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Date: Mon, 5 Oct 2015 17:39:55 -0700 From: Laura Abbott <labbott@...hat.com> To: Segher Boessenkool <segher@...nel.crashing.org>, Peter Bergner <bergner@...t.ibm.com> Cc: Denis Kirjanov <kda@...ux-powerpc.org>, "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>, Paul Mackerras <paulus@...ba.org>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: Re: Missing operand for tlbie instruction on Power7 On 10/03/2015 05:00 PM, Segher Boessenkool wrote: > On Fri, Oct 02, 2015 at 09:24:46PM -0500, Peter Bergner wrote: >>>> Ok, than we can just zero out r5 for example and use it in tlbie as RS, >>>> right? >>> >>> That won't assemble _unless_ your assembler is in POWER7 mode. It also >>> won't do the right thing at run time on older machines. >> >> Correct, getting this to work on both pre-power7 and power7 and later >> is tricky. One really horrible hack would be to do: >> >> li r0,0 >> tlbie r4,0 >> >> On pre-power7, the "0" will be taken as a zero L operand and on >> power7 and later, it'll be r0, but with a zero value we loaded in >> the insn before. I know, really ugly. :-) > > Hide the "li 0,0" somewhere earlier, and write it as "tlbie 4,0", and > don't write a comment -- we *like* tricky! > > It should really be a separate macro define for power7 and 4xx etc.; > and the macro should not be called "tlbia", but something that makes > it obvious at the usage sites that it is in fact a macro; and why a > macro anyway, a function call might be better here? > > > Segher > I can't speculate on why it is a macro but would something such as the following work? Alternatively, we could move the assembly into swusp_asm64.S which appears to be the only 64-bit caller of tlbia diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index dd0fc18..53e5f59 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -434,14 +434,30 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,945) #endif /* - * This instruction is not implemented on the PPC 603 or 601; however, on + * tlbia is not implemented on the PPC 603 or 601; however, on * the 403GCX and 405GP tlbia IS defined and tlbie is not. * All of these instructions exist in the 8xx, they have magical powers, * and they must be used. + * + * The ISA 2.06 update for POWER7 changed the number of arguments to tlbie + * so it gets its own special case as well as any config that may set + * mtune=power7 such as CONFIG_PPC_BOOK3S_64 */ -#if !defined(CONFIG_4xx) && !defined(CONFIG_8xx) -#define tlbia \ +#if defined(CONFIG_4xx) || defined(CONFIG_8xx) +#define TLBIA_ACTION tlbia +#elif defined(CONFIG_POWER7_CPU) || defined(CONFIG_PPC_BOOK3S_64) +#define TLBIA_ACTION \ + li r4,1024; \ + mtctr r4; \ + lis r4,KERNELBASE@h; \ + li r0,0; \ +0: tlbie r4,r0; \ + addi r4,r4,0x1000; \ + bdnz 0b + +#else +#define TLBIA_ACTION \ li r4,1024; \ mtctr r4; \ lis r4,KERNELBASE@h; \ diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index dc0488b..40c3b33 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -901,7 +901,7 @@ _ENTRY(__restore_cpu_setup) load_up_mmu: sync /* Force all PTE updates to finish */ isync - tlbia /* Clear all TLB entries */ + TLBIA_ACTION /* Clear all TLB entries */ sync /* wait for tlbia/tlbie to finish */ TLBSYNC /* ... on all CPUs */ /* Load the SDR1 register (hash table base & size) */ diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index 7d7d863..6a83ec2 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -869,7 +869,7 @@ start_here: /* Load up the kernel context */ 2: sync /* Flush to memory before changing TLB */ - tlbia + TLBIA_ACTION isync /* Flush shadow TLBs */ /* set up the PTE pointers for the Abatron bdiGDB. @@ -897,7 +897,7 @@ start_here: * virtual to physical and more importantly sets the cache mode. */ initial_mmu: - tlbia /* Invalidate all TLB entries */ + TLBIA_ACTION /* Invalidate all TLB entries */ isync /* We should still be executing code at physical address 0x0000xxxx diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 78c1eba..533d736 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -711,7 +711,7 @@ start_here: /* Load up the kernel context */ 2: SYNC /* Force all PTE updates to finish */ - tlbia /* Clear all TLB entries */ + TLBIA_ACTION /* Clear all TLB entries */ sync /* wait for tlbia/tlbie to finish */ TLBSYNC /* ... on all CPUs */ @@ -741,7 +741,7 @@ start_here: * these mappings is mapped by page tables. */ initial_mmu: - tlbia /* Invalidate all TLB entries */ + TLBIA_ACTION /* Invalidate all TLB entries */ /* Always pin the first 8 MB ITLB to prevent ITLB misses while mucking around with SRR0/SRR1 in asm */ diff --git a/arch/powerpc/kernel/swsusp_asm64.S b/arch/powerpc/kernel/swsusp_asm64.S index 988f38d..2bcc49e 100644 --- a/arch/powerpc/kernel/swsusp_asm64.S +++ b/arch/powerpc/kernel/swsusp_asm64.S @@ -185,7 +185,7 @@ nothing_to_copy: sync - tlbia + TLBIA_ACTION #endif ld r11,swsusp_save_area_ptr@toc(r2) diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S index 115347f..9805c4c 100644 --- a/arch/powerpc/mm/hash_low_32.S +++ b/arch/powerpc/mm/hash_low_32.S @@ -696,7 +696,7 @@ _GLOBAL(_tlbia) stwcx. r8,0,r9 bne- 10b sync - tlbia + TLBIA_ACTION sync TLBSYNC li r0,0 @@ -706,7 +706,7 @@ _GLOBAL(_tlbia) isync #else /* CONFIG_SMP */ sync - tlbia + TLBIA_ACTION sync #endif /* CONFIG_SMP */ blr -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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