Patchwork [v2,5/7] powerpc/85xx: Add MChk handler for SRIO port

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Submitter Alexandre Bounine
Date March 8, 2010, 7:10 p.m.
Message ID <20100308191005.GE4324@amak.tundra.com>
Download mbox | patch
Permalink /patch/47140/
State Superseded
Delegated to: Kumar Gala
Headers show

Comments

Alexandre Bounine - March 8, 2010, 7:10 p.m.
From: Alexandre Bounine <alexandre.bounine@idt.com>

Add Machine Check exception handling into RapidIO port driver
for Freescale SoCs (MPC85xx).

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Tested-by: Thomas Moll <thomas.moll@sysgo.com>
---

 fsl_rio.c |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 70 insertions(+), 4 deletions(-)


---

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Timur Tabi - June 30, 2010, 8:55 p.m.
On Mon, Mar 8, 2010 at 2:10 PM, Alexandre Bounine <abounine@tundra.com> wrote:
>
> From: Alexandre Bounine <alexandre.bounine@idt.com>
>
> Add Machine Check exception handling into RapidIO port driver
> for Freescale SoCs (MPC85xx).
>
> Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
> Tested-by: Thomas Moll <thomas.moll@sysgo.com>
...

> +static int fsl_rio_mcheck_exception(struct pt_regs *regs)
> +{
> +       const struct exception_table_entry *entry = NULL;
> +       unsigned long reason = (mfspr(SPRN_MCSR) & MCSR_MASK);

MCSR_MASK is not defined anywhere, so when I compile this code, I get this:

  CC      arch/powerpc/sysdev/fsl_rio.o
arch/powerpc/sysdev/fsl_rio.c: In function 'fsl_rio_mcheck_exception':
arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
(first use in this function)
arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier
is reported only once
arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears in.)
Timur Tabi - June 30, 2010, 9 p.m.
On Wed, Jun 30, 2010 at 3:55 PM, Timur Tabi <timur.tabi@gmail.com> wrote:

> MCSR_MASK is not defined anywhere, so when I compile this code, I get this:

Never mind.  I see that it's been fixed already, and that the patch
that removed MCSR_MASK was posted around the same time that this patch
was posted.
Michael Neuling - Aug. 3, 2010, 6:06 a.m.
> > MCSR_MASK is not defined anywhere, so when I compile this code, I get this:
> 
> Never mind.  I see that it's been fixed already, and that the patch
> that removed MCSR_MASK was posted around the same time that this patch
> was posted.

I don't know what happened here but 2.6.35 is broken because of this
problem:

arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared (first use in this function)
arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier is reported only once
arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears in.)
arch/powerpc/sysdev/fsl_rio.c:250: error: 'MCSR_BUS_RBERR' undeclared (first use in this function)

Mikey
Bounine, Alexandre - Aug. 3, 2010, 12:17 p.m.
This happened after change to book-e definitions.
There are patches that address this issue.

> -----Original Message-----
> From: Michael Neuling [mailto:mikey@neuling.org]
> Sent: Tuesday, August 03, 2010 2:07 AM
> To: Timur Tabi
> Cc: Alexandre Bounine; linuxppc-dev@lists.ozlabs.org;
linux-kernel@vger.kernel.org;
> thomas.moll@sysgo.com
> Subject: Re: [PATCH v2 5/7] powerpc/85xx: Add MChk handler for SRIO
port
> 
> > > MCSR_MASK is not defined anywhere, so when I compile this code, I
get this:
> >
> > Never mind.  I see that it's been fixed already, and that the patch
> > that removed MCSR_MASK was posted around the same time that this
patch
> > was posted.
> 
> I don't know what happened here but 2.6.35 is broken because of this
> problem:
> 
> arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
(first use in this function)
> arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier
is reported only once
> arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears
in.)
> arch/powerpc/sysdev/fsl_rio.c:250: error: 'MCSR_BUS_RBERR' undeclared
(first use in this function)
> 
> Mikey
Timur Tabi - Aug. 3, 2010, 1:01 p.m.
On Tue, Aug 3, 2010 at 7:17 AM, Bounine, Alexandre
<Alexandre.Bounine@idt.com> wrote:
> This happened after change to book-e definitions.
> There are patches that address this issue.

And those patches should have been applied before 2.6.35 was released.
 Someone dropped the ball.  2.6.35 is broken for a number of PowerPC
boards:

$ make mpc85xx_defconfig
...
$ make
...
  CC      arch/powerpc/sysdev/fsl_rio.o
arch/powerpc/sysdev/fsl_rio.c: In function 'fsl_rio_mcheck_exception':
arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
(first use in this function)
arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier
is reported only once
arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears in.)
make[1]: *** [arch/powerpc/sysdev/fsl_rio.o] Error 1
Bounine, Alexandre - Aug. 3, 2010, 1:24 p.m.
Yang Li pointed to these patches in his post from July 23, 2010.
It would be nice to have these patches in mainline code. 

> -----Original Message-----
> From: timur.tabi@gmail.com [mailto:timur.tabi@gmail.com] On Behalf Of
Timur Tabi
> Sent: Tuesday, August 03, 2010 9:02 AM
> To: Bounine, Alexandre
> Cc: Michael Neuling; Alexandre Bounine; linuxppc-dev@lists.ozlabs.org;
linux-kernel@vger.kernel.org;
> thomas.moll@sysgo.com; Kumar Gala
> Subject: Re: [PATCH v2 5/7] powerpc/85xx: Add MChk handler for SRIO
port
> 
> On Tue, Aug 3, 2010 at 7:17 AM, Bounine, Alexandre
> <Alexandre.Bounine@idt.com> wrote:
> > This happened after change to book-e definitions.
> > There are patches that address this issue.
> 
> And those patches should have been applied before 2.6.35 was released.
>  Someone dropped the ball.  2.6.35 is broken for a number of PowerPC
> boards:
> 
> $ make mpc85xx_defconfig
> ....
> $ make
> ....
>   CC      arch/powerpc/sysdev/fsl_rio.o
> arch/powerpc/sysdev/fsl_rio.c: In function 'fsl_rio_mcheck_exception':
> arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
> (first use in this function)
> arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier
> is reported only once
> arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears
in.)
> make[1]: *** [arch/powerpc/sysdev/fsl_rio.o] Error 1
> 
> --
> Timur Tabi
> Linux kernel developer at Freescale
Michael Neuling - Aug. 5, 2010, 3:34 a.m.
In message <0CE8B6BE3C4AD74AB97D9D29BD24E552011430BC@CORPEXCH1.na.ads.idt.com> you wrote:
> Yang Li pointed to these patches in his post from July 23, 2010.
> It would be nice to have these patches in mainline code.=20

This is still broken in Kumar's latest tree.  Do you guys wanna repost
them so Kumar can pick them up easily?

Mikey

> 
> > -----Original Message-----
> > From: timur.tabi@gmail.com [mailto:timur.tabi@gmail.com] On Behalf Of
> Timur Tabi
> > Sent: Tuesday, August 03, 2010 9:02 AM
> > To: Bounine, Alexandre
> > Cc: Michael Neuling; Alexandre Bounine; linuxppc-dev@lists.ozlabs.org;
> linux-kernel@vger.kernel.org;
> > thomas.moll@sysgo.com; Kumar Gala
> > Subject: Re: [PATCH v2 5/7] powerpc/85xx: Add MChk handler for SRIO
> port
> >=20
> > On Tue, Aug 3, 2010 at 7:17 AM, Bounine, Alexandre
> > <Alexandre.Bounine@idt.com> wrote:
> > > This happened after change to book-e definitions.
> > > There are patches that address this issue.
> >=20
> > And those patches should have been applied before 2.6.35 was released.
> >  Someone dropped the ball.  2.6.35 is broken for a number of PowerPC
> > boards:
> >=20
> > $ make mpc85xx_defconfig
> > ....
> > $ make
> > ....
> >   CC      arch/powerpc/sysdev/fsl_rio.o
> > arch/powerpc/sysdev/fsl_rio.c: In function 'fsl_rio_mcheck_exception':
> > arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
> > (first use in this function)
> > arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared identifier
> > is reported only once
> > arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it appears
> in.)
> > make[1]: *** [arch/powerpc/sysdev/fsl_rio.o] Error 1
> >=20
> > --
> > Timur Tabi
> > Linux kernel developer at Freescale
>
Bounine, Alexandre - Aug. 5, 2010, 5:25 p.m.
Below is a copy of Leo's message with pointers to the patches.

Alex.
 
>Subject: [PATCH] RapidIO,powerpc/85xx: remove MCSR_MASK in fsl_rio
>
>Fixes compile problem caused by MCSR_MASK removal from book-E
definitions.

Hi Alex,

Only with your patch, there will still be problem on SRIO platforms
other than MPC85xx.

I have posted a patch series to fix this together with several
compatibility issues a month before.

http://patchwork.ozlabs.org/patch/56135/
http://patchwork.ozlabs.org/patch/56136/
http://patchwork.ozlabs.org/patch/56138/
http://patchwork.ozlabs.org/patch/56137/


Can anyone pick the patch series quickly as currently there is a compile
error when SRIO is enabled.

- Leo


> -----Original Message-----
> From: Michael Neuling [mailto:mikey@neuling.org]
> Sent: Wednesday, August 04, 2010 11:34 PM
> To: Bounine, Alexandre
> Cc: Timur Tabi; Alexandre Bounine; linuxppc-dev@lists.ozlabs.org;
linux-kernel@vger.kernel.org;
> thomas.moll@sysgo.com; Kumar Gala
> Subject: Re: [PATCH v2 5/7] powerpc/85xx: Add MChk handler for SRIO
port
> 
> 
> 
> In message
<0CE8B6BE3C4AD74AB97D9D29BD24E552011430BC@CORPEXCH1.na.ads.idt.com> you
wrote:
> > Yang Li pointed to these patches in his post from July 23, 2010.
> > It would be nice to have these patches in mainline code.=20
> 
> This is still broken in Kumar's latest tree.  Do you guys wanna repost
> them so Kumar can pick them up easily?
> 
> Mikey
> 
> >
> > > -----Original Message-----
> > > From: timur.tabi@gmail.com [mailto:timur.tabi@gmail.com] On Behalf
Of
> > Timur Tabi
> > > Sent: Tuesday, August 03, 2010 9:02 AM
> > > To: Bounine, Alexandre
> > > Cc: Michael Neuling; Alexandre Bounine;
linuxppc-dev@lists.ozlabs.org;
> > linux-kernel@vger.kernel.org;
> > > thomas.moll@sysgo.com; Kumar Gala
> > > Subject: Re: [PATCH v2 5/7] powerpc/85xx: Add MChk handler for
SRIO
> > port
> > >=20
> > > On Tue, Aug 3, 2010 at 7:17 AM, Bounine, Alexandre
> > > <Alexandre.Bounine@idt.com> wrote:
> > > > This happened after change to book-e definitions.
> > > > There are patches that address this issue.
> > >=20
> > > And those patches should have been applied before 2.6.35 was
released.
> > >  Someone dropped the ball.  2.6.35 is broken for a number of
PowerPC
> > > boards:
> > >=20
> > > $ make mpc85xx_defconfig
> > > ....
> > > $ make
> > > ....
> > >   CC      arch/powerpc/sysdev/fsl_rio.o
> > > arch/powerpc/sysdev/fsl_rio.c: In function
'fsl_rio_mcheck_exception':
> > > arch/powerpc/sysdev/fsl_rio.c:248: error: 'MCSR_MASK' undeclared
> > > (first use in this function)
> > > arch/powerpc/sysdev/fsl_rio.c:248: error: (Each undeclared
identifier
> > > is reported only once
> > > arch/powerpc/sysdev/fsl_rio.c:248: error: for each function it
appears
> > in.)
> > > make[1]: *** [arch/powerpc/sysdev/fsl_rio.o] Error 1
> > >=20
> > > --
> > > Timur Tabi
> > > Linux kernel developer at Freescale
> >
Kumar Gala - Aug. 5, 2010, 5:53 p.m.
On Aug 5, 2010, at 12:25 PM, Bounine, Alexandre wrote:

> Below is a copy of Leo's message with pointers to the patches.
> 
> Alex.
> 
>> Subject: [PATCH] RapidIO,powerpc/85xx: remove MCSR_MASK in fsl_rio
>> 
>> Fixes compile problem caused by MCSR_MASK removal from book-E
> definitions.
> 
> Hi Alex,
> 
> Only with your patch, there will still be problem on SRIO platforms
> other than MPC85xx.
> 
> I have posted a patch series to fix this together with several
> compatibility issues a month before.
> 
> http://patchwork.ozlabs.org/patch/56135/
> http://patchwork.ozlabs.org/patch/56136/
> http://patchwork.ozlabs.org/patch/56138/
> http://patchwork.ozlabs.org/patch/56137/
> 
> 
> Can anyone pick the patch series quickly as currently there is a compile
> error when SRIO is enabled.
> 
> - Leo

I'm looking at this now and wondering what we added the mcheck handler for in the first place and what its trying to accomplish.

- k
Bounine, Alexandre - Aug. 5, 2010, 6:17 p.m.
> I'm looking at this now and wondering what we added the mcheck handler
for in the first place and what
> its trying to accomplish.
> 
> - k

This protects system from hanging if RIO link fails or enters error
state. In some situations following maintenance read may initiate link
recovery from error state.

As it is now, MCheck mostly prevents system from hanging, but it also
adds sense to return status of maintenance read routine. I am using
return status in my new set of patches to check if RIO link is valid
during error recovery.

Alex.

Patch

diff -x '*.pj' -X dontdiff_2.6.32-rc5 -pNur w33a/arch/powerpc/sysdev/fsl_rio.c w33b/arch/powerpc/sysdev/fsl_rio.c
--- w33a/arch/powerpc/sysdev/fsl_rio.c	2010-03-08 10:38:10.121013000 -0500
+++ w33b/arch/powerpc/sysdev/fsl_rio.c	2010-03-08 11:23:03.274215000 -0500
@@ -31,6 +31,8 @@ 
 #include <linux/kfifo.h>
 
 #include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/uaccess.h>
 
 #undef DEBUG_PW	/* Port-Write debugging */
 
@@ -46,6 +48,8 @@ 
 #define RIO_ESCSR		0x158
 #define RIO_CCSR		0x15c
 #define RIO_LTLEDCSR		0x0608
+#define  RIO_LTLEDCSR_IER	0x80000000
+#define  RIO_LTLEDCSR_PRT	0x01000000
 #define RIO_LTLEECSR		0x060c
 #define RIO_EPWISR		0x10010
 #define RIO_ISR_AACR		0x10120
@@ -213,6 +217,54 @@  struct rio_priv {
 	spinlock_t pw_fifo_lock;
 };
 
+#define __fsl_read_rio_config(x, addr, err, op)		\
+	__asm__ __volatile__(				\
+		"1:	"op" %1,0(%2)\n"		\
+		"	eieio\n"			\
+		"2:\n"					\
+		".section .fixup,\"ax\"\n"		\
+		"3:	li %1,-1\n"			\
+		"	li %0,%3\n"			\
+		"	b 2b\n"				\
+		".section __ex_table,\"a\"\n"		\
+		"	.align 2\n"			\
+		"	.long 1b,3b\n"			\
+		".text"					\
+		: "=r" (err), "=r" (x)			\
+		: "b" (addr), "i" (-EFAULT), "0" (err))
+
+static void __iomem *rio_regs_win;
+
+static int (*saved_mcheck_exception)(struct pt_regs *regs);
+
+static int fsl_rio_mcheck_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *entry = NULL;
+	unsigned long reason = (mfspr(SPRN_MCSR) & MCSR_MASK);
+
+	if (reason & MCSR_BUS_RBERR) {
+		reason = in_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR));
+		if (reason & (RIO_LTLEDCSR_IER | RIO_LTLEDCSR_PRT)) {
+			/* Check if we are prepared to handle this fault */
+			entry = search_exception_tables(regs->nip);
+			if (entry) {
+				pr_debug("RIO: %s - MC Exception handled\n",
+					 __func__);
+				out_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR),
+					 0);
+				regs->msr |= MSR_RI;
+				regs->nip = entry->fixup;
+				return 1;
+			}
+		}
+	}
+
+	if (saved_mcheck_exception)
+		return saved_mcheck_exception(regs);
+	else
+		return cur_cpu_spec->machine_check(regs);
+}
+
 /**
  * fsl_rio_doorbell_send - Send a MPC85xx doorbell message
  * @mport: RapidIO master port info
@@ -313,6 +365,7 @@  fsl_rio_config_read(struct rio_mport *mp
 {
 	struct rio_priv *priv = mport->priv;
 	u8 *data;
+	u32 rval, err = 0;
 
 	pr_debug
 	    ("fsl_rio_config_read: index %d destid %d hopcount %d offset %8.8x len %d\n",
@@ -323,17 +376,24 @@  fsl_rio_config_read(struct rio_mport *mp
 	data = (u8 *) priv->maint_win + offset;
 	switch (len) {
 	case 1:
-		*val = in_8((u8 *) data);
+		__fsl_read_rio_config(rval, data, err, "lbz");
 		break;
 	case 2:
-		*val = in_be16((u16 *) data);
+		__fsl_read_rio_config(rval, data, err, "lhz");
 		break;
 	default:
-		*val = in_be32((u32 *) data);
+		__fsl_read_rio_config(rval, data, err, "lwz");
 		break;
 	}
 
-	return 0;
+	if (err) {
+		pr_debug("RIO: cfg_read error %d for %x:%x:%x\n",
+			 err, destid, hopcount, offset);
+	}
+
+	*val = rval;
+
+	return err;
 }
 
 /**
@@ -1364,6 +1424,7 @@  int fsl_rio_setup(struct of_device *dev)
 	rio_register_mport(port);
 
 	priv->regs_win = ioremap(regs.start, regs.end - regs.start + 1);
+	rio_regs_win = priv->regs_win;
 
 	/* Probe the master port phy type */
 	ccsr = in_be32(priv->regs_win + RIO_CCSR);
@@ -1432,6 +1493,11 @@  int fsl_rio_setup(struct of_device *dev)
 	fsl_rio_doorbell_init(port);
 	fsl_rio_port_write_init(port);
 
+	saved_mcheck_exception = ppc_md.machine_check_exception;
+	ppc_md.machine_check_exception = fsl_rio_mcheck_exception;
+	/* Ensure that RFXE is set */
+	mtspr(SPRN_HID1, (mfspr(SPRN_HID1) | 0x20000));
+
 	return 0;
 err:
 	iounmap(priv->regs_win);