13 files changed, 139 insertions, 3 deletions

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 13a63379e496..77f52b26dad6 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -425,6 +425,8 @@ label##_relon_hv:						\
 #define SOFTEN_VALUE_0xa00      PACA_IRQ_DBELL
 #define SOFTEN_VALUE_0xe80      PACA_IRQ_DBELL
 #define SOFTEN_VALUE_0xe82      PACA_IRQ_DBELL
+#define SOFTEN_VALUE_0xe60      PACA_IRQ_HMI
+#define SOFTEN_VALUE_0xe62      PACA_IRQ_HMI
 
 #define __SOFTEN_TEST(h, vec)                                           \
         lbz     r10,PACASOFTIRQEN(r13);                                 \
diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index 418fb654370d..1bbb3013d6aa 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h
@@ -11,6 +11,7 @@ typedef struct {
         unsigned int pmu_irqs;
         unsigned int mce_exceptions;
         unsigned int spurious_irqs;
+        unsigned int hmi_exceptions;
 #ifdef CONFIG_PPC_DOORBELL
         unsigned int doorbell_irqs;
 #endif
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 10be1dd01c6b..b59ac27a6b7d 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -25,6 +25,7 @@
 #define PACA_IRQ_EE             0x04
 #define PACA_IRQ_DEC            0x08 /* Or FIT */
 #define PACA_IRQ_EE_EDGE        0x10 /* BookE only */
+#define PACA_IRQ_HMI            0x20
 
 #endif /* CONFIG_PPC64 */
 
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index 9601741080e5..ecf7e133a4f2 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -98,6 +98,7 @@
 #define BOOK3S_INTERRUPT_H_DATA_STORAGE 0xe00
 #define BOOK3S_INTERRUPT_H_INST_STORAGE 0xe20
 #define BOOK3S_INTERRUPT_H_EMUL_ASSIST  0xe40
+#define BOOK3S_INTERRUPT_HMI            0xe60
 #define BOOK3S_INTERRUPT_H_DOORBELL     0xe80
 #define BOOK3S_INTERRUPT_PERFMON        0xf00
 #define BOOK3S_INTERRUPT_ALTIVEC        0xf20
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 5c7e74ddee4c..44e90516519b 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -174,6 +174,10 @@ struct machdep_calls {
         /* Exception handlers */
         int             (*system_reset_exception)(struct pt_regs *regs);
         int             (*machine_check_exception)(struct pt_regs *regs);
+        int             (*handle_hmi_exception)(struct pt_regs *regs);
+
+        /* Early exception handlers called in realmode */
+        int             (*hmi_exception_early)(struct pt_regs *regs);
 
         /* Called during machine check exception to retrive fixup address. */
         bool            (*mce_check_early_recovery)(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 7f5fd5396261..efc16c37b959 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -915,6 +915,8 @@ extern void opal_msglog_init(void);
 
 extern int opal_machine_check(struct pt_regs *regs);
 extern bool opal_mce_check_early_recovery(struct pt_regs *regs);
+extern int opal_hmi_exception_early(struct pt_regs *regs);
+extern int opal_handle_hmi_exception(struct pt_regs *regs);
 
 extern void opal_shutdown(void);
 extern int opal_resync_timebase(void);
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d6b22e8c8ee1..5bbd1bc8c3b0 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -915,6 +915,11 @@ restore_check_irq_replay:
         addi    r3,r1,STACK_FRAME_OVERHEAD;
         bl      do_IRQ
         b       ret_from_except
+1:      cmpwi   cr0,r3,0xe60
+        bne     1f
+        addi    r3,r1,STACK_FRAME_OVERHEAD;
+        bl      handle_hmi_exception
+        b       ret_from_except
 1:      cmpwi   cr0,r3,0x900
         bne     1f
         addi    r3,r1,STACK_FRAME_OVERHEAD;
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index f521b2dac051..6144d5a6bfe7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -335,7 +335,7 @@ emulation_assist_trampoline:
 hv_exception_trampoline:
         SET_SCRATCH0(r13)
         EXCEPTION_PROLOG_0(PACA_EXGEN)
-        b       hmi_exception_hv
+        b       hmi_exception_early
 
         . = 0xe80
 hv_doorbell_trampoline:
@@ -589,8 +589,64 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
         KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe22)
         STD_EXCEPTION_HV_OOL(0xe42, emulation_assist)
         KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe42)
-        STD_EXCEPTION_HV_OOL(0xe62, hmi_exception) /* need to flush cache ? */
+        MASKABLE_EXCEPTION_HV_OOL(0xe62, hmi_exception)
         KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe62)
+
+        .globl hmi_exception_early
+hmi_exception_early:
+        EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0xe60)
+        mr      r10,r1                  /* Save r1                      */
+        ld      r1,PACAEMERGSP(r13)     /* Use emergency stack          */
+        subi    r1,r1,INT_FRAME_SIZE    /* alloc stack frame            */
+        std     r9,_CCR(r1)             /* save CR in stackframe        */
+        mfspr   r11,SPRN_HSRR0          /* Save HSRR0 */
+        std     r11,_NIP(r1)            /* save HSRR0 in stackframe     */
+        mfspr   r12,SPRN_HSRR1          /* Save SRR1 */
+        std     r12,_MSR(r1)            /* save SRR1 in stackframe      */
+        std     r10,0(r1)               /* make stack chain pointer     */
+        std     r0,GPR0(r1)             /* save r0 in stackframe        */
+        std     r10,GPR1(r1)            /* save r1 in stackframe        */
+        EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN)
+        EXCEPTION_PROLOG_COMMON_3(0xe60)
+        addi    r3,r1,STACK_FRAME_OVERHEAD
+        bl      hmi_exception_realmode
+        /* Windup the stack. */
+        /* Clear MSR_RI before setting SRR0 and SRR1. */
+        li      r0,MSR_RI
+        mfmsr   r9                      /* get MSR value */
+        andc    r9,r9,r0
+        mtmsrd  r9,1                    /* Clear MSR_RI */
+        /* Move original HSRR0 and HSRR1 into the respective regs */
+        ld      r9,_MSR(r1)
+        mtspr   SPRN_HSRR1,r9
+        ld      r3,_NIP(r1)
+        mtspr   SPRN_HSRR0,r3
+        ld      r9,_CTR(r1)
+        mtctr   r9
+        ld      r9,_XER(r1)
+        mtxer   r9
+        ld      r9,_LINK(r1)
+        mtlr    r9
+        REST_GPR(0, r1)
+        REST_8GPRS(2, r1)
+        REST_GPR(10, r1)
+        ld      r11,_CCR(r1)
+        mtcr    r11
+        REST_GPR(11, r1)
+        REST_2GPRS(12, r1)
+        /* restore original r1. */
+        ld      r1,GPR1(r1)
+
+        /*
+         * Go to virtual mode and pull the HMI event information from
+         * firmware.
+         */
+        .globl hmi_exception_after_realmode
+hmi_exception_after_realmode:
+        SET_SCRATCH0(r13)
+        EXCEPTION_PROLOG_0(PACA_EXGEN)
+        b       hmi_exception_hv
+
         MASKABLE_EXCEPTION_HV_OOL(0xe82, h_doorbell)
         KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe82)
 
@@ -611,6 +667,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
  * - If it was a decrementer interrupt, we bump the dec to max and and return.
  * - If it was a doorbell we return immediately since doorbells are edge
  *   triggered and won't automatically refire.
+ * - If it was a HMI we return immediately since we handled it in realmode
+ *   and it won't refire.
  * - else we hard disable and return.
  * This is called with r10 containing the value to OR to the paca field.
  */
@@ -628,6 +686,8 @@ masked_##_H##interrupt:					\
         b       2f;                                     \
 1:      cmpwi   r10,PACA_IRQ_DBELL;                     \
         beq     2f;                                     \
+        cmpwi   r10,PACA_IRQ_HMI;                       \
+        beq     2f;                                     \
         mfspr   r10,SPRN_##_H##SRR1;                    \
         rldicl  r10,r10,48,1; /* clear MSR_EE */        \
         rotldi  r10,r10,16;                             \
@@ -767,7 +827,7 @@ kvmppc_skip_Hinterrupt:
         STD_EXCEPTION_COMMON(0xd00, single_step, single_step_exception)
         STD_EXCEPTION_COMMON(0xe00, trap_0e, unknown_exception)
         STD_EXCEPTION_COMMON(0xe40, emulation_assist, emulation_assist_interrupt)
-        STD_EXCEPTION_COMMON(0xe60, hmi_exception, unknown_exception)
+        STD_EXCEPTION_COMMON_ASYNC(0xe60, hmi_exception, handle_hmi_exception)
 #ifdef CONFIG_PPC_DOORBELL
         STD_EXCEPTION_COMMON_ASYNC(0xe80, h_doorbell, doorbell_exception)
 #else
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 248ee7e5bebd..4c5891de162e 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -189,6 +189,11 @@ notrace unsigned int __check_irq_replay(void)
         }
 #endif /* CONFIG_PPC_BOOK3E */
 
+        /* Check if an hypervisor Maintenance interrupt happened */
+        local_paca->irq_happened &= ~PACA_IRQ_HMI;
+        if (happened & PACA_IRQ_HMI)
+                return 0xe60;
+
         /* There should be nothing left ! */
         BUG_ON(local_paca->irq_happened != 0);
 
@@ -377,6 +382,14 @@ int arch_show_interrupts(struct seq_file *p, int prec)
                 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
         seq_printf(p, "  Machine check exceptions\n");
 
+        if (cpu_has_feature(CPU_FTR_HVMODE)) {
+                seq_printf(p, "%*s: ", prec, "HMI");
+                for_each_online_cpu(j)
+                        seq_printf(p, "%10u ",
+                                        per_cpu(irq_stat, j).hmi_exceptions);
+                seq_printf(p, "  Hypervisor Maintenance Interrupts\n");
+        }
+
 #ifdef CONFIG_PPC_DOORBELL
         if (cpu_has_feature(CPU_FTR_DBELL)) {
                 seq_printf(p, "%*s: ", prec, "DBL");
@@ -400,6 +413,7 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
         sum += per_cpu(irq_stat, cpu).mce_exceptions;
         sum += per_cpu(irq_stat, cpu).spurious_irqs;
         sum += per_cpu(irq_stat, cpu).timer_irqs_others;
+        sum += per_cpu(irq_stat, cpu).hmi_exceptions;
 #ifdef CONFIG_PPC_DOORBELL
         sum += per_cpu(irq_stat, cpu).doorbell_irqs;
 #endif
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index cb9cfe448ee8..0dc43f9932cf 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -302,6 +302,16 @@ long machine_check_early(struct pt_regs *regs)
         return handled;
 }
 
+long hmi_exception_realmode(struct pt_regs *regs)
+{
+        __get_cpu_var(irq_stat).hmi_exceptions++;
+
+        if (ppc_md.hmi_exception_early)
+                ppc_md.hmi_exception_early(regs);
+
+        return 0;
+}
+
 #endif
 
 /*
@@ -738,6 +748,20 @@ void SMIException(struct pt_regs *regs)
         die("System Management Interrupt", regs, SIGABRT);
 }
 
+void handle_hmi_exception(struct pt_regs *regs)
+{
+        struct pt_regs *old_regs;
+
+        old_regs = set_irq_regs(regs);
+        irq_enter();
+
+        if (ppc_md.handle_hmi_exception)
+                ppc_md.handle_hmi_exception(regs);
+
+        irq_exit();
+        set_irq_regs(old_regs);
+}
+
 void unknown_exception(struct pt_regs *regs)
 {
         enum ctx_state prev_state = exception_enter();
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 868347ef09fd..0de9309b9a55 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -159,6 +159,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
         cmpwi   r12, BOOK3S_INTERRUPT_EXTERNAL
 BEGIN_FTR_SECTION
         beq     11f
+        cmpwi   cr2, r12, BOOK3S_INTERRUPT_HMI
+        beq     cr2, 14f                        /* HMI check */
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
 
         /* RFI into the highmem handler, or branch to interrupt handler */
@@ -179,6 +181,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
 
 13:     b       machine_check_fwnmi
 
+14:     mtspr   SPRN_HSRR0, r8
+        mtspr   SPRN_HSRR1, r7
+        b       hmi_exception_after_realmode
+
 kvmppc_primary_no_guest:
         /* We handle this much like a ceded vcpu */
         /* set our bit in napping_threads */
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 6ef2e5c5bc64..d20d69921376 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -514,6 +514,20 @@ int opal_machine_check(struct pt_regs *regs)
         return 0;
 }
 
+/* Early hmi handler called in real mode. */
+int opal_hmi_exception_early(struct pt_regs *regs)
+{
+        /* TODO: Call opal hmi handler. */
+        return 0;
+}
+
+/* HMI exception handler called in virtual mode during check_irq_replay. */
+int opal_handle_hmi_exception(struct pt_regs *regs)
+{
+        /* TODO: Retrive and print HMI event from OPAL. */
+        return 0;
+}
+
 static uint64_t find_recovery_address(uint64_t nip)
 {
         int i;
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index d9b88fa7c5a3..5a0e2dc6de5f 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -264,6 +264,8 @@ static void __init pnv_setup_machdep_opal(void)
         ppc_md.halt = pnv_halt;
         ppc_md.machine_check_exception = opal_machine_check;
         ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
+        ppc_md.hmi_exception_early = opal_hmi_exception_early;
+        ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
 }
 
 #ifdef CONFIG_PPC_POWERNV_RTAS