[PATCH 07/21] X86_64, UV: Enable/Disable UV1 only workaround code

From: Mike Travis
Date: Thu Apr 28 2016 - 19:16:27 EST


This patch allows enabling or disabling of the "EXTRA APIC ID BITS"
workaround found only on UV100/UV1000 systems. This workaround was
required by the Intel Nahelm Processor (used in that architecture)
because it could only support a limited number of CPU threads within
the SSI. This was due to only having 8 APIC ID bits thus a workaround
was added to add and remove extra bits to the APIC ID. It also required
a specialized UV1 only apic driver.

Signed-off-by: Mike Travis <travis@xxxxxxx>
Tested-by: Nathan Zimmer <nzimmer@xxxxxxx>
---
arch/x86/Kconfig | 14 ++++++++++++++
arch/x86/include/asm/uv/uv_hub.h | 11 ++++-------
arch/x86/include/asm/uv/uv_mmrs.h | 2 ++
arch/x86/kernel/apic/x2apic_uv_x.c | 26 +++++++++++++++++++++++---
4 files changed, 43 insertions(+), 10 deletions(-)

--- linux.orig/arch/x86/Kconfig
+++ linux/arch/x86/Kconfig
@@ -489,6 +489,20 @@ config X86_UV
This option is needed in order to support SGI Ultraviolet systems.
If you don't have one of these, you should say N here.

+config X86_UV1_SUPPORTED
+ bool "SGI Ultraviolet Series 1 Supported"
+ depends on X86_UV
+ default n
+ ---help---
+ Set this option if you have a UV100/UV1000 system. By setting
+ this option extra execution time and space is introduced for
+ workarounds designed for processors limited to only 8 apicid bits.
+ This limited the number of processors that could be supported in
+ an SSI. With the Intel release of the SandyBridge Processor (used
+ in UV2000 systems), the "x2apic" mode was introduced to extend
+ the number of apicid bits. Thus more processors are supported
+ without these workarounds and the specialized UV1 only apic driver.
+
# Following is an alphabetically sorted list of 32 bit extended platforms
# Please maintain the alphabetic order if and when there are additions

--- linux.orig/arch/x86/include/asm/uv/uv_hub.h
+++ linux/arch/x86/include/asm/uv/uv_hub.h
@@ -289,25 +289,21 @@ union uvh_apicid {
#define UV4_GLOBAL_MMR32_SIZE (16UL * 1024 * 1024)

#define UV_LOCAL_MMR_BASE ( \
- is_uv1_hub() ? UV1_LOCAL_MMR_BASE : \
is_uv2_hub() ? UV2_LOCAL_MMR_BASE : \
is_uv3_hub() ? UV3_LOCAL_MMR_BASE : \
/*is_uv4_hub*/ UV4_LOCAL_MMR_BASE)

#define UV_GLOBAL_MMR32_BASE ( \
- is_uv1_hub() ? UV1_GLOBAL_MMR32_BASE : \
is_uv2_hub() ? UV2_GLOBAL_MMR32_BASE : \
is_uv3_hub() ? UV3_GLOBAL_MMR32_BASE : \
/*is_uv4_hub*/ UV4_GLOBAL_MMR32_BASE)

#define UV_LOCAL_MMR_SIZE ( \
- is_uv1_hub() ? UV1_LOCAL_MMR_SIZE : \
is_uv2_hub() ? UV2_LOCAL_MMR_SIZE : \
is_uv3_hub() ? UV3_LOCAL_MMR_SIZE : \
/*is_uv4_hub*/ UV4_LOCAL_MMR_SIZE)

#define UV_GLOBAL_MMR32_SIZE ( \
- is_uv1_hub() ? UV1_GLOBAL_MMR32_SIZE : \
is_uv2_hub() ? UV2_GLOBAL_MMR32_SIZE : \
is_uv3_hub() ? UV3_GLOBAL_MMR32_SIZE : \
/*is_uv4_hub*/ UV4_GLOBAL_MMR32_SIZE)
@@ -445,9 +441,6 @@ static inline int uv_apicid_to_pnode(int
*/
static inline int uv_apicid_to_socket(int apicid)
{
- if (is_uv1_hub())
- return (apicid >> (uv_hub_info->apic_pnode_shift - 1)) & 1;
- else
return 0;
}

@@ -704,7 +697,11 @@ static inline void uv_set_cpu_scir_bits(
}
}

+#ifdef UV1_HUB_IS_SUPPORTED
extern unsigned int uv_apicid_hibits;
+#else
+#define uv_apicid_hibits 0
+#endif
static unsigned long uv_hub_ipi_value(int apicid, int vector, int mode)
{
apicid |= uv_apicid_hibits;
--- linux.orig/arch/x86/include/asm/uv/uv_mmrs.h
+++ linux/arch/x86/include/asm/uv/uv_mmrs.h
@@ -95,7 +95,9 @@
#define UV4_HUB_PART_NUMBER 0x99a1

/* Compat: Indicate which UV Hubs are supported. */
+#ifdef CONFIG_X86_UV1_SUPPORTED
#define UV1_HUB_IS_SUPPORTED 1
+#endif
#define UV2_HUB_IS_SUPPORTED 1
#define UV3_HUB_IS_SUPPORTED 1
#define UV4_HUB_IS_SUPPORTED 1
--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c
+++ linux/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -39,7 +39,9 @@
#include <asm/x86_init.h>
#include <asm/nmi.h>

+#ifdef UV1_HUB_IS_SUPPORTED
DEFINE_PER_CPU(int, x2apic_extra_bits);
+#endif

#define PR_DEVEL(fmt, args...) pr_devel("%s: " fmt, __func__, args)

@@ -50,8 +52,10 @@ static u64 gru_dist_lmask, gru_dist_umas
static union uvh_apicid uvh_apicid;
int uv_min_hub_revision_id;
EXPORT_SYMBOL_GPL(uv_min_hub_revision_id);
+#ifdef UV1_HUB_IS_SUPPORTED
unsigned int uv_apicid_hibits;
EXPORT_SYMBOL_GPL(uv_apicid_hibits);
+#endif

static struct apic apic_x2apic_uv_x;

@@ -145,6 +149,7 @@ static void __init early_get_apic_pnode_
* interrupts potentially passing through the UV HUB. This prevents
* a deadlock between interrupts and IO port operations.
*/
+#ifdef UV1_HUB_IS_SUPPORTED
static void __init uv_set_apicid_hibit(void)
{
union uv1h_lb_target_physical_apic_id_mask_u apicid_mask;
@@ -156,6 +161,7 @@ static void __init uv_set_apicid_hibit(v
apicid_mask.s1.bit_enables & UV_APICID_HIBIT_MASK;
}
}
+#endif

static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
@@ -190,13 +196,14 @@ static int __init uv_acpi_madt_oem_check
uv_system_type = UV_X2APIC;
uv_apic = 0;

+#ifdef UV1_HUB_IS_SUPPORTED
} else if (!strcmp(oem_table_id, "UVH")) { /* only UV1 systems */
uv_system_type = UV_NON_UNIQUE_APIC;
__this_cpu_write(x2apic_extra_bits,
pnodeid << uvh_apicid.s.pnode_shift);
uv_set_apicid_hibit();
uv_apic = 1;
-
+#endif
} else if (!strcmp(oem_table_id, "UVL")) { /* only used for */
uv_system_type = UV_LEGACY_APIC; /* very small systems */
uv_apic = 0;
@@ -252,7 +259,6 @@ static int uv_wakeup_secondary(int phys_
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) |
@@ -344,7 +350,7 @@ uv_cpu_mask_to_apicid_and(const struct c
}

if (likely(cpu < nr_cpu_ids)) {
- *apicid = per_cpu(x86_cpu_to_apicid, cpu) | uv_apicid_hibits;
+ *apicid = per_cpu(x86_cpu_to_apicid, cpu);
return 0;
}

@@ -353,21 +359,29 @@ uv_cpu_mask_to_apicid_and(const struct c

static unsigned int x2apic_get_apic_id(unsigned long x)
{
+#ifdef UV1_HUB_IS_SUPPORTED
unsigned int id;

WARN_ON(preemptible() && num_online_cpus() > 1);
id = x | __this_cpu_read(x2apic_extra_bits);

return id;
+#else
+ return x;
+#endif
}

static unsigned long set_apic_id(unsigned int id)
{
+#ifdef UV1_HUB_IS_SUPPORTED
unsigned long x;

/* maskout x2apic_extra_bits ? */
x = id;
return x;
+#else
+ return id;
+#endif
}

static unsigned int uv_read_apic_id(void)
@@ -442,10 +456,16 @@ static struct apic __refdata apic_x2apic
.safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
};

+#ifdef UV1_HUB_IS_SUPPORTED
static void set_x2apic_extra_bits(int pnode)
{
__this_cpu_write(x2apic_extra_bits, pnode << uvh_apicid.s.pnode_shift);
}
+#else
+static inline void set_x2apic_extra_bits(int pnode)
+{
+}
+#endif

/*
* Called on boot cpu.

--