[patch 27/47] Get rid of additional_cpus kernel parameter.

Martin Schwidefsky
2007-12-20T15:38:41Z

[-- Attachment #1: 126-additional-cpus.diff --]
[-- Type: text/plain, Size: 12853 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

It caused only a lot of confusion. From now on cpu hotplug of up to
NR_CPUS will work by default. If somebody wants to limit that then
the possible_cpus parameter can be used.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

Documentation/cpu-hotplug.txt | 2
arch/s390/kernel/early.c | 1
arch/s390/kernel/setup.c | 1
arch/s390/kernel/smp.c | 178 +++++++++++++++++-------------------------
drivers/s390/char/sclp_cmd.c | 46 ----------
include/asm-s390/sclp.h | 1
include/asm-s390/smp.h | 3
7 files changed, 78 insertions(+), 154 deletions(-)

Index: quilt-2.6/arch/s390/kernel/early.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/early.c
+++ quilt-2.6/arch/s390/kernel/early.c
@@ -278,7 +278,6 @@ void __init startup_init(void)
setup_lowcore_early();
sclp_read_info_early();
sclp_facilities_detect();
- sclp_read_cpu_info_early();
memsize = sclp_memory_detect();
#ifndef CONFIG_64BIT
/*
Index: quilt-2.6/arch/s390/kernel/setup.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/setup.c
+++ quilt-2.6/arch/s390/kernel/setup.c
@@ -922,7 +922,6 @@ setup_arch(char **cmdline_p)

cpu_init();
__cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
- smp_setup_cpu_possible_map();

/*
* Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c
+++ quilt-2.6/arch/s390/kernel/smp.c
@@ -54,7 +54,7 @@ EXPORT_SYMBOL(lowcore_ptr);
cpumask_t cpu_online_map = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);

-cpumask_t cpu_possible_map = CPU_MASK_NONE;
+cpumask_t cpu_possible_map = CPU_MASK_ALL;
EXPORT_SYMBOL(cpu_possible_map);

static struct task_struct *current_set[NR_CPUS];
@@ -399,7 +399,7 @@ static void __init smp_get_save_area(uns
"kernel was compiled with NR_CPUS=%i\n", cpu, NR_CPUS);
return;
}
- zfcpdump_save_areas[cpu] = alloc_bootmem(sizeof(union save_area));
+ zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
__cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
sigp_busy)
@@ -435,67 +435,6 @@ static int cpu_stopped(int cpu)
return 0;
}

-/*
- * Lets check how many CPUs we have.
- */
-static void __init smp_count_cpus(unsigned int *configured_cpus,
- unsigned int *standby_cpus)
-{
- unsigned int cpu;
- struct sclp_cpu_info *info;
- u16 boot_cpu_addr, cpu_addr;
-
- boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
- current_thread_info()->cpu = 0;
- *configured_cpus = 1;
- *standby_cpus = 0;
-
- info = alloc_bootmem_pages(sizeof(*info));
- if (!info)
- disabled_wait((unsigned long) __builtin_return_address(0));
-
- /* Use sigp detection algorithm if sclp doesn't work. */
- if (sclp_get_cpu_info(info)) {
- smp_use_sigp_detection = 1;
- for (cpu = 0; cpu <= 65535; cpu++) {
- if (cpu == boot_cpu_addr)
- continue;
- __cpu_logical_map[CPU_INIT_NO] = cpu;
- if (cpu_stopped(CPU_INIT_NO))
- (*configured_cpus)++;
- }
- goto out;
- }
-
- if (info->has_cpu_type) {
- for (cpu = 0; cpu < info->combined; cpu++) {
- if (info->cpu[cpu].address == boot_cpu_addr) {
- smp_cpu_type = info->cpu[cpu].type;
- break;
- }
- }
- }
- /* Count cpus. */
- for (cpu = 0; cpu < info->combined; cpu++) {
- if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
- continue;
- cpu_addr = info->cpu[cpu].address;
- if (cpu_addr == boot_cpu_addr)
- continue;
- __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
- if (!cpu_stopped(CPU_INIT_NO)) {
- (*standby_cpus)++;
- continue;
- }
- smp_get_save_area(*configured_cpus, cpu_addr);
- (*configured_cpus)++;
- }
-out:
- printk(KERN_INFO "CPUs: %d configured, %d standby\n",
- *configured_cpus, *standby_cpus);
- free_bootmem((unsigned long) info, sizeof(*info));
-}
-
static int cpu_known(int cpu_id)
{
int cpu;
@@ -529,7 +468,7 @@ static int smp_rescan_cpus_sigp(cpumask_
return 0;
}

-static int __init_refok smp_rescan_cpus_sclp(cpumask_t avail)
+static int smp_rescan_cpus_sclp(cpumask_t avail)
{
struct sclp_cpu_info *info;
int cpu_id, logical_cpu, cpu;
@@ -538,10 +477,7 @@ static int __init_refok smp_rescan_cpus_
logical_cpu = first_cpu(avail);
if (logical_cpu == NR_CPUS)
return 0;
- if (slab_is_available())
- info = kmalloc(sizeof(*info), GFP_KERNEL);
- else
- info = alloc_bootmem(sizeof(*info));
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
rc = sclp_get_cpu_info(info);
@@ -564,10 +500,7 @@ static int __init_refok smp_rescan_cpus_
break;
}
out:
- if (slab_is_available())
- kfree(info);
- else
- free_bootmem((unsigned long) info, sizeof(*info));
+ kfree(info);
return rc;
}

@@ -575,15 +508,71 @@ static int smp_rescan_cpus(void)
{
cpumask_t avail;

- cpus_setall(avail);
- cpus_and(avail, avail, cpu_possible_map);
- cpus_andnot(avail, avail, cpu_present_map);
+ cpus_xor(avail, cpu_possible_map, cpu_present_map);
if (smp_use_sigp_detection)
return smp_rescan_cpus_sigp(avail);
else
return smp_rescan_cpus_sclp(avail);
}

+static void __init smp_detect_cpus(void)
+{
+ unsigned int cpu, c_cpus, s_cpus;
+ struct sclp_cpu_info *info;
+ u16 boot_cpu_addr, cpu_addr;
+
+ c_cpus = 1;
+ s_cpus = 0;
+ boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ panic("smp_detect_cpus failed to allocate memory\n");
+ /* Use sigp detection algorithm if sclp doesn't work. */
+ if (sclp_get_cpu_info(info)) {
+ smp_use_sigp_detection = 1;
+ for (cpu = 0; cpu <= 65535; cpu++) {
+ if (cpu == boot_cpu_addr)
+ continue;
+ __cpu_logical_map[CPU_INIT_NO] = cpu;
+ if (!cpu_stopped(CPU_INIT_NO))
+ continue;
+ smp_get_save_area(c_cpus, cpu);
+ c_cpus++;
+ }
+ goto out;
+ }
+
+ if (info->has_cpu_type) {
+ for (cpu = 0; cpu < info->combined; cpu++) {
+ if (info->cpu[cpu].address == boot_cpu_addr) {
+ smp_cpu_type = info->cpu[cpu].type;
+ break;
+ }
+ }
+ }
+
+ for (cpu = 0; cpu < info->combined; cpu++) {
+ if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
+ continue;
+ cpu_addr = info->cpu[cpu].address;
+ if (cpu_addr == boot_cpu_addr)
+ continue;
+ __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
+ if (!cpu_stopped(CPU_INIT_NO)) {
+ s_cpus++;
+ continue;
+ }
+ smp_get_save_area(c_cpus, cpu_addr);
+ c_cpus++;
+ }
+out:
+ kfree(info);
+ printk(KERN_INFO "CPUs: %d configured, %d standby\n", c_cpus, s_cpus);
+ lock_cpu_hotplug();
+ smp_rescan_cpus();
+ unlock_cpu_hotplug();
+}
+
/*
* Activate a secondary processor.
*/
@@ -674,41 +663,20 @@ int __cpu_up(unsigned int cpu)
return 0;
}

-static unsigned int __initdata additional_cpus;
-static unsigned int __initdata possible_cpus;
-
-void __init smp_setup_cpu_possible_map(void)
+static int __init setup_possible_cpus(char *s)
{
- unsigned int pos_cpus, cpu;
- unsigned int configured_cpus, standby_cpus;
+ int pcpus, cpu;

- smp_count_cpus(&configured_cpus, &standby_cpus);
- pos_cpus = min(configured_cpus + standby_cpus + additional_cpus,
- (unsigned int) NR_CPUS);
- if (possible_cpus)
- pos_cpus = min(possible_cpus, (unsigned int) NR_CPUS);
- for (cpu = 0; cpu < pos_cpus; cpu++)
+ pcpus = simple_strtoul(s, NULL, 0);
+ cpu_possible_map = cpumask_of_cpu(0);
+ for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
cpu_set(cpu, cpu_possible_map);
- cpu_present_map = cpumask_of_cpu(0);
- smp_rescan_cpus();
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-static int __init setup_additional_cpus(char *s)
-{
- additional_cpus = simple_strtoul(s, NULL, 0);
- return 0;
-}
-early_param("additional_cpus", setup_additional_cpus);
-
-static int __init setup_possible_cpus(char *s)
-{
- possible_cpus = simple_strtoul(s, NULL, 0);
return 0;
}
early_param("possible_cpus", setup_possible_cpus);

+#ifdef CONFIG_HOTPLUG_CPU
+
int __cpu_disable(void)
{
struct ec_creg_mask_parms cr_parms;
@@ -768,6 +736,8 @@ void __init smp_prepare_cpus(unsigned in
unsigned int cpu;
int i;

+ smp_detect_cpus();
+
/* request the 0x1201 emergency signal external interrupt */
if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
panic("Couldn't request external interrupt 0x1201");
@@ -816,6 +786,8 @@ void __init smp_prepare_boot_cpu(void)
{
BUG_ON(smp_processor_id() != 0);

+ current_thread_info()->cpu = 0;
+ cpu_set(0, cpu_present_map);
cpu_set(0, cpu_online_map);
S390_lowcore.percpu_offset = __per_cpu_offset[0];
current_set[0] = current;
Index: quilt-2.6/Documentation/cpu-hotplug.txt
===================================================================
--- quilt-2.6.orig/Documentation/cpu-hotplug.txt
+++ quilt-2.6/Documentation/cpu-hotplug.txt
@@ -50,7 +50,7 @@ additional_cpus=n (*) Use this to limit
cpu_possible_map = cpu_present_map + additional_cpus

(*) Option valid only for following architectures
-- x86_64, ia64, s390
+- x86_64, ia64

ia64 and x86_64 use the number of disabled local apics in ACPI tables MADT
to determine the number of potentially hot-pluggable cpus. The implementation
Index: quilt-2.6/drivers/s390/char/sclp_cmd.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/sclp_cmd.c
+++ quilt-2.6/drivers/s390/char/sclp_cmd.c
@@ -191,9 +191,6 @@ struct read_cpu_info_sccb {
u8 reserved[4096 - 16];
} __attribute__((packed, aligned(PAGE_SIZE)));

-static struct read_cpu_info_sccb __initdata early_read_cpu_info_sccb;
-static struct sclp_cpu_info __initdata sclp_cpu_info;
-
static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
struct read_cpu_info_sccb *sccb)
{
@@ -208,48 +205,16 @@ static void sclp_fill_cpu_info(struct sc
info->combined * sizeof(struct sclp_cpu_entry));
}

-void __init sclp_read_cpu_info_early(void)
+int sclp_get_cpu_info(struct sclp_cpu_info *info)
{
int rc;
struct read_cpu_info_sccb *sccb;

if (!SCLP_HAS_CPU_INFO)
- return;
-
- sccb = &early_read_cpu_info_sccb;
- do {
- memset(sccb, 0, sizeof(*sccb));
- sccb->header.length = sizeof(*sccb);
- rc = sclp_cmd_sync_early(SCLP_CMDW_READ_CPU_INFO, sccb);
- } while (rc == -EBUSY);
-
- if (rc)
- return;
- if (sccb->header.response_code != 0x10)
- return;
- sclp_fill_cpu_info(&sclp_cpu_info, sccb);
-}
-
-static int __init sclp_get_cpu_info_early(struct sclp_cpu_info *info)
-{
- if (!SCLP_HAS_CPU_INFO)
return -EOPNOTSUPP;
- *info = sclp_cpu_info;
- return 0;
-}
-
-static int sclp_get_cpu_info_late(struct sclp_cpu_info *info)
-{
- int rc;
- struct read_cpu_info_sccb *sccb;
-
- if (!SCLP_HAS_CPU_INFO)
- return -EOPNOTSUPP;
- sccb = (struct read_cpu_info_sccb *) __get_free_page(GFP_KERNEL
- | GFP_DMA);
+ sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!sccb)
return -ENOMEM;
- memset(sccb, 0, sizeof(*sccb));
sccb->header.length = sizeof(*sccb);
rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
if (rc)
@@ -266,13 +231,6 @@ out:
return rc;
}

-int __init_refok sclp_get_cpu_info(struct sclp_cpu_info *info)
-{
- if (slab_is_available())
- return sclp_get_cpu_info_late(info);
- return sclp_get_cpu_info_early(info);
-}
-
struct cpu_configure_sccb {
struct sccb_header header;
} __attribute__((packed, aligned(8)));
Index: quilt-2.6/include/asm-s390/sclp.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/sclp.h
+++ quilt-2.6/include/asm-s390/sclp.h
@@ -46,7 +46,6 @@ int sclp_get_cpu_info(struct sclp_cpu_in
int sclp_cpu_configure(u8 cpu);
int sclp_cpu_deconfigure(u8 cpu);
void sclp_read_info_early(void);
-void sclp_read_cpu_info_early(void);
void sclp_facilities_detect(void);
unsigned long long sclp_memory_detect(void);
int sclp_sdias_blk_count(void);
Index: quilt-2.6/include/asm-s390/smp.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/smp.h
+++ quilt-2.6/include/asm-s390/smp.h
@@ -35,8 +35,6 @@ extern void machine_restart_smp(char *);
extern void machine_halt_smp(void);
extern void machine_power_off_smp(void);

-extern void smp_setup_cpu_possible_map(void);
-
#define NO_PROC_ID 0xFF /* No processor magic marker */

/*
@@ -103,7 +101,6 @@ static inline void smp_send_stop(void)

#define hard_smp_processor_id() 0
#define smp_cpu_not_running(cpu) 1
-#define smp_setup_cpu_possible_map() do { } while (0)
#endif

extern union save_area *zfcpdump_save_areas[NR_CPUS + 1];