diff options
| author | Dimitri Sivanich <sivanich@sgi.com> | 2010-11-16 16:23:52 -0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-11-18 10:41:25 +0100 |
| commit | 8191c9f69202d4dbc66063cb92059b8a58640d34 (patch) | |
| tree | 97efeba3b3224390bfac251ecb9e4a037c544453 /arch/x86/kernel | |
| parent | 9223081f54e3dc5045fe41a475165d9003c9a779 (diff) | |
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(-)
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/apic/x2apic_uv_x.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 194539aea17..c1c52c341f4 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) |