Re: [patch 1/5] x84_64, apic: Use probe routines to simplify apicselection

From: Suresh Siddha
Date: Mon May 16 2011 - 19:51:32 EST

On Mon, 2011-05-16 at 01:08 -0700, Ingo Molnar wrote:
> Ok, looks like a step forward in the right direction.
>
> Wouldnt it be more self-contained if the probe function returned an apic driver
> pointer?
>
> We could add an __apicdriver section trick to 'know' about all APIC probing
> functions - and we'd call them one by one and use the first one that returns a
> non-NULL result.
>
> Then we'd have the generic fallback APIC drivers as well - not marked
> __apicdriver but used by the probe function directly.
>
> Or we could have them as __apicdriver as well, but then the .o link ordering
> matters to probing order.
>

So how does something like the appended look? There are multiple apic
driver routines and apic name string that is being looked at by the
generic code. So I exported the struct apic * using the section trick.

Untested for now. If you are ok, then I will post with a better
changelog.

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
---
arch/x86/include/asm/apic.h | 11 +++--
arch/x86/kernel/apic/Makefile | 17 +++++---
arch/x86/kernel/apic/apic_flat_64.c | 12 +++++-
arch/x86/kernel/apic/bigsmp_32.c | 2 +
arch/x86/kernel/apic/es7000_32.c | 7 ++-
arch/x86/kernel/apic/numaq_32.c | 7 ++-
arch/x86/kernel/apic/probe_32.c | 65 +++++++++++-----------------------
arch/x86/kernel/apic/probe_64.c | 43 ++++++----------------
arch/x86/kernel/apic/summit_32.c | 6 ++-
arch/x86/kernel/apic/x2apic_cluster.c | 4 +-
arch/x86/kernel/apic/x2apic_phys.c | 6 ++-
arch/x86/kernel/apic/x2apic_uv_x.c | 4 +-
arch/x86/kernel/vmlinux.lds.S | 6 +++
13 files changed, 94 insertions(+), 96 deletions(-)

Index: linux-2.6-tip/arch/x86/include/asm/apic.h
===================================================================
--- linux-2.6-tip.orig/arch/x86/include/asm/apic.h
+++ linux-2.6-tip/arch/x86/include/asm/apic.h
@@ -380,6 +380,12 @@ struct apic {
*/
extern struct apic *apic;

+#define apicdriver(sym) \
+ static struct apic *__apicdriver_##sym __used \
+ __attribute__ ((__section__(".apicdrivers"))) = &sym
+
+extern struct apic *__apicdrivers[], *__apicdrivers_end[];
+
/*
* APIC functionality to boot other CPUs - only used on SMP:
*/
@@ -458,15 +464,10 @@ static inline unsigned default_get_apic_
#define DEFAULT_TRAMPOLINE_PHYS_HIGH 0x469

#ifdef CONFIG_X86_64
-extern struct apic apic_flat;
-extern struct apic apic_physflat;
-extern struct apic apic_x2apic_cluster;
-extern struct apic apic_x2apic_phys;
extern int default_acpi_madt_oem_check(char *, char *);

extern void apic_send_IPI_self(int vector);

-extern struct apic apic_x2apic_uv_x;
DECLARE_PER_CPU(int, x2apic_extra_bits);

extern int default_cpu_present_to_apicid(int mps_cpu);
Index: linux-2.6-tip/arch/x86/kernel/apic/Makefile
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/Makefile
+++ linux-2.6-tip/arch/x86/kernel/apic/Makefile
@@ -2,20 +2,25 @@
# Makefile for local APIC drivers and for the IO-APIC code
#

-obj-$(CONFIG_X86_LOCAL_APIC) += apic.o apic_noop.o probe_$(BITS).o ipi.o
+obj-$(CONFIG_X86_LOCAL_APIC) += apic.o apic_noop.o ipi.o
obj-y += hw_nmi.o

obj-$(CONFIG_X86_IO_APIC) += io_apic.o
obj-$(CONFIG_SMP) += ipi.o

ifeq ($(CONFIG_X86_64),y)
-obj-y += apic_flat_64.o
-obj-$(CONFIG_X86_X2APIC) += x2apic_cluster.o
-obj-$(CONFIG_X86_X2APIC) += x2apic_phys.o
+# APIC probe will depend on the listing order here
obj-$(CONFIG_X86_UV) += x2apic_uv_x.o
+obj-$(CONFIG_X86_X2APIC) += x2apic_phys.o
+obj-$(CONFIG_X86_X2APIC) += x2apic_cluster.o
+obj-y += apic_flat_64.o
endif

-obj-$(CONFIG_X86_BIGSMP) += bigsmp_32.o
+# APIC probe will depend on the listing order here
obj-$(CONFIG_X86_NUMAQ) += numaq_32.o
-obj-$(CONFIG_X86_ES7000) += es7000_32.o
obj-$(CONFIG_X86_SUMMIT) += summit_32.o
+obj-$(CONFIG_X86_BIGSMP) += bigsmp_32.o
+obj-$(CONFIG_X86_ES7000) += es7000_32.o
+
+# For 32bit, probe_32 need to be listed last
+obj-$(CONFIG_X86_LOCAL_APIC) += probe_$(BITS).o
Index: linux-2.6-tip/arch/x86/kernel/apic/apic_flat_64.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/apic_flat_64.c
+++ linux-2.6-tip/arch/x86/kernel/apic/apic_flat_64.c
@@ -24,6 +24,8 @@
#include <acpi/acpi_bus.h>
#endif

+static struct apic apic_physflat;
+
static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
return 1;
@@ -164,7 +166,7 @@ static int flat_phys_pkg_id(int initial_
return initial_apic_id >> index_msb;
}

-struct apic apic_flat = {
+static struct apic apic_flat = {
.name = "flat",
.probe = NULL,
.acpi_madt_oem_check = flat_acpi_madt_oem_check,
@@ -320,7 +322,7 @@ static int physflat_probe(void)
return 0;
}

-struct apic apic_physflat = {
+static struct apic apic_physflat = {

.name = "physical flat",
.probe = physflat_probe,
@@ -377,3 +379,9 @@ struct apic apic_physflat = {
.wait_icr_idle = native_apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_apic_wait_icr_idle,
};
+
+/*
+ * We need to check for Physflat first, so don't change this order!
+ */
+apicdriver(apic_physflat);
+apicdriver(apic_flat);
Index: linux-2.6-tip/arch/x86/kernel/apic/probe_64.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/probe_64.c
+++ linux-2.6-tip/arch/x86/kernel/apic/probe_64.c
@@ -23,27 +23,9 @@
#include <asm/ipi.h>
#include <asm/setup.h>

-extern struct apic apic_flat;
-extern struct apic apic_physflat;
-extern struct apic apic_x2xpic_uv_x;
-extern struct apic apic_x2apic_phys;
-extern struct apic apic_x2apic_cluster;
-
-struct apic __read_mostly *apic = &apic_flat;
+struct apic __read_mostly *apic;
EXPORT_SYMBOL_GPL(apic);

-static struct apic *apic_probe[] __initdata = {
-#ifdef CONFIG_X86_UV
- &apic_x2apic_uv_x,
-#endif
-#ifdef CONFIG_X86_X2APIC
- &apic_x2apic_phys,
- &apic_x2apic_cluster,
-#endif
- &apic_physflat,
- NULL,
-};
-
static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
{
return hard_smp_processor_id() >> index_msb;
@@ -54,19 +36,19 @@ static int apicid_phys_pkg_id(int initia
*/
void __init default_setup_apic_routing(void)
{
- int i;
+ struct apic **list;

enable_IR_x2apic();

- for (i = 0; apic_probe[i]; ++i) {
- if (apic_probe[i]->probe()) {
- apic = apic_probe[i];
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if ((*list)->probe()) {
+ apic = *list;
+ printk(KERN_INFO "APIC routing finalized to %s.\n",
+ apic->name);
break;
}
}

- printk(KERN_INFO "APIC routing finalized to %s.\n", apic->name);
-
if (is_vsmp_box()) {
/* need to update phys_pkg_id */
apic->phys_pkg_id = apicid_phys_pkg_id;
@@ -82,13 +64,14 @@ void apic_send_IPI_self(int vector)

int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
- int i;
+ struct apic **list;

- for (i = 0; apic_probe[i]; ++i) {
- if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
- apic = apic_probe[i];
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if ((*list)->acpi_madt_oem_check(oem_id, oem_table_id)) {
+ apic = *list;
printk(KERN_INFO "Setting APIC routing to %s.\n",
- apic->name);
+ apic->name);
+
return 1;
}
}
Index: linux-2.6-tip/arch/x86/kernel/apic/x2apic_cluster.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/x2apic_cluster.c
+++ linux-2.6-tip/arch/x86/kernel/apic/x2apic_cluster.c
@@ -208,7 +208,7 @@ static int x2apic_cluster_probe(void)
return 0;
}

-struct apic apic_x2apic_cluster = {
+static struct apic apic_x2apic_cluster = {

.name = "cluster x2apic",
.probe = x2apic_cluster_probe,
@@ -264,3 +264,5 @@ struct apic apic_x2apic_cluster = {
.wait_icr_idle = native_x2apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
};
+
+apicdriver(apic_x2apic_cluster);
Index: linux-2.6-tip/arch/x86/kernel/apic/x2apic_phys.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/x2apic_phys.c
+++ linux-2.6-tip/arch/x86/kernel/apic/x2apic_phys.c
@@ -11,6 +11,8 @@

int x2apic_phys;

+static struct apic apic_x2apic_phys;
+
static int set_x2apic_phys_mode(char *arg)
{
x2apic_phys = 1;
@@ -112,7 +114,7 @@ static int x2apic_phys_probe(void)
return apic == &apic_x2apic_phys;
}

-struct apic apic_x2apic_phys = {
+static struct apic apic_x2apic_phys = {

.name = "physical x2apic",
.probe = x2apic_phys_probe,
@@ -168,3 +170,5 @@ struct apic apic_x2apic_phys = {
.wait_icr_idle = native_x2apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
};
+
+apicdriver(apic_x2apic_phys);
Index: linux-2.6-tip/arch/x86/kernel/apic/x2apic_uv_x.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/x2apic_uv_x.c
+++ linux-2.6-tip/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -331,7 +331,7 @@ static int uv_probe(void)
return apic == &apic_x2apic_uv_x;
}

-struct apic __refdata apic_x2apic_uv_x = {
+static struct apic apic_x2apic_uv_x = {

.name = "UV large system",
.probe = uv_probe,
@@ -864,3 +864,5 @@ void __init uv_system_init(void)
if (is_kdump_kernel())
reboot_type = BOOT_ACPI;
}
+
+apicdriver(apic_x2apic_uv_x);
Index: linux-2.6-tip/arch/x86/kernel/vmlinux.lds.S
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/vmlinux.lds.S
+++ linux-2.6-tip/arch/x86/kernel/vmlinux.lds.S
@@ -305,6 +305,12 @@ SECTIONS
__iommu_table_end = .;
}

+ .apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
+ __apicdrivers = .;
+ *(.apicdrivers);
+ __apicdrivers_end = .;
+ }
+
. = ALIGN(8);
/*
* .exit.text is discard at runtime, not link time, to deal with
Index: linux-2.6-tip/arch/x86/kernel/apic/bigsmp_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/bigsmp_32.c
+++ linux-2.6-tip/arch/x86/kernel/apic/bigsmp_32.c
@@ -254,3 +254,5 @@ struct apic apic_bigsmp = {

.x86_32_early_logical_apicid = bigsmp_early_logical_apicid,
};
+
+apicdriver(apic_bigsmp);
Index: linux-2.6-tip/arch/x86/kernel/apic/es7000_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/es7000_32.c
+++ linux-2.6-tip/arch/x86/kernel/apic/es7000_32.c
@@ -620,7 +620,7 @@ static int es7000_mps_oem_check_cluster(
}

/* We've been warned by a false positive warning.Use __refdata to keep calm. */
-struct apic __refdata apic_es7000_cluster = {
+static struct apic __refdata apic_es7000_cluster = {

.name = "es7000",
.probe = probe_es7000,
@@ -685,7 +685,7 @@ struct apic __refdata apic_es7000_cluste
.x86_32_early_logical_apicid = es7000_early_logical_apicid,
};

-struct apic __refdata apic_es7000 = {
+static struct apic __refdata apic_es7000 = {

.name = "es7000",
.probe = probe_es7000,
@@ -747,3 +747,6 @@ struct apic __refdata apic_es7000 = {

.x86_32_early_logical_apicid = es7000_early_logical_apicid,
};
+
+apicdriver(apic_es7000);
+apicdriver(apic_es7000_cluster);
Index: linux-2.6-tip/arch/x86/kernel/apic/numaq_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/numaq_32.c
+++ linux-2.6-tip/arch/x86/kernel/apic/numaq_32.c
@@ -73,7 +73,6 @@ int mp_bus_id_to_node[MAX_MP_BUSSES]
int mp_bus_id_to_local[MAX_MP_BUSSES];
int quad_local_to_mp_bus_id[NR_CPUS/4][4];

-
static inline void numaq_register_node(int node, struct sys_cfg_data *scd)
{
struct eachquadmem *eq = scd->eq + node;
@@ -472,8 +471,8 @@ static void numaq_setup_portio_remap(voi
(u_long) xquad_portio, (u_long) num_quads*XQUAD_PORTIO_QUAD);
}

-/* Use __refdata to keep false positive warning calm. */
-struct apic __refdata apic_numaq = {
+/* Use __refdata to keep false positive warning calm. */
+static struct apic __refdata apic_numaq = {

.name = "NUMAQ",
.probe = probe_numaq,
@@ -537,3 +536,5 @@ struct apic __refdata apic_numaq = {
.x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid,
.x86_32_numa_cpu_node = numaq_numa_cpu_node,
};
+
+apicdriver(apic_numaq);
Index: linux-2.6-tip/arch/x86/kernel/apic/probe_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/probe_32.c
+++ linux-2.6-tip/arch/x86/kernel/apic/probe_32.c
@@ -174,44 +174,20 @@ struct apic apic_default = {
.x86_32_early_logical_apicid = default_x86_32_early_logical_apicid,
};

-extern struct apic apic_numaq;
-extern struct apic apic_summit;
-extern struct apic apic_bigsmp;
-extern struct apic apic_es7000;
-extern struct apic apic_es7000_cluster;
-
struct apic *apic = &apic_default;
EXPORT_SYMBOL_GPL(apic);

-static struct apic *apic_probe[] __initdata = {
-#ifdef CONFIG_X86_NUMAQ
- &apic_numaq,
-#endif
-#ifdef CONFIG_X86_SUMMIT
- &apic_summit,
-#endif
-#ifdef CONFIG_X86_BIGSMP
- &apic_bigsmp,
-#endif
-#ifdef CONFIG_X86_ES7000
- &apic_es7000,
- &apic_es7000_cluster,
-#endif
- &apic_default, /* must be last */
- NULL,
-};
-
static int cmdline_apic __initdata;
static int __init parse_apic(char *arg)
{
- int i;
+ struct apic **list;

if (!arg)
return -EINVAL;

- for (i = 0; apic_probe[i]; i++) {
- if (!strcmp(apic_probe[i]->name, arg)) {
- apic = apic_probe[i];
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if (!strcmp((*list)->name, arg)) {
+ apic = *list;
cmdline_apic = 1;
return 0;
}
@@ -222,6 +198,8 @@ static int __init parse_apic(char *arg)
}
early_param("apic", parse_apic);

+extern struct apic apic_bigsmp;
+
void __init generic_bigsmp_probe(void)
{
#ifdef CONFIG_X86_BIGSMP
@@ -245,15 +223,16 @@ void __init generic_bigsmp_probe(void)
void __init generic_apic_probe(void)
{
if (!cmdline_apic) {
- int i;
- for (i = 0; apic_probe[i]; i++) {
- if (apic_probe[i]->probe()) {
- apic = apic_probe[i];
+ struct apic **list;
+
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if ((*list)->probe()) {
+ apic = *list;
break;
}
}
/* Not visible without early console */
- if (!apic_probe[i])
+ if (list == __apicdrivers_end)
panic("Didn't find an APIC driver");
}
printk(KERN_INFO "Using APIC driver %s\n", apic->name);
@@ -264,16 +243,16 @@ void __init generic_apic_probe(void)
int __init
generic_mps_oem_check(struct mpc_table *mpc, char *oem, char *productid)
{
- int i;
+ struct apic **list;

- for (i = 0; apic_probe[i]; ++i) {
- if (!apic_probe[i]->mps_oem_check)
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if (!((*list)->mps_oem_check))
continue;
- if (!apic_probe[i]->mps_oem_check(mpc, oem, productid))
+ if (!(*list)->mps_oem_check(mpc, oem, productid))
continue;

if (!cmdline_apic) {
- apic = apic_probe[i];
+ apic = *list;
printk(KERN_INFO "Switched to APIC driver `%s'.\n",
apic->name);
}
@@ -284,16 +263,16 @@ generic_mps_oem_check(struct mpc_table *

int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
- int i;
+ struct apic **list;

- for (i = 0; apic_probe[i]; ++i) {
- if (!apic_probe[i]->acpi_madt_oem_check)
+ for (list = __apicdrivers; list < __apicdrivers_end; list++) {
+ if (!(*list)->acpi_madt_oem_check)
continue;
- if (!apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id))
+ if (!(*list)->acpi_madt_oem_check(oem_id, oem_table_id))
continue;

if (!cmdline_apic) {
- apic = apic_probe[i];
+ apic = *list;
printk(KERN_INFO "Switched to APIC driver `%s'.\n",
apic->name);
}
Index: linux-2.6-tip/arch/x86/kernel/apic/summit_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/apic/summit_32.c
+++ linux-2.6-tip/arch/x86/kernel/apic/summit_32.c
@@ -93,7 +93,7 @@ static int summit_mps_oem_check(struct m
}

/* Hook from generic ACPI tables.c */
-static int summit_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+static struct apic *summit_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
if (!strncmp(oem_id, "IBM", 3) &&
(!strncmp(oem_table_id, "SERVIGIL", 8)
@@ -491,7 +491,7 @@ void setup_summit(void)
}
#endif

-struct apic apic_summit = {
+static struct apic apic_summit = {

.name = "summit",
.probe = probe_summit,
@@ -552,3 +552,5 @@ struct apic apic_summit = {

.x86_32_early_logical_apicid = summit_early_logical_apicid,
};
+
+apicdriver(apic_summit);


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