[POWERPC] cell: Support pinhole-reset on IBM cell blades

[Linux Kernel Mailing List]

Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3addf55c9415f9da039947b33d064332137e49fe
Commit:     3addf55c9415f9da039947b33d064332137e49fe
Parent:     fa7f374bbf6d8e5fc7dd281a62498041066aaf43
Author:     Arnd Bergmann <[EMAIL PROTECTED]>
AuthorDate: Thu Aug 23 03:01:26 2007 +1000
Committer:  Paul Mackerras <[EMAIL PROTECTED]>
CommitDate: Sat Aug 25 16:58:26 2007 +1000

    [POWERPC] cell: Support pinhole-reset on IBM cell blades
    
    The Cell Broadband Engine has a method of injecting a
    system-reset-exception from an external source into the
    operating system, which should trigger the regular behaviour
    of entering xmon or kdump.
    
    Unfortunately, the exception handler cannot distinguish it from
    other interrupt causes by the SRR1 register, which gets used
    for this on Power 6 and others.
    
    IBM Blade servers that want to support triggering the
    system reset exception using a pinhole button in the front
    panel therefore use an extra register to determine the
    reset cause.
    
    Signed-off-by: Arnd Bergmann <[EMAIL PROTECTED]>
    
    --
    Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]>
---
 arch/powerpc/platforms/cell/cbe_regs.h  |    8 ++++++--
 arch/powerpc/platforms/cell/pervasive.c |   26 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/cell/cbe_regs.h 
b/arch/powerpc/platforms/cell/cbe_regs.h
index 17d5971..b24025f 100644
--- a/arch/powerpc/platforms/cell/cbe_regs.h
+++ b/arch/powerpc/platforms/cell/cbe_regs.h
@@ -113,10 +113,14 @@ struct cbe_pmd_regs {
        u64     checkstop_fir;                                  /* 0x0c00 */
        u64     recoverable_fir;                                /* 0x0c08 */
        u64     spec_att_mchk_fir;                              /* 0x0c10 */
-       u64     fir_mode_reg;                                   /* 0x0c18 */
+       u32     fir_mode_reg;                                   /* 0x0c18 */
+       u8      pad_0x0c1c_0x0c20 [4];                          /* 0x0c1c */
+#define CBE_PMD_FIR_MODE_M8            0x00800
        u64     fir_enable_mask;                                /* 0x0c20 */
 
-       u8      pad_0x0c28_0x1000 [0x1000 - 0x0c28];            /* 0x0c28 */
+       u8      pad_0x0c28_0x0ca8 [0x0ca8 - 0x0c28];            /* 0x0c28 */
+       u64     ras_esc_0;                                      /* 0x0ca8 */
+       u8      pad_0x0cb0_0x1000 [0x1000 - 0x0cb0];            /* 0x0cb0 */
 };
 
 extern struct cbe_pmd_regs __iomem *cbe_get_pmd_regs(struct device_node *np);
diff --git a/arch/powerpc/platforms/cell/pervasive.c 
b/arch/powerpc/platforms/cell/pervasive.c
index 812bf56..4ede22d 100644
--- a/arch/powerpc/platforms/cell/pervasive.c
+++ b/arch/powerpc/platforms/cell/pervasive.c
@@ -38,6 +38,8 @@
 #include "pervasive.h"
 #include "cbe_regs.h"
 
+static int sysreset_hack;
+
 static void cbe_power_save(void)
 {
        unsigned long ctrl, thread_switch_control;
@@ -85,6 +87,9 @@ static void cbe_power_save(void)
 
 static int cbe_system_reset_exception(struct pt_regs *regs)
 {
+       int cpu;
+       struct cbe_pmd_regs __iomem *pmd;
+
        switch (regs->msr & SRR1_WAKEMASK) {
        case SRR1_WAKEEE:
                do_IRQ(regs);
@@ -93,6 +98,18 @@ static int cbe_system_reset_exception(struct pt_regs *regs)
                timer_interrupt(regs);
                break;
        case SRR1_WAKEMT:
+               /*
+                * The BMC can inject user triggered system reset exceptions,
+                * but cannot set the system reset reason in srr1,
+                * so check an extra register here.
+                */
+               if (sysreset_hack && (cpu = smp_processor_id()) == 0) {
+                       pmd = cbe_get_cpu_pmd_regs(cpu);
+                       if (in_be64(&pmd->ras_esc_0) & 0xffff) {
+                               out_be64(&pmd->ras_esc_0, 0);
+                               return 0;
+                       }
+               }
                break;
 #ifdef CONFIG_CBE_RAS
        case SRR1_WAKESYSERR:
@@ -113,9 +130,12 @@ static int cbe_system_reset_exception(struct pt_regs *regs)
 void __init cbe_pervasive_init(void)
 {
        int cpu;
+
        if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
                return;
 
+       sysreset_hack = machine_is_compatible("IBM,CBPLUS-1.0");
+
        for_each_possible_cpu(cpu) {
                struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu);
                if (!regs)
@@ -124,6 +144,12 @@ void __init cbe_pervasive_init(void)
                 /* Enable Pause(0) control bit */
                out_be64(&regs->pmcr, in_be64(&regs->pmcr) |
                                            CBE_PMD_PAUSE_ZERO_CONTROL);
+
+               /* Enable JTAG system-reset hack */
+               if (sysreset_hack)
+                       out_be32(&regs->fir_mode_reg,
+                               in_be32(&regs->fir_mode_reg) |
+                               CBE_PMD_FIR_MODE_M8);
        }
 
        ppc_md.power_save = cbe_power_save;
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html