[PATCH] PPC64 (1/3) Rework PPC64 cpu map setup

From: Paul Mackerras
Date: Mon Aug 30 2004 - 00:09:25 EST

Move all cpu map initializations to one place (except for the online
map -- cpus mark themselves online as they come up). This sets up
cpu_possible_map early enough that we can use num_possible_cpus for
allocating irqstacks instead of NR_CPUS. Hopefully this should also
help set the stage for kexec.

Signed-off-by: Nathan Lynch <nathanl@xxxxxxxxxxxxxx>
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>

diff -urN linux-2.5/arch/ppc64/kernel/prom.c akpm/arch/ppc64/kernel/prom.c
--- linux-2.5/arch/ppc64/kernel/prom.c 2004-08-24 07:22:47.000000000 +1000
+++ akpm/arch/ppc64/kernel/prom.c 2004-08-30 14:51:01.437354816 +1000
@@ -939,20 +939,11 @@
prom_getprop(node, "reg", &reg, sizeof(reg));
lpaca[cpuid].hw_cpu_id = reg;

-#ifdef CONFIG_SMP
- cpu_set(cpuid, RELOC(cpu_possible_map));
- cpu_set(cpuid, RELOC(cpu_present_map));
- if (reg == 0)
- cpu_set(cpuid, RELOC(cpu_online_map));
-#endif /* CONFIG_SMP */
cpuid++;
}
return;
}

- /* Initially, we must have one active CPU. */
- _systemcfg->processorCount = 1;
-
prom_debug("prom_hold_cpus: start...\n");
prom_debug(" 1) spinloop = 0x%x\n", (unsigned long)spinloop);
prom_debug(" 1) *spinloop = 0x%x\n", *spinloop);
@@ -1038,23 +1029,13 @@
* even if we never start it. */
if (cpuid >= NR_CPUS)
goto next;
-#ifdef CONFIG_SMP
- /* Set the number of active processors. */
- _systemcfg->processorCount++;
- cpu_set(cpuid, RELOC(cpu_possible_map));
- cpu_set(cpuid, RELOC(cpu_present_map));
-#endif
} else {
prom_printf("... failed: %x\n", *acknowledge);
}
}
#ifdef CONFIG_SMP
- else {
+ else
prom_printf("%x : booting cpu %s\n", cpuid, path);
- cpu_set(cpuid, RELOC(cpu_possible_map));
- cpu_set(cpuid, RELOC(cpu_online_map));
- cpu_set(cpuid, RELOC(cpu_present_map));
- }
#endif
next:
#ifdef CONFIG_SMP
@@ -1067,9 +1048,6 @@
prom_printf("%x : preparing thread ... ",
interrupt_server[i]);
if (_naca->smt_state) {
- cpu_set(cpuid, RELOC(cpu_present_map));
- cpu_set(cpuid, RELOC(cpu_possible_map));
- _systemcfg->processorCount++;
prom_printf("available\n");
} else {
prom_printf("not available\n");
@@ -1099,11 +1077,7 @@
pir & 0x3ff;
}
}
-/* cpu_set(i+1, cpu_online_map); */
- cpu_set(i+1, RELOC(cpu_possible_map));
- cpu_set(i+1, RELOC(cpu_present_map));
}
- _systemcfg->processorCount *= 2;
} else {
prom_printf("Processor is not HMT capable\n");
}
diff -urN linux-2.5/arch/ppc64/kernel/setup.c akpm/arch/ppc64/kernel/setup.c
--- linux-2.5/arch/ppc64/kernel/setup.c 2004-08-24 07:22:47.000000000 +1000
+++ akpm/arch/ppc64/kernel/setup.c 2004-08-30 14:51:01.430355880 +1000
@@ -155,6 +155,94 @@
early_console_initialized = 0;
}

+#if !defined(CONFIG_PPC_ISERIES) && defined(CONFIG_SMP)
+/**
+ * setup_cpu_maps - initialize the following cpu maps:
+ * cpu_possible_map
+ * cpu_present_map
+ * cpu_sibling_map
+ *
+ * Having the possible map set up early allows us to restrict allocations
+ * of things like irqstacks to num_possible_cpus() rather than NR_CPUS.
+ *
+ * We do not initialize the online map here; cpus set their own bits in
+ * cpu_online_map as they come up.
+ *
+ * This function is valid only for Open Firmware systems. finish_device_tree
+ * must be called before using this.
+ */
+static void __init setup_cpu_maps(void)
+{
+ struct device_node *dn = NULL;
+ int cpu = 0;
+
+ while ((dn = of_find_node_by_type(dn, "cpu")) && cpu < NR_CPUS) {
+ u32 *intserv;
+ int j, len = sizeof(u32), nthreads;
+
+ intserv = (u32 *)get_property(dn, "ibm,ppc-interrupt-server#s",
+ &len);
+ nthreads = len / sizeof(u32);
+
+ for (j = 0; j < nthreads && cpu < NR_CPUS; j++) {
+ cpu_set(cpu, cpu_possible_map);
+ cpu_set(cpu, cpu_present_map);
+ cpu++;
+ }
+ }
+
+ /*
+ * On pSeries LPAR, we need to know how many cpus
+ * could possibly be added to this partition.
+ */
+ if (systemcfg->platform == PLATFORM_PSERIES_LPAR &&
+ (dn = of_find_node_by_path("/rtas"))) {
+ int num_addr_cell, num_size_cell, maxcpus;
+ unsigned int *ireg;
+
+ num_addr_cell = prom_n_addr_cells(dn);
+ num_size_cell = prom_n_size_cells(dn);
+
+ ireg = (unsigned int *)
+ get_property(dn, "ibm,lrdr-capacity", NULL);
+
+ if (!ireg)
+ goto out;
+
+ maxcpus = ireg[num_addr_cell + num_size_cell];
+
+ /* Double maxcpus for processors which have SMT capability */
+ if (cur_cpu_spec->cpu_features & CPU_FTR_SMT)
+ maxcpus *= 2;
+
+ if (maxcpus > NR_CPUS) {
+ printk(KERN_WARNING
+ "Partition configured for %d cpus, "
+ "operating system maximum is %d.\n",
+ maxcpus, NR_CPUS);
+ maxcpus = NR_CPUS;
+ } else
+ printk(KERN_INFO "Partition configured for %d cpus.\n",
+ maxcpus);
+
+ for (cpu = 0; cpu < maxcpus; cpu++)
+ cpu_set(cpu, cpu_possible_map);
+ out:
+ of_node_put(dn);
+ }
+
+ /*
+ * Do the sibling map; assume only two threads per processor.
+ */
+ for_each_cpu(cpu) {
+ cpu_set(cpu, cpu_sibling_map[cpu]);
+ if (cur_cpu_spec->cpu_features & CPU_FTR_SMT)
+ cpu_set(cpu ^ 0x1, cpu_sibling_map[cpu]);
+ }
+
+ systemcfg->processorCount = num_present_cpus();
+}
+#endif /* !defined(CONFIG_PPC_ISERIES) && defined(CONFIG_SMP) */
/*
* Do some initial setup of the system. The parameters are those which
* were passed in from the bootloader.
@@ -220,6 +308,13 @@
}
#endif /* CONFIG_BOOTX_TEXT */

+#ifdef CONFIG_PPC_PMAC
+ if (systemcfg->platform == PLATFORM_POWERMAC) {
+ finish_device_tree();
+ pmac_init(r3, r4, r5, r6, r7);
+ }
+#endif /* CONFIG_PPC_PMAC */
+
#ifdef CONFIG_PPC_PSERIES
if (systemcfg->platform & PLATFORM_PSERIES) {
early_console_initialized = 1;
@@ -227,31 +322,32 @@
__irq_offset_value = NUM_ISA_INTERRUPTS;
finish_device_tree();
chrp_init(r3, r4, r5, r6, r7);
+ }
+#endif /* CONFIG_PPC_PSERIES */

#ifdef CONFIG_SMP
- /* Start secondary threads on SMT systems; primary threads
- * are already in the running state.
- */
- for_each_present_cpu(i) {
- if (query_cpu_stopped
- (get_hard_smp_processor_id(i)) == 0) {
- printk("%16.16x : starting thread\n", i);
- rtas_call(rtas_token("start-cpu"), 3, 1, &ret,
- get_hard_smp_processor_id(i),
- (u32)*((unsigned long *)pseries_secondary_smp_init),
- i);
- }
+#ifndef CONFIG_PPC_ISERIES
+ /*
+ * iSeries has already initialized the cpu maps at this point.
+ */
+ setup_cpu_maps();
+#endif /* CONFIG_PPC_ISERIES */
+
+#ifdef CONFIG_PPC_PSERIES
+ /* Start secondary threads on SMT systems; primary threads
+ * are already in the running state.
+ */
+ for_each_present_cpu(i) {
+ if (query_cpu_stopped(get_hard_smp_processor_id(i)) == 0) {
+ printk("%16.16x : starting thread\n", i);
+ rtas_call(rtas_token("start-cpu"), 3, 1, &ret,
+ get_hard_smp_processor_id(i),
+ (u32)*((unsigned long *)pseries_secondary_smp_init),
+ i);
}
-#endif /* CONFIG_SMP */
}
#endif /* CONFIG_PPC_PSERIES */
-
-#ifdef CONFIG_PPC_PMAC
- if (systemcfg->platform == PLATFORM_POWERMAC) {
- finish_device_tree();
- pmac_init(r3, r4, r5, r6, r7);
- }
-#endif /* CONFIG_PPC_PMAC */
+#endif /* CONFIG_SMP */

#if defined(CONFIG_HOTPLUG_CPU) && !defined(CONFIG_PPC_PMAC)
rtas_stop_self_args.token = rtas_token("stop-self");
diff -urN linux-2.5/arch/ppc64/kernel/smp.c akpm/arch/ppc64/kernel/smp.c
--- linux-2.5/arch/ppc64/kernel/smp.c 2004-08-30 10:55:36.000000000 +1000
+++ akpm/arch/ppc64/kernel/smp.c 2004-08-30 14:51:01.441354208 +1000
@@ -401,56 +401,11 @@
}
return 1;
}
-
-static inline void look_for_more_cpus(void)
-{
- int num_addr_cell, num_size_cell, len, i, maxcpus;
- struct device_node *np;
- unsigned int *ireg;
-
- /* Find the property which will tell us about how many CPUs
- * we're allowed to have. */
- if ((np = find_path_device("/rtas")) == NULL) {
- printk(KERN_ERR "Could not find /rtas in device tree!");
- return;
- }
- num_addr_cell = prom_n_addr_cells(np);
- num_size_cell = prom_n_size_cells(np);
-
- ireg = (unsigned int *)get_property(np, "ibm,lrdr-capacity", &len);
- if (ireg == NULL) {
- /* FIXME: make sure not marked as lrdr_capable() */
- return;
- }
-
- maxcpus = ireg[num_addr_cell + num_size_cell];
-
- /* Double maxcpus for processors which have SMT capability */
- if (cur_cpu_spec->cpu_features & CPU_FTR_SMT)
- maxcpus *= 2;
-
-
- if (maxcpus > NR_CPUS) {
- printk(KERN_WARNING
- "Partition configured for %d cpus, "
- "operating system maximum is %d.\n", maxcpus, NR_CPUS);
- maxcpus = NR_CPUS;
- } else
- printk(KERN_INFO "Partition configured for %d cpus.\n",
- maxcpus);
-
- /* Make those cpus (which might appear later) possible too. */
- for (i = 0; i < maxcpus; i++)
- cpu_set(i, cpu_possible_map);
-}
#else /* ... CONFIG_HOTPLUG_CPU */
static inline int __devinit smp_startup_cpu(unsigned int lcpu)
{
return 1;
}
-static inline void look_for_more_cpus(void)
-{
-}
#endif /* CONFIG_HOTPLUG_CPU */

static void smp_pSeries_kick_cpu(int nr)
@@ -832,8 +787,6 @@
*/
do_gtod.tb_orig_stamp = tb_last_stamp;
systemcfg->tb_orig_stamp = tb_last_stamp;
-
- look_for_more_cpus();
#endif

max_cpus = smp_ops->probe();
@@ -846,19 +799,12 @@
for_each_cpu(cpu)
if (cpu != boot_cpuid)
smp_create_idle(cpu);
-
- for_each_cpu(cpu) {
- cpu_set(cpu, cpu_sibling_map[cpu]);
- if (cur_cpu_spec->cpu_features & CPU_FTR_SMT)
- cpu_set(cpu ^ 0x1, cpu_sibling_map[cpu]);
- }
}

void __devinit smp_prepare_boot_cpu(void)
{
BUG_ON(smp_processor_id() != boot_cpuid);

- /* cpu_possible is set up in prom.c */
cpu_set(boot_cpuid, cpu_online_map);

paca[boot_cpuid].__current = current;
-
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