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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
Catalin Marinase73fc882011-08-23 14:07:23 +010055 add \rd, \phys, #TEXT_OFFSET - PG_DIR_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 .endm
Nicolas Pitre37d07b72005-10-29 21:44:56 +010057
Linus Torvalds1da177e2005-04-16 15:20:36 -070058/*
59 * Kernel startup entry point.
60 * ---------------------------
61 *
62 * This is normally called from the decompressor code. The requirements
63 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
Grant Likely4c2896e2011-04-28 14:27:20 -060064 * r1 = machine nr, r2 = atags or dtb pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 *
66 * This code is mostly position independent, so if you link the kernel at
67 * 0xc0008000, you call this at __pa(0xc0008000).
68 *
69 * See linux/arch/arm/tools/mach-types for the complete list of machine
70 * numbers for r1.
71 *
72 * We're trying to keep crap to a minimum; DO NOT add any machine specific
73 * crap here - that's what the boot loader (or in extreme, well justified
74 * circumstances, zImage) is for.
75 */
Dave Martin540b5732011-07-13 15:53:30 +010076 .arm
77
Tim Abbott2abc1c52009-10-02 16:32:46 -040078 __HEAD
Linus Torvalds1da177e2005-04-16 15:20:36 -070079ENTRY(stext)
Ben Dooks97bcb0f2013-02-01 09:40:42 +000080 ARM_BE8(setend be ) @ ensure we are in BE8 mode
Dave Martin540b5732011-07-13 15:53:30 +010081
82 THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM.
83 THUMB( bx r9 ) @ If this is a Thumb-2 kernel,
84 THUMB( .thumb ) @ switch to Thumb now.
85 THUMB(1: )
86
Dave Martin80c59da2012-02-09 08:47:17 -080087#ifdef CONFIG_ARM_VIRT_EXT
88 bl __hyp_stub_install
89#endif
90 @ ensure svc mode and all interrupts masked
91 safe_svcmode_maskall r9
92
Russell King0f44ba12006-02-24 21:04:56 +000093 mrc p15, 0, r9, c0, c0 @ get processor id
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 bl __lookup_processor_type @ r5=procinfo r9=cpuid
95 movs r10, r5 @ invalid processor (r5=0)?
Dave Martina75e5242010-11-29 19:43:28 +010096 THUMB( it eq ) @ force fixup-able long branch encoding
Russell King3c0bdac2005-11-25 15:43:22 +000097 beq __error_p @ yes, error 'p'
Russell King0eb0511d2010-11-22 12:06:28 +000098
Catalin Marinas294064f2012-01-09 12:24:47 +010099#ifdef CONFIG_ARM_LPAE
100 mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0
101 and r3, r3, #0xf @ extract VMSA support
102 cmp r3, #5 @ long-descriptor translation table format?
103 THUMB( it lo ) @ force fixup-able long branch encoding
104 blo __error_p @ only classic page table format
105#endif
106
Russell King72a20e22011-01-04 19:04:00 +0000107#ifndef CONFIG_XIP_KERNEL
108 adr r3, 2f
109 ldmia r3, {r4, r8}
110 sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET)
111 add r8, r8, r4 @ PHYS_OFFSET
112#else
Nicolas Pitre1b9f95f2011-07-05 22:52:51 -0400113 ldr r8, =PHYS_OFFSET @ always constant in this case
Russell King72a20e22011-01-04 19:04:00 +0000114#endif
115
Russell King0eb0511d2010-11-22 12:06:28 +0000116 /*
Grant Likely4c2896e2011-04-28 14:27:20 -0600117 * r1 = machine no, r2 = atags or dtb,
Russell King72a20e22011-01-04 19:04:00 +0000118 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
Russell King0eb0511d2010-11-22 12:06:28 +0000119 */
Bill Gatliff9d20fdd2007-05-31 22:02:22 +0100120 bl __vet_atags
Russell Kingf00ec482010-09-04 10:47:48 +0100121#ifdef CONFIG_SMP_ON_UP
122 bl __fixup_smp
123#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000124#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
125 bl __fixup_pv_table
126#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 bl __create_page_tables
128
129 /*
130 * The following calls CPU specific code in a position independent
131 * manner. See arch/arm/mm/proc-*.S for details. r10 = base of
Russell King6fc31d52011-01-12 17:50:42 +0000132 * xxx_proc_info structure selected by __lookup_processor_type
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * above. On return, the CPU will be ready for the MMU to be
134 * turned on, and r0 will hold the CPU control register value.
135 */
Russell Kinga4ae4132010-10-04 16:22:34 +0100136 ldr r13, =__mmap_switched @ address to jump to after
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 @ mmu has been enabled
Russell King00945012010-10-04 17:56:13 +0100138 adr lr, BSYM(1f) @ return (PIC) address
Catalin Marinasd4279582011-05-26 11:22:44 +0100139 mov r8, r4 @ set TTBR1 to swapper_pg_dir
Catalin Marinasb86040a2009-07-24 12:32:54 +0100140 ARM( add pc, r10, #PROCINFO_INITFUNC )
141 THUMB( add r12, r10, #PROCINFO_INITFUNC )
142 THUMB( mov pc, r12 )
Russell King00945012010-10-04 17:56:13 +01001431: b __enable_mmu
Catalin Marinas93ed3972008-08-28 11:22:32 +0100144ENDPROC(stext)
Russell Kinga4ae4132010-10-04 16:22:34 +0100145 .ltorg
Russell King72a20e22011-01-04 19:04:00 +0000146#ifndef CONFIG_XIP_KERNEL
1472: .long .
148 .long PAGE_OFFSET
149#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
151/*
152 * Setup the initial page tables. We only setup the barest
153 * amount which are required to get the kernel running, which
154 * generally means mapping in the kernel code.
155 *
Russell King72a20e22011-01-04 19:04:00 +0000156 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 *
158 * Returns:
Russell King786f1b72010-10-04 17:51:54 +0100159 * r0, r3, r5-r7 corrupted
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400160 * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162__create_page_tables:
Russell King72a20e22011-01-04 19:04:00 +0000163 pgtbl r4, r8 @ page table address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 /*
Catalin Marinase73fc882011-08-23 14:07:23 +0100166 * Clear the swapper page table
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 */
168 mov r0, r4
169 mov r3, #0
Catalin Marinase73fc882011-08-23 14:07:23 +0100170 add r6, r0, #PG_DIR_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711: str r3, [r0], #4
172 str r3, [r0], #4
173 str r3, [r0], #4
174 str r3, [r0], #4
175 teq r0, r6
176 bne 1b
177
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000178#ifdef CONFIG_ARM_LPAE
179 /*
180 * Build the PGD table (first level) to point to the PMD table. A PGD
181 * entry is 64-bit wide.
182 */
183 mov r0, r4
184 add r3, r4, #0x1000 @ first PMD table address
185 orr r3, r3, #3 @ PGD block type
186 mov r6, #4 @ PTRS_PER_PGD
187 mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER
Will Deacond61947a2013-02-28 17:46:16 +01001881:
189#ifdef CONFIG_CPU_ENDIAN_BE8
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000190 str r7, [r0], #4 @ set top PGD entry bits
Will Deacond61947a2013-02-28 17:46:16 +0100191 str r3, [r0], #4 @ set bottom PGD entry bits
192#else
193 str r3, [r0], #4 @ set bottom PGD entry bits
194 str r7, [r0], #4 @ set top PGD entry bits
195#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000196 add r3, r3, #0x1000 @ next PMD table
197 subs r6, r6, #1
198 bne 1b
199
200 add r4, r4, #0x1000 @ point to the PMD tables
Will Deacond61947a2013-02-28 17:46:16 +0100201#ifdef CONFIG_CPU_ENDIAN_BE8
202 add r4, r4, #4 @ we only write the bottom word
203#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000204#endif
205
Russell King8799ee92006-06-29 18:24:21 +0100206 ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208 /*
Russell King786f1b72010-10-04 17:51:54 +0100209 * Create identity mapping to cater for __enable_mmu.
210 * This identity mapping will be removed by paging_init().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 */
Will Deacon72662e02011-11-23 12:03:27 +0000212 adr r0, __turn_mmu_on_loc
Russell King786f1b72010-10-04 17:51:54 +0100213 ldmia r0, {r3, r5, r6}
214 sub r0, r0, r3 @ virt->phys offset
Will Deacon72662e02011-11-23 12:03:27 +0000215 add r5, r5, r0 @ phys __turn_mmu_on
216 add r6, r6, r0 @ phys __turn_mmu_on_end
Catalin Marinase73fc882011-08-23 14:07:23 +0100217 mov r5, r5, lsr #SECTION_SHIFT
218 mov r6, r6, lsr #SECTION_SHIFT
Russell King786f1b72010-10-04 17:51:54 +0100219
Catalin Marinase73fc882011-08-23 14:07:23 +01002201: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base
221 str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping
222 cmp r5, r6
223 addlo r5, r5, #1 @ next section
224 blo 1b
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
226 /*
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100227 * Map our RAM from the start to the end of the kernel .bss section.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 */
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100229 add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
230 ldr r6, =(_end - 1)
231 orr r3, r8, r7
232 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
2331: str r3, [r0], #1 << PMD_ORDER
234 add r3, r3, #1 << SECTION_SHIFT
235 cmp r0, r6
236 bls 1b
237
238#ifdef CONFIG_XIP_KERNEL
239 /*
240 * Map the kernel image separately as it is not located in RAM.
241 */
242#define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
Russell King786f1b72010-10-04 17:51:54 +0100243 mov r3, pc
Catalin Marinase73fc882011-08-23 14:07:23 +0100244 mov r3, r3, lsr #SECTION_SHIFT
245 orr r3, r7, r3, lsl #SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100246 add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER)
247 str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]!
248 ldr r6, =(_edata_loc - 1)
Catalin Marinase73fc882011-08-23 14:07:23 +0100249 add r0, r0, #1 << PMD_ORDER
250 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
Nicolas Pitree98ff7f2007-02-22 16:18:09 +01002511: cmp r0, r6
Catalin Marinase73fc882011-08-23 14:07:23 +0100252 add r3, r3, #1 << SECTION_SHIFT
253 strls r3, [r0], #1 << PMD_ORDER
Nicolas Pitree98ff7f2007-02-22 16:18:09 +0100254 bls 1b
Nicolas Pitreec3622d2007-02-21 15:32:28 +0100255#endif
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 /*
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100258 * Then map boot params address in r2 if specified.
Nicolas Pitre6f16f492013-01-15 18:51:32 +0100259 * We map 2 sections in case the ATAGs/DTB crosses a section boundary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100261 mov r0, r2, lsr #SECTION_SHIFT
262 movs r0, r0, lsl #SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100263 subne r3, r0, r8
264 addne r3, r3, #PAGE_OFFSET
265 addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER)
266 orrne r6, r7, r0
Nicolas Pitre6f16f492013-01-15 18:51:32 +0100267 strne r6, [r3], #1 << PMD_ORDER
268 addne r6, r6, #1 << SECTION_SHIFT
Nicolas Pitre9fa16b72012-07-04 04:58:12 +0100269 strne r6, [r3]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
Paul Bolle4e1db262013-04-03 12:24:45 +0100271#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
Will Deacond61947a2013-02-28 17:46:16 +0100272 sub r4, r4, #4 @ Fixup page table pointer
273 @ for 64-bit descriptors
274#endif
275
Russell Kingc77b0422005-07-01 11:56:55 +0100276#ifdef CONFIG_DEBUG_LL
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100277#if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 /*
279 * Map in IO space for serial debugging.
280 * This allows debug messages to be output
281 * via a serial console before paging_init.
282 */
Nicolas Pitre639da5e2011-08-31 22:55:46 -0400283 addruart r7, r3, r0
Jeremy Kerrc2933932010-07-07 11:19:48 +0800284
Catalin Marinase73fc882011-08-23 14:07:23 +0100285 mov r3, r3, lsr #SECTION_SHIFT
286 mov r3, r3, lsl #PMD_ORDER
Jeremy Kerrc2933932010-07-07 11:19:48 +0800287
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 add r0, r4, r3
Catalin Marinase73fc882011-08-23 14:07:23 +0100289 mov r3, r7, lsr #SECTION_SHIFT
Jeremy Kerrc2933932010-07-07 11:19:48 +0800290 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
Catalin Marinase73fc882011-08-23 14:07:23 +0100291 orr r3, r7, r3, lsl #SECTION_SHIFT
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000292#ifdef CONFIG_ARM_LPAE
293 mov r7, #1 << (54 - 32) @ XN
Will Deacond61947a2013-02-28 17:46:16 +0100294#ifdef CONFIG_CPU_ENDIAN_BE8
295 str r7, [r0], #4
296 str r3, [r0], #4
297#else
298 str r3, [r0], #4
299 str r7, [r0], #4
300#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000301#else
302 orr r3, r3, #PMD_SECT_XN
Nicolas Pitref67860a72012-03-18 20:29:42 +0100303 str r3, [r0], #4
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000304#endif
Jeremy Kerrc2933932010-07-07 11:19:48 +0800305
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100306#else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */
307 /* we don't need any serial debugging mappings */
Jeremy Kerrc2933932010-07-07 11:19:48 +0800308 ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
Nicolas Pitre9b5a1462012-02-22 21:58:03 +0100309#endif
Jeremy Kerrc2933932010-07-07 11:19:48 +0800310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
312 /*
Russell King3c0bdac2005-11-25 15:43:22 +0000313 * If we're using the NetWinder or CATS, we also need to map
314 * in the 16550-type serial port for the debug messages
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100316 add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER)
Russell Kingc77b0422005-07-01 11:56:55 +0100317 orr r3, r7, #0x7c000000
318 str r3, [r0]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320#ifdef CONFIG_ARCH_RPC
321 /*
322 * Map in screen at 0x02000000 & SCREEN2_BASE
323 * Similar reasons here - for debug. This is
324 * only for Acorn RiscPC architectures.
325 */
Catalin Marinase73fc882011-08-23 14:07:23 +0100326 add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER)
Russell Kingc77b0422005-07-01 11:56:55 +0100327 orr r3, r7, #0x02000000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 str r3, [r0]
Catalin Marinase73fc882011-08-23 14:07:23 +0100329 add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 str r3, [r0]
331#endif
Russell Kingc77b0422005-07-01 11:56:55 +0100332#endif
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000333#ifdef CONFIG_ARM_LPAE
334 sub r4, r4, #0x1000 @ point to the PGD table
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400335 mov r4, r4, lsr #ARCH_PGD_SHIFT
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000336#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 mov pc, lr
Catalin Marinas93ed3972008-08-28 11:22:32 +0100338ENDPROC(__create_page_tables)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 .ltorg
Dave Martin4f79a5d2010-11-29 19:43:24 +0100340 .align
Will Deacon72662e02011-11-23 12:03:27 +0000341__turn_mmu_on_loc:
Russell King786f1b72010-10-04 17:51:54 +0100342 .long .
Will Deacon72662e02011-11-23 12:03:27 +0000343 .long __turn_mmu_on
344 .long __turn_mmu_on_end
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
Russell King00945012010-10-04 17:56:13 +0100346#if defined(CONFIG_SMP)
Russell King24491892013-07-31 11:37:17 +0100347 .text
Russell King00945012010-10-04 17:56:13 +0100348ENTRY(secondary_startup)
349 /*
350 * Common entry point for secondary CPUs.
351 *
352 * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
353 * the processor type - there is no need to check the machine type
354 * as it has already been validated by the primary processor.
355 */
Ben Dooks97bcb0f2013-02-01 09:40:42 +0000356
357 ARM_BE8(setend be) @ ensure we are in BE8 mode
358
Dave Martin80c59da2012-02-09 08:47:17 -0800359#ifdef CONFIG_ARM_VIRT_EXT
Marc Zyngier6e484be2013-01-04 17:44:14 +0000360 bl __hyp_stub_install_secondary
Dave Martin80c59da2012-02-09 08:47:17 -0800361#endif
362 safe_svcmode_maskall r9
363
Russell King00945012010-10-04 17:56:13 +0100364 mrc p15, 0, r9, c0, c0 @ get processor id
365 bl __lookup_processor_type
366 movs r10, r5 @ invalid processor?
367 moveq r0, #'p' @ yes, error 'p'
Dave Martina75e5242010-11-29 19:43:28 +0100368 THUMB( it eq ) @ force fixup-able long branch encoding
Russell King00945012010-10-04 17:56:13 +0100369 beq __error_p
370
371 /*
372 * Use the page tables supplied from __cpu_up.
373 */
374 adr r4, __secondary_data
375 ldmia r4, {r5, r7, r12} @ address to jump to after
Catalin Marinasd4279582011-05-26 11:22:44 +0100376 sub lr, r4, r5 @ mmu has been enabled
377 ldr r4, [r7, lr] @ get secondary_data.pgdir
378 add r7, r7, #4
379 ldr r8, [r7, lr] @ get secondary_data.swapper_pg_dir
Russell King00945012010-10-04 17:56:13 +0100380 adr lr, BSYM(__enable_mmu) @ return address
381 mov r13, r12 @ __secondary_switched address
382 ARM( add pc, r10, #PROCINFO_INITFUNC ) @ initialise processor
383 @ (return control reg)
384 THUMB( add r12, r10, #PROCINFO_INITFUNC )
385 THUMB( mov pc, r12 )
386ENDPROC(secondary_startup)
387
388 /*
389 * r6 = &secondary_data
390 */
391ENTRY(__secondary_switched)
392 ldr sp, [r7, #4] @ get secondary_data.stack
393 mov fp, #0
394 b secondary_start_kernel
395ENDPROC(__secondary_switched)
396
Dave Martin4f79a5d2010-11-29 19:43:24 +0100397 .align
398
Russell King00945012010-10-04 17:56:13 +0100399 .type __secondary_data, %object
400__secondary_data:
401 .long .
402 .long secondary_data
403 .long __secondary_switched
404#endif /* defined(CONFIG_SMP) */
405
406
407
408/*
409 * Setup common bits before finally enabling the MMU. Essentially
410 * this is just loading the page table pointer and domain access
411 * registers.
Russell King865a4fa2010-10-04 18:02:59 +0100412 *
413 * r0 = cp#15 control register
414 * r1 = machine ID
Grant Likely4c2896e2011-04-28 14:27:20 -0600415 * r2 = atags or dtb pointer
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400416 * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
Russell King865a4fa2010-10-04 18:02:59 +0100417 * r9 = processor ID
418 * r13 = *virtual* address to jump to upon completion
Russell King00945012010-10-04 17:56:13 +0100419 */
420__enable_mmu:
Catalin Marinas8428e842011-11-07 18:05:53 +0100421#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
Russell King00945012010-10-04 17:56:13 +0100422 orr r0, r0, #CR_A
423#else
424 bic r0, r0, #CR_A
425#endif
426#ifdef CONFIG_CPU_DCACHE_DISABLE
427 bic r0, r0, #CR_C
428#endif
429#ifdef CONFIG_CPU_BPREDICT_DISABLE
430 bic r0, r0, #CR_Z
431#endif
432#ifdef CONFIG_CPU_ICACHE_DISABLE
433 bic r0, r0, #CR_I
434#endif
Cyril Chemparathy4756dcb2012-07-21 15:55:04 -0400435#ifndef CONFIG_ARM_LPAE
Russell King00945012010-10-04 17:56:13 +0100436 mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
437 domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
438 domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
439 domain_val(DOMAIN_IO, DOMAIN_CLIENT))
440 mcr p15, 0, r5, c3, c0, 0 @ load domain access register
441 mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
Catalin Marinas1b6ba462011-11-22 17:30:29 +0000442#endif
Russell King00945012010-10-04 17:56:13 +0100443 b __turn_mmu_on
444ENDPROC(__enable_mmu)
445
446/*
447 * Enable the MMU. This completely changes the structure of the visible
448 * memory space. You will not be able to trace execution through this.
449 * If you have an enquiry about this, *please* check the linux-arm-kernel
450 * mailing list archives BEFORE sending another post to the list.
451 *
452 * r0 = cp#15 control register
Russell King865a4fa2010-10-04 18:02:59 +0100453 * r1 = machine ID
Grant Likely4c2896e2011-04-28 14:27:20 -0600454 * r2 = atags or dtb pointer
Russell King865a4fa2010-10-04 18:02:59 +0100455 * r9 = processor ID
Russell King00945012010-10-04 17:56:13 +0100456 * r13 = *virtual* address to jump to upon completion
457 *
458 * other registers depend on the function called upon completion
459 */
460 .align 5
Will Deacon4e8ee7d2011-11-23 12:26:25 +0000461 .pushsection .idmap.text, "ax"
462ENTRY(__turn_mmu_on)
Russell King00945012010-10-04 17:56:13 +0100463 mov r0, r0
Will Deacond675d0b2011-11-22 17:30:28 +0000464 instr_sync
Russell King00945012010-10-04 17:56:13 +0100465 mcr p15, 0, r0, c1, c0, 0 @ write control reg
466 mrc p15, 0, r3, c0, c0, 0 @ read id reg
Will Deacond675d0b2011-11-22 17:30:28 +0000467 instr_sync
Russell King00945012010-10-04 17:56:13 +0100468 mov r3, r3
469 mov r3, r13
470 mov pc, r3
Will Deacon72662e02011-11-23 12:03:27 +0000471__turn_mmu_on_end:
Russell King00945012010-10-04 17:56:13 +0100472ENDPROC(__turn_mmu_on)
Will Deacon4e8ee7d2011-11-23 12:26:25 +0000473 .popsection
Russell King00945012010-10-04 17:56:13 +0100474
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
Russell Kingf00ec482010-09-04 10:47:48 +0100476#ifdef CONFIG_SMP_ON_UP
Russell King4a9cb362011-02-10 15:25:18 +0000477 __INIT
Russell Kingf00ec482010-09-04 10:47:48 +0100478__fixup_smp:
Russell Kinge98ff0f2011-01-30 16:40:20 +0000479 and r3, r9, #0x000f0000 @ architecture version
480 teq r3, #0x000f0000 @ CPU ID supported?
Russell Kingf00ec482010-09-04 10:47:48 +0100481 bne __fixup_smp_on_up @ no, assume UP
482
Russell Kinge98ff0f2011-01-30 16:40:20 +0000483 bic r3, r9, #0x00ff0000
484 bic r3, r3, #0x0000000f @ mask 0xff00fff0
485 mov r4, #0x41000000
Russell King0eb0511d2010-11-22 12:06:28 +0000486 orr r4, r4, #0x0000b000
Russell Kinge98ff0f2011-01-30 16:40:20 +0000487 orr r4, r4, #0x00000020 @ val 0x4100b020
488 teq r3, r4 @ ARM 11MPCore?
Russell Kingf00ec482010-09-04 10:47:48 +0100489 moveq pc, lr @ yes, assume SMP
490
491 mrc p15, 0, r0, c0, c0, 5 @ read MPIDR
Russell Kinge98ff0f2011-01-30 16:40:20 +0000492 and r0, r0, #0xc0000000 @ multiprocessing extensions and
493 teq r0, #0x80000000 @ not part of a uniprocessor system?
Santosh Shilimkarbc41b872013-09-27 21:56:31 +0100494 bne __fixup_smp_on_up @ no, assume UP
495
496 @ Core indicates it is SMP. Check for Aegis SOC where a single
497 @ Cortex-A9 CPU is present but SMP operations fault.
498 mov r4, #0x41000000
499 orr r4, r4, #0x0000c000
500 orr r4, r4, #0x00000090
501 teq r3, r4 @ Check for ARM Cortex-A9
502 movne pc, lr @ Not ARM Cortex-A9,
503
504 @ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the
505 @ below address check will need to be #ifdef'd or equivalent
506 @ for the Aegis platform.
507 mrc p15, 4, r0, c15, c0 @ get SCU base address
508 teq r0, #0x0 @ '0' on actual UP A9 hardware
509 beq __fixup_smp_on_up @ So its an A9 UP
510 ldr r0, [r0, #4] @ read SCU Config
Victor Kamensky10593b22013-11-07 08:42:40 +0100511ARM_BE8(rev r0, r0) @ byteswap if big endian
Santosh Shilimkarbc41b872013-09-27 21:56:31 +0100512 and r0, r0, #0x3 @ number of CPUs
513 teq r0, #0x0 @ is 1?
514 movne pc, lr
Russell Kingf00ec482010-09-04 10:47:48 +0100515
516__fixup_smp_on_up:
517 adr r0, 1f
Russell King0eb0511d2010-11-22 12:06:28 +0000518 ldmia r0, {r3 - r5}
Russell Kingf00ec482010-09-04 10:47:48 +0100519 sub r3, r0, r3
Russell King0eb0511d2010-11-22 12:06:28 +0000520 add r4, r4, r3
521 add r5, r5, r3
Russell King4a9cb362011-02-10 15:25:18 +0000522 b __do_fixup_smp_on_up
Russell Kingf00ec482010-09-04 10:47:48 +0100523ENDPROC(__fixup_smp)
524
Dave Martin4f79a5d2010-11-29 19:43:24 +0100525 .align
Russell Kingf00ec482010-09-04 10:47:48 +01005261: .word .
527 .word __smpalt_begin
528 .word __smpalt_end
529
530 .pushsection .data
531 .globl smp_on_up
532smp_on_up:
533 ALT_SMP(.long 1)
534 ALT_UP(.long 0)
535 .popsection
Russell Kingf00ec482010-09-04 10:47:48 +0100536#endif
537
Russell King4a9cb362011-02-10 15:25:18 +0000538 .text
539__do_fixup_smp_on_up:
540 cmp r4, r5
541 movhs pc, lr
542 ldmia r4!, {r0, r6}
543 ARM( str r6, [r0, r3] )
544 THUMB( add r0, r0, r3 )
545#ifdef __ARMEB__
546 THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian.
547#endif
548 THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords
549 THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3.
550 THUMB( strh r6, [r0] )
551 b __do_fixup_smp_on_up
552ENDPROC(__do_fixup_smp_on_up)
553
554ENTRY(fixup_smp)
555 stmfd sp!, {r4 - r6, lr}
556 mov r4, r0
557 add r5, r0, r1
558 mov r3, #0
559 bl __do_fixup_smp_on_up
560 ldmfd sp!, {r4 - r6, pc}
561ENDPROC(fixup_smp)
562
Sricharan R830fd4d2013-10-29 07:29:56 +0100563#ifdef __ARMEB__
Sricharan Rf52bb722013-07-29 20:26:22 +0530564#define LOW_OFFSET 0x4
565#define HIGH_OFFSET 0x0
566#else
567#define LOW_OFFSET 0x0
568#define HIGH_OFFSET 0x4
569#endif
570
Russell Kingdc21af92011-01-04 19:09:43 +0000571#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
572
573/* __fixup_pv_table - patch the stub instructions with the delta between
574 * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and
575 * can be expressed by an immediate shifter operand. The stub instruction
576 * has a form of '(add|sub) rd, rn, #imm'.
577 */
578 __HEAD
579__fixup_pv_table:
580 adr r0, 1f
Sricharan Rf52bb722013-07-29 20:26:22 +0530581 ldmia r0, {r3-r7}
582 mvn ip, #0
583 subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET
Russell Kingdc21af92011-01-04 19:09:43 +0000584 add r4, r4, r3 @ adjust table start address
585 add r5, r5, r3 @ adjust table end address
Sricharan Rf52bb722013-07-29 20:26:22 +0530586 add r6, r6, r3 @ adjust __pv_phys_offset address
587 add r7, r7, r3 @ adjust __pv_offset address
588 str r8, [r6, #LOW_OFFSET] @ save computed PHYS_OFFSET to __pv_phys_offset
589 strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits
Russell Kingdc21af92011-01-04 19:09:43 +0000590 mov r6, r3, lsr #24 @ constant for add/sub instructions
591 teq r3, r6, lsl #24 @ must be 16MiB aligned
Nicolas Pitreb511d752011-02-21 06:53:35 +0100592THUMB( it ne @ cross section branch )
Russell Kingdc21af92011-01-04 19:09:43 +0000593 bne __error
Sricharan Rf52bb722013-07-29 20:26:22 +0530594 str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits
Russell Kingdc21af92011-01-04 19:09:43 +0000595 b __fixup_a_pv_table
596ENDPROC(__fixup_pv_table)
597
598 .align
5991: .long .
600 .long __pv_table_begin
601 .long __pv_table_end
6022: .long __pv_phys_offset
Sricharan Rf52bb722013-07-29 20:26:22 +0530603 .long __pv_offset
Russell Kingdc21af92011-01-04 19:09:43 +0000604
605 .text
606__fixup_a_pv_table:
Sricharan Rf52bb722013-07-29 20:26:22 +0530607 adr r0, 3f
608 ldr r6, [r0]
609 add r6, r6, r3
610 ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word
611 ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word
612 mov r6, r6, lsr #24
613 cmn r0, #1
Nicolas Pitreb511d752011-02-21 06:53:35 +0100614#ifdef CONFIG_THUMB2_KERNEL
Sricharan Rf52bb722013-07-29 20:26:22 +0530615 moveq r0, #0x200000 @ set bit 21, mov to mvn instruction
Nicolas Pitredaece592011-08-12 00:14:29 +0100616 lsls r6, #24
617 beq 2f
Nicolas Pitreb511d752011-02-21 06:53:35 +0100618 clz r7, r6
619 lsr r6, #24
620 lsl r6, r7
621 bic r6, #0x0080
622 lsrs r7, #1
623 orrcs r6, #0x0080
624 orr r6, r6, r7, lsl #12
625 orr r6, #0x4000
Nicolas Pitredaece592011-08-12 00:14:29 +0100626 b 2f
6271: add r7, r3
628 ldrh ip, [r7, #2]
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100629ARM_BE8(rev16 ip, ip)
Sricharan Rf52bb722013-07-29 20:26:22 +0530630 tst ip, #0x4000
631 and ip, #0x8f00
632 orrne ip, r6 @ mask in offset bits 31-24
633 orreq ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100634ARM_BE8(rev16 ip, ip)
Nicolas Pitreb511d752011-02-21 06:53:35 +0100635 strh ip, [r7, #2]
Russell King20989902013-10-28 00:43:41 +0000636 bne 2f
637 ldrh ip, [r7]
638ARM_BE8(rev16 ip, ip)
639 bic ip, #0x20
640 orr ip, ip, r0, lsr #16
641ARM_BE8(rev16 ip, ip)
642 strh ip, [r7]
Nicolas Pitredaece592011-08-12 00:14:29 +01006432: cmp r4, r5
Nicolas Pitreb511d752011-02-21 06:53:35 +0100644 ldrcc r7, [r4], #4 @ use branch for delay slot
Nicolas Pitredaece592011-08-12 00:14:29 +0100645 bcc 1b
Nicolas Pitreb511d752011-02-21 06:53:35 +0100646 bx lr
647#else
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100648#ifdef CONFIG_CPU_ENDIAN_BE8
649 moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction
650#else
Sricharan Rf52bb722013-07-29 20:26:22 +0530651 moveq r0, #0x400000 @ set bit 22, mov to mvn instruction
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100652#endif
Nicolas Pitredaece592011-08-12 00:14:29 +0100653 b 2f
6541: ldr ip, [r7, r3]
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100655#ifdef CONFIG_CPU_ENDIAN_BE8
656 @ in BE8, we load data in BE, but instructions still in LE
657 bic ip, ip, #0xff000000
Russell King20989902013-10-28 00:43:41 +0000658 tst ip, #0x000f0000 @ check the rotation field
659 orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24
660 biceq ip, ip, #0x00004000 @ clear bit 22
Victor Kamenskyd9a790d2013-11-07 08:42:42 +0100661 orreq ip, ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100662#else
Russell Kingdc21af92011-01-04 19:09:43 +0000663 bic ip, ip, #0x000000ff
Sricharan Rf52bb722013-07-29 20:26:22 +0530664 tst ip, #0xf00 @ check the rotation field
665 orrne ip, ip, r6 @ mask in offset bits 31-24
666 biceq ip, ip, #0x400000 @ clear bit 22
667 orreq ip, ip, r0 @ mask in offset bits 7-0
Ben Dooks2f9bf9b2013-02-01 16:23:08 +0100668#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000669 str ip, [r7, r3]
Nicolas Pitredaece592011-08-12 00:14:29 +01006702: cmp r4, r5
Russell Kingdc21af92011-01-04 19:09:43 +0000671 ldrcc r7, [r4], #4 @ use branch for delay slot
Nicolas Pitredaece592011-08-12 00:14:29 +0100672 bcc 1b
Russell Kingdc21af92011-01-04 19:09:43 +0000673 mov pc, lr
Nicolas Pitreb511d752011-02-21 06:53:35 +0100674#endif
Russell Kingdc21af92011-01-04 19:09:43 +0000675ENDPROC(__fixup_a_pv_table)
676
Sricharan R830fd4d2013-10-29 07:29:56 +0100677 .align
Sricharan Rf52bb722013-07-29 20:26:22 +05306783: .long __pv_offset
679
Russell Kingdc21af92011-01-04 19:09:43 +0000680ENTRY(fixup_pv_table)
681 stmfd sp!, {r4 - r7, lr}
Russell Kingdc21af92011-01-04 19:09:43 +0000682 mov r3, #0 @ no offset
683 mov r4, r0 @ r0 = table start
684 add r5, r0, r1 @ r1 = table size
Russell Kingdc21af92011-01-04 19:09:43 +0000685 bl __fixup_a_pv_table
686 ldmfd sp!, {r4 - r7, pc}
687ENDPROC(fixup_pv_table)
688
Russell Kingdc21af92011-01-04 19:09:43 +0000689 .data
690 .globl __pv_phys_offset
691 .type __pv_phys_offset, %object
692__pv_phys_offset:
Sricharan Rf52bb722013-07-29 20:26:22 +0530693 .quad 0
694 .size __pv_phys_offset, . -__pv_phys_offset
695
696 .globl __pv_offset
697 .type __pv_offset, %object
Russell Kingdc21af92011-01-04 19:09:43 +0000698__pv_offset:
Sricharan Rf52bb722013-07-29 20:26:22 +0530699 .quad 0
700 .size __pv_offset, . -__pv_offset
Russell Kingdc21af92011-01-04 19:09:43 +0000701#endif
702
Hyok S. Choi75d90832006-03-27 14:58:25 +0100703#include "head-common.S"