From 8191c9f69202d4dbc66063cb92059b8a58640d34 Mon Sep 17 00:00:00 2001 From: Dimitri Sivanich Date: Tue, 16 Nov 2010 16:23:52 -0600 Subject: x86: UV: Address interrupt/IO port operation conflict This patch for SGI UV systems addresses a problem whereby interrupt transactions being looped back from a local IOH, through the hub to a local CPU can (erroneously) conflict with IO port operations and other transactions. To workaound this we set a high bit in the APIC IDs used for interrupts. This bit appears to be ignored by the sockets, but it avoids the conflict in the hub. Signed-off-by: Dimitri Sivanich LKML-Reference: <20101116222352.GA8155@sgi.com> Signed-off-by: Ingo Molnar ___ arch/x86/include/asm/uv/uv_hub.h | 4 ++++ arch/x86/include/asm/uv/uv_mmrs.h | 19 ++++++++++++++++++- arch/x86/kernel/apic/x2apic_uv_x.c | 25 +++++++++++++++++++++++-- arch/x86/platform/uv/tlb_uv.c | 2 +- arch/x86/platform/uv/uv_time.c | 4 +++- 5 files changed, 49 insertions(+), 5 deletions(-) --- arch/x86/include/asm/uv/uv_hub.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/include/asm/uv/uv_hub.h') diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h index e969f691cbfd..a501741c2335 100644 --- a/arch/x86/include/asm/uv/uv_hub.h +++ b/arch/x86/include/asm/uv/uv_hub.h @@ -199,6 +199,8 @@ union uvh_apicid { #define UVH_APICID 0x002D0E00L #define UV_APIC_PNODE_SHIFT 6 +#define UV_APICID_HIBIT_MASK 0xffff0000 + /* Local Bus from cpu's perspective */ #define LOCAL_BUS_BASE 0x1c00000 #define LOCAL_BUS_SIZE (4 * 1024 * 1024) @@ -491,8 +493,10 @@ static inline void uv_set_cpu_scir_bits(int cpu, unsigned char value) } } +extern unsigned int uv_apicid_hibits; static unsigned long uv_hub_ipi_value(int apicid, int vector, int mode) { + apicid |= uv_apicid_hibits; return (1UL << UVH_IPI_INT_SEND_SHFT) | ((apicid) << UVH_IPI_INT_APIC_ID_SHFT) | (mode << UVH_IPI_INT_DELIVERY_MODE_SHFT) | -- cgit v1.2.3