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

From: Alexandre Bounine
Date: Mon Mar 08 2010 - 14:10:31 EST



From: Alexandre Bounine <alexandre.bounine@xxxxxxx>

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

Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Tested-by: Thomas Moll <thomas.moll@xxxxxxxxx>
---

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

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);

---

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