powerpc/cpu: enable nr_cpus for crash kernel
Subsystems (4)
PATCH v6 1/1 powerpc/cpu: enable nr_cpus for crash kernel
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 <[email protected]>
---
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(-)
arch/powerpc/include/asm/smp.h +1 -0
@@ -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 );
arch/powerpc/kernel/prom.c +94 -29
189 lines not on this page · raw message
arch/powerpc/kernel/setup-common.c +5 -53
87 lines not on this page · raw message
drivers/of/fdt.c +1 -1
@@ -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 );
include/linux/of_fdt.h +2 -0
@@ -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,
Signature · 1 line
2.7.4
I had tested this patch for P9/P8/ guest on powerKVM and powerVM. All of them works fine.
Quoted 364 lines · Pingfan Liu
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()andsmp_setup_cpu_maps().
This patch tries to foldsmp_setup_cpu_maps()into the "previous" oneSigned-off-by Pingfan Liu <[email protected]>---
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 wholesmp_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(-)arch/powerpc/include/asm/smp.h +1
-0@@ -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 );arch/powerpc/kernel/prom.c +94
-29@@ -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 ();arch/powerpc/kernel/setup-common.c +5
-53@@ -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 ();drivers/of/fdt.c +1
-1@@ -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 );include/linux/of_fdt.h +2
-1@@ -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 :
Quoted 11 lines
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()andsmp_setup_cpu_maps().
This patch tries to foldsmp_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
Quoted 342 lines
Signed-off-by Pingfan Liu <[email protected]>---
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 wholesmp_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(-)arch/powerpc/include/asm/smp.h +1
-0@@ -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 );arch/powerpc/kernel/prom.c +94
-29@@ -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 ();arch/powerpc/kernel/setup-common.c +5
-53@@ -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 ();drivers/of/fdt.c +1
-1@@ -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 );include/linux/of_fdt.h +0
-0
include/linux/of_fdt.h extern void *of_fdt_get_property(const void *blob, · line 37
Quoted 8 lines
include/linux/of_fdt.h +2
-0@@ -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,
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Hi Christophe,
The latest series is
https://lore.kernel.org/linuxppc-dev/[email protected]/
And Michael has his implement on:
https://lore.kernel.org/all/[email protected]/T/#m46128446bce1095631162a1927415733a3bf0633
Thanks,
Pingfan
Quoted 376 lines · Christophe Leroy
Hi,
Quoted 11 lines · Pingfan Liu
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()andsmp_setup_cpu_maps().
This patch tries to foldsmp_setup_cpu_maps()into the "previous" oneThis patch is pretty old and doesn't apply anymore. If still relevant can you please rebase and resubmit.
Thanks
ChristopheQuoted 342 lines
Signed-off-by Pingfan Liu <[email protected]>---
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 wholesmp_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(-)arch/powerpc/include/asm/smp.h +1
-0@@ -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 );arch/powerpc/kernel/prom.c +94
-29@@ -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 ();arch/powerpc/kernel/setup-common.c +5
-53@@ -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 ();drivers/of/fdt.c +1
-1@@ -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 );include/linux/of_fdt.h +0
-0include/linux/of_fdt.h extern void *of_fdt_get_property(const void *blob, · line 37
Quoted 8 lines
include/linux/of_fdt.h +2
-0@@ -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,_______________________________________________
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