f00ec48fad
UP systems do not implement all the instructions that SMP systems have, so in order to boot a SMP kernel on a UP system, we need to rewrite parts of the kernel. Do this using an 'alternatives' scheme, where the kernel code and data is modified prior to initialization to replace the SMP instructions, thereby rendering the problematical code ineffectual. We use the linker to generate a list of 32-bit word locations and their replacement values, and run through these replacements when we detect a UP system. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
36 lines
702 B
C
36 lines
702 B
C
/*
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* ARM specific SMP header, this contains our implementation
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* details.
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*/
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#ifndef __ASMARM_SMP_PLAT_H
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#define __ASMARM_SMP_PLAT_H
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#include <asm/cputype.h>
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/* all SMP configurations have the extended CPUID registers */
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static inline int tlb_ops_need_broadcast(void)
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{
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return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
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}
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static inline int cache_ops_need_broadcast(void)
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{
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return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
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}
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/*
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* Return true if we are running on a SMP platform
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*/
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static inline bool is_smp(void)
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{
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#ifndef CONFIG_SMP
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return false;
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#elif defined(CONFIG_SMP_ON_UP)
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extern unsigned int smp_on_up;
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return !!smp_on_up;
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#else
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return true;
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#endif
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}
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#endif
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