rapidio, powerpc/85xx: Add MChk handler for SRIO port

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>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index 73d5f3e..4646cc7 100644 (file)
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -32,6 +32,8 @@
 #include <linux/kfifo.h>
 
 #include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/uaccess.h>
 
 #undef DEBUG_PW        /* Port-Write debugging */
 
@@ -47,6 +49,8 @@
 #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
@@ -214,6 +218,54 @@ 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
@@ -314,6 +366,7 @@ fsl_rio_config_read(struct rio_mport *mport, int index, u16 destid,
 {
        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",
@@ -324,17 +377,24 @@ fsl_rio_config_read(struct rio_mport *mport, int index, u16 destid,
        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;
 }
 
 /**
@@ -1365,6 +1425,7 @@ 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);
@@ -1433,6 +1494,11 @@ 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);