Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754437Ab1ESKmm (ORCPT ); Thu, 19 May 2011 06:42:42 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:54233 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754291Ab1ESKmk (ORCPT ); Thu, 19 May 2011 06:42:40 -0400 Date: Thu, 19 May 2011 06:43:30 -0400 From: Josh Boyer To: Eric Van Hensbergen Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, bg-linux@lists.anl-external.org Subject: Re: [PATCH 4/7] [RFC] enable L1_WRITETHROUGH mode for BG/P Message-ID: <20110519104330.GA25179@zod.rchland.ibm.com> References: <1305753895-24845-1-git-send-email-ericvh@gmail.com> <1305753895-24845-4-git-send-email-ericvh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1305753895-24845-4-git-send-email-ericvh@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6993 Lines: 221 On Wed, May 18, 2011 at 04:24:52PM -0500, Eric Van Hensbergen wrote: >BG/P nodes need to be configured for writethrough to work in SMP >configurations. This patch adds the right hooks in the MMU code >to make sure L1_WRITETHROUGH configurations are setup for BG/P. > >Signed-off-by: Eric Van Hensbergen >--- > arch/powerpc/include/asm/mmu-44x.h | 2 ++ > arch/powerpc/kernel/head_44x.S | 24 ++++++++++++++++++++++-- > arch/powerpc/kernel/misc_32.S | 15 +++++++++++++++ > arch/powerpc/lib/copy_32.S | 10 ++++++++++ > arch/powerpc/mm/44x_mmu.c | 7 +++++-- > arch/powerpc/platforms/Kconfig | 5 +++++ > arch/powerpc/platforms/Kconfig.cputype | 4 ++++ > 7 files changed, 63 insertions(+), 4 deletions(-) > >diff --git a/arch/powerpc/include/asm/mmu-44x.h b/arch/powerpc/include/asm/mmu-44x.h >index bf52d70..ca1b90c 100644 >--- a/arch/powerpc/include/asm/mmu-44x.h >+++ b/arch/powerpc/include/asm/mmu-44x.h >@@ -8,6 +8,7 @@ > > #define PPC44x_MMUCR_TID 0x000000ff > #define PPC44x_MMUCR_STS 0x00010000 >+#define PPC44x_MMUCR_U2 0x00200000 > > #define PPC44x_TLB_PAGEID 0 > #define PPC44x_TLB_XLAT 1 >@@ -32,6 +33,7 @@ > > /* Storage attribute and access control fields */ > #define PPC44x_TLB_ATTR_MASK 0x0000ff80 >+#define PPC44x_TLB_WL1 0x00100000 /* Write-through L1 */ > #define PPC44x_TLB_U0 0x00008000 /* User 0 */ > #define PPC44x_TLB_U1 0x00004000 /* User 1 */ > #define PPC44x_TLB_U2 0x00002000 /* User 2 */ >diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S >index 5e12b74..1f7ae60 100644 >--- a/arch/powerpc/kernel/head_44x.S >+++ b/arch/powerpc/kernel/head_44x.S >@@ -429,7 +429,16 @@ finish_tlb_load_44x: > andi. r10,r12,_PAGE_USER /* User page ? */ > beq 1f /* nope, leave U bits empty */ > rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */ >-1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */ >+1: >+#ifdef CONFIG_L1_WRITETHROUGH >+ andi. r10, r11, PPC44x_TLB_I >+ bne 2f >+ oris r11,r11,PPC44x_TLB_WL1@h /* Add coherency for */ >+ /* non-inhibited */ >+ ori r11,r11,PPC44x_TLB_U2|PPC44x_TLB_M >+2: >+#endif /* CONFIG_L1_WRITETHROUGH */ >+ tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */ > > /* Done...restore registers and get out of here. > */ >@@ -799,7 +808,11 @@ skpinv: addi r4,r4,1 /* Increment */ > sync > > /* Initialize MMUCR */ >+#ifdef CONFIG_L1_WRITETHROUGH >+ lis r5, PPC44x_MMUCR_U2@h >+#else > li r5,0 >+#endif /* CONFIG_L1_WRITETHROUGH */ > mtspr SPRN_MMUCR,r5 > sync > >@@ -814,7 +827,14 @@ skpinv: addi r4,r4,1 /* Increment */ > /* attrib fields */ > /* Added guarded bit to protect against speculative loads/stores */ > li r5,0 >- ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G) >+#ifdef CONFIG_L1_WRITETHROUGH >+ ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | \ >+ PPC44x_TLB_G | PPC44x_TLB_U2) >+ oris r5,r5,PPC44x_TLB_WL1@h >+#else >+ ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | \ >+ PPC44x_TLB_G) >+#endif /* CONFIG_L1_WRITETHROUGH > > li r0,63 /* TLB slot 63 */ > >diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S >index 094bd98..d88369b 100644 >--- a/arch/powerpc/kernel/misc_32.S >+++ b/arch/powerpc/kernel/misc_32.S >@@ -506,7 +506,20 @@ _GLOBAL(clear_pages) > li r0,PAGE_SIZE/L1_CACHE_BYTES > slw r0,r0,r4 > mtctr r0 >+#ifdef CONFIG_L1_WRITETHROUGH >+ /* assuming 32 byte cacheline */ >+ li r4, 0 >+1: stw r4, 0(r3) >+ stw r4, 4(r3) >+ stw r4, 8(r3) >+ stw r4, 12(r3) >+ stw r4, 16(r3) >+ stw r4, 20(r3) >+ stw r4, 24(r3) >+ stw r4, 28(r3) >+#else > 1: dcbz 0,r3 >+#endif /* CONFIG_L1_WRITETHROUGH */ > addi r3,r3,L1_CACHE_BYTES > bdnz 1b > blr >@@ -550,7 +563,9 @@ _GLOBAL(copy_page) > mtctr r0 > 1: > dcbt r11,r4 >+#ifndef CONFIG_L1_WRITETHROUGH > dcbz r5,r3 >+#endif > COPY_16_BYTES > #if L1_CACHE_BYTES >= 32 > COPY_16_BYTES >diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S >index 55f19f9..98a07e3 100644 >--- a/arch/powerpc/lib/copy_32.S >+++ b/arch/powerpc/lib/copy_32.S >@@ -98,7 +98,11 @@ _GLOBAL(cacheable_memzero) > bdnz 4b > 3: mtctr r9 > li r7,4 >+#ifdef CONFIG_L1_WRITETHROUGH >+10: >+#else > 10: dcbz r7,r6 >+#endif /* CONFIG_L1_WRITETHROUGH */ > addi r6,r6,CACHELINE_BYTES > bdnz 10b > clrlwi r5,r8,32-LG_CACHELINE_BYTES >@@ -187,7 +191,9 @@ _GLOBAL(cacheable_memcpy) > mtctr r0 > beq 63f > 53: >+#ifndef CONFIG_L1_WRITETHROUGH > dcbz r11,r6 >+#endif /* CONFIG_L1_WRITETHROUGH */ > COPY_16_BYTES > #if L1_CACHE_BYTES >= 32 > COPY_16_BYTES >@@ -368,7 +374,11 @@ _GLOBAL(__copy_tofrom_user) > mtctr r8 > > 53: dcbt r3,r4 >+#ifdef CONFIG_L1_WRITETHROUGH >+54: >+#else > 54: dcbz r11,r6 >+#endif > .section __ex_table,"a" > .align 2 > .long 54b,105f >diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c >index 024acab..b684c8a 100644 >--- a/arch/powerpc/mm/44x_mmu.c >+++ b/arch/powerpc/mm/44x_mmu.c >@@ -80,9 +80,12 @@ static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys) > : > #ifdef CONFIG_PPC47x > : "r" (PPC47x_TLB2_S_RWX), >-#else >+#elseif CONFIG_L1_WRITETHROUGH >+ : "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_WL1 \ >+ | PPC44x_TLB_U2 | PPC44x_TLB_M), >+#else /* neither CONFIG_PPC47x or CONFIG_L1_WRITETHROUGH */ > : "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G), >-#endif >+#endif /* CONFIG_PPC47x */ > "r" (phys), > "r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M), > "r" (entry), >diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig >index f7b0772..684a281 100644 >--- a/arch/powerpc/platforms/Kconfig >+++ b/arch/powerpc/platforms/Kconfig >@@ -348,4 +348,9 @@ config XILINX_PCI > bool "Xilinx PCI host bridge support" > depends on PCI && XILINX_VIRTEX > >+config L1_WRITETHROUGH >+ bool "Blue Gene/P enabled writethrough mode" >+ depends on BGP >+ default y You add this config option here, named generically, but then make it depend on BGP. It sees it should be named BGP_L1_WRITETHROUGH, and then just selected by the BGP platform. But then.... > endmenu >diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype >index 111138c..3a3c711 100644 >--- a/arch/powerpc/platforms/Kconfig.cputype >+++ b/arch/powerpc/platforms/Kconfig.cputype >@@ -329,9 +329,13 @@ config NOT_COHERENT_CACHE > bool > depends on 4xx || 8xx || E200 || PPC_MPC512x || GAMECUBE_COMMON > default n if PPC_47x >+ default n if BGP > default y > > config CHECK_CACHE_COHERENCY > bool > >+config L1_WRITETHROUGH >+ bool You add an identical option down here. Confused. josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/