| Message ID | 1526977424-25243-1-git-send-email-kernelfans@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v6,(proposal)] powerpc/cpu: enable nr_cpus for crash kernel | expand |
I had tested this patch for P9/P8/ guest on powerKVM and powerVM. All of them works fine. On Tue, May 22, 2018 at 4:23 PM, Pingfan Liu <kernelfans@gmail.com> wrote: > For kexec -p, the boot cpu can be not the cpu0, this causes the problem > to alloc paca[]. In theory, there is no requirement to assign cpu's logical > id as its present seq by device tree. But we have something like > cpu_first_thread_sibling(), which makes assumption on the mapping inside > a core. Hence partially changing the mapping, i.e. unbind the mapping of > core while keep the mapping inside a core. After this patch, the core with > boot-cpu will always be mapped into core 0. > > And at present, the code to discovery cpu spreads over two functions: > early_init_dt_scan_cpus() and smp_setup_cpu_maps(). > This patch tries to fold smp_setup_cpu_maps() into the "previous" one > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > --- > v5 -> v6: > simplify the loop logic (Hope it can answer Benjamin's concern) > concentrate the cpu recovery code to early stage (Hope it can answer Michael's concern) > Todo: (if this method is accepted) > fold the whole smp_setup_cpu_maps() > > arch/powerpc/include/asm/smp.h | 1 + > arch/powerpc/kernel/prom.c | 123 ++++++++++++++++++++++++++++--------- > arch/powerpc/kernel/setup-common.c | 58 ++--------------- > drivers/of/fdt.c | 2 +- > include/linux/of_fdt.h | 2 + > 5 files changed, 103 insertions(+), 83 deletions(-) > > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > index fac963e..80c7693 100644 > --- a/arch/powerpc/include/asm/smp.h > +++ b/arch/powerpc/include/asm/smp.h > @@ -30,6 +30,7 @@ > #include <asm/percpu.h> > > extern int boot_cpuid; > +extern int threads_in_core; > extern int spinning_secondaries; > > extern void cpu_die(void); > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index 4922162..2ae0b4a 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -77,7 +77,6 @@ unsigned long tce_alloc_start, tce_alloc_end; > u64 ppc64_rma_size; > #endif > static phys_addr_t first_memblock_size; > -static int __initdata boot_cpu_count; > > static int __init early_parse_mem(char *p) > { > @@ -305,6 +304,14 @@ static void __init check_cpu_feature_properties(unsigned long node) > } > } > > +struct bootinfo { > + int boot_thread_id; > + unsigned int cpu_cnt; > + int cpu_hwids[NR_CPUS]; > + bool avail[NR_CPUS]; > +}; > +static struct bootinfo *bt_info; > + > static int __init early_init_dt_scan_cpus(unsigned long node, > const char *uname, int depth, > void *data) > @@ -312,10 +319,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > const char *type = of_get_flat_dt_prop(node, "device_type", NULL); > const __be32 *prop; > const __be32 *intserv; > - int i, nthreads; > + int i, nthreads, maxidx; > int len; > - int found = -1; > - int found_thread = 0; > + int found_thread = -1; > + struct bootinfo *info = data; > + bool avail; > + int rotate_cnt, id; > > /* We are scanning "cpu" nodes only */ > if (type == NULL || strcmp(type, "cpu") != 0) > @@ -325,8 +334,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len); > if (!intserv) > intserv = of_get_flat_dt_prop(node, "reg", &len); > + avail = of_fdt_device_is_available(initial_boot_params, node); > +#if 0 > + //todo > + if (!avail) > + avail = !of_fdt_property_match_string(node, > + "enable-method", "spin-table"); > +#endif > > - nthreads = len / sizeof(int); > + threads_in_core = nthreads = len / sizeof(int); > > /* > * Now see if any of these threads match our boot cpu. > @@ -338,9 +354,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > * booted proc. > */ > if (fdt_version(initial_boot_params) >= 2) { > + info->cpu_hwids[info->cpu_cnt] = > + be32_to_cpu(intserv[i]); > if (be32_to_cpu(intserv[i]) == > fdt_boot_cpuid_phys(initial_boot_params)) { > - found = boot_cpu_count; > found_thread = i; > } > } else { > @@ -351,22 +368,37 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > */ > if (of_get_flat_dt_prop(node, > "linux,boot-cpu", NULL) != NULL) > - found = boot_cpu_count; > + found_thread = info->cpu_cnt; > } > + info->avail[info->cpu_cnt] = avail; > + > #ifdef CONFIG_SMP > /* logical cpu id is always 0 on UP kernels */ > - boot_cpu_count++; > + info->cpu_cnt++; > #endif > } > > /* Not the boot CPU */ > - if (found < 0) > + if (found_thread < 0) > return 0; > > - DBG("boot cpu: logical %d physical %d\n", found, > + /* always mapping boot-core to core 0 to cope with kexec -p */ > + maxidx = info->cpu_cnt - 1; > + rotate_cnt = nthreads; > + while (rotate_cnt-- > 0) { > + avail = info->avail[maxidx]; > + id = info->cpu_hwids[maxidx]; > + for (i = maxidx; i > 0; i--) { > + info->avail[i] = info->avail[i - 1]; > + info->cpu_hwids[i] = info->cpu_hwids[i - 1]; > + } > + info->avail[i] = avail; > + info->cpu_hwids[i] = id; > + } > + > + info->boot_thread_id = found_thread; > + DBG("boot cpu: logical %d physical %d\n", found_thread, > be32_to_cpu(intserv[found_thread])); > - boot_cpuid = found; > - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread])); > > /* > * PAPR defines "logical" PVR values for cpus that > @@ -675,6 +707,55 @@ static void __init tm_init(void) > static void tm_init(void) { } > #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ > > +static void early_setup_cpu_mapping(void) > +{ > + unsigned int cpu, cnt; > + int nr_cpus_aligned; > + > + bt_info = __va(memblock_alloc(sizeof(struct bootinfo), > + sizeof(unsigned long))); > + memset(bt_info, 0, sizeof(struct bootinfo)); > + bt_info->boot_thread_id = -1; > + /* Retrieve CPU related informations from the flat tree > + * (altivec support, boot CPU ID, ...) > + */ > + of_scan_flat_dt(early_init_dt_scan_cpus, bt_info); > + > + if (bt_info->boot_thread_id < 0) { > + pr_err("Failed to identify boot CPU !\n"); > + BUG(); > + } > + > + boot_cpuid = bt_info->boot_thread_id; > + /* work around subcore mode */ > + nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, threads_in_core); > + if (nr_cpus_aligned != nr_cpu_ids) { > + pr_info("nr_cpus is forced to be aligned up from: %d to: %d\n", > + nr_cpu_ids, nr_cpus_aligned); > + nr_cpu_ids = nr_cpus_aligned; > + } > + cnt = (nr_cpu_ids < bt_info->cpu_cnt) ? nr_cpu_ids > + : bt_info->cpu_cnt; > + > + allocate_pacas(); > + for (cpu = 0; cpu < cnt; cpu++) { > + set_cpu_present(cpu, bt_info->avail[cpu]); > + DBG("set cpu present: %d -> hwid:%d\n", > + cpu, bt_info->cpu_hwids[cpu]); > + set_hard_smp_processor_id(cpu, bt_info->cpu_hwids[cpu]); > + set_cpu_possible(cpu, true); > + } > + > +#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > + /* We'll later wait for secondaries to check in; there are > + * NCPUS-1 non-boot CPUs :-) > + */ > + spinning_secondaries = bt_info->cpu_cnt - 1; > +#endif > + memblock_free(__pa(bt_info), sizeof(struct bootinfo)); > + bt_info = NULL; > +} > + > void __init early_init_devtree(void *params) > { > phys_addr_t limit; > @@ -745,27 +826,11 @@ void __init early_init_devtree(void *params) > * FIXME .. and the initrd too? */ > move_device_tree(); > > - allocate_pacas(); > - > DBG("Scanning CPUs ...\n"); > > dt_cpu_ftrs_scan(); > > - /* Retrieve CPU related informations from the flat tree > - * (altivec support, boot CPU ID, ...) > - */ > - of_scan_flat_dt(early_init_dt_scan_cpus, NULL); > - if (boot_cpuid < 0) { > - printk("Failed to identify boot CPU !\n"); > - BUG(); > - } > - > -#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > - /* We'll later wait for secondaries to check in; there are > - * NCPUS-1 non-boot CPUs :-) > - */ > - spinning_secondaries = boot_cpu_count - 1; > -#endif > + early_setup_cpu_mapping(); > > mmu_early_init_devtree(); > > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c > index 66f7cc6..46d034a 100644 > --- a/arch/powerpc/kernel/setup-common.c > +++ b/arch/powerpc/kernel/setup-common.c > @@ -86,7 +86,9 @@ struct machdep_calls *machine_id; > EXPORT_SYMBOL(machine_id); > > int boot_cpuid = -1; > +int threads_in_core = 1; > EXPORT_SYMBOL_GPL(boot_cpuid); > +EXPORT_SYMBOL_GPL(threads_in_core); > > /* > * These are used in binfmt_elf.c to put aux entries on the stack > @@ -460,61 +462,11 @@ void __init smp_setup_cpu_maps(void) > { > struct device_node *dn; > int cpu = 0; > - int nthreads = 1; > - > - DBG("smp_setup_cpu_maps()\n"); > - > - for_each_node_by_type(dn, "cpu") { > - const __be32 *intserv; > - __be32 cpu_be; > - int j, len; > - > - DBG(" * %pOF...\n", dn); > - > - intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", > - &len); > - if (intserv) { > - DBG(" ibm,ppc-interrupt-server#s -> %d threads\n", > - nthreads); > - } else { > - DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n"); > - intserv = of_get_property(dn, "reg", &len); > - if (!intserv) { > - cpu_be = cpu_to_be32(cpu); > - intserv = &cpu_be; /* assume logical == phys */ > - len = 4; > - } > - } > - > - nthreads = len / sizeof(int); > - > - for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { > - bool avail; > - > - DBG(" thread %d -> cpu %d (hard id %d)\n", > - j, cpu, be32_to_cpu(intserv[j])); > - > - avail = of_device_is_available(dn); > - if (!avail) > - avail = !of_property_match_string(dn, > - "enable-method", "spin-table"); > - > - set_cpu_present(cpu, avail); > - set_hard_smp_processor_id(cpu, be32_to_cpu(intserv[j])); > - set_cpu_possible(cpu, true); > - cpu++; > - } > - > - if (cpu >= nr_cpu_ids) { > - of_node_put(dn); > - break; > - } > - } > > /* If no SMT supported, nthreads is forced to 1 */ > if (!cpu_has_feature(CPU_FTR_SMT)) { > DBG(" SMT disabled ! nthreads forced to 1\n"); > - nthreads = 1; > + threads_in_core = 1; > } > > #ifdef CONFIG_PPC64 > @@ -539,7 +491,7 @@ void __init smp_setup_cpu_maps(void) > > /* Double maxcpus for processors which have SMT capability */ > if (cpu_has_feature(CPU_FTR_SMT)) > - maxcpus *= nthreads; > + maxcpus *= threads_in_core; > > if (maxcpus > nr_cpu_ids) { > printk(KERN_WARNING > @@ -565,7 +517,7 @@ void __init smp_setup_cpu_maps(void) > * every CPU in the system. If that is not the case, then some code > * here will have to be reworked > */ > - cpu_init_thread_core_maps(nthreads); > + cpu_init_thread_core_maps(threads_in_core); > > /* Now that possible cpus are set, set nr_cpu_ids for later use */ > setup_nr_cpu_ids(); > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 84aa9d6..16d6b02 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -130,7 +130,7 @@ bool of_fdt_is_big_endian(const void *blob, unsigned long node) > return false; > } > > -static bool of_fdt_device_is_available(const void *blob, unsigned long node) > +bool of_fdt_device_is_available(const void *blob, unsigned long node) > { > const char *status = fdt_getprop(blob, node, "status", NULL); > > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index b9cd9eb..28756c5 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -30,6 +30,8 @@ extern void *of_fdt_get_property(const void *blob, > int *size); > extern bool of_fdt_is_big_endian(const void *blob, > unsigned long node); > +extern bool of_fdt_device_is_available(const void *blob, > + unsigned long node); > extern int of_fdt_match(const void *blob, unsigned long node, > const char *const *compat); > extern void *of_fdt_unflatten_tree(const unsigned long *blob, > -- > 2.7.4 >
Hi, Le 22/05/2018 à 10:23, Pingfan Liu a écrit : > For kexec -p, the boot cpu can be not the cpu0, this causes the problem > to alloc paca[]. In theory, there is no requirement to assign cpu's logical > id as its present seq by device tree. But we have something like > cpu_first_thread_sibling(), which makes assumption on the mapping inside > a core. Hence partially changing the mapping, i.e. unbind the mapping of > core while keep the mapping inside a core. After this patch, the core with > boot-cpu will always be mapped into core 0. > > And at present, the code to discovery cpu spreads over two functions: > early_init_dt_scan_cpus() and smp_setup_cpu_maps(). > This patch tries to fold smp_setup_cpu_maps() into the "previous" one This patch is pretty old and doesn't apply anymore. If still relevant can you please rebase and resubmit. Thanks Christophe > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > --- > v5 -> v6: > simplify the loop logic (Hope it can answer Benjamin's concern) > concentrate the cpu recovery code to early stage (Hope it can answer Michael's concern) > Todo: (if this method is accepted) > fold the whole smp_setup_cpu_maps() > > arch/powerpc/include/asm/smp.h | 1 + > arch/powerpc/kernel/prom.c | 123 ++++++++++++++++++++++++++++--------- > arch/powerpc/kernel/setup-common.c | 58 ++--------------- > drivers/of/fdt.c | 2 +- > include/linux/of_fdt.h | 2 + > 5 files changed, 103 insertions(+), 83 deletions(-) > > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > index fac963e..80c7693 100644 > --- a/arch/powerpc/include/asm/smp.h > +++ b/arch/powerpc/include/asm/smp.h > @@ -30,6 +30,7 @@ > #include <asm/percpu.h> > > extern int boot_cpuid; > +extern int threads_in_core; > extern int spinning_secondaries; > > extern void cpu_die(void); > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index 4922162..2ae0b4a 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -77,7 +77,6 @@ unsigned long tce_alloc_start, tce_alloc_end; > u64 ppc64_rma_size; > #endif > static phys_addr_t first_memblock_size; > -static int __initdata boot_cpu_count; > > static int __init early_parse_mem(char *p) > { > @@ -305,6 +304,14 @@ static void __init check_cpu_feature_properties(unsigned long node) > } > } > > +struct bootinfo { > + int boot_thread_id; > + unsigned int cpu_cnt; > + int cpu_hwids[NR_CPUS]; > + bool avail[NR_CPUS]; > +}; > +static struct bootinfo *bt_info; > + > static int __init early_init_dt_scan_cpus(unsigned long node, > const char *uname, int depth, > void *data) > @@ -312,10 +319,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > const char *type = of_get_flat_dt_prop(node, "device_type", NULL); > const __be32 *prop; > const __be32 *intserv; > - int i, nthreads; > + int i, nthreads, maxidx; > int len; > - int found = -1; > - int found_thread = 0; > + int found_thread = -1; > + struct bootinfo *info = data; > + bool avail; > + int rotate_cnt, id; > > /* We are scanning "cpu" nodes only */ > if (type == NULL || strcmp(type, "cpu") != 0) > @@ -325,8 +334,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len); > if (!intserv) > intserv = of_get_flat_dt_prop(node, "reg", &len); > + avail = of_fdt_device_is_available(initial_boot_params, node); > +#if 0 > + //todo > + if (!avail) > + avail = !of_fdt_property_match_string(node, > + "enable-method", "spin-table"); > +#endif > > - nthreads = len / sizeof(int); > + threads_in_core = nthreads = len / sizeof(int); > > /* > * Now see if any of these threads match our boot cpu. > @@ -338,9 +354,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > * booted proc. > */ > if (fdt_version(initial_boot_params) >= 2) { > + info->cpu_hwids[info->cpu_cnt] = > + be32_to_cpu(intserv[i]); > if (be32_to_cpu(intserv[i]) == > fdt_boot_cpuid_phys(initial_boot_params)) { > - found = boot_cpu_count; > found_thread = i; > } > } else { > @@ -351,22 +368,37 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > */ > if (of_get_flat_dt_prop(node, > "linux,boot-cpu", NULL) != NULL) > - found = boot_cpu_count; > + found_thread = info->cpu_cnt; > } > + info->avail[info->cpu_cnt] = avail; > + > #ifdef CONFIG_SMP > /* logical cpu id is always 0 on UP kernels */ > - boot_cpu_count++; > + info->cpu_cnt++; > #endif > } > > /* Not the boot CPU */ > - if (found < 0) > + if (found_thread < 0) > return 0; > > - DBG("boot cpu: logical %d physical %d\n", found, > + /* always mapping boot-core to core 0 to cope with kexec -p */ > + maxidx = info->cpu_cnt - 1; > + rotate_cnt = nthreads; > + while (rotate_cnt-- > 0) { > + avail = info->avail[maxidx]; > + id = info->cpu_hwids[maxidx]; > + for (i = maxidx; i > 0; i--) { > + info->avail[i] = info->avail[i - 1]; > + info->cpu_hwids[i] = info->cpu_hwids[i - 1]; > + } > + info->avail[i] = avail; > + info->cpu_hwids[i] = id; > + } > + > + info->boot_thread_id = found_thread; > + DBG("boot cpu: logical %d physical %d\n", found_thread, > be32_to_cpu(intserv[found_thread])); > - boot_cpuid = found; > - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread])); > > /* > * PAPR defines "logical" PVR values for cpus that > @@ -675,6 +707,55 @@ static void __init tm_init(void) > static void tm_init(void) { } > #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ > > +static void early_setup_cpu_mapping(void) > +{ > + unsigned int cpu, cnt; > + int nr_cpus_aligned; > + > + bt_info = __va(memblock_alloc(sizeof(struct bootinfo), > + sizeof(unsigned long))); > + memset(bt_info, 0, sizeof(struct bootinfo)); > + bt_info->boot_thread_id = -1; > + /* Retrieve CPU related informations from the flat tree > + * (altivec support, boot CPU ID, ...) > + */ > + of_scan_flat_dt(early_init_dt_scan_cpus, bt_info); > + > + if (bt_info->boot_thread_id < 0) { > + pr_err("Failed to identify boot CPU !\n"); > + BUG(); > + } > + > + boot_cpuid = bt_info->boot_thread_id; > + /* work around subcore mode */ > + nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, threads_in_core); > + if (nr_cpus_aligned != nr_cpu_ids) { > + pr_info("nr_cpus is forced to be aligned up from: %d to: %d\n", > + nr_cpu_ids, nr_cpus_aligned); > + nr_cpu_ids = nr_cpus_aligned; > + } > + cnt = (nr_cpu_ids < bt_info->cpu_cnt) ? nr_cpu_ids > + : bt_info->cpu_cnt; > + > + allocate_pacas(); > + for (cpu = 0; cpu < cnt; cpu++) { > + set_cpu_present(cpu, bt_info->avail[cpu]); > + DBG("set cpu present: %d -> hwid:%d\n", > + cpu, bt_info->cpu_hwids[cpu]); > + set_hard_smp_processor_id(cpu, bt_info->cpu_hwids[cpu]); > + set_cpu_possible(cpu, true); > + } > + > +#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > + /* We'll later wait for secondaries to check in; there are > + * NCPUS-1 non-boot CPUs :-) > + */ > + spinning_secondaries = bt_info->cpu_cnt - 1; > +#endif > + memblock_free(__pa(bt_info), sizeof(struct bootinfo)); > + bt_info = NULL; > +} > + > void __init early_init_devtree(void *params) > { > phys_addr_t limit; > @@ -745,27 +826,11 @@ void __init early_init_devtree(void *params) > * FIXME .. and the initrd too? */ > move_device_tree(); > > - allocate_pacas(); > - > DBG("Scanning CPUs ...\n"); > > dt_cpu_ftrs_scan(); > > - /* Retrieve CPU related informations from the flat tree > - * (altivec support, boot CPU ID, ...) > - */ > - of_scan_flat_dt(early_init_dt_scan_cpus, NULL); > - if (boot_cpuid < 0) { > - printk("Failed to identify boot CPU !\n"); > - BUG(); > - } > - > -#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > - /* We'll later wait for secondaries to check in; there are > - * NCPUS-1 non-boot CPUs :-) > - */ > - spinning_secondaries = boot_cpu_count - 1; > -#endif > + early_setup_cpu_mapping(); > > mmu_early_init_devtree(); > > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c > index 66f7cc6..46d034a 100644 > --- a/arch/powerpc/kernel/setup-common.c > +++ b/arch/powerpc/kernel/setup-common.c > @@ -86,7 +86,9 @@ struct machdep_calls *machine_id; > EXPORT_SYMBOL(machine_id); > > int boot_cpuid = -1; > +int threads_in_core = 1; > EXPORT_SYMBOL_GPL(boot_cpuid); > +EXPORT_SYMBOL_GPL(threads_in_core); > > /* > * These are used in binfmt_elf.c to put aux entries on the stack > @@ -460,61 +462,11 @@ void __init smp_setup_cpu_maps(void) > { > struct device_node *dn; > int cpu = 0; > - int nthreads = 1; > - > - DBG("smp_setup_cpu_maps()\n"); > - > - for_each_node_by_type(dn, "cpu") { > - const __be32 *intserv; > - __be32 cpu_be; > - int j, len; > - > - DBG(" * %pOF...\n", dn); > - > - intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", > - &len); > - if (intserv) { > - DBG(" ibm,ppc-interrupt-server#s -> %d threads\n", > - nthreads); > - } else { > - DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n"); > - intserv = of_get_property(dn, "reg", &len); > - if (!intserv) { > - cpu_be = cpu_to_be32(cpu); > - intserv = &cpu_be; /* assume logical == phys */ > - len = 4; > - } > - } > - > - nthreads = len / sizeof(int); > - > - for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { > - bool avail; > - > - DBG(" thread %d -> cpu %d (hard id %d)\n", > - j, cpu, be32_to_cpu(intserv[j])); > - > - avail = of_device_is_available(dn); > - if (!avail) > - avail = !of_property_match_string(dn, > - "enable-method", "spin-table"); > - > - set_cpu_present(cpu, avail); > - set_hard_smp_processor_id(cpu, be32_to_cpu(intserv[j])); > - set_cpu_possible(cpu, true); > - cpu++; > - } > - > - if (cpu >= nr_cpu_ids) { > - of_node_put(dn); > - break; > - } > - } > > /* If no SMT supported, nthreads is forced to 1 */ > if (!cpu_has_feature(CPU_FTR_SMT)) { > DBG(" SMT disabled ! nthreads forced to 1\n"); > - nthreads = 1; > + threads_in_core = 1; > } > > #ifdef CONFIG_PPC64 > @@ -539,7 +491,7 @@ void __init smp_setup_cpu_maps(void) > > /* Double maxcpus for processors which have SMT capability */ > if (cpu_has_feature(CPU_FTR_SMT)) > - maxcpus *= nthreads; > + maxcpus *= threads_in_core; > > if (maxcpus > nr_cpu_ids) { > printk(KERN_WARNING > @@ -565,7 +517,7 @@ void __init smp_setup_cpu_maps(void) > * every CPU in the system. If that is not the case, then some code > * here will have to be reworked > */ > - cpu_init_thread_core_maps(nthreads); > + cpu_init_thread_core_maps(threads_in_core); > > /* Now that possible cpus are set, set nr_cpu_ids for later use */ > setup_nr_cpu_ids(); > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 84aa9d6..16d6b02 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -130,7 +130,7 @@ bool of_fdt_is_big_endian(const void *blob, unsigned long node) > return false; > } > > -static bool of_fdt_device_is_available(const void *blob, unsigned long node) > +bool of_fdt_device_is_available(const void *blob, unsigned long node) > { > const char *status = fdt_getprop(blob, node, "status", NULL); > > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index b9cd9eb..28756c5 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -30,6 +30,8 @@ extern void *of_fdt_get_property(const void *blob, > int *size); > extern bool of_fdt_is_big_endian(const void *blob, > unsigned long node); > +extern bool of_fdt_device_is_available(const void *blob, > + unsigned long node); > extern int of_fdt_match(const void *blob, unsigned long node, > const char *const *compat); > extern void *of_fdt_unflatten_tree(const unsigned long *blob,
Hi Christophe, The latest series is https://lore.kernel.org/linuxppc-dev/20231017022806.4523-1-piliu@redhat.com/ And Michael has his implement on: https://lore.kernel.org/all/20231229120107.2281153-3-mpe@ellerman.id.au/T/#m46128446bce1095631162a1927415733a3bf0633 Thanks, Pingfan On Fri, Jan 26, 2024 at 3:40 AM Christophe Leroy <christophe.leroy@csgroup.eu> wrote: > > Hi, > > Le 22/05/2018 à 10:23, Pingfan Liu a écrit : > > For kexec -p, the boot cpu can be not the cpu0, this causes the problem > > to alloc paca[]. In theory, there is no requirement to assign cpu's logical > > id as its present seq by device tree. But we have something like > > cpu_first_thread_sibling(), which makes assumption on the mapping inside > > a core. Hence partially changing the mapping, i.e. unbind the mapping of > > core while keep the mapping inside a core. After this patch, the core with > > boot-cpu will always be mapped into core 0. > > > > And at present, the code to discovery cpu spreads over two functions: > > early_init_dt_scan_cpus() and smp_setup_cpu_maps(). > > This patch tries to fold smp_setup_cpu_maps() into the "previous" one > > This patch is pretty old and doesn't apply anymore. If still relevant > can you please rebase and resubmit. > > Thanks > Christophe > > > > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > > --- > > v5 -> v6: > > simplify the loop logic (Hope it can answer Benjamin's concern) > > concentrate the cpu recovery code to early stage (Hope it can answer Michael's concern) > > Todo: (if this method is accepted) > > fold the whole smp_setup_cpu_maps() > > > > arch/powerpc/include/asm/smp.h | 1 + > > arch/powerpc/kernel/prom.c | 123 ++++++++++++++++++++++++++++--------- > > arch/powerpc/kernel/setup-common.c | 58 ++--------------- > > drivers/of/fdt.c | 2 +- > > include/linux/of_fdt.h | 2 + > > 5 files changed, 103 insertions(+), 83 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > > index fac963e..80c7693 100644 > > --- a/arch/powerpc/include/asm/smp.h > > +++ b/arch/powerpc/include/asm/smp.h > > @@ -30,6 +30,7 @@ > > #include <asm/percpu.h> > > > > extern int boot_cpuid; > > +extern int threads_in_core; > > extern int spinning_secondaries; > > > > extern void cpu_die(void); > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > > index 4922162..2ae0b4a 100644 > > --- a/arch/powerpc/kernel/prom.c > > +++ b/arch/powerpc/kernel/prom.c > > @@ -77,7 +77,6 @@ unsigned long tce_alloc_start, tce_alloc_end; > > u64 ppc64_rma_size; > > #endif > > static phys_addr_t first_memblock_size; > > -static int __initdata boot_cpu_count; > > > > static int __init early_parse_mem(char *p) > > { > > @@ -305,6 +304,14 @@ static void __init check_cpu_feature_properties(unsigned long node) > > } > > } > > > > +struct bootinfo { > > + int boot_thread_id; > > + unsigned int cpu_cnt; > > + int cpu_hwids[NR_CPUS]; > > + bool avail[NR_CPUS]; > > +}; > > +static struct bootinfo *bt_info; > > + > > static int __init early_init_dt_scan_cpus(unsigned long node, > > const char *uname, int depth, > > void *data) > > @@ -312,10 +319,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > const char *type = of_get_flat_dt_prop(node, "device_type", NULL); > > const __be32 *prop; > > const __be32 *intserv; > > - int i, nthreads; > > + int i, nthreads, maxidx; > > int len; > > - int found = -1; > > - int found_thread = 0; > > + int found_thread = -1; > > + struct bootinfo *info = data; > > + bool avail; > > + int rotate_cnt, id; > > > > /* We are scanning "cpu" nodes only */ > > if (type == NULL || strcmp(type, "cpu") != 0) > > @@ -325,8 +334,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len); > > if (!intserv) > > intserv = of_get_flat_dt_prop(node, "reg", &len); > > + avail = of_fdt_device_is_available(initial_boot_params, node); > > +#if 0 > > + //todo > > + if (!avail) > > + avail = !of_fdt_property_match_string(node, > > + "enable-method", "spin-table"); > > +#endif > > > > - nthreads = len / sizeof(int); > > + threads_in_core = nthreads = len / sizeof(int); > > > > /* > > * Now see if any of these threads match our boot cpu. > > @@ -338,9 +354,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > * booted proc. > > */ > > if (fdt_version(initial_boot_params) >= 2) { > > + info->cpu_hwids[info->cpu_cnt] = > > + be32_to_cpu(intserv[i]); > > if (be32_to_cpu(intserv[i]) == > > fdt_boot_cpuid_phys(initial_boot_params)) { > > - found = boot_cpu_count; > > found_thread = i; > > } > > } else { > > @@ -351,22 +368,37 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > */ > > if (of_get_flat_dt_prop(node, > > "linux,boot-cpu", NULL) != NULL) > > - found = boot_cpu_count; > > + found_thread = info->cpu_cnt; > > } > > + info->avail[info->cpu_cnt] = avail; > > + > > #ifdef CONFIG_SMP > > /* logical cpu id is always 0 on UP kernels */ > > - boot_cpu_count++; > > + info->cpu_cnt++; > > #endif > > } > > > > /* Not the boot CPU */ > > - if (found < 0) > > + if (found_thread < 0) > > return 0; > > > > - DBG("boot cpu: logical %d physical %d\n", found, > > + /* always mapping boot-core to core 0 to cope with kexec -p */ > > + maxidx = info->cpu_cnt - 1; > > + rotate_cnt = nthreads; > > + while (rotate_cnt-- > 0) { > > + avail = info->avail[maxidx]; > > + id = info->cpu_hwids[maxidx]; > > + for (i = maxidx; i > 0; i--) { > > + info->avail[i] = info->avail[i - 1]; > > + info->cpu_hwids[i] = info->cpu_hwids[i - 1]; > > + } > > + info->avail[i] = avail; > > + info->cpu_hwids[i] = id; > > + } > > + > > + info->boot_thread_id = found_thread; > > + DBG("boot cpu: logical %d physical %d\n", found_thread, > > be32_to_cpu(intserv[found_thread])); > > - boot_cpuid = found; > > - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread])); > > > > /* > > * PAPR defines "logical" PVR values for cpus that > > @@ -675,6 +707,55 @@ static void __init tm_init(void) > > static void tm_init(void) { } > > #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ > > > > +static void early_setup_cpu_mapping(void) > > +{ > > + unsigned int cpu, cnt; > > + int nr_cpus_aligned; > > + > > + bt_info = __va(memblock_alloc(sizeof(struct bootinfo), > > + sizeof(unsigned long))); > > + memset(bt_info, 0, sizeof(struct bootinfo)); > > + bt_info->boot_thread_id = -1; > > + /* Retrieve CPU related informations from the flat tree > > + * (altivec support, boot CPU ID, ...) > > + */ > > + of_scan_flat_dt(early_init_dt_scan_cpus, bt_info); > > + > > + if (bt_info->boot_thread_id < 0) { > > + pr_err("Failed to identify boot CPU !\n"); > > + BUG(); > > + } > > + > > + boot_cpuid = bt_info->boot_thread_id; > > + /* work around subcore mode */ > > + nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, threads_in_core); > > + if (nr_cpus_aligned != nr_cpu_ids) { > > + pr_info("nr_cpus is forced to be aligned up from: %d to: %d\n", > > + nr_cpu_ids, nr_cpus_aligned); > > + nr_cpu_ids = nr_cpus_aligned; > > + } > > + cnt = (nr_cpu_ids < bt_info->cpu_cnt) ? nr_cpu_ids > > + : bt_info->cpu_cnt; > > + > > + allocate_pacas(); > > + for (cpu = 0; cpu < cnt; cpu++) { > > + set_cpu_present(cpu, bt_info->avail[cpu]); > > + DBG("set cpu present: %d -> hwid:%d\n", > > + cpu, bt_info->cpu_hwids[cpu]); > > + set_hard_smp_processor_id(cpu, bt_info->cpu_hwids[cpu]); > > + set_cpu_possible(cpu, true); > > + } > > + > > +#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > > + /* We'll later wait for secondaries to check in; there are > > + * NCPUS-1 non-boot CPUs :-) > > + */ > > + spinning_secondaries = bt_info->cpu_cnt - 1; > > +#endif > > + memblock_free(__pa(bt_info), sizeof(struct bootinfo)); > > + bt_info = NULL; > > +} > > + > > void __init early_init_devtree(void *params) > > { > > phys_addr_t limit; > > @@ -745,27 +826,11 @@ void __init early_init_devtree(void *params) > > * FIXME .. and the initrd too? */ > > move_device_tree(); > > > > - allocate_pacas(); > > - > > DBG("Scanning CPUs ...\n"); > > > > dt_cpu_ftrs_scan(); > > > > - /* Retrieve CPU related informations from the flat tree > > - * (altivec support, boot CPU ID, ...) > > - */ > > - of_scan_flat_dt(early_init_dt_scan_cpus, NULL); > > - if (boot_cpuid < 0) { > > - printk("Failed to identify boot CPU !\n"); > > - BUG(); > > - } > > - > > -#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) > > - /* We'll later wait for secondaries to check in; there are > > - * NCPUS-1 non-boot CPUs :-) > > - */ > > - spinning_secondaries = boot_cpu_count - 1; > > -#endif > > + early_setup_cpu_mapping(); > > > > mmu_early_init_devtree(); > > > > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c > > index 66f7cc6..46d034a 100644 > > --- a/arch/powerpc/kernel/setup-common.c > > +++ b/arch/powerpc/kernel/setup-common.c > > @@ -86,7 +86,9 @@ struct machdep_calls *machine_id; > > EXPORT_SYMBOL(machine_id); > > > > int boot_cpuid = -1; > > +int threads_in_core = 1; > > EXPORT_SYMBOL_GPL(boot_cpuid); > > +EXPORT_SYMBOL_GPL(threads_in_core); > > > > /* > > * These are used in binfmt_elf.c to put aux entries on the stack > > @@ -460,61 +462,11 @@ void __init smp_setup_cpu_maps(void) > > { > > struct device_node *dn; > > int cpu = 0; > > - int nthreads = 1; > > - > > - DBG("smp_setup_cpu_maps()\n"); > > - > > - for_each_node_by_type(dn, "cpu") { > > - const __be32 *intserv; > > - __be32 cpu_be; > > - int j, len; > > - > > - DBG(" * %pOF...\n", dn); > > - > > - intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", > > - &len); > > - if (intserv) { > > - DBG(" ibm,ppc-interrupt-server#s -> %d threads\n", > > - nthreads); > > - } else { > > - DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n"); > > - intserv = of_get_property(dn, "reg", &len); > > - if (!intserv) { > > - cpu_be = cpu_to_be32(cpu); > > - intserv = &cpu_be; /* assume logical == phys */ > > - len = 4; > > - } > > - } > > - > > - nthreads = len / sizeof(int); > > - > > - for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { > > - bool avail; > > - > > - DBG(" thread %d -> cpu %d (hard id %d)\n", > > - j, cpu, be32_to_cpu(intserv[j])); > > - > > - avail = of_device_is_available(dn); > > - if (!avail) > > - avail = !of_property_match_string(dn, > > - "enable-method", "spin-table"); > > - > > - set_cpu_present(cpu, avail); > > - set_hard_smp_processor_id(cpu, be32_to_cpu(intserv[j])); > > - set_cpu_possible(cpu, true); > > - cpu++; > > - } > > - > > - if (cpu >= nr_cpu_ids) { > > - of_node_put(dn); > > - break; > > - } > > - } > > > > /* If no SMT supported, nthreads is forced to 1 */ > > if (!cpu_has_feature(CPU_FTR_SMT)) { > > DBG(" SMT disabled ! nthreads forced to 1\n"); > > - nthreads = 1; > > + threads_in_core = 1; > > } > > > > #ifdef CONFIG_PPC64 > > @@ -539,7 +491,7 @@ void __init smp_setup_cpu_maps(void) > > > > /* Double maxcpus for processors which have SMT capability */ > > if (cpu_has_feature(CPU_FTR_SMT)) > > - maxcpus *= nthreads; > > + maxcpus *= threads_in_core; > > > > if (maxcpus > nr_cpu_ids) { > > printk(KERN_WARNING > > @@ -565,7 +517,7 @@ void __init smp_setup_cpu_maps(void) > > * every CPU in the system. If that is not the case, then some code > > * here will have to be reworked > > */ > > - cpu_init_thread_core_maps(nthreads); > > + cpu_init_thread_core_maps(threads_in_core); > > > > /* Now that possible cpus are set, set nr_cpu_ids for later use */ > > setup_nr_cpu_ids(); > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > > index 84aa9d6..16d6b02 100644 > > --- a/drivers/of/fdt.c > > +++ b/drivers/of/fdt.c > > @@ -130,7 +130,7 @@ bool of_fdt_is_big_endian(const void *blob, unsigned long node) > > return false; > > } > > > > -static bool of_fdt_device_is_available(const void *blob, unsigned long node) > > +bool of_fdt_device_is_available(const void *blob, unsigned long node) > > { > > const char *status = fdt_getprop(blob, node, "status", NULL); > > > > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > > index b9cd9eb..28756c5 100644 > > --- a/include/linux/of_fdt.h > > +++ b/include/linux/of_fdt.h > > @@ -30,6 +30,8 @@ extern void *of_fdt_get_property(const void *blob, > > int *size); > > extern bool of_fdt_is_big_endian(const void *blob, > > unsigned long node); > > +extern bool of_fdt_device_is_available(const void *blob, > > + unsigned long node); > > extern int of_fdt_match(const void *blob, unsigned long node, > > const char *const *compat); > > extern void *of_fdt_unflatten_tree(const unsigned long *blob, > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index fac963e..80c7693 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -30,6 +30,7 @@ #include <asm/percpu.h> extern int boot_cpuid; +extern int threads_in_core; extern int spinning_secondaries; extern void cpu_die(void); diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 4922162..2ae0b4a 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -77,7 +77,6 @@ unsigned long tce_alloc_start, tce_alloc_end; u64 ppc64_rma_size; #endif static phys_addr_t first_memblock_size; -static int __initdata boot_cpu_count; static int __init early_parse_mem(char *p) { @@ -305,6 +304,14 @@ static void __init check_cpu_feature_properties(unsigned long node) } } +struct bootinfo { + int boot_thread_id; + unsigned int cpu_cnt; + int cpu_hwids[NR_CPUS]; + bool avail[NR_CPUS]; +}; +static struct bootinfo *bt_info; + static int __init early_init_dt_scan_cpus(unsigned long node, const char *uname, int depth, void *data) @@ -312,10 +319,12 @@ static int __init early_init_dt_scan_cpus(unsigned long node, const char *type = of_get_flat_dt_prop(node, "device_type", NULL); const __be32 *prop; const __be32 *intserv; - int i, nthreads; + int i, nthreads, maxidx; int len; - int found = -1; - int found_thread = 0; + int found_thread = -1; + struct bootinfo *info = data; + bool avail; + int rotate_cnt, id; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) @@ -325,8 +334,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len); if (!intserv) intserv = of_get_flat_dt_prop(node, "reg", &len); + avail = of_fdt_device_is_available(initial_boot_params, node); +#if 0 + //todo + if (!avail) + avail = !of_fdt_property_match_string(node, + "enable-method", "spin-table"); +#endif - nthreads = len / sizeof(int); + threads_in_core = nthreads = len / sizeof(int); /* * Now see if any of these threads match our boot cpu. @@ -338,9 +354,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node, * booted proc. */ if (fdt_version(initial_boot_params) >= 2) { + info->cpu_hwids[info->cpu_cnt] = + be32_to_cpu(intserv[i]); if (be32_to_cpu(intserv[i]) == fdt_boot_cpuid_phys(initial_boot_params)) { - found = boot_cpu_count; found_thread = i; } } else { @@ -351,22 +368,37 @@ static int __init early_init_dt_scan_cpus(unsigned long node, */ if (of_get_flat_dt_prop(node, "linux,boot-cpu", NULL) != NULL) - found = boot_cpu_count; + found_thread = info->cpu_cnt; } + info->avail[info->cpu_cnt] = avail; + #ifdef CONFIG_SMP /* logical cpu id is always 0 on UP kernels */ - boot_cpu_count++; + info->cpu_cnt++; #endif } /* Not the boot CPU */ - if (found < 0) + if (found_thread < 0) return 0; - DBG("boot cpu: logical %d physical %d\n", found, + /* always mapping boot-core to core 0 to cope with kexec -p */ + maxidx = info->cpu_cnt - 1; + rotate_cnt = nthreads; + while (rotate_cnt-- > 0) { + avail = info->avail[maxidx]; + id = info->cpu_hwids[maxidx]; + for (i = maxidx; i > 0; i--) { + info->avail[i] = info->avail[i - 1]; + info->cpu_hwids[i] = info->cpu_hwids[i - 1]; + } + info->avail[i] = avail; + info->cpu_hwids[i] = id; + } + + info->boot_thread_id = found_thread; + DBG("boot cpu: logical %d physical %d\n", found_thread, be32_to_cpu(intserv[found_thread])); - boot_cpuid = found; - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread])); /* * PAPR defines "logical" PVR values for cpus that @@ -675,6 +707,55 @@ static void __init tm_init(void) static void tm_init(void) { } #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +static void early_setup_cpu_mapping(void) +{ + unsigned int cpu, cnt; + int nr_cpus_aligned; + + bt_info = __va(memblock_alloc(sizeof(struct bootinfo), + sizeof(unsigned long))); + memset(bt_info, 0, sizeof(struct bootinfo)); + bt_info->boot_thread_id = -1; + /* Retrieve CPU related informations from the flat tree + * (altivec support, boot CPU ID, ...) + */ + of_scan_flat_dt(early_init_dt_scan_cpus, bt_info); + + if (bt_info->boot_thread_id < 0) { + pr_err("Failed to identify boot CPU !\n"); + BUG(); + } + + boot_cpuid = bt_info->boot_thread_id; + /* work around subcore mode */ + nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, threads_in_core); + if (nr_cpus_aligned != nr_cpu_ids) { + pr_info("nr_cpus is forced to be aligned up from: %d to: %d\n", + nr_cpu_ids, nr_cpus_aligned); + nr_cpu_ids = nr_cpus_aligned; + } + cnt = (nr_cpu_ids < bt_info->cpu_cnt) ? nr_cpu_ids + : bt_info->cpu_cnt; + + allocate_pacas(); + for (cpu = 0; cpu < cnt; cpu++) { + set_cpu_present(cpu, bt_info->avail[cpu]); + DBG("set cpu present: %d -> hwid:%d\n", + cpu, bt_info->cpu_hwids[cpu]); + set_hard_smp_processor_id(cpu, bt_info->cpu_hwids[cpu]); + set_cpu_possible(cpu, true); + } + +#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) + /* We'll later wait for secondaries to check in; there are + * NCPUS-1 non-boot CPUs :-) + */ + spinning_secondaries = bt_info->cpu_cnt - 1; +#endif + memblock_free(__pa(bt_info), sizeof(struct bootinfo)); + bt_info = NULL; +} + void __init early_init_devtree(void *params) { phys_addr_t limit; @@ -745,27 +826,11 @@ void __init early_init_devtree(void *params) * FIXME .. and the initrd too? */ move_device_tree(); - allocate_pacas(); - DBG("Scanning CPUs ...\n"); dt_cpu_ftrs_scan(); - /* Retrieve CPU related informations from the flat tree - * (altivec support, boot CPU ID, ...) - */ - of_scan_flat_dt(early_init_dt_scan_cpus, NULL); - if (boot_cpuid < 0) { - printk("Failed to identify boot CPU !\n"); - BUG(); - } - -#if defined(CONFIG_SMP) && defined(CONFIG_PPC64) - /* We'll later wait for secondaries to check in; there are - * NCPUS-1 non-boot CPUs :-) - */ - spinning_secondaries = boot_cpu_count - 1; -#endif + early_setup_cpu_mapping(); mmu_early_init_devtree(); diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 66f7cc6..46d034a 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -86,7 +86,9 @@ struct machdep_calls *machine_id; EXPORT_SYMBOL(machine_id); int boot_cpuid = -1; +int threads_in_core = 1; EXPORT_SYMBOL_GPL(boot_cpuid); +EXPORT_SYMBOL_GPL(threads_in_core); /* * These are used in binfmt_elf.c to put aux entries on the stack @@ -460,61 +462,11 @@ void __init smp_setup_cpu_maps(void) { struct device_node *dn; int cpu = 0; - int nthreads = 1; - - DBG("smp_setup_cpu_maps()\n"); - - for_each_node_by_type(dn, "cpu") { - const __be32 *intserv; - __be32 cpu_be; - int j, len; - - DBG(" * %pOF...\n", dn); - - intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", - &len); - if (intserv) { - DBG(" ibm,ppc-interrupt-server#s -> %d threads\n", - nthreads); - } else { - DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n"); - intserv = of_get_property(dn, "reg", &len); - if (!intserv) { - cpu_be = cpu_to_be32(cpu); - intserv = &cpu_be; /* assume logical == phys */ - len = 4; - } - } - - nthreads = len / sizeof(int); - - for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { - bool avail; - - DBG(" thread %d -> cpu %d (hard id %d)\n", - j, cpu, be32_to_cpu(intserv[j])); - - avail = of_device_is_available(dn); - if (!avail) - avail = !of_property_match_string(dn, - "enable-method", "spin-table"); - - set_cpu_present(cpu, avail); - set_hard_smp_processor_id(cpu, be32_to_cpu(intserv[j])); - set_cpu_possible(cpu, true); - cpu++; - } - - if (cpu >= nr_cpu_ids) { - of_node_put(dn); - break; - } - } /* If no SMT supported, nthreads is forced to 1 */ if (!cpu_has_feature(CPU_FTR_SMT)) { DBG(" SMT disabled ! nthreads forced to 1\n"); - nthreads = 1; + threads_in_core = 1; } #ifdef CONFIG_PPC64 @@ -539,7 +491,7 @@ void __init smp_setup_cpu_maps(void) /* Double maxcpus for processors which have SMT capability */ if (cpu_has_feature(CPU_FTR_SMT)) - maxcpus *= nthreads; + maxcpus *= threads_in_core; if (maxcpus > nr_cpu_ids) { printk(KERN_WARNING @@ -565,7 +517,7 @@ void __init smp_setup_cpu_maps(void) * every CPU in the system. If that is not the case, then some code * here will have to be reworked */ - cpu_init_thread_core_maps(nthreads); + cpu_init_thread_core_maps(threads_in_core); /* Now that possible cpus are set, set nr_cpu_ids for later use */ setup_nr_cpu_ids(); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 84aa9d6..16d6b02 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -130,7 +130,7 @@ bool of_fdt_is_big_endian(const void *blob, unsigned long node) return false; } -static bool of_fdt_device_is_available(const void *blob, unsigned long node) +bool of_fdt_device_is_available(const void *blob, unsigned long node) { const char *status = fdt_getprop(blob, node, "status", NULL); diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index b9cd9eb..28756c5 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -30,6 +30,8 @@ extern void *of_fdt_get_property(const void *blob, int *size); extern bool of_fdt_is_big_endian(const void *blob, unsigned long node); +extern bool of_fdt_device_is_available(const void *blob, + unsigned long node); extern int of_fdt_match(const void *blob, unsigned long node, const char *const *compat); extern void *of_fdt_unflatten_tree(const unsigned long *blob,
For kexec -p, the boot cpu can be not the cpu0, this causes the problem to alloc paca[]. In theory, there is no requirement to assign cpu's logical id as its present seq by device tree. But we have something like cpu_first_thread_sibling(), which makes assumption on the mapping inside a core. Hence partially changing the mapping, i.e. unbind the mapping of core while keep the mapping inside a core. After this patch, the core with boot-cpu will always be mapped into core 0. And at present, the code to discovery cpu spreads over two functions: early_init_dt_scan_cpus() and smp_setup_cpu_maps(). This patch tries to fold smp_setup_cpu_maps() into the "previous" one Signed-off-by: Pingfan Liu <kernelfans@gmail.com> --- v5 -> v6: simplify the loop logic (Hope it can answer Benjamin's concern) concentrate the cpu recovery code to early stage (Hope it can answer Michael's concern) Todo: (if this method is accepted) fold the whole smp_setup_cpu_maps() arch/powerpc/include/asm/smp.h | 1 + arch/powerpc/kernel/prom.c | 123 ++++++++++++++++++++++++++++--------- arch/powerpc/kernel/setup-common.c | 58 ++--------------- drivers/of/fdt.c | 2 +- include/linux/of_fdt.h | 2 + 5 files changed, 103 insertions(+), 83 deletions(-)