* Tony Lindgren <tony@xxxxxxxxxxx> [100902 17:00]: > * Tony Lindgren <tony@xxxxxxxxxxx> [100902 12:20]: > > Heh, turns out there's a bit of a bug in the code snippet above :) It should > be !((mpidr >> 30) & 1) instead, otherwise it always returns 0. This too can check for value of 2. Also we probably want to do the CPU type checks too. Updated patch below. Tony
From: Tony Lindgren <tony@xxxxxxxxxxx> Date: Mon, 30 Aug 2010 14:00:54 -0700 Subject: [PATCH] ARM: Add inline function smp_cpu() for early init testing Add inline function smp_cpu() for early init checks, and change build_mem_type_table to use it. Inline function copied from cpu_is_part_of_mp_system() by Will Deacon <will.deacon@xxxxxxx>. Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h index 8db3512..50a4f0b 100644 --- a/arch/arm/include/asm/smp_plat.h +++ b/arch/arm/include/asm/smp_plat.h @@ -39,4 +39,24 @@ static inline int cache_ops_need_broadcast(void) #define UP(instr...) _str(instr) #endif +static inline int smp_cpu(void) +{ + u32 val; + + val = read_cpuid(CPUID_ID); + + /* Check for ARM CPU */ + if ((val & 0xff000000) != 0x41000000) + return 0; + + /* Check for ARMv6 or 7 */ + if ((val & 0x00070000) != 0x00070000) + return 0; + + /* Check MPIDR */ + asm ("mrc p15, 0, %0, c0, c0, 5" : "=r" (val)); + + return (val >> 30) == 2; +} + #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 }