[PATCH V2 41/68] powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code

Balbir Singh bsingharora at gmail.com
Fri Apr 22 17:32:49 AEST 2016



On 09/04/16 16:13, Aneesh Kumar K.V wrote:
> We also use MMU_FTR_RADIX to branch out from code path specific to
> hash.
> 
> No functionality change.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
>  arch/powerpc/kernel/entry_64.S         |  7 +++++--
>  arch/powerpc/kernel/exceptions-64s.S   | 28 +++++++++++++++++++++++-----
>  arch/powerpc/kernel/machine_kexec_64.c |  6 ++++--
>  arch/powerpc/kernel/mce_power.c        | 10 ++++++++++
>  arch/powerpc/kernel/process.c          | 15 +++++++++------
>  arch/powerpc/xmon/xmon.c               |  2 +-
>  6 files changed, 52 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 9916d150b28c..8b9d68676d2b 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -519,7 +519,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_STCX_CHECKS_ADDRESS)
>  	std	r6,PACACURRENT(r13)	/* Set new 'current' */
>  
>  	ld	r8,KSP(r4)	/* new stack pointer */
> -#ifdef CONFIG_PPC_BOOK3S
> +#ifdef CONFIG_PPC_STD_MMU_64
> +BEGIN_MMU_FTR_SECTION
> +	b	2f
> +END_MMU_FTR_SECTION_IFSET(MMU_FTR_RADIX)
>  BEGIN_FTR_SECTION
>  	clrrdi	r6,r8,28	/* get its ESID */
>  	clrrdi	r9,r1,28	/* get current sp ESID */
> @@ -565,7 +568,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
>  	slbmte	r7,r0
>  	isync
>  2:
> -#endif /* !CONFIG_PPC_BOOK3S */
> +#endif /* CONFIG_PPC_STD_MMU_64 */
>  
>  	CURRENT_THREAD_INFO(r7, r8)  /* base of new stack */
>  	/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 7716cebf4b8e..d2afec81d04d 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -983,7 +983,13 @@ data_access_common:
>  	ld	r3,PACA_EXGEN+EX_DAR(r13)
>  	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
>  	li	r5,0x300
> +	std	r3,_DAR(r1)
> +	std	r4,_DSISR(r1)
> +BEGIN_MMU_FTR_SECTION
>  	b	do_hash_page		/* Try to handle as hpte fault */
> +MMU_FTR_SECTION_ELSE
> +	b	handle_page_fault

Normal kernel page fault handler?

> +ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_RADIX)
>  
>  	.align  7
>  	.globl  h_data_storage_common
> @@ -1008,7 +1014,13 @@ instruction_access_common:
>  	ld	r3,_NIP(r1)
>  	andis.	r4,r12,0x5820
>  	li	r5,0x400
> +	std	r3,_DAR(r1)
> +	std	r4,_DSISR(r1)
> +BEGIN_MMU_FTR_SECTION
>  	b	do_hash_page		/* Try to handle as hpte fault */
> +MMU_FTR_SECTION_ELSE
> +	b	handle_page_fault
> +ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_RADIX)
>  
>  	STD_EXCEPTION_COMMON(0xe20, h_instr_storage, unknown_exception)
>  
> @@ -1476,8 +1488,11 @@ slb_miss_realmode:
>  	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
>  	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
>  
> +#ifdef CONFIG_PPC_STD_MMU_64
> +BEGIN_MMU_FTR_SECTION
>  	bl	slb_allocate_realmode
> -
> +END_MMU_FTR_SECTION_IFCLR(MMU_FTR_RADIX)
> +#endif
>  	/* All done -- return from exception. */
>  
>  	ld	r10,PACA_EXSLB+EX_LR(r13)
> @@ -1485,7 +1500,9 @@ slb_miss_realmode:
>  	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
>  
>  	mtlr	r10
> -
> +BEGIN_MMU_FTR_SECTION
> +	b	2f
> +END_MMU_FTR_SECTION_IFSET(MMU_FTR_RADIX)
>  	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
>  	beq-	2f
>  
> @@ -1536,9 +1553,7 @@ power4_fixup_nap:
>   */
>  	.align	7
>  do_hash_page:
> -	std	r3,_DAR(r1)
> -	std	r4,_DSISR(r1)
> -
> +#ifdef CONFIG_PPC_STD_MMU_64
>  	andis.	r0,r4,0xa410		/* weird error? */
>  	bne-	handle_page_fault	/* if not, try to insert a HPTE */
>  	andis.  r0,r4,DSISR_DABRMATCH at h
> @@ -1566,6 +1581,7 @@ do_hash_page:
>  
>  	/* Error */
>  	blt-	13f
> +#endif /* CONFIG_PPC_STD_MMU_64 */
>  
>  /* Here we have a page fault that hash_page can't handle. */
>  handle_page_fault:
> @@ -1592,6 +1608,7 @@ handle_dabr_fault:
>  12:	b       ret_from_except_lite
>  
>  
> +#ifdef CONFIG_PPC_STD_MMU_64
>  /* We have a page fault that hash_page could handle but HV refused
>   * the PTE insertion
>   */
> @@ -1601,6 +1618,7 @@ handle_dabr_fault:
>  	ld	r4,_DAR(r1)
>  	bl	low_hash_fault
>  	b	ret_from_except
> +#endif
>  
>  /*
>   * We come here as a result of a DSI at a point where we don't want
> diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
> index 0fbd75d185d7..1da864c00db0 100644
> --- a/arch/powerpc/kernel/machine_kexec_64.c
> +++ b/arch/powerpc/kernel/machine_kexec_64.c
> @@ -76,6 +76,7 @@ int default_machine_kexec_prepare(struct kimage *image)
>  	 * end of the blocked region (begin >= high).  Use the
>  	 * boolean identity !(a || b)  === (!a && !b).
>  	 */
> +#ifdef CONFIG_PPC_STD_MMU_64
>  	if (htab_address) {
>  		low = __pa(htab_address);
>  		high = low + htab_size_bytes;
> @@ -88,6 +89,7 @@ int default_machine_kexec_prepare(struct kimage *image)
>  				return -ETXTBSY;
>  		}
>  	}
> +#endif /* CONFIG_PPC_STD_MMU_64 */
>  
>  	/* We also should not overwrite the tce tables */
>  	for_each_node_by_type(node, "pci") {
> @@ -381,7 +383,7 @@ void default_machine_kexec(struct kimage *image)
>  	/* NOTREACHED */
>  }
>  
> -#ifndef CONFIG_PPC_BOOK3E
> +#ifdef CONFIG_PPC_STD_MMU_64
>  /* Values we need to export to the second kernel via the device tree. */
>  static unsigned long htab_base;
>  static unsigned long htab_size;
> @@ -428,4 +430,4 @@ static int __init export_htab_values(void)
>  	return 0;
>  }
>  late_initcall(export_htab_values);
> -#endif /* !CONFIG_PPC_BOOK3E */
> +#endif /* CONFIG_PPC_STD_MMU_64 */
> diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
> index ee62b197502d..92a66a2a9b85 100644
> --- a/arch/powerpc/kernel/mce_power.c
> +++ b/arch/powerpc/kernel/mce_power.c
> @@ -77,6 +77,7 @@ void __flush_tlb_power9(unsigned int action)
>  
>  
>  /* flush SLBs and reload */
> +#ifdef CONFIG_PPC_MMU_STD_64
>  static void flush_and_reload_slb(void)
>  {
>  	struct slb_shadow *slb;
> @@ -110,6 +111,7 @@ static void flush_and_reload_slb(void)
>  		asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
>  	}
>  }
> +#endif
>  
>  static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
>  {
> @@ -120,6 +122,7 @@ static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
>  	 * reset the error bits whenever we handle them so that at the end
>  	 * we can check whether we handled all of them or not.
>  	 * */
> +#ifdef CONFIG_PPC_MMU_STD_64
>  	if (dsisr & slb_error_bits) {
>  		flush_and_reload_slb();
>  		/* reset error bits */
> @@ -131,6 +134,7 @@ static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
>  		/* reset error bits */
>  		dsisr &= ~P7_DSISR_MC_TLB_MULTIHIT_MFTLB;
>  	}
> +#endif
>  	/* Any other errors we don't understand? */
>  	if (dsisr & 0xffffffffUL)
>  		handled = 0;
> @@ -150,6 +154,7 @@ static long mce_handle_common_ierror(uint64_t srr1)
>  	switch (P7_SRR1_MC_IFETCH(srr1)) {
>  	case 0:
>  		break;
> +#ifdef CONFIG_PPC_MMU_STD_64
>  	case P7_SRR1_MC_IFETCH_SLB_PARITY:
>  	case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
>  		/* flush and reload SLBs for SLB errors. */
> @@ -162,6 +167,7 @@ static long mce_handle_common_ierror(uint64_t srr1)
>  			handled = 1;
>  		}
>  		break;
> +#endif
>  	default:
>  		break;
>  	}
> @@ -175,10 +181,12 @@ static long mce_handle_ierror_p7(uint64_t srr1)
>  
>  	handled = mce_handle_common_ierror(srr1);
>  
> +#ifdef CONFIG_PPC_MMU_STD_64
>  	if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
>  		flush_and_reload_slb();
>  		handled = 1;
>  	}
> +#endif
>  	return handled;
>  }
>  
> @@ -321,10 +329,12 @@ static long mce_handle_ierror_p8(uint64_t srr1)
>  
>  	handled = mce_handle_common_ierror(srr1);
>  
> +#ifdef CONFIG_PPC_MMU_STD_64
>  	if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
>  		flush_and_reload_slb();
>  		handled = 1;
>  	}
> +#endif
>  	return handled;
>  }
>  
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index d7a9df51b974..e35b018be765 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -1075,7 +1075,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
>  	}
>  #endif /* CONFIG_PPC64 */
>  
> -#ifdef CONFIG_PPC_BOOK3S_64
> +#ifdef CONFIG_PPC_STD_MMU_64
>  	batch = this_cpu_ptr(&ppc64_tlb_batch);
>  	if (batch->active) {
>  		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
> @@ -1083,7 +1083,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
>  			__flush_tlb_pending(batch);
>  		batch->active = 0;
>  	}
> -#endif /* CONFIG_PPC_BOOK3S_64 */
> +#endif /* CONFIG_PPC_STD_MMU_64 */
>  
>  #ifdef CONFIG_PPC_ADV_DEBUG_REGS
>  	switch_booke_debug_regs(&new->thread.debug);
> @@ -1129,7 +1129,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
>  
>  	last = _switch(old_thread, new_thread);
>  
> -#ifdef CONFIG_PPC_BOOK3S_64
> +#ifdef CONFIG_PPC_STD_MMU_64
>  	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
>  		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
>  		batch = this_cpu_ptr(&ppc64_tlb_batch);
> @@ -1138,8 +1138,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
>  
>  	if (current_thread_info()->task->thread.regs)
>  		restore_math(current_thread_info()->task->thread.regs);
> -
> -#endif /* CONFIG_PPC_BOOK3S_64 */
> +#endif /* CONFIG_PPC_STD_MMU_64 */
>  
>  	return last;
>  }
> @@ -1374,6 +1373,9 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
>  	unsigned long sp_vsid;
>  	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
>  
> +	if (radix_enabled())
> +		return;
> +
>  	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
>  		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
>  			<< SLB_VSID_SHIFT_1T;
> @@ -1920,7 +1922,8 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
>  	 * the heap, we can put it above 1TB so it is backed by a 1TB
>  	 * segment. Otherwise the heap will be in the bottom 1TB
>  	 * which always uses 256MB segments and this may result in a
> -	 * performance penalty.
> +	 * performance penalty. We don't need to worry about radix. For
> +	 * radix, mmu_highuser_ssize remains unchanged from 256MB.
>  	 */
>  	if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
>  		base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 942796fa4767..308283b7b60c 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -2913,7 +2913,7 @@ static void xmon_print_symbol(unsigned long address, const char *mid,
>  	printf("%s", after);
>  }
>  
> -#ifdef CONFIG_PPC_BOOK3S_64
> +#ifdef CONFIG_PPC_STD_MMU_64
>  void dump_segments(void)
>  {
>  	int i;
> 


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