[Suggestion] PowerPC: kernel: cross compiling issue with allmodconfig

Hello Maintainers:

  do next-* tree support powerpc POWER7 with allmodconfig ?

  I met an issue, can we bear it (or I need additional trying) ?


Compiling:
  make V=1 EXTRA_CFLAGS=-W ARCH=powerpc allmodconfig
    set cpu type POWER7 in menuconfig.
    set cross-compiler in menuconfig.
      under Fedora 16 x86_64 laptop
      /usr/bin/powerpc64-linux-gnu-gcc -v
        gcc version 4.7.1 20120606 (Red Hat 4.7.1-0.1.20120606) (GCC)

Issue:
  error:
    /android/public-kernel/linux-next/arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
    /android/public-kernel/linux-next/arch/powerpc/kernel/exceptions-64s.S:1304: Error: attempt to move .org backwards

  command:
    powerpc64-linux-gnu-gcc -m64 -Wp,-MD,arch/powerpc/kernel/.head_64.o.d  -nostdinc -isystem /usr/lib/gcc/powerpc64-linux-gnu/4.7.1/include -I/android/public-kernel/linux-next/arch/powerpc/include -Iarch/powerpc/include/generated  -I/android/public-kernel/linux-next/include -Iinclude -I/android/public-kernel/linux-next/arch/powerpc/include/uapi -Iarch/powerpc/include/generated/uapi -I/android/public-kernel/linux-next/include/uapi -Iinclude/generated/uapi -include /android/public-kernel/linux-next/include/linux/kconfig.h -D__KERNEL__  -I/android/public-kernel/linux-next/arch/powerpc -Iarch/powerpc -D__ASSEMBLY__  -I/android/public-kernel/linux-next/arch/powerpc -Iarch/powerpc -Wa,-maltivec -gdwarf-2   -c -o arch/powerpc/kernel/head_64.o /android/public-kernel/linux-next/arch/powerpc/kernel/head_64.S

  (head_64.S includes exceptions-64.S)


  thanks.

-- 
Chen Gang

Asianux Corporation

  do next-* tree support powerpc POWER7 with allmodconfig ?

  I met an issue, can we bear it (or I need additional trying) ?


Compiling:
  make V=1 EXTRA_CFLAGS=-W ARCH=powerpc allmodconfig
    set cpu type POWER7 in menuconfig.
    set cross-compiler in menuconfig.
      under Fedora 16 x86_64 laptop
      /usr/bin/powerpc64-linux-gnu-gcc -v
        gcc version 4.7.1 20120606 (Red Hat 4.7.1-0.1.20120606) (GCC)

Issue:
  error:
    /android/public-kernel/linux-next/arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
    /android/public-kernel/linux-next/arch/powerpc/kernel/exceptions-64s.S:1304: Error: attempt to move .org backwards

  command:
    powerpc64-linux-gnu-gcc -m64 -Wp,-MD,arch/powerpc/kernel/.head_64.o.d  -nostdinc -isystem /usr/lib/gcc/powerpc64-linux-gnu/4.7.1/include -I/android/public-kernel/linux-next/arch/powerpc/include -Iarch/powerpc/include/generated  -I/android/public-kernel/linux-next/include -Iinclude -I/android/public-kernel/linux-next/arch/powerpc/include/uapi -Iarch/powerpc/include/generated/uapi -I/android/public-kernel/linux-next/include/uapi -Iinclude/generated/uapi -include /android/public-kernel/linux-next/include/linux/kconfig.h -D__KERNEL__  -I/android/public-kernel/linux-next/arch/powerpc -Iarch/powerpc -D__ASSEMBLY__  -I/android/public-kernel/linux-next/arch/powerpc -Iarch/powerpc -Wa,-maltivec -gdwarf-2   -c -o arch/powerpc/kernel/head_64.o /android/public-kernel/linux-next/arch/powerpc/kernel/head_64.S

  (head_64.S includes exceptions-64.S)

Yep it's a known problem but no one has bothered to fix it since it
doesn't happen in a config that anyone cares about like
pseries_defconfig and ppc64_defconfig.  We've been moving code around in
this area a lot recently hence the breakage.

It should be fixed though.  Patches welcome. :-)

Mikey

于 2013年03月15日 12:52, Michael Neuling 写道:

Yep it's a known problem but no one has bothered to fix it since it
doesn't happen in a config that anyone cares about like
pseries_defconfig and ppc64_defconfig.  We've been moving code around in
this area a lot recently hence the breakage.

It should be fixed though.  Patches welcome. :-)

  thanks, and I should try, and very glad to try.

  :-)  :-)

  excuse me, I try to provide related patch within this month (2013-03-31), is it ok ?
  the reason is:
    I am not familiar with ppc assembly code, neither ppc kernel,
    so need additional time resource.
      (originally, I worked for x86(_64) core dump analysing for kernel and user programs)

  thanks.

-- 
Chen Gang

Asianux Corporation

Hello All:

summary:
  the root cause is no enough room in exception area (0x5500 -- 0x7000).

  it is caused by the patches "for saving/restre PPR":
    they consumed much space of this area (0x5500 -- 0x7000).
    for pseries_defconfig and ppc64_defconfig, it is still ok.
    but for allmodconfig and "some additional config", it will cause issue.

  the solving patch "Make room in exception vector area" can make room larger.
    it can let "some additional config" ok.
    but for allmodconfig, it is still not enough.


details
  reason:
    it is caused by:
       commit number: 13e7a8e846c2ea38a552b986ea49332f965bbb7a
       commit number: 44e9309f1f357794b7ae93d5f3e3e6f11d2b8a7f
    they are "for saving/restore PPR"
    by Haren Myneni [off-list ref] Thu, 6 Dec 2012
    compiling result:
      pseries_defconfig: pass   (cpu for POWER7)
      ppc64_defconfig:   pass   (cpu for POWER7)
      allmodconfig:      failed (cpu for POWER7)

  analysing:
    solving patch:
      ------------------------------------------------------------------
      commit number: 61383407677aef05928541a00678591abea2d84c
      Author: Benjamin Herrenschmidt [off-list ref]
      Date:   Thu Jan 10 17:44:19 2013 +1100

        powerpc: Make room in exception vector area
    
        The FWNMI region is fixed at 0x7000 and the vector are now
        overflowing that with some configurations. Fix that by moving
        some hash management code out of that region as it doesn't need
        to be that close to the call sites (isn't accessed using
        conditional branches).
      ------------------------------------------------------------------

      but for allmodconfig (not only for "some configurations"):
        it really can reduce much overflow bytes,
          (maybe from hundreds bytes to dozens bytes)
        but still not enough (still content overflow bytes)

    additional trying:
	after del CONFIG_VSX and CONFIG_PPC_970_NAP in allmodconfig,
          (will reduce dozens bytes in the region .0x5500 -- .0x7000)
        it can pass compiling (not overflow).


next:
  I am sorry:
      I am not quite familiar with the detail features of powerpc.
      it seems I am not the suitable member to continue trying.

  I prefer Benjamin to continue trying (just like what he has done).

  if Benjamin will not do it (e.g. maybe no time to do)
    I should continue: "make additional room in exception vector area".
      (if get no reply within a week: before 2013-03-28, I should continue)



  welcome any members' (especially Benjamin) suggestions or completions.

  thanks.

  :-)


On 2013年03月15日 13:14, Chen Gang wrote:

于 2013年03月15日 12:52, Michael Neuling 写道:

quoted

Yep it's a known problem but no one has bothered to fix it since it
doesn't happen in a config that anyone cares about like
pseries_defconfig and ppc64_defconfig.  We've been moving code around in
this area a lot recently hence the breakage.

It should be fixed though.  Patches welcome. :-)

  thanks, and I should try, and very glad to try.

  :-)  :-)

  excuse me, I try to provide related patch within this month (2013-03-31), is it ok ?
  the reason is:
    I am not familiar with ppc assembly code, neither ppc kernel,
    so need additional time resource.
      (originally, I worked for x86(_64) core dump analysing for kernel and user programs)

  thanks.

-- 
Chen Gang

Asianux Corporation

Chen Gang [off-list ref] wrote:

Hello All:
=20
summary:
  the root cause is no enough room in exception area (0x5500 -- 0x7000).
=20
  it is caused by the patches "for saving/restre PPR":
    they consumed much space of this area (0x5500 -- 0x7000).
    for pseries_defconfig and ppc64_defconfig, it is still ok.
    but for allmodconfig and "some additional config", it will cause issu=

e.

=20
  the solving patch "Make room in exception vector area" can make room la=

rger.

    it can let "some additional config" ok.
    but for allmodconfig, it is still not enough.
=20
=20
details
  reason:
    it is caused by:
       commit number: 13e7a8e846c2ea38a552b986ea49332f965bbb7a
       commit number: 44e9309f1f357794b7ae93d5f3e3e6f11d2b8a7f
    they are "for saving/restore PPR"
    by Haren Myneni [off-list ref] Thu, 6 Dec 2012
    compiling result:
      pseries_defconfig: pass   (cpu for POWER7)
      ppc64_defconfig:   pass   (cpu for POWER7)
      allmodconfig:      failed (cpu for POWER7)
=20
  analysing:
    solving patch:
      ------------------------------------------------------------------
      commit number: 61383407677aef05928541a00678591abea2d84c
      Author: Benjamin Herrenschmidt [off-list ref]
      Date:   Thu Jan 10 17:44:19 2013 +1100
=20
        powerpc: Make room in exception vector area
=20=20=20=20=20
        The FWNMI region is fixed at 0x7000 and the vector are now
        overflowing that with some configurations. Fix that by moving
        some hash management code out of that region as it doesn't need
        to be that close to the call sites (isn't accessed using
        conditional branches).
      ------------------------------------------------------------------
=20
      but for allmodconfig (not only for "some configurations"):
        it really can reduce much overflow bytes,
          (maybe from hundreds bytes to dozens bytes)
        but still not enough (still content overflow bytes)
=20
    additional trying:
	after del CONFIG_VSX and CONFIG_PPC_970_NAP in allmodconfig,
          (will reduce dozens bytes in the region .0x5500 -- .0x7000)
        it can pass compiling (not overflow).
=20
=20
next:
  I am sorry:
      I am not quite familiar with the detail features of powerpc.
      it seems I am not the suitable member to continue trying.
=20
  I prefer Benjamin to continue trying (just like what he has done).
=20
  if Benjamin will not do it (e.g. maybe no time to do)
    I should continue: "make additional room in exception vector area".
      (if get no reply within a week: before 2013-03-28, I should continu=

e)

=20
=20
=20
  welcome any members' (especially Benjamin) suggestions or completions.

This is great, thanks a lot.=20=20

If you want this to be picked up by the maintainer, you'll need to add
your signed-off-by.

The signed-off-by is to indicate that your happy for it to be included
and that you're legally allowed to do so.  See
http://gerrit.googlecode.com/svn/documentation/2.0/user-signedoffby.html
for more info.

Mikey

=20
  thanks.
=20
  :-)
=20
=20
On 2013=E5=B9=B403=E6=9C=8815=E6=97=A5 13:14, Chen Gang wrote:

quoted

=E4=BA=8E 2013=E5=B9=B403=E6=9C=8815=E6=97=A5 12:52, Michael Neuling =

=E5=86=99=E9=81=93:

quoted

quoted

Yep it's a known problem but no one has bothered to fix it since it
doesn't happen in a config that anyone cares about like
pseries_defconfig and ppc64_defconfig.  We've been moving code around =

in

quoted

quoted

this area a lot recently hence the breakage.

It should be fixed though.  Patches welcome. :-)

=20
  thanks, and I should try, and very glad to try.
=20
  :-)  :-)
=20
  excuse me, I try to provide related patch within this month (2013-03-=

31), is it ok ?

quoted

  the reason is:
    I am not familiar with ppc assembly code, neither ppc kernel,
    so need additional time resource.
      (originally, I worked for x86(_64) core dump analysing for kernel=

 and user programs)

quoted

=20
  thanks.
=20

=20
=20
--=20
Chen Gang
=20
Asianux Corporation
=20

On 2013年03月22日 06:54, Michael Neuling wrote:

This is great, thanks a lot.  

If you want this to be picked up by the maintainer, you'll need to add
your signed-off-by.

The signed-off-by is to indicate that your happy for it to be included
and that you're legally allowed to do so.  See
http://gerrit.googlecode.com/svn/documentation/2.0/user-signedoffby.html
for more info.

Mikey

  thanks, too.
  I prefer Benjamin to have a closer look for my fixing.
  if pass his checking, I will send a patch.
    (he is on vacation, now, and he will check it when he is back).

  Regards

-- 
Chen Gang

Asianux Corporation

Chen Gang [off-list ref] wrote:

On 2013=E5=B9=B403=E6=9C=8822=E6=97=A5 06:54, Michael Neuling wrote:

quoted

This is great, thanks a lot.=20=20
=20
If you want this to be picked up by the maintainer, you'll need to add
your signed-off-by.
=20
The signed-off-by is to indicate that your happy for it to be included
and that you're legally allowed to do so.  See
http://gerrit.googlecode.com/svn/documentation/2.0/user-signedoffby.html
for more info.
=20
Mikey

=20
  thanks, too.
  I prefer Benjamin to have a closer look for my fixing.
  if pass his checking, I will send a patch.
    (he is on vacation, now, and he will check it when he is back).

benh asked paulus or sfr to send in while he was away.

So please send your signed off by now (if you can), or someone is going
to rewrite it, sent it upstream bypassing you.

Mikey

On 2013年03月25日 08:03, Michael Neuling wrote:

benh asked paulus or sfr to send in while he was away.

So please send your signed off by now (if you can), or someone is going
to rewrite it, sent it upstream bypassing you.

Mikey

  thanks, I will send patch now.

  :-)

-- 
Chen Gang

Asianux Corporation

  The FWNMI region is fixed at 0x7000 and the vector are now overflowing
  that with allmodconfig. Fix that by moving slb_miss_realmode code out
  of that region as it doesn't need to be that close to the call sites
  (it is a _GLOBAL function)

Signed-off-by: Chen Gang <redacted>
---
 arch/powerpc/kernel/exceptions-64s.S |  144 +++++++++++++++++-----------------
 1 files changed, 72 insertions(+), 72 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 200afa5..56bd923 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S

@@ -1066,78 +1066,6 @@ unrecov_user_slb:
 #endif /* __DISABLED__ */
 
 
-/*
- * r13 points to the PACA, r9 contains the saved CR,
- * r12 contain the saved SRR1, SRR0 is still ready for return
- * r3 has the faulting address
- * r9 - r13 are saved in paca->exslb.
- * r3 is saved in paca->slb_r3
- * We assume we aren't going to take any exceptions during this procedure.
- */
-_GLOBAL(slb_miss_realmode)
-	mflr	r10
-#ifdef CONFIG_RELOCATABLE
-	mtctr	r11
-#endif
-
-	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
-	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
-
-	bl	.slb_allocate_realmode
-
-	/* All done -- return from exception. */
-
-	ld	r10,PACA_EXSLB+EX_LR(r13)
-	ld	r3,PACA_EXSLB+EX_R3(r13)
-	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
-
-	mtlr	r10
-
-	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
-	beq-	2f
-
-.machine	push
-.machine	"power4"
-	mtcrf	0x80,r9
-	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
-.machine	pop
-
-	RESTORE_PPR_PACA(PACA_EXSLB, r9)
-	ld	r9,PACA_EXSLB+EX_R9(r13)
-	ld	r10,PACA_EXSLB+EX_R10(r13)
-	ld	r11,PACA_EXSLB+EX_R11(r13)
-	ld	r12,PACA_EXSLB+EX_R12(r13)
-	ld	r13,PACA_EXSLB+EX_R13(r13)
-	rfid
-	b	.	/* prevent speculative execution */
-
-2:	mfspr	r11,SPRN_SRR0
-	ld	r10,PACAKBASE(r13)
-	LOAD_HANDLER(r10,unrecov_slb)
-	mtspr	SPRN_SRR0,r10
-	ld	r10,PACAKMSR(r13)
-	mtspr	SPRN_SRR1,r10
-	rfid
-	b	.
-
-unrecov_slb:
-	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
-	DISABLE_INTS
-	bl	.save_nvgprs
-1:	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	.unrecoverable_exception
-	b	1b
-
-
-#ifdef CONFIG_PPC_970_NAP
-power4_fixup_nap:
-	andc	r9,r9,r10
-	std	r9,TI_LOCAL_FLAGS(r11)
-	ld	r10,_LINK(r1)		/* make idle task do the */
-	std	r10,_NIP(r1)		/* equivalent of a blr */
-	blr
-#endif
-
 	.align	7
 	.globl alignment_common
 alignment_common:

@@ -1336,6 +1264,78 @@ _GLOBAL(opal_mc_secondary_handler)
 
 
 /*
+ * r13 points to the PACA, r9 contains the saved CR,
+ * r12 contain the saved SRR1, SRR0 is still ready for return
+ * r3 has the faulting address
+ * r9 - r13 are saved in paca->exslb.
+ * r3 is saved in paca->slb_r3
+ * We assume we aren't going to take any exceptions during this procedure.
+ */
+_GLOBAL(slb_miss_realmode)
+	mflr	r10
+#ifdef CONFIG_RELOCATABLE
+	mtctr	r11
+#endif
+
+	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
+	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
+
+	bl	.slb_allocate_realmode
+
+	/* All done -- return from exception. */
+
+	ld	r10,PACA_EXSLB+EX_LR(r13)
+	ld	r3,PACA_EXSLB+EX_R3(r13)
+	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
+
+	mtlr	r10
+
+	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
+	beq-	2f
+
+.machine	push
+.machine	"power4"
+	mtcrf	0x80,r9
+	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
+.machine	pop
+
+	RESTORE_PPR_PACA(PACA_EXSLB, r9)
+	ld	r9,PACA_EXSLB+EX_R9(r13)
+	ld	r10,PACA_EXSLB+EX_R10(r13)
+	ld	r11,PACA_EXSLB+EX_R11(r13)
+	ld	r12,PACA_EXSLB+EX_R12(r13)
+	ld	r13,PACA_EXSLB+EX_R13(r13)
+	rfid
+	b	.	/* prevent speculative execution */
+
+2:	mfspr	r11,SPRN_SRR0
+	ld	r10,PACAKBASE(r13)
+	LOAD_HANDLER(r10,unrecov_slb)
+	mtspr	SPRN_SRR0,r10
+	ld	r10,PACAKMSR(r13)
+	mtspr	SPRN_SRR1,r10
+	rfid
+	b	.
+
+unrecov_slb:
+	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
+	DISABLE_INTS
+	bl	.save_nvgprs
+1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.unrecoverable_exception
+	b	1b
+
+
+#ifdef CONFIG_PPC_970_NAP
+power4_fixup_nap:
+	andc	r9,r9,r10
+	std	r9,TI_LOCAL_FLAGS(r11)
+	ld	r10,_LINK(r1)		/* make idle task do the */
+	std	r10,_NIP(r1)		/* equivalent of a blr */
+	blr
+#endif
+
+/*
  * Hash table stuff
  */
 	.align	7

-- 
1.7.7.6

Hi all,

On Mon, 25 Mar 2013 09:31:31 +0800 Chen Gang [off-list ref] wrote:

  The FWNMI region is fixed at 0x7000 and the vector are now overflowing
  that with allmodconfig. Fix that by moving slb_miss_realmode code out
  of that region as it doesn't need to be that close to the call sites
  (it is a _GLOBAL function)

Signed-off-by: Chen Gang <redacted>
---
 arch/powerpc/kernel/exceptions-64s.S |  144 +++++++++++++++++-----------------
 1 files changed, 72 insertions(+), 72 deletions(-)

Thanks, Chen,

I have applied this to linux-next today and pending the builds overnight,
will send it to Linus tomorrow or Wednesday.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

On 2013年03月25日 13:14, Stephen Rothwell wrote:

Hi all,

On Mon, 25 Mar 2013 09:31:31 +0800 Chen Gang [off-list ref] wrote:

quoted

quoted

  The FWNMI region is fixed at 0x7000 and the vector are now overflowing
  that with allmodconfig. Fix that by moving slb_miss_realmode code out
  of that region as it doesn't need to be that close to the call sites
  (it is a _GLOBAL function)

Signed-off-by: Chen Gang <redacted>
---
 arch/powerpc/kernel/exceptions-64s.S |  144 +++++++++++++++++-----------------
 1 files changed, 72 insertions(+), 72 deletions(-)

Thanks, Chen,

I have applied this to linux-next today and pending the builds overnight,
will send it to Linus tomorrow or Wednesday.

  thanks.

  :-)

-- 
Chen Gang

Asianux Corporation

Stephen Rothwell [off-list ref] wrote:

Hi all,

On Mon, 25 Mar 2013 09:31:31 +0800 Chen Gang [off-list ref] wrote:

quoted

  The FWNMI region is fixed at 0x7000 and the vector are now overflowing
  that with allmodconfig. Fix that by moving slb_miss_realmode code out
  of that region as it doesn't need to be that close to the call sites
  (it is a _GLOBAL function)

Signed-off-by: Chen Gang <redacted>
---
 arch/powerpc/kernel/exceptions-64s.S |  144 +++++++++++++++++-----------------
 1 files changed, 72 insertions(+), 72 deletions(-)

Thanks, Chen,

I have applied this to linux-next today and pending the builds overnight,
will send it to Linus tomorrow or Wednesday.

sfr,

FYI you're gonna need this one also to make allmodconfig work.

  http://patchwork.ozlabs.org/patch/230244/

Mikey

Hi Mikey,

On Mon, 25 Mar 2013 17:07:17 +1100 Michael Neuling [off-list ref] wrote:

FYI you're gonna need this one also to make allmodconfig work.

  http://patchwork.ozlabs.org/patch/230244/

Thanks for that, I will add it to linux-next tomorrow.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au