[PATCH 1/6] ARM: Add inline function smp_cpu() for early init testing
Shilimkar, Santosh
santosh.shilimkar at ti.com
Fri Sep 3 08:12:22 EDT 2010
> > BTW, so far looks like we should only need this during init to set up
> things.
>
> Here's this one updated to replace smp_cpu() instead of smp_on_up().
>
diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h
index 8db3512..82bc488 100644
--- a/arch/arm/include/asm/smp_plat.h
+++ b/arch/arm/include/asm/smp_plat.h
@@ -39,4 +39,11 @@ static inline int cache_ops_need_broadcast(void)
#define UP(instr...) _str(instr)
#endif
+static inline int smp_cpu(void)
+{
+ u32 mpidr;
+ asm volatile("mrc p15, 0, %0, c0, c0, 5" : "=r" (mpidr));
+ return (mpidr >> 31) ? !(mpidr >> 30) : 0;
+}
+
Will this be called on UP machines ?? if yes, then mpidr register is not
available on those
#endif
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 6e1c4f6..2bfaefd 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -430,15 +430,17 @@ static void __init build_mem_type_table(void)
/*
* Mark memory with the "shared" attribute for SMP systems
*/
- user_pgprot |= L_PTE_SHARED;
- kern_pgprot |= L_PTE_SHARED;
- vecs_pgprot |= L_PTE_SHARED;
- mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
- mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
- mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
- mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
- mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
- mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
+ if (smp_cpu()) {
+ user_pgprot |= L_PTE_SHARED;
+ kern_pgprot |= L_PTE_SHARED;
+ vecs_pgprot |= L_PTE_SHARED;
+ mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
+ mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
+ mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
+ mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
+ mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
+ mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
+ }
#endif
}
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