[SPARC64]: Sun4v interrupt handling.

Sun4v has 4 interrupt queues: cpu, device, resumable errors,
and non-resumable errors.  A set of head/tail offset pointers
help maintain a work queue in physical memory.  The entries
are 64-bytes in size.

Each queue is allocated then registered with the hypervisor
as we bring cpus up.

The two error queues each get a kernel side buffer that we
use to quickly empty the main interrupt queue before we
call up to C code to log the event and possibly take evasive
action.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 184 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c
index 8f3fce24359d..5417ff1b9345 100644
--- a/arch/sparc64/kernel/traps.c
+++ b/arch/sparc64/kernel/traps.c
@@ -1668,6 +1668,186 @@ void cheetah_plus_parity_error(int type, struct pt_regs *regs)
                regs->tpc);
 }
 
+struct sun4v_error_entry {
+        u64             err_handle;
+        u64             err_stick;
+
+        u32             err_type;
+#define SUN4V_ERR_TYPE_UNDEFINED        0
+#define SUN4V_ERR_TYPE_UNCORRECTED_RES  1
+#define SUN4V_ERR_TYPE_PRECISE_NONRES   2
+#define SUN4V_ERR_TYPE_DEFERRED_NONRES  3
+#define SUN4V_ERR_TYPE_WARNING_RES      4
+
+        u32             err_attrs;
+#define SUN4V_ERR_ATTRS_PROCESSOR       0x00000001
+#define SUN4V_ERR_ATTRS_MEMORY          0x00000002
+#define SUN4V_ERR_ATTRS_PIO             0x00000004
+#define SUN4V_ERR_ATTRS_INT_REGISTERS   0x00000008
+#define SUN4V_ERR_ATTRS_FPU_REGISTERS   0x00000010
+#define SUN4V_ERR_ATTRS_USER_MODE       0x01000000
+#define SUN4V_ERR_ATTRS_PRIV_MODE       0x02000000
+#define SUN4V_ERR_ATTRS_RES_QUEUE_FULL  0x80000000
+
+        u64             err_raddr;
+        u32             err_size;
+        u16             err_cpu;
+        u16             err_pad;
+};
+
+static atomic_t sun4v_resum_oflow_cnt = ATOMIC_INIT(0);
+static atomic_t sun4v_nonresum_oflow_cnt = ATOMIC_INIT(0);
+
+static const char *sun4v_err_type_to_str(u32 type)
+{
+        switch (type) {
+        case SUN4V_ERR_TYPE_UNDEFINED:
+                return "undefined";
+        case SUN4V_ERR_TYPE_UNCORRECTED_RES:
+                return "uncorrected resumable";
+        case SUN4V_ERR_TYPE_PRECISE_NONRES:
+                return "precise nonresumable";
+        case SUN4V_ERR_TYPE_DEFERRED_NONRES:
+                return "deferred nonresumable";
+        case SUN4V_ERR_TYPE_WARNING_RES:
+                return "warning resumable";
+        default:
+                return "unknown";
+        };
+}
+
+static void sun4v_log_error(struct sun4v_error_entry *ent, int cpu, const char *pfx, atomic_t *ocnt)
+{
+        int cnt;
+
+        printk("%s: Reporting on cpu %d\n", pfx, cpu);
+        printk("%s: err_handle[%lx] err_stick[%lx] err_type[%08x:%s]\n",
+               pfx,
+               ent->err_handle, ent->err_stick,
+               ent->err_type,
+               sun4v_err_type_to_str(ent->err_type));
+        printk("%s: err_attrs[%08x:%s %s %s %s %s %s %s %s]\n",
+               pfx,
+               ent->err_attrs,
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_PROCESSOR) ?
+                "processor" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_MEMORY) ?
+                "memory" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_PIO) ?
+                "pio" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_INT_REGISTERS) ?
+                "integer-regs" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_FPU_REGISTERS) ?
+                "fpu-regs" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_USER_MODE) ?
+                "user" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_PRIV_MODE) ?
+                "privileged" : ""),
+               ((ent->err_attrs & SUN4V_ERR_ATTRS_RES_QUEUE_FULL) ?
+                "queue-full" : ""));
+        printk("%s: err_raddr[%016lx] err_size[%u] err_cpu[%u]\n",
+               pfx,
+               ent->err_raddr, ent->err_size, ent->err_cpu);
+
+        if ((cnt = atomic_read(ocnt)) != 0) {
+                atomic_set(ocnt, 0);
+                wmb();
+                printk("%s: Queue overflowed %d times.\n",
+                       pfx, cnt);
+        }
+}
+
+/* We run with %pil set to 15 and PSTATE_IE enabled in %pstate.
+ * Log the event and clear the first word of the entry.
+ */
+void sun4v_resum_error(struct pt_regs *regs, unsigned long offset)
+{
+        struct sun4v_error_entry *ent, local_copy;
+        struct trap_per_cpu *tb;
+        unsigned long paddr;
+        int cpu;
+
+        cpu = get_cpu();
+
+        tb = &trap_block[cpu];
+        paddr = tb->resum_kernel_buf_pa + offset;
+        ent = __va(paddr);
+
+        memcpy(&local_copy, ent, sizeof(struct sun4v_error_entry));
+
+        /* We have a local copy now, so release the entry.  */
+        ent->err_handle = 0;
+        wmb();
+
+        put_cpu();
+
+        sun4v_log_error(&local_copy, cpu,
+                        KERN_ERR "RESUMABLE ERROR",
+                        &sun4v_resum_oflow_cnt);
+}
+
+/* If we try to printk() we'll probably make matters worse, by trying
+ * to retake locks this cpu already holds or causing more errors. So
+ * just bump a counter, and we'll report these counter bumps above.
+ */
+void sun4v_resum_overflow(struct pt_regs *regs)
+{
+        atomic_inc(&sun4v_resum_oflow_cnt);
+}
+
+/* We run with %pil set to 15 and PSTATE_IE enabled in %pstate.
+ * Log the event, clear the first word of the entry, and die.
+ */
+void sun4v_nonresum_error(struct pt_regs *regs, unsigned long offset)
+{
+        struct sun4v_error_entry *ent, local_copy;
+        struct trap_per_cpu *tb;
+        unsigned long paddr;
+        int cpu;
+
+        cpu = get_cpu();
+
+        tb = &trap_block[cpu];
+        paddr = tb->nonresum_kernel_buf_pa + offset;
+        ent = __va(paddr);
+
+        memcpy(&local_copy, ent, sizeof(struct sun4v_error_entry));
+
+        /* We have a local copy now, so release the entry.  */
+        ent->err_handle = 0;
+        wmb();
+
+        put_cpu();
+
+#ifdef CONFIG_PCI
+        /* Check for the special PCI poke sequence. */
+        if (pci_poke_in_progress && pci_poke_cpu == cpu) {
+                pci_poke_faulted = 1;
+                regs->tpc += 4;
+                regs->tnpc = regs->tpc + 4;
+                return;
+        }
+#endif
+
+        sun4v_log_error(&local_copy, cpu,
+                        KERN_EMERG "NON-RESUMABLE ERROR",
+                        &sun4v_nonresum_oflow_cnt);
+
+        panic("Non-resumable error.");
+}
+
+/* If we try to printk() we'll probably make matters worse, by trying
+ * to retake locks this cpu already holds or causing more errors. So
+ * just bump a counter, and we'll report these counter bumps above.
+ */
+void sun4v_nonresum_overflow(struct pt_regs *regs)
+{
+        /* XXX Actually even this can make not that much sense.  Perhaps
+         * XXX we should just pull the plug and panic directly from here?
+         */
+        atomic_inc(&sun4v_nonresum_oflow_cnt);
+}
+
 void do_fpe_common(struct pt_regs *regs)
 {
         if (regs->tstate & TSTATE_PRIV) {
@@ -2190,8 +2370,12 @@ void __init trap_init(void)
              offsetof(struct trap_per_cpu, dev_mondo_pa)) ||
             (TRAP_PER_CPU_RESUM_MONDO_PA !=
              offsetof(struct trap_per_cpu, resum_mondo_pa)) ||
+            (TRAP_PER_CPU_RESUM_KBUF_PA !=
+             offsetof(struct trap_per_cpu, resum_kernel_buf_pa)) ||
             (TRAP_PER_CPU_NONRESUM_MONDO_PA !=
              offsetof(struct trap_per_cpu, nonresum_mondo_pa)) ||
+            (TRAP_PER_CPU_NONRESUM_KBUF_PA !=
+             offsetof(struct trap_per_cpu, nonresum_kernel_buf_pa)) ||
             (TRAP_PER_CPU_FAULT_INFO !=
              offsetof(struct trap_per_cpu, fault_info)))
                 trap_per_cpu_offsets_are_bolixed_dave();