x86: UV BAU messaging timeouts

This patch replaces a 'nop' uv_enable_timeouts() in the
UV TLB shootdown code. (somehow, long ago that function got
eviscerated)

If any cpu in the destination node does not get interrupted by the
message and post completion in a reasonable time the hardware
should respond to the sender with an error.  This function
enables such timeouts.

Tested on the UV hardware simulator.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
LKML-Reference: <E1LpjXU-00007e-Qh@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/include/asm/uv/uv_mmrs.h b/arch/x86/include/asm/uv/uv_mmrs.h
index db68ac8..2cae46c 100644 (file)
--- a/arch/x86/include/asm/uv/uv_mmrs.h
+++ b/arch/x86/include/asm/uv/uv_mmrs.h
@@ -17,6 +17,11 @@
 /* ========================================================================= */
 /*                           UVH_BAU_DATA_CONFIG                             */
 /* ========================================================================= */
+#define UVH_LB_BAU_MISC_CONTROL 0x320170UL
+#define UV_ENABLE_INTD_SOFT_ACK_MODE_SHIFT 15
+#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHIFT 16
+#define UV_INTD_SOFT_ACK_TIMEOUT_PERIOD 0x000000000bUL
+/* 1011 timebase 7 (168millisec) * 3 ticks -> 500ms */
 #define UVH_BAU_DATA_CONFIG 0x61680UL
 #define UVH_BAU_DATA_CONFIG_32 0x0438
 

diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index b833bc6..fced96e 100644 (file)
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -445,24 +445,58 @@ void uv_bau_message_interrupt(struct pt_regs *regs)
        set_irq_regs(old_regs);
 }
 
+/*
+ * uv_enable_timeouts
+ *
+ * Each target blade (i.e. blades that have cpu's) needs to have
+ * shootdown message timeouts enabled.  The timeout does not cause
+ * an interrupt, but causes an error message to be returned to
+ * the sender.
+ */
 static void uv_enable_timeouts(void)
 {
-       int i;
        int blade;
-       int last_blade;
+       int nblades;
        int pnode;
-       int cur_cpu = 0;
-       unsigned long apicid;
+       unsigned long mmr_image;
+
+       nblades = uv_num_possible_blades();
 
-       last_blade = -1;
-       for_each_online_node(i) {
-               blade = uv_node_to_blade_id(i);
-               if (blade == last_blade)
+       for (blade = 0; blade < nblades; blade++) {
+               if (!uv_blade_nr_possible_cpus(blade))
                        continue;
-               last_blade = blade;
-               apicid = per_cpu(x86_cpu_to_apicid, cur_cpu);
+
                pnode = uv_blade_to_pnode(blade);
-               cur_cpu += uv_blade_nr_possible_cpus(i);
+               mmr_image =
+                   uv_read_global_mmr64(pnode, UVH_LB_BAU_MISC_CONTROL);
+               /*
+                * Set the timeout period and then lock it in, in three
+                * steps; captures and locks in the period.
+                *
+                * To program the period, the SOFT_ACK_MODE must be off.
+                */
+               mmr_image &= ~((unsigned long)1 <<
+                              UV_ENABLE_INTD_SOFT_ACK_MODE_SHIFT);
+               uv_write_global_mmr64
+                   (pnode, UVH_LB_BAU_MISC_CONTROL, mmr_image);
+               /*
+                * Set the 4-bit period.
+                */
+               mmr_image &= ~((unsigned long)0xf <<
+                       UV_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHIFT);
+               mmr_image |= (UV_INTD_SOFT_ACK_TIMEOUT_PERIOD <<
+                            UV_INTD_SOFT_ACK_TIMEOUT_PERIOD_SHIFT);
+               uv_write_global_mmr64
+                   (pnode, UVH_LB_BAU_MISC_CONTROL, mmr_image);
+               /*
+                * Subsequent reversals of the timebase bit (3) cause an
+                * immediate timeout of one or all INTD resources as
+                * indicated in bits 2:0 (7 causes all of them to timeout).
+                */
+               mmr_image |= ((unsigned long)1 <<
+                             UV_ENABLE_INTD_SOFT_ACK_MODE_SHIFT);
+               uv_write_global_mmr64
+                   (pnode, UVH_LB_BAU_MISC_CONTROL, mmr_image);
        }
 }