Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Fri, 2008-10-17 at 09:02 -0500, Nate Case wrote: With this patch it compiles and boots fine. The option -mabi=no-spe is not required. Please don't accept this patch yet. My past testing showed that -mabi=no-spe was required for my toolchain. I'll go back and double check though. OK, I went back and re-tested. Kernel: 2.6.27 CPU: MPC8572 Toolchain: Cross-compiler built using crosstool-ng gcc 4.3.1, default target CFLAGS include '-mabi=spe -mspe' binutils 2.18.90 snapshot (built with --enable-spe=yes) Kbuild flagsResult -- -mno-spe (*)FAILED -mno-spe -mabi=no-spe FAILED -mno-spe -mspe=no OK -mspe=noOK (*) 2.6.27 default In the failure case, the kernel would repeatedly dump out SPE used in kernel (task=, pc=). I think I was fooled before because I added _both_ -mspe=no and -mabi=no-spe to my KBUILD_CFLAGS and saw the problem go away. Since I trusted the documentation that -mspe=no and -mno-spe were the same, I assumed that -mabi=no-spe was the key. So, I've changed my mind. I now agree with Sebastian that -mabi=no-spe is not required. -mno-spe -mspe=no is probably the safe way to go. -- Nate Case [EMAIL PROTECTED] ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Oct 24, 2008, at 6:51 PM, Nate Case wrote: On Fri, 2008-10-17 at 09:02 -0500, Nate Case wrote: With this patch it compiles and boots fine. The option -mabi=no-spe is not required. Please don't accept this patch yet. My past testing showed that -mabi=no-spe was required for my toolchain. I'll go back and double check though. OK, I went back and re-tested. Kernel: 2.6.27 CPU: MPC8572 Toolchain: Cross-compiler built using crosstool-ng gcc 4.3.1, default target CFLAGS include '-mabi=spe -mspe' binutils 2.18.90 snapshot (built with --enable-spe=yes) Kbuild flagsResult -- -mno-spe (*)FAILED -mno-spe -mabi=no-spe FAILED -mno-spe -mspe=no OK -mspe=noOK (*) 2.6.27 default In the failure case, the kernel would repeatedly dump out SPE used in kernel (task=, pc=). I think I was fooled before because I added _both_ -mspe=no and -mabi=no-spe to my KBUILD_CFLAGS and saw the problem go away. Since I trusted the documentation that -mspe=no and -mno-spe were the same, I assumed that -mabi=no-spe was the key. So, I've changed my mind. I now agree with Sebastian that -mabi=no-spe is not required. -mno-spe -mspe=no is probably the safe way to go. -- Nate Case [EMAIL PROTECTED] thanks for testing this all out. I'll submit a patch to remove the -mabi=.*spe.* foo. - k ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Wed, 2008-10-15 at 16:43 +0200, Sebastian Andrzej Siewior wrote: With this patch it compiles and boots fine. The option -mabi=no-spe is not required. Please don't accept this patch yet. My past testing showed that -mabi=no-spe was required for my toolchain. I'll go back and double check though. - Nate Case [EMAIL PROTECTED] ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
* Nate Case | 2008-10-17 09:02:11 [-0500]: On Wed, 2008-10-15 at 16:43 +0200, Sebastian Andrzej Siewior wrote: With this patch it compiles and boots fine. The option -mabi=no-spe is not required. Please don't accept this patch yet. My past testing showed that -mabi=no-spe was required for my toolchain. I'll go back and double check though. Okay. Here my compiler details: | powerpc-linux-gnuspe-gcc -v | Using built-in specs. | Target: powerpc-linux-gnuspe | Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.1-9' | --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs | --enable-languages=c,c++,obj-c++ --prefix=/usr --enable-shared | --with-system-zlib --libexecdir=/usr/lib --without-included-gettext | --enable-threads=posix --enable-nls | --with-gxx-include-dir=/usr/powerpc-linux-gnuspe/include/c++/4.3.1 | --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug | --disable-multilib --disable-multilib --with-cpu=8540 | --enable-e500_double --with-long-double-128 --enable-checking=release | --program-prefix=powerpc-linux-gnuspe- | --includedir=/usr/powerpc-linux-gnuspe/include --build=i486-linux-gnu | --host=i486-linux-gnu --target=powerpc-linux-gnuspe | Thread model: posix | gcc version 4.3.1 (Debian 4.3.1-9) ths told me that we need all three options in this order because of how they interact with gcc's internal flags. - Nate Case [EMAIL PROTECTED] Sebastian ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
* Kumar Gala | 2008-10-15 08:25:54 [-0500]: On Oct 15, 2008, at 3:59 AM, Sebastian Andrzej Siewior wrote: * Sebastian Andrzej Siewior | 2008-10-15 00:49:46 [+0200]: is the -mabi=no-spe really needed? It seems to work the other way around (without -mabi=no-spe but with -mabi=no-spe) alteast I did not find anything in do_syslog() or while browsing through the dissasm. I do a boot check tomorrow. Okay. I recompiled with -mspe=no and was able to boot without trouble. It didn't work with -mabi=no-spe. I'm confused.. what did you change from your patch? This is the patch it right now: --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -103,6 +103,7 @@ KBUILD_CFLAGS += $(call cc-option,-mno-altivec) # No SPE instruction when building kernel KBUILD_CFLAGS += $(call cc-option,-mno-spe) +KBUILD_CFLAGS += $(call cc-option,-mspe=no) # Enable unit-at-a-time mode when possible. It shrinks the # kernel considerably. -- With this patch it compiles and boots fine. The option -mabi=no-spe is not required. - k Sebastian ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Oct 15, 2008, at 9:43 AM, Sebastian Andrzej Siewior wrote: * Kumar Gala | 2008-10-15 08:25:54 [-0500]: On Oct 15, 2008, at 3:59 AM, Sebastian Andrzej Siewior wrote: * Sebastian Andrzej Siewior | 2008-10-15 00:49:46 [+0200]: is the -mabi=no-spe really needed? It seems to work the other way around (without -mabi=no-spe but with -mabi=no-spe) alteast I did not find anything in do_syslog() or while browsing through the dissasm. I do a boot check tomorrow. Okay. I recompiled with -mspe=no and was able to boot without trouble. It didn't work with -mabi=no-spe. I'm confused.. what did you change from your patch? This is the patch it right now: --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -103,6 +103,7 @@ KBUILD_CFLAGS += $(call cc-option,-mno-altivec) # No SPE instruction when building kernel KBUILD_CFLAGS += $(call cc-option,-mno-spe) +KBUILD_CFLAGS += $(call cc-option,-mspe=no) # Enable unit-at-a-time mode when possible. It shrinks the # kernel considerably. -- With this patch it compiles and boots fine. The option -mabi=no-spe is not required. ok. can post a clean patch w/just this change. - k ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
* Sebastian Andrzej Siewior | 2008-10-15 00:49:46 [+0200]: is the -mabi=no-spe really needed? It seems to work the other way around (without -mabi=no-spe but with -mabi=no-spe) alteast I did not find anything in do_syslog() or while browsing through the dissasm. I do a boot check tomorrow. Okay. I recompiled with -mspe=no and was able to boot without trouble. It didn't work with -mabi=no-spe. - k Sebastian ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Oct 15, 2008, at 3:59 AM, Sebastian Andrzej Siewior wrote: * Sebastian Andrzej Siewior | 2008-10-15 00:49:46 [+0200]: is the -mabi=no-spe really needed? It seems to work the other way around (without -mabi=no-spe but with -mabi=no-spe) alteast I did not find anything in do_syslog() or while browsing through the dissasm. I do a boot check tomorrow. Okay. I recompiled with -mspe=no and was able to boot without trouble. It didn't work with -mabi=no-spe. I'm confused.. what did you change from your patch? - k ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Mon, 2008-09-01 at 16:23 +0200, Sebastian Siewior wrote: those two are requried on my fresh gcc 4.3.1 Signed-off-by: Thiemo Seufer [EMAIL PROTECTED] Signed-off-by: Sebastian Siewior [EMAIL PROTECTED] --- Not sure if this is intendent or a gcc bug but with -mno-spe the spe opcodes were not used floating point anymore but for 64bit save/restore for instance. I wouldn't say this is due to a broken compiler. As I understand it, -mabi=no-spe and -mspe=no serve two different purposes. One is for disabling the SPE instructions and the other controls the ABI (which would make those 64-bit save/restores I'm guessing). I don't know why you'd ever want to use the SPE ABI without -mspe=yes, but gcc does provide that flexibility. -mno-spe: Deprecated way to say no SPE instructions -mspe=no: New way to do -mno-spe -mabi=no-spe: Disable SPE ABI Some compilers may enable -mabi=spe and/or -mspe=yes by default, so explicitly disabling both is necessary. I recently built a SPE toolchain which enabled both by default, so I ran into the SPE used in kernel problem when the kernel only passed -mno-spe. - Nate Case [EMAIL PROTECTED] ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Sep 1, 2008, at 9:23 AM, Sebastian Siewior wrote: From: Thiemo Seufer [EMAIL PROTECTED] those two are requried on my fresh gcc 4.3.1 Signed-off-by: Thiemo Seufer [EMAIL PROTECTED] Signed-off-by: Sebastian Siewior [EMAIL PROTECTED] --- Not sure if this is intendent or a gcc bug but with -mno-spe the spe opcodes were not used floating point anymore but for 64bit save/restore for instance. what code is getting generated for you that is causing issue? arch/powerpc/Makefile |3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index b7d4c4c..3727e4f 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -108,7 +108,10 @@ endif KBUILD_CFLAGS += $(call cc-option,-mno-altivec) # No SPE instruction when building kernel +# (We use all available options to help semi-broken compilers) KBUILD_CFLAGS += $(call cc-option,-mno-spe) +KBUILD_CFLAGS += $(call cc-option,-mspe=no) Why does -mno-spe work? From my gcc-4.3 info pages: `-mspe=YES/NO' This option has been deprecated. Use `-mspe' and `-mno-spe' instead. +KBUILD_CFLAGS += $(call cc-option,-mabi=no-spe) is the -mabi=no-spe really needed? - k ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
On Tue, 2008-10-14 at 16:23 -0500, Kumar Gala wrote: Why does -mno-spe work? From my gcc-4.3 info pages: `-mspe=YES/NO' This option has been deprecated. Use `-mspe' and `-mno-spe' instead. +KBUILD_CFLAGS += $(call cc-option,-mabi=no-spe) is the -mabi=no-spe really needed? My guess is that the -mabi=no-spe was the real key of what made it work for him. I went through the same thing with my toolchain. You do need -mabi=no-spe if your toolchain defaults to -mabi=spe like mine does. I know that the more generic toolchains out there (CodeSourcery, ELDK) default to -mabi=no-spe, so in that case it would not be necessary. I don't know what generated instructions are actually to blame, but I do know that if you compile certain programs with -mno-spe -mabi=spe vs. -mno-spe -mabi=no-spe, the results will differ. In the case of the kernel, you'll get a bunch of SPE used in kernel messages with the -mno-spe -mabi=spe combination. - Nate Case [EMAIL PROTECTED] ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
* Kumar Gala | 2008-10-14 16:23:05 [-0500]: Not sure if this is intendent or a gcc bug but with -mno-spe the spe opcodes were not used floating point anymore but for 64bit save/restore for instance. what code is getting generated for you that is causing issue? Without the patch do_syslog() looks like this: |c0025840 do_syslog: |c0025840: 94 21 ff 50 stwur1,-176(r1) |c0025844: 7c 08 02 a6 mflrr0 |c0025848: 13 21 73 21 evstdd r25,112(r1) |c002584c: 13 41 7b 21 evstdd r26,120(r1) |c0025850: 7c 9a 23 78 mr r26,r4 |c0025854: 13 61 83 21 evstdd r27,128(r1) |c0025858: 7c bb 2b 78 mr r27,r5 |c002585c: 13 e1 a3 21 evstdd r31,160(r1) |c0025860: 7c 7f 1b 78 mr r31,r3 |c0025864: 90 01 00 b4 stw r0,180(r1) |c0025868: 12 21 33 21 evstdd r17,48(r1) |c002586c: 12 41 3b 21 evstdd r18,56(r1) |c0025870: 12 61 43 21 evstdd r19,64(r1) |c0025874: 12 81 4b 21 evstdd r20,72(r1) |c0025878: 12 a1 53 21 evstdd r21,80(r1) |c002587c: 12 c1 5b 21 evstdd r22,88(r1) |c0025880: 12 e1 63 21 evstdd r23,96(r1) |c0025884: 13 01 6b 21 evstdd r24,104(r1) |c0025888: 13 81 8b 21 evstdd r28,136(r1) |c002588c: 13 a1 93 21 evstdd r29,144(r1) |c0025890: 13 c1 9b 21 evstdd r30,152(r1) |c0025894: 48 0f 00 b5 bl c0115948 cap_syslog |c0025898: 7c 79 1b 79 mr. r25,r3 |c002589c: 40 82 04 54 bne-c0025cf0 do_syslog+0x4b0 |c00258a0: 2b 9f 00 0a cmplwi cr7,r31,10 |c00258a4: 41 9d 04 40 bgt-cr7,c0025ce4 do_syslog+0x4a4 |c00258a8: 3d 20 c0 27 lis r9,-16345 |c00258ac: 57 e0 10 3a rlwinm r0,r31,2,0,29 |c00258b0: 39 29 a6 e4 addir9,r9,-22812 |c00258b4: 7c 09 00 2e lwzxr0,r9,r0 |c00258b8: 7c 00 4a 14 add r0,r0,r9 |c00258bc: 7c 09 03 a6 mtctr r0 |c00258c0: 4e 80 04 20 bctr |c00258c4: 3b e0 00 00 li r31,0 do_syslog() is not the only one. 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index b7d4c4c..3727e4f 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -108,7 +108,10 @@ endif KBUILD_CFLAGS += $(call cc-option,-mno-altivec) # No SPE instruction when building kernel +# (We use all available options to help semi-broken compilers) KBUILD_CFLAGS += $(call cc-option,-mno-spe) +KBUILD_CFLAGS += $(call cc-option,-mspe=no) Why does -mno-spe work? Good question. Without this option and only with -mabi=no-spe the do_syslog() looks like the following: |c0025270 do_syslog: |c0025270: 94 21 ff 90 stwur1,-112(r1) |c0025274: 7c 08 02 a6 mflrr0 |c0025278: be 21 00 34 stmwr17,52(r1) |c002527c: 7c 9a 23 78 mr r26,r4 |c0025280: 90 01 00 74 stw r0,116(r1) |c0025284: 7c bb 2b 78 mr r27,r5 |c0025288: 7c 7f 1b 78 mr r31,r3 |c002528c: 48 0e ce c5 bl c0112150 cap_syslog |c0025290: 7c 79 1b 79 mr. r25,r3 |c0025294: 40 82 04 54 bne-c00256e8 do_syslog+0x478 |c0025298: 2b 9f 00 0a cmplwi cr7,r31,10 |c002529c: 41 9d 04 40 bgt-cr7,c00256dc do_syslog+0x46c |c00252a0: 3d 20 c0 26 lis r9,-16346 |c00252a4: 57 e0 10 3a rlwinm r0,r31,2,0,29 |c00252a8: 39 29 36 e4 addir9,r9,14052 |c00252ac: 7c 09 00 2e lwzxr0,r9,r0 |c00252b0: 7c 00 4a 14 add r0,r0,r9 |c00252b4: 7c 09 03 a6 mtctr r0 |c00252b8: 4e 80 04 20 bctr |c00252bc: 3b e0 00 00 li r31,0 |c00252c0: 48 00 01 c4 b c0025484 do_syslog+0x214 |c00252c4: 2f 9a 00 00 cmpwi cr7,r26,0 |c00252c8: 41 9e 04 14 beq-cr7,c00256dc do_syslog+0x46c |c00252cc: 2f 9b 00 00 cmpwi cr7,r27,0 |c00252d0: 41 9c 04 0c blt-cr7,c00256dc do_syslog+0x46c |c00252d4: 41 9e 04 14 beq-cr7,c00256e8 do_syslog+0x478 |c00252d8: 80 02 03 3c lwz r0,828(r2) |c00252dc: 7f 9a 00 40 cmplw cr7,r26,r0 |c00252e0: 41 9d 04 04 bgt-cr7,c00256e4 do_syslog+0x474 |c00252e4: 7c 1a 00 50 subfr0,r26,r0 |c00252e8: 39 3b ff ff addir9,r27,-1 |c00252ec: 7f 89 00 40 cmplw cr7,r9,r0 |c00252f0: 41 9d 03 f4 bgt-cr7,c00256e4 do_syslog+0x474 |c00252f4: 3d 20 c0 39 lis r9,-16327 |c00252f8: 39 09 8e f8 addir8,r9,-28936 |c00252fc: 81 29 8e f8 lwz r9,-28936(r9) |c0025300: 80 08 00 04 lwz r0,4(r8) |c0025304: 7f 80 48 00 cmpwcr7,r0,r9 |c0025308: 40 be 00 a4 bne+cr7,c00253ac do_syslog+0x13c |c002530c: 3d 20 c0 04 lis r9,-16380 |c0025310: 39 61 00 14 addir11,r1,20
[PATCH] powerpc: enforce a non-spe kernel build even on broken compilers
From: Thiemo Seufer [EMAIL PROTECTED] those two are requried on my fresh gcc 4.3.1 Signed-off-by: Thiemo Seufer [EMAIL PROTECTED] Signed-off-by: Sebastian Siewior [EMAIL PROTECTED] --- Not sure if this is intendent or a gcc bug but with -mno-spe the spe opcodes were not used floating point anymore but for 64bit save/restore for instance. arch/powerpc/Makefile |3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index b7d4c4c..3727e4f 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -108,7 +108,10 @@ endif KBUILD_CFLAGS += $(call cc-option,-mno-altivec) # No SPE instruction when building kernel +# (We use all available options to help semi-broken compilers) KBUILD_CFLAGS += $(call cc-option,-mno-spe) +KBUILD_CFLAGS += $(call cc-option,-mspe=no) +KBUILD_CFLAGS += $(call cc-option,-mabi=no-spe) # Enable unit-at-a-time mode when possible. It shrinks the # kernel considerably. -- 1.5.6.5 ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
