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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2005-06-18 09:33:31 +0100 |
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committer | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2005-06-18 09:33:31 +0100 |
commit | e65f38ed0bb7af367ff919c573cf29643fc5f9e8 (patch) | |
tree | 2b89f5f0a9175cf1107bc52c7302eb1acf8aa1a1 /arch/arm/kernel/head.S | |
parent | 5ab6091db0b644f59c2f16c5e41028496b709160 (diff) | |
download | lwn-e65f38ed0bb7af367ff919c573cf29643fc5f9e8.tar.gz lwn-e65f38ed0bb7af367ff919c573cf29643fc5f9e8.zip |
[PATCH] ARM SMP: Add support for startup of secondary processors
Create a temporary page table to startup secondary processors. This
page table must have a 1:1 virtual/physical mapping for the kernel
in addition to the standard mappings to ensure that the secondary
CPU can enable its MMU safely.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/head.S')
-rw-r--r-- | arch/arm/kernel/head.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 4733877296d4..bd4823c74645 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -2,6 +2,8 @@ * linux/arch/arm/kernel/head.S * * Copyright (C) 1994-2002 Russell King + * Copyright (c) 2003 ARM Limited + * All Rights Reserved * * 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 @@ -165,6 +167,48 @@ __mmap_switched: stmia r6, {r0, r4} @ Save control register values b start_kernel +#if defined(CONFIG_SMP) + .type secondary_startup, #function +ENTRY(secondary_startup) + /* + * Common entry point for secondary CPUs. + * + * Ensure that we're in SVC mode, and IRQs are disabled. Lookup + * the processor type - there is no need to check the machine type + * as it has already been validated by the primary processor. + */ + msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC + bl __lookup_processor_type + movs r10, r5 @ invalid processor? + moveq r0, #'p' @ yes, error 'p' + beq __error + + /* + * Use the page tables supplied from __cpu_up. + */ + adr r4, __secondary_data + ldmia r4, {r5, r6, r13} @ address to jump to after + sub r4, r4, r5 @ mmu has been enabled + ldr r4, [r6, r4] @ get secondary_data.pgdir + adr lr, __enable_mmu @ return address + add pc, r10, #12 @ initialise processor + @ (return control reg) + + /* + * r6 = &secondary_data + */ +ENTRY(__secondary_switched) + ldr sp, [r6, #4] @ get secondary_data.stack + mov fp, #0 + b secondary_start_kernel + + .type __secondary_data, %object +__secondary_data: + .long . + .long secondary_data + .long __secondary_switched +#endif /* defined(CONFIG_SMP) */ + /* |