[tip:x86/uv] x86: UV BAU messaging timeouts

From: Cliff Wickman
Date: Fri Apr 03 2009 - 12:28:54 EST


Commit-ID: c4c4688f72e638708e5f6b5c259699de82a36fec
Gitweb: http://git.kernel.org/tip/c4c4688f72e638708e5f6b5c259699de82a36fec
Author: Cliff Wickman <cpw@xxxxxxx>
AuthorDate: Fri, 3 Apr 2009 08:34:32 -0500
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 3 Apr 2009 18:25:27 +0200

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@xxxxxxx>
LKML-Reference: <E1LpjXU-00007e-Qh@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
arch/x86/include/asm/uv/uv_mmrs.h | 5 +++
arch/x86/kernel/tlb_uv.c | 56 +++++++++++++++++++++++++++++-------
2 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/uv/uv_mmrs.h b/arch/x86/include/asm/uv/uv_mmrs.h
index db68ac8..2cae46c 100644
--- 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
--- 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);
}
}

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