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Subject[tip:x86/urgent] x86: UV: Address interrupt/IO port operation conflict
Commit-ID:  8191c9f69202d4dbc66063cb92059b8a58640d34
Gitweb: http://git.kernel.org/tip/8191c9f69202d4dbc66063cb92059b8a58640d34
Author: Dimitri Sivanich <sivanich@sgi.com>
AuthorDate: Tue, 16 Nov 2010 16:23:52 -0600
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 18 Nov 2010 10:41:25 +0100

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 <sivanich@sgi.com>
LKML-Reference: <20101116222352.GA8155@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
___

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 ++++
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(-)

diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h
index e969f69..a501741 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) |
diff --git a/arch/x86/include/asm/uv/uv_mmrs.h b/arch/x86/include/asm/uv/uv_mmrs.h
index 6d90adf..20cafea 100644
--- a/arch/x86/include/asm/uv/uv_mmrs.h
+++ b/arch/x86/include/asm/uv/uv_mmrs.h
@@ -5,7 +5,7 @@
*
* SGI UV MMR definitions
*
- * Copyright (C) 2007-2008 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2007-2010 Silicon Graphics, Inc. All rights reserved.
*/

#ifndef _ASM_X86_UV_UV_MMRS_H
@@ -754,6 +754,23 @@ union uvh_lb_bau_sb_descriptor_base_u {
};

/* ========================================================================= */
+/* UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK */
+/* ========================================================================= */
+#define UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK 0x320130UL
+#define UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK_32 0x009f0
+
+#define UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK_BIT_ENABLES_SHFT 0
+#define UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK_BIT_ENABLES_MASK 0x00000000ffffffffUL
+
+union uvh_lb_target_physical_apic_id_mask_u {
+ unsigned long v;
+ struct uvh_lb_target_physical_apic_id_mask_s {
+ unsigned long bit_enables : 32; /* RW */
+ unsigned long rsvd_32_63 : 32; /* */
+ } s;
+};
+
+/* ========================================================================= */
/* UVH_NODE_ID */
/* ========================================================================= */
#define UVH_NODE_ID 0x0UL
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 194539a..c1c52c3 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -44,6 +44,8 @@ static u64 gru_start_paddr, gru_end_paddr;
static union uvh_apicid uvh_apicid;
int uv_min_hub_revision_id;
EXPORT_SYMBOL_GPL(uv_min_hub_revision_id);
+unsigned int uv_apicid_hibits;
+EXPORT_SYMBOL_GPL(uv_apicid_hibits);
static DEFINE_SPINLOCK(uv_nmi_lock);

static inline bool is_GRU_range(u64 start, u64 end)
@@ -85,6 +87,23 @@ static void __init early_get_apic_pnode_shift(void)
uvh_apicid.s.pnode_shift = UV_APIC_PNODE_SHIFT;
}

+/*
+ * Add an extra bit as dictated by bios to the destination apicid of
+ * interrupts potentially passing through the UV HUB. This prevents
+ * a deadlock between interrupts and IO port operations.
+ */
+static void __init uv_set_apicid_hibit(void)
+{
+ union uvh_lb_target_physical_apic_id_mask_u apicid_mask;
+ unsigned long *mmr;
+
+ mmr = early_ioremap(UV_LOCAL_MMR_BASE |
+ UVH_LB_TARGET_PHYSICAL_APIC_ID_MASK, sizeof(*mmr));
+ apicid_mask.v = *mmr;
+ early_iounmap(mmr, sizeof(*mmr));
+ uv_apicid_hibits = apicid_mask.s.bit_enables & UV_APICID_HIBIT_MASK;
+}
+
static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
int nodeid;
@@ -102,6 +121,7 @@ static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
__get_cpu_var(x2apic_extra_bits) =
nodeid << (uvh_apicid.s.pnode_shift - 1);
uv_system_type = UV_NON_UNIQUE_APIC;
+ uv_set_apicid_hibit();
return 1;
}
}
@@ -155,6 +175,7 @@ static int __cpuinit uv_wakeup_secondary(int phys_apicid, unsigned long start_ri
int pnode;

pnode = uv_apicid_to_pnode(phys_apicid);
+ phys_apicid |= uv_apicid_hibits;
val = (1UL << UVH_IPI_INT_SEND_SHFT) |
(phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) |
((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) |
@@ -236,7 +257,7 @@ static unsigned int uv_cpu_mask_to_apicid(const struct cpumask *cpumask)
int cpu = cpumask_first(cpumask);

if ((unsigned)cpu < nr_cpu_ids)
- return per_cpu(x86_cpu_to_apicid, cpu);
+ return per_cpu(x86_cpu_to_apicid, cpu) | uv_apicid_hibits;
else
return BAD_APICID;
}
@@ -255,7 +276,7 @@ uv_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
if (cpumask_test_cpu(cpu, cpu_online_mask))
break;
}
- return per_cpu(x86_cpu_to_apicid, cpu);
+ return per_cpu(x86_cpu_to_apicid, cpu) | uv_apicid_hibits;
}

static unsigned int x2apic_get_apic_id(unsigned long x)
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index a318194..ba9caa8 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1455,7 +1455,7 @@ static void __init uv_init_uvhub(int uvhub, int vector)
* the below initialization can't be in firmware because the
* messaging IRQ will be determined by the OS
*/
- apicid = uvhub_to_first_apicid(uvhub);
+ apicid = uvhub_to_first_apicid(uvhub) | uv_apicid_hibits;
uv_write_global_mmr64(pnode, UVH_BAU_DATA_CONFIG,
((apicid << 32) | vector));
}
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 56e421b..9daf5d1 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -89,6 +89,7 @@ static void uv_rtc_send_IPI(int cpu)

apicid = cpu_physical_id(cpu);
pnode = uv_apicid_to_pnode(apicid);
+ apicid |= uv_apicid_hibits;
val = (1UL << UVH_IPI_INT_SEND_SHFT) |
(apicid << UVH_IPI_INT_APIC_ID_SHFT) |
(X86_PLATFORM_IPI_VECTOR << UVH_IPI_INT_VECTOR_SHFT);
@@ -107,6 +108,7 @@ static int uv_intr_pending(int pnode)
static int uv_setup_intr(int cpu, u64 expires)
{
u64 val;
+ unsigned long apicid = cpu_physical_id(cpu) | uv_apicid_hibits;
int pnode = uv_cpu_to_pnode(cpu);

uv_write_global_mmr64(pnode, UVH_RTC1_INT_CONFIG,
@@ -117,7 +119,7 @@ static int uv_setup_intr(int cpu, u64 expires)
UVH_EVENT_OCCURRED0_RTC1_MASK);

val = (X86_PLATFORM_IPI_VECTOR << UVH_RTC1_INT_CONFIG_VECTOR_SHFT) |
- ((u64)cpu_physical_id(cpu) << UVH_RTC1_INT_CONFIG_APIC_ID_SHFT);
+ ((u64)apicid << UVH_RTC1_INT_CONFIG_APIC_ID_SHFT);

/* Set configuration */
uv_write_global_mmr64(pnode, UVH_RTC1_INT_CONFIG, val);

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