14:07:23 +0100292 orr r3, r7, r3, lsl #SECTION_SHIFT
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000293#ifdef CONFIG_ARM_LPAE
294 mov r7, #1 << (54 - 32) @ XN
Will Deacond61947a2013-02-28 17:46:16 +0100295#ifdef CONFIG_CPU_ENDIAN_BE8
296 str r7, [r0], #4
297 str r3, [r0], #4
298#else
299 str r3, [r0], #4
300 str r7, [r0], #4
301#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000302#else
303 orr r3, r3, #PMD_SECT_XN
Nicolas Pitref67860a72012-03-18 20:29:42 +0100304 str r3, [r0], #4
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000305#endif
Jeremy Kerrc2933932010-07-07 11:19:48 +0800306
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100307#else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */
308 /* we don't need any serial debugging mappings */
Jeremy Kerrc2933932010-07-07 11:19:48 +0800309 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100310#endif
Jeremy Kerrc2933932010-07-07 11:19:48 +0800311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
313 /*
Russell King3c0bdac2005-11-25 15:43:22 +0000314 * If we're using the NetWinder or CATS, we also need to map
315 * in the 16550-type serial port for the debug messages
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100317 add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER)
Russell Kingc77b0422005-07-01 11:56:55 +0100318 orr r3, r7, #0x7c000000
319 str r3, [r0]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321#ifdef CONFIG_ARCH_RPC
322 /*
323 * Map in screen at 0x02000000 & SCREEN2_BASE
324 * Similar reasons here - for debug. This is
325 * only for Acorn RiscPC architectures.
326 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100327 add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER)
Russell Kingc77b0422005-07-01 11:56:55 +0100328 orr r3, r7, #0x02000000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 str r3, [r0]
Catalin Marinase73fc882011-08-23 14:07:23 +0100330 add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 str r3, [r0]
332#endif
Russell Kingc77b0422005-07-01 11:56:55 +0100333#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000334#ifdef CONFIG_ARM_LPAE
335 sub r4, r4, #0x1000 @ point to the PGD table
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400336 mov r4, r4, lsr #ARCH_PGD_SHIFT
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000337#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 mov pc, lr
Catalin Marinas93ed3972008-08-28 11:22:32 +0100339ENDPROC(__create_page_tables)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 .ltorg
Dave Martin4f79a5d2010-11-29 19:43:24 +0100341 .align
Will Deacon72662e02011-11-23 12:03:27 +0000342__turn_mmu_on_loc:
Russell King786f1b72010-10-04 17:51:54 +0100343 .long .
Will Deacon72662e02011-11-23 12:03:27 +0000344 .long __turn_mmu_on
345 .long __turn_mmu_on_end
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Russell King00945012010-10-04 17:56:13 +0100347#if defined(CONFIG_SMP)
Russell King24491892013-07-31 11:37:17 +0100348 .text
Russell King00945012010-10-04 17:56:13 +0100349ENTRY(secondary_startup)
350 /*
351 * Common entry point for secondary CPUs.
352 *
353 * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
354 * the processor type - there is no need to check the machine type
355 * as it has already been validated by the primary processor.
356 */
Ben Dooks97bcb0f2013-02-01 09:40:42 +0000357
358 ARM_BE8(setend be) @ ensure we are in BE8 mode
359
Dave Martin80c59da2012-02-09 08:47:17 -0800360#ifdef CONFIG_ARM_VIRT_EXT
Marc Zyngier6e484be2013-01-04 17:44:14 +0000361 bl __hyp_stub_install_secondary
Dave Martin80c59da2012-02-09 08:47:17 -0800362#endif
363 safe_svcmode_maskall r9
364
Russell King00945012010-10-04 17:56:13 +0100365 mrc p15, 0, r9, c0, c0 @ get processor id
366 bl __lookup_processor_type
367 movs r10, r5 @ invalid processor?
368 moveq r0, #'p' @ yes, error 'p'
Dave Martina75e5242010-11-29 19:43:28 +0100369 THUMB( it eq ) @ force fixup-able long branch encoding
Russell King00945012010-10-04 17:56:13 +0100370 beq __error_p
371
372 /*
373 * Use the page tables supplied from __cpu_up.
374 */
375 adr r4, __secondary_data
376 ldmia r4, {r5, r7, r12} @ address to jump to after
Catalin Marinasd4279582011-05-26 11:22:44 +0100377 sub lr, r4, r5 @ mmu has been enabled
378 ldr r4, [r7, lr] @ get secondary_data.pgdir
379 add r7, r7, #4
380 ldr r8, [r7, lr] @ get secondary_data.swapper_pg_dir
Russell King00945012010-10-04 17:56:13 +0100381 adr lr, BSYM(__enable_mmu) @ return address
382 mov r13, r12 @ __secondary_switched address
383 ARM( add pc, r10, #PROCINFO_INITFUNC ) @ initialise processor
384 @ (return control reg)
385 THUMB( add r12, r10, #PROCINFO_INITFUNC )
386 THUMB( mov pc, r12 )
387ENDPROC(secondary_startup)
388
389 /*
390 * r6 = &secondary_data
391 */
392ENTRY(__secondary_switched)
393 ldr sp, [r7, #4] @ get secondary_data.stack
394 mov fp, #0
395 b secondary_start_kernel
396ENDPROC(__secondary_switched)
397
Dave Martin4f79a5d2010-11-29 19:43:24 +0100398 .align
399
Russell King00945012010-10-04 17:56:13 +0100400 .type __secondary_data, %object
401__secondary_data:
402 .long .
403 .long secondary_data
404 .long __secondary_switched
405#endif /* defined(CONFIG_SMP) */
406
407
408
409/*
410 * Setup common bits before finally enabling the MMU. Essentially
411 * this is just loading the page table pointer and domain access
412 * registers.
Russell King865a4fa2010-10-04 18:02:59 +0100413 *
414 * r0 = cp#15 control register
415 * r1 = machine ID
Grant Likely4c2896e2011-04-28 14:27:20 -0600416 * r2 = atags or dtb pointer
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400417 * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
Russell King865a4fa2010-10-04 18:02:59 +0100418 * r9 = processor ID
419 * r13 = *virtual* address to jump to upon completion
Russell King00945012010-10-04 17:56:13 +0100420 */
421__enable_mmu:
Catalin Marinas8428e842011-11-07 18:05:53 +0100422#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
Russell King00945012010-10-04 17:56:13 +0100423 orr r0, r0, #CR_A
424#else
425 bic r0, r0, #CR_A
426#endif
427#ifdef CONFIG_CPU_DCACHE_DISABLE
428 bic r0, r0, #CR_C
429#endif
430#ifdef CONFIG_CPU_BPREDICT_DISABLE
431 bic r0, r0, #CR_Z
432#endif
433#ifdef CONFIG_CPU_ICACHE_DISABLE
434 bic r0, r0, #CR_I
435#endif
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400436#ifndef CONFIG_ARM_LPAE
Russell King00945012010-10-04 17:56:13 +0100437 mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
438 domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
439 domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
440 domain_val(DOMAIN_IO, DOMAIN_CLIENT))
441 mcr p15, 0, r5, c3, c0, 0 @ load domain access register
442 mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000443#endif
Russell King00945012010-10-04 17:56:13 +0100444 b __turn_mmu_on
445ENDPROC(__enable_mmu)
446
447/*
448 * Enable the MMU. This completely changes the structure of the visible
449 * memory space. You will not be able to trace execution through this.
450 * If you have an enquiry about this, *please* check the linux-arm-kernel
451 * mailing list archives BEFORE sending another post to the list.
452 *
453 * r0 = cp#15 control register
Russell King865a4fa2010-10-04 18:02:59 +0100454 * r1 = machine ID
Grant Likely4c2896e2011-04-28 14:27:20 -0600455 * r2 = atags or dtb pointer
Russell King865a4fa2010-10-04 18:02:59 +0100456 * r9 = processor ID
Russell King00945012010-10-04 17:56:13 +0100457 * r13 = *virtual* address to jump to upon completion
458 *
459 * other registers depend on the function called upon completion
460 */
461 .align 5
Will Deacon4e8ee7d2011-11-23 12:26:25 +0000462 .pushsection .idmap.text, "ax"
463ENTRY(__turn_mmu_on)
Russell King00945012010-10-04 17:56:13 +0100464 mov r0, r0
Will Deacond675d0b2011-11-22 17:30:28 +0000465 instr_sync
Russell King00945012010-10-04 17:56:13 +0100466 mcr p15, 0, r0, c1, c0, 0 @ write control reg
467 mrc p15, 0, r3, c0, c0, 0 @ read id reg
Will Deacond675d0b2011-11-22 17:30:28 +0000468 instr_sync
Russell King00945012010-10-04 17:56:13 +0100469 mov r3, r3
470 mov r3, r13
471 mov pc, r3
Will Deacon72662e02011-11-23 12:03:27 +0000472__turn_mmu_on_end:
Russell King00945012010-10-04 17:56:13 +0100473ENDPROC(__turn_mmu_on)
Will Deacon4e8ee7d2011-11-23 12:26:25 +0000474 .popsection
Russell King00945012010-10-04 17:56:13 +0100475
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
Russell Kingf00ec482010-09-04 10:47:48 +0100477#ifdef CONFIG_SMP_ON_UP
Russell King4a9cb362011-02-10 15:25:18 +0000478 __INIT
Russell Kingf00ec482010-09-04 10:47:48 +0100479__fixup_smp:
Russell Kinge98ff0f2011-01-30 16:40:20 +0000480 and r3, r9, #0x000f0000 @ architecture version
481 teq r3, #0x000f0000 @ CPU ID supported?
Russell Kingf00ec482010-09-04 10:47:48 +0100482 bne __fixup_smp_on_up @ no, assume UP
483
Russell Kinge98ff0f2011-01-30 16:40:20 +0000484 bic r3, r9, #0x00ff0000
485 bic r3, r3, #0x0000000f @ mask 0xff00fff0
486 mov r4, #0x41000000
Russell King0eb0511d2010-11-22 12:06:28 +0000487 orr r4, r4, #0x0000b000
Russell Kinge98ff0f2011-01-30 16:40:20 +0000488 orr r4, r4, #0x00000020 @ val 0x4100b020
489 teq r3, r4 @ ARM 11MPCore?
Russell Kingf00ec482010-09-04 10:47:48 +0100490 moveq pc, lr @ yes, assume SMP
491
492 mrc p15, 0, r0, c0, c0, 5 @ read MPIDR
Russell Kinge98ff0f2011-01-30 16:40:20 +0000493 and r0, r0, #0xc0000000 @ multiprocessing extensions and
494 teq r0, #0x80000000 @ not part of a uniprocessor system?
Santosh Shilimkarbc41b872013-09-27 21:56:31 +0100495 bne __fixup_smp_on_up @ no, assume UP
496
497 @ Core indicates it is SMP. Check for Aegis SOC where a single
498 @ Cortex-A9 CPU is present but SMP operations fault.
499 mov r4, #0x41000000
500 orr r4, r4, #0x0000c000
501 orr r4, r4, #0x00000090
502 teq r3, r4 @ Check for ARM Cortex-A9
503 movne pc, lr @ Not ARM Cortex-A9,
504
505 @ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the
506 @ below address check will need to be #ifdef'd or equivalent
507 @ for the Aegis platform.
508 mrc p15, 4, r0, c15, c0 @ get SCU base address
509 teq r0, #0x0 @ '0' on actual UP A9 hardware
510 beq __fixup_smp_on_up @ So its an A9 UP
511 ldr r0, [r0, #4] @ read SCU Config
Victor Kamensky10593b22013-11-07 08:42:40 +0100512ARM_BE8(rev r0, r0) @ byteswap if big endian
Santosh Shilimkarbc41b872013-09-27 21:56:31 +0100513 and r0, r0, #0x3 @ number of CPUs
514 teq r0, #0x0 @ is 1?
515 movne pc, lr
Russell Kingf00ec482010-09-04 10:47:48 +0100516
517__fixup_smp_on_up:
518 adr r0, 1f
Russell King0eb0511d2010-11-22 12:06:28 +0000519 ldmia r0, {r3 - r5}
Russell Kingf00ec482010-09-04 10:47:48 +0100520 sub r3, r0, r3
Russell King0eb0511d2010-11-22 12:06:28 +0000521 add r4, r4, r3
522 add r5, r5, r3
Russell King4a9cb362011-02-10 15:25:18 +0000523 b __do_fixup_smp_on_up
Russell Kingf00ec482010-09-04 10:47:48 +0100524ENDPROC(__fixup_smp)
525
Dave Martin4f79a5d2010-11-29 19:43:24 +0100526 .align
Russell Kingf00ec482010-09-04 10:47:48 +01005271: .word .
528 .word __smpalt_begin
529 .word __smpalt_end
530
531 .pushsection .data
532 .globl smp_on_up
533smp_on_up:
534 ALT_SMP(.long 1)
535 ALT_UP(.long 0)
536 .popsection
Russell Kingf00ec482010-09-04 10:47:48 +0100537#endif
538
Russell King4a9cb362011-02-10 15:25:18 +0000539 .text
540__do_fixup_smp_on_up:
541 cmp r4, r5
542 movhs pc, lr
543 ldmia r4!, {r0, r6}
544 ARM( str r6, [r0, r3] )
545 THUMB( add r0, r0, r3 )
546#ifdef __ARMEB__
547 THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian.
548#endif
549 THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords
550 THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3.
551 THUMB( strh r6, [r0] )
552 b __do_fixup_smp_on_up
553ENDPROC(__do_fixup_smp_on_up)
554
555ENTRY(fixup_smp)
556 stmfd sp!, {r4 - r6, lr}
557 mov r4, r0
558 add r5, r0, r1
559 mov r3, #0
560 bl __do_fixup_smp_on_up
561 ldmfd sp!, {r4 - r6, pc}
562ENDPROC(fixup_smp)
563
Sricharan R830fd4d2013-10-29 07:29:56 +0100564#ifdef __ARMEB__
Sricharan Rf52bb722013-07-29 20:26:22 +0530565#define LOW_OFFSET 0x4
566#define HIGH_OFFSET 0x0
567#else
568#define LOW_OFFSET 0x0
569#define HIGH_OFFSET 0x4
570#endif
571
Russell Kingdc21af92011-01-04 19:09:43 +0000572#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
573
574/* __fixup_pv_table - patch the stub instructions with the delta between
575 * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and
576 * can be expressed by an immediate shifter operand. The stub instruction
577 * has a form of '(add|sub) rd, rn, #imm'.
578 */
579 __HEAD
580__fixup_pv_table:
581 adr r0, 1f
Sricharan Rf52bb722013-07-29 20:26:22 +0530582 ldmia r0, {r3-r7}
583 mvn ip, #0
584 subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET
Russell Kingdc21af92011-01-04 19:09:43 +0000585 add r4, r4, r3 @ adjust table start address
586 add r5, r5, r3 @ adjust table end address
Sricharan Rf52bb722013-07-29 20:26:22 +0530587 add r6, r6, r3 @ adjust __pv_phys_offset address
588 add r7, r7, r3 @ adjust __pv_offset address
589 str r8, [r6, #LOW_OFFSET] @ save computed PHYS_OFFSET to __pv_phys_offset
590 strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits
Russell Kingdc21af92011-01-04 19:09:43 +0000591 mov r6, r3, lsr #24 @ constant for add/sub instructions
592 teq r3, r6, lsl #24 @ must be 16MiB aligned
Nicolas Pitreb511d752011-02-21 06:53:35 +0100593THUMB( it ne @ cross section branch )
Russell Kingdc21af92011-01-04 19:09:43 +0000594 bne __error
Sricharan Rf52bb722013-07-29 20:26:22 +0530595 str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits
Russell Kingdc21af92011-01-04 19:09:43 +0000596 b __fixup_a_pv_table
597ENDPROC(__fixup_pv_table)
598
599 .align
6001: .long .
601 .long __pv_table_begin
602 .long __pv_table_end
6032: .long __pv_phys_offset
Sricharan Rf52bb722013-07-29 20:26:22 +0530604 .long __pv_offset
Russell Kingdc21af92011-01-04 19:09:43 +0000605
606 .text
607__fixup_a_pv_table:
Sricharan Rf52bb722013-07-29 20:26:22 +0530608 adr r0, 3f
609 ldr r6, [r0]
610 add r6, r6, r3
611 ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word
612 ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word
613 mov r6, r6, lsr #24
614 cmn r0, #1
Nicolas Pitreb511d752011-02-21 06:53:35 +0100615#ifdef CONFIG_THUMB2_KERNEL
Sricharan Rf52bb722013-07-29 20:26:22 +0530616 moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
Nicolas Pitredaece592011-08-12 00:14:29 +0100617 lsls r6, #24
618 beq 2f
Nicolas Pitreb511d752011-02-21 06:53:35 +0100619 clz r7, r6
620 lsr r6, #24
621 lsl r6, r7
622 bic r6, #0x0080
623 lsrs r7, #1
624 orrcs r6, #0x0080
625 orr r6, r6, r7, lsl #12
626 orr r6, #0x4000
Nicolas Pitredaece592011-08-12 00:14:29 +0100627 b 2f
6281: add r7, r3
629 ldrh ip, [r7, #2]
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100630ARM_BE8(rev16 ip, ip)
Sricharan Rf52bb722013-07-29 20:26:22 +0530631 tst ip, #0x4000
632 and ip, #0x8f00
633 orrne ip, r6 @ mask in offset bits 31-24
634 orreq ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100635ARM_BE8(rev16 ip, ip)
Nicolas Pitreb511d752011-02-21 06:53:35 +0100636 strh ip, [r7, #2]
Russell King20989902013-10-28 00:43:41 +0000637 bne 2f
638 ldrh ip, [r7]
639ARM_BE8(rev16 ip, ip)
640 bic ip, #0x20
641 orr ip, ip, r0, lsr #16
642ARM_BE8(rev16 ip, ip)
643 strh ip, [r7]
Nicolas Pitredaece592011-08-12 00:14:29 +01006442: cmp r4, r5
Nicolas Pitreb511d752011-02-21 06:53:35 +0100645 ldrcc r7, [r4], #4 @ use branch for delay slot
Nicolas Pitredaece592011-08-12 00:14:29 +0100646 bcc 1b
Nicolas Pitreb511d752011-02-21 06:53:35 +0100647 bx lr
648#else
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100649#ifdef CONFIG_CPU_ENDIAN_BE8
650 moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction
651#else
Sricharan Rf52bb722013-07-29 20:26:22 +0530652 moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100653#endif
Nicolas Pitredaece592011-08-12 00:14:29 +0100654 b 2f
6551: ldr ip, [r7, r3]
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100656#ifdef CONFIG_CPU_ENDIAN_BE8
657 @ in BE8, we load data in BE, but instructions still in LE
658 bic ip, ip, #0xff000000
Russell King20989902013-10-28 00:43:41 +0000659 tst ip, #0x000f0000 @ check the rotation field
660 orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24
661 biceq ip, ip, #0x00004000 @ clear bit 22
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100662 orreq ip, ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100663#else
Russell Kingdc21af92011-01-04 19:09:43 +0000664 bic ip, ip, #0x000000ff
Sricharan Rf52bb722013-07-29 20:26:22 +0530665 tst ip, #0xf00 @ check the rotation field
666 orrne ip, ip, r6 @ mask in offset bits 31-24
667 biceq ip, ip, #0x400000 @ clear bit 22
668 orreq ip, ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100669#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000670 str ip, [r7, r3]
Nicolas Pitredaece592011-08-12 00:14:29 +01006712: cmp r4, r5
Russell Kingdc21af92011-01-04 19:09:43 +0000672 ldrcc r7, [r4], #4 @ use branch for delay slot
Nicolas Pitredaece592011-08-12 00:14:29 +0100673 bcc 1b
Russell Kingdc21af92011-01-04 19:09:43 +0000674 mov pc, lr
Nicolas Pitreb511d752011-02-21 06:53:35 +0100675#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000676ENDPROC(__fixup_a_pv_table)
677
Sricharan R830fd4d2013-10-29 07:29:56 +0100678 .align
Sricharan Rf52bb722013-07-29 20:26:22 +05306793: .long __pv_offset
680
Russell Kingdc21af92011-01-04 19:09:43 +0000681ENTRY(fixup_pv_table)
682 stmfd sp!, {r4 - r7, lr}
Russell Kingdc21af92011-01-04 19:09:43 +0000683 mov r3, #0 @ no offset
684 mov r4, r0 @ r0 = table start
685 add r5, r0, r1 @ r1 = table size
Russell Kingdc21af92011-01-04 19:09:43 +0000686 bl __fixup_a_pv_table
687 ldmfd sp!, {r4 - r7, pc}
688ENDPROC(fixup_pv_table)
689
Russell Kingdc21af92011-01-04 19:09:43 +0000690 .data
691 .globl __pv_phys_offset
692 .type __pv_phys_offset, %object
693__pv_phys_offset:
Sricharan Rf52bb722013-07-29 20:26:22 +0530694 .quad 0
695 .size __pv_phys_offset, . -__pv_phys_offset
696
697 .globl __pv_offset
698 .type __pv_offset, %object
Russell Kingdc21af92011-01-04 19:09:43 +0000699__pv_offset:
Sricharan Rf52bb722013-07-29 20:26:22 +0530700 .quad 0
701 .size __pv_offset, . -__pv_offset
Russell Kingdc21af92011-01-04 19:09:43 +0000702#endif
703
Hyok S. Choi75d90832006-03-27 14:58:25 +0100704#include "head-common.S"