From 3addf55c9415f9da039947b33d064332137e49fe Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 23 Aug 2007 03:01:26 +1000 Subject: [PATCH] [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 -- Signed-off-by: Paul Mackerras --- 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 17d597144877..b24025f2ac7a 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 812bf563ed65..4ede22d363fa 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(®s->pmcr, in_be64(®s->pmcr) | CBE_PMD_PAUSE_ZERO_CONTROL); + + /* Enable JTAG system-reset hack */ + if (sysreset_hack) + out_be32(®s->fir_mode_reg, + in_be32(®s->fir_mode_reg) | + CBE_PMD_FIR_MODE_M8); } ppc_md.power_save = cbe_power_save; -- 2.20.1