| Message ID | 20231009113036.45988-3-piliu@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | enable nr_cpus for powerpc | expand |
On 09/10/23 5:00 pm, Pingfan Liu wrote: > *** Idea *** > For kexec -p, the boot cpu can be not the cpu0, this causes the problem > of allocating memory for paca_ptrs[]. However, in theory, there is no > requirement to assign cpu's logical id as its present sequence in the > device tree. But there is something like cpu_first_thread_sibling(), > which makes assumption on the mapping inside a core. Hence partially > loosening the mapping, i.e. unbind the mapping of core while keep the > mapping inside a core. > > *** Implement *** > At this early stage, there are plenty of memory to utilize. Hence, this > patch allocates interim memory to link the cpu info on a list, then > reorder cpus by changing the list head. As a result, there is a rotate > shift between the sequence number in dt and the cpu logical number. > > *** Result *** > After this patch, a boot-cpu's logical id will always be mapped into the > range [0,threads_per_core). > > Besides this, at this phase, all threads in the boot core are forced to > be onlined. This restriction will be lifted in a later patch with > extra effort. > > Signed-off-by: Pingfan Liu <piliu@redhat.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu> > Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> > Cc: Wen Xiong <wenxiong@us.ibm.com> > Cc: Baoquan He <bhe@redhat.com> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: kexec@lists.infradead.org > To: linuxppc-dev@lists.ozlabs.org > --- > arch/powerpc/kernel/prom.c | 25 +++++---- > arch/powerpc/kernel/setup-common.c | 87 +++++++++++++++++++++++------- > 2 files changed, 85 insertions(+), 27 deletions(-) > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index ec82f5bda908..87272a2d8c10 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -76,7 +76,9 @@ u64 ppc64_rma_size; > unsigned int boot_cpu_node_count __ro_after_init; > #endif > static phys_addr_t first_memblock_size; > +#ifdef CONFIG_SMP > static int __initdata boot_cpu_count; > +#endif > > static int __init early_parse_mem(char *p) > { > @@ -331,8 +333,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > const __be32 *intserv; > int i, nthreads; > int len; > - int found = -1; > - int found_thread = 0; > + bool found = false; > > /* We are scanning "cpu" nodes only */ > if (type == NULL || strcmp(type, "cpu") != 0) > @@ -355,8 +356,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > for (i = 0; i < nthreads; i++) { > if (be32_to_cpu(intserv[i]) == > fdt_boot_cpuid_phys(initial_boot_params)) { > - found = boot_cpu_count; > - found_thread = i; > + /* > + * always map the boot-cpu logical id into the > + * range of [0, thread_per_core) > + */ > + boot_cpuid = i; > + found = true; > + /* This works around the hole in paca_ptrs[]. */ > + if (nr_cpu_ids < nthreads) > + set_nr_cpu_ids(nthreads); > } > #ifdef CONFIG_SMP > /* logical cpu id is always 0 on UP kernels */ > @@ -365,14 +373,13 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > } > > /* Not the boot CPU */ > - if (found < 0) > + if (!found) > return 0; > > - DBG("boot cpu: logical %d physical %d\n", found, > - be32_to_cpu(intserv[found_thread])); > - boot_cpuid = found; > + DBG("boot cpu: logical %d physical %d\n", boot_cpuid, > + be32_to_cpu(intserv[boot_cpuid])); > > - boot_cpu_hwid = be32_to_cpu(intserv[found_thread]); > + boot_cpu_hwid = be32_to_cpu(intserv[boot_cpuid]); > > /* > * PAPR defines "logical" PVR values for cpus that > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c > index 1b19a9815672..81291e13dec0 100644 > --- a/arch/powerpc/kernel/setup-common.c > +++ b/arch/powerpc/kernel/setup-common.c > @@ -36,6 +36,7 @@ > #include <linux/of_platform.h> > #include <linux/hugetlb.h> > #include <linux/pgtable.h> > +#include <linux/list.h> > #include <asm/io.h> > #include <asm/paca.h> > #include <asm/processor.h> > @@ -425,6 +426,13 @@ static void __init cpu_init_thread_core_maps(int tpc) > > u32 *cpu_to_phys_id = NULL; > > +struct interrupt_server_node { > + struct list_head node; > + bool avail; > + int len; > + __be32 *intserv; > +}; > + > /** > * setup_cpu_maps - initialize the following cpu maps: > * cpu_possible_mask > @@ -446,11 +454,16 @@ u32 *cpu_to_phys_id = NULL; > void __init smp_setup_cpu_maps(void) > { > struct device_node *dn; > - int cpu = 0; > - int nthreads = 1; > + int shift = 0, cpu = 0; > + int j, nthreads = 1; > + int len; > + struct interrupt_server_node *intserv_node, *n; > + struct list_head *bt_node, head; > + bool avail, found_boot_cpu = false; > > DBG("smp_setup_cpu_maps()\n"); > > + INIT_LIST_HEAD(&head); > cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32), > __alignof__(u32)); > if (!cpu_to_phys_id) > @@ -460,7 +473,6 @@ void __init smp_setup_cpu_maps(void) > for_each_node_by_type(dn, "cpu") { > const __be32 *intserv; > __be32 cpu_be; > - int j, len; > > DBG(" * %pOF...\n", dn); > > @@ -480,29 +492,68 @@ void __init smp_setup_cpu_maps(void) > } > } > > - nthreads = len / sizeof(int); > + avail = of_device_is_available(dn); > + if (!avail) > + avail = !of_property_match_string(dn, > + "enable-method", "spin-table"); > > - 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"); > + intserv_node = memblock_alloc(sizeof(struct interrupt_server_node) + len, > + __alignof__(u32)); > + if (!intserv_node) > + panic("%s: Failed to allocate %zu bytes align=0x%zx\n", > + __func__, > + sizeof(struct interrupt_server_node) + len, > + __alignof__(u32)); > + intserv_node->intserv = (__be32 *)((char *)intserv_node + > + sizeof(struct interrupt_server_node)); This initialization won't be needed if the member was: __be32 intserv[]; > + intserv_node->len = len; > + memcpy(intserv_node->intserv, intserv, len); > + intserv_node->avail = avail; > + INIT_LIST_HEAD(&intserv_node->node); > + list_add_tail(&intserv_node->node, &head); INIT_LIST_HEAD(&intserv_node->node); is not needed as list_add_tail() initializes both next & prev anyway. Thanks Hari
On Tue, Oct 10, 2023 at 04:07:00PM +0530, Hari Bathini wrote: > > > On 09/10/23 5:00 pm, Pingfan Liu wrote: > > *** Idea *** > > For kexec -p, the boot cpu can be not the cpu0, this causes the problem > > of allocating memory for paca_ptrs[]. However, in theory, there is no > > requirement to assign cpu's logical id as its present sequence in the > > device tree. But there is something like cpu_first_thread_sibling(), > > which makes assumption on the mapping inside a core. Hence partially > > loosening the mapping, i.e. unbind the mapping of core while keep the > > mapping inside a core. > > > > *** Implement *** > > At this early stage, there are plenty of memory to utilize. Hence, this > > patch allocates interim memory to link the cpu info on a list, then > > reorder cpus by changing the list head. As a result, there is a rotate > > shift between the sequence number in dt and the cpu logical number. > > > > *** Result *** > > After this patch, a boot-cpu's logical id will always be mapped into the > > range [0,threads_per_core). > > > > Besides this, at this phase, all threads in the boot core are forced to > > be onlined. This restriction will be lifted in a later patch with > > extra effort. > > > > Signed-off-by: Pingfan Liu <piliu@redhat.com> > > Cc: Michael Ellerman <mpe@ellerman.id.au> > > Cc: Nicholas Piggin <npiggin@gmail.com> > > Cc: Christophe Leroy <christophe.leroy@csgroup.eu> > > Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> > > Cc: Wen Xiong <wenxiong@us.ibm.com> > > Cc: Baoquan He <bhe@redhat.com> > > Cc: Ming Lei <ming.lei@redhat.com> > > Cc: kexec@lists.infradead.org > > To: linuxppc-dev@lists.ozlabs.org > > --- > > arch/powerpc/kernel/prom.c | 25 +++++---- > > arch/powerpc/kernel/setup-common.c | 87 +++++++++++++++++++++++------- > > 2 files changed, 85 insertions(+), 27 deletions(-) > > > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > > index ec82f5bda908..87272a2d8c10 100644 > > --- a/arch/powerpc/kernel/prom.c > > +++ b/arch/powerpc/kernel/prom.c > > @@ -76,7 +76,9 @@ u64 ppc64_rma_size; > > unsigned int boot_cpu_node_count __ro_after_init; > > #endif > > static phys_addr_t first_memblock_size; > > +#ifdef CONFIG_SMP > > static int __initdata boot_cpu_count; > > +#endif > > static int __init early_parse_mem(char *p) > > { > > @@ -331,8 +333,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > const __be32 *intserv; > > int i, nthreads; > > int len; > > - int found = -1; > > - int found_thread = 0; > > + bool found = false; > > /* We are scanning "cpu" nodes only */ > > if (type == NULL || strcmp(type, "cpu") != 0) > > @@ -355,8 +356,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > for (i = 0; i < nthreads; i++) { > > if (be32_to_cpu(intserv[i]) == > > fdt_boot_cpuid_phys(initial_boot_params)) { > > - found = boot_cpu_count; > > - found_thread = i; > > + /* > > + * always map the boot-cpu logical id into the > > + * range of [0, thread_per_core) > > + */ > > + boot_cpuid = i; > > + found = true; > > + /* This works around the hole in paca_ptrs[]. */ > > + if (nr_cpu_ids < nthreads) > > + set_nr_cpu_ids(nthreads); > > } > > #ifdef CONFIG_SMP > > /* logical cpu id is always 0 on UP kernels */ > > @@ -365,14 +373,13 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > } > > /* Not the boot CPU */ > > - if (found < 0) > > + if (!found) > > return 0; > > - DBG("boot cpu: logical %d physical %d\n", found, > > - be32_to_cpu(intserv[found_thread])); > > - boot_cpuid = found; > > + DBG("boot cpu: logical %d physical %d\n", boot_cpuid, > > + be32_to_cpu(intserv[boot_cpuid])); > > - boot_cpu_hwid = be32_to_cpu(intserv[found_thread]); > > + boot_cpu_hwid = be32_to_cpu(intserv[boot_cpuid]); > > /* > > * PAPR defines "logical" PVR values for cpus that > > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c > > index 1b19a9815672..81291e13dec0 100644 > > --- a/arch/powerpc/kernel/setup-common.c > > +++ b/arch/powerpc/kernel/setup-common.c > > @@ -36,6 +36,7 @@ > > #include <linux/of_platform.h> > > #include <linux/hugetlb.h> > > #include <linux/pgtable.h> > > +#include <linux/list.h> > > #include <asm/io.h> > > #include <asm/paca.h> > > #include <asm/processor.h> > > @@ -425,6 +426,13 @@ static void __init cpu_init_thread_core_maps(int tpc) > > u32 *cpu_to_phys_id = NULL; > > +struct interrupt_server_node { > > + struct list_head node; > > + bool avail; > > + int len; > > + __be32 *intserv; > > +}; > > + > > /** > > * setup_cpu_maps - initialize the following cpu maps: > > * cpu_possible_mask > > @@ -446,11 +454,16 @@ u32 *cpu_to_phys_id = NULL; > > void __init smp_setup_cpu_maps(void) > > { > > struct device_node *dn; > > - int cpu = 0; > > - int nthreads = 1; > > + int shift = 0, cpu = 0; > > + int j, nthreads = 1; > > + int len; > > + struct interrupt_server_node *intserv_node, *n; > > + struct list_head *bt_node, head; > > + bool avail, found_boot_cpu = false; > > DBG("smp_setup_cpu_maps()\n"); > > + INIT_LIST_HEAD(&head); > > cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32), > > __alignof__(u32)); > > if (!cpu_to_phys_id) > > @@ -460,7 +473,6 @@ void __init smp_setup_cpu_maps(void) > > for_each_node_by_type(dn, "cpu") { > > const __be32 *intserv; > > __be32 cpu_be; > > - int j, len; > > DBG(" * %pOF...\n", dn); > > @@ -480,29 +492,68 @@ void __init smp_setup_cpu_maps(void) > > } > > } > > - nthreads = len / sizeof(int); > > + avail = of_device_is_available(dn); > > + if (!avail) > > + avail = !of_property_match_string(dn, > > + "enable-method", "spin-table"); > > - 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"); > > + intserv_node = memblock_alloc(sizeof(struct interrupt_server_node) + len, > > + __alignof__(u32)); > > + if (!intserv_node) > > + panic("%s: Failed to allocate %zu bytes align=0x%zx\n", > > + __func__, > > + sizeof(struct interrupt_server_node) + len, > > + __alignof__(u32)); > > > + intserv_node->intserv = (__be32 *)((char *)intserv_node + > > + sizeof(struct interrupt_server_node)); > > This initialization won't be needed if the member was: > > __be32 intserv[]; > Thank you, I will use your suggestion. > > + intserv_node->len = len; > > + memcpy(intserv_node->intserv, intserv, len); > > + intserv_node->avail = avail; > > > + INIT_LIST_HEAD(&intserv_node->node); > > + list_add_tail(&intserv_node->node, &head); > > INIT_LIST_HEAD(&intserv_node->node); is not needed as list_add_tail() > initializes both next & prev anyway. > You are right. I will remove the unnecessary initialization in the next version. Thanks, Pingfan
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index ec82f5bda908..87272a2d8c10 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -76,7 +76,9 @@ u64 ppc64_rma_size; unsigned int boot_cpu_node_count __ro_after_init; #endif static phys_addr_t first_memblock_size; +#ifdef CONFIG_SMP static int __initdata boot_cpu_count; +#endif static int __init early_parse_mem(char *p) { @@ -331,8 +333,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, const __be32 *intserv; int i, nthreads; int len; - int found = -1; - int found_thread = 0; + bool found = false; /* We are scanning "cpu" nodes only */ if (type == NULL || strcmp(type, "cpu") != 0) @@ -355,8 +356,15 @@ static int __init early_init_dt_scan_cpus(unsigned long node, for (i = 0; i < nthreads; i++) { if (be32_to_cpu(intserv[i]) == fdt_boot_cpuid_phys(initial_boot_params)) { - found = boot_cpu_count; - found_thread = i; + /* + * always map the boot-cpu logical id into the + * range of [0, thread_per_core) + */ + boot_cpuid = i; + found = true; + /* This works around the hole in paca_ptrs[]. */ + if (nr_cpu_ids < nthreads) + set_nr_cpu_ids(nthreads); } #ifdef CONFIG_SMP /* logical cpu id is always 0 on UP kernels */ @@ -365,14 +373,13 @@ static int __init early_init_dt_scan_cpus(unsigned long node, } /* Not the boot CPU */ - if (found < 0) + if (!found) return 0; - DBG("boot cpu: logical %d physical %d\n", found, - be32_to_cpu(intserv[found_thread])); - boot_cpuid = found; + DBG("boot cpu: logical %d physical %d\n", boot_cpuid, + be32_to_cpu(intserv[boot_cpuid])); - boot_cpu_hwid = be32_to_cpu(intserv[found_thread]); + boot_cpu_hwid = be32_to_cpu(intserv[boot_cpuid]); /* * PAPR defines "logical" PVR values for cpus that diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 1b19a9815672..81291e13dec0 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -36,6 +36,7 @@ #include <linux/of_platform.h> #include <linux/hugetlb.h> #include <linux/pgtable.h> +#include <linux/list.h> #include <asm/io.h> #include <asm/paca.h> #include <asm/processor.h> @@ -425,6 +426,13 @@ static void __init cpu_init_thread_core_maps(int tpc) u32 *cpu_to_phys_id = NULL; +struct interrupt_server_node { + struct list_head node; + bool avail; + int len; + __be32 *intserv; +}; + /** * setup_cpu_maps - initialize the following cpu maps: * cpu_possible_mask @@ -446,11 +454,16 @@ u32 *cpu_to_phys_id = NULL; void __init smp_setup_cpu_maps(void) { struct device_node *dn; - int cpu = 0; - int nthreads = 1; + int shift = 0, cpu = 0; + int j, nthreads = 1; + int len; + struct interrupt_server_node *intserv_node, *n; + struct list_head *bt_node, head; + bool avail, found_boot_cpu = false; DBG("smp_setup_cpu_maps()\n"); + INIT_LIST_HEAD(&head); cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32), __alignof__(u32)); if (!cpu_to_phys_id) @@ -460,7 +473,6 @@ void __init smp_setup_cpu_maps(void) for_each_node_by_type(dn, "cpu") { const __be32 *intserv; __be32 cpu_be; - int j, len; DBG(" * %pOF...\n", dn); @@ -480,29 +492,68 @@ void __init smp_setup_cpu_maps(void) } } - nthreads = len / sizeof(int); + avail = of_device_is_available(dn); + if (!avail) + avail = !of_property_match_string(dn, + "enable-method", "spin-table"); - 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"); + intserv_node = memblock_alloc(sizeof(struct interrupt_server_node) + len, + __alignof__(u32)); + if (!intserv_node) + panic("%s: Failed to allocate %zu bytes align=0x%zx\n", + __func__, + sizeof(struct interrupt_server_node) + len, + __alignof__(u32)); + intserv_node->intserv = (__be32 *)((char *)intserv_node + + sizeof(struct interrupt_server_node)); + intserv_node->len = len; + memcpy(intserv_node->intserv, intserv, len); + intserv_node->avail = avail; + INIT_LIST_HEAD(&intserv_node->node); + list_add_tail(&intserv_node->node, &head); + + if (!found_boot_cpu) { + nthreads = len / sizeof(int); + for (j = 0 ; j < nthreads; j++) { + if (be32_to_cpu(intserv[j]) == boot_cpu_hwid) { + bt_node = &intserv_node->node; + found_boot_cpu = true; + /* + * Record the round-shift between dt + * seq and cpu logical number + */ + shift = cpu - j; + break; + } + + cpu++; + } + } + } + cpu = 0; + list_del_init(&head); + /* Select the primary thread, the boot cpu's slibing, as the logic 0 */ + list_add_tail(&head, bt_node); + pr_info("the round shift between dt seq and the cpu logic number: %d\n", shift); + list_for_each_entry(intserv_node, &head, node) { + + avail = intserv_node->avail; + nthreads = intserv_node->len / sizeof(int); + for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { set_cpu_present(cpu, avail); set_cpu_possible(cpu, true); - cpu_to_phys_id[cpu] = be32_to_cpu(intserv[j]); + cpu_to_phys_id[cpu] = be32_to_cpu(intserv_node->intserv[j]); + DBG(" thread %d -> cpu %d (hard id %d)\n", + j, cpu, be32_to_cpu(intserv_node->intserv[j])); cpu++; } + } - if (cpu >= nr_cpu_ids) { - of_node_put(dn); - break; - } + list_for_each_entry_safe(intserv_node, n, &head, node) { + len = sizeof(struct interrupt_server_node) + intserv_node->len; + memblock_free(intserv_node, len); } /* If no SMT supported, nthreads is forced to 1 */
*** Idea *** For kexec -p, the boot cpu can be not the cpu0, this causes the problem of allocating memory for paca_ptrs[]. However, in theory, there is no requirement to assign cpu's logical id as its present sequence in the device tree. But there is something like cpu_first_thread_sibling(), which makes assumption on the mapping inside a core. Hence partially loosening the mapping, i.e. unbind the mapping of core while keep the mapping inside a core. *** Implement *** At this early stage, there are plenty of memory to utilize. Hence, this patch allocates interim memory to link the cpu info on a list, then reorder cpus by changing the list head. As a result, there is a rotate shift between the sequence number in dt and the cpu logical number. *** Result *** After this patch, a boot-cpu's logical id will always be mapped into the range [0,threads_per_core). Besides this, at this phase, all threads in the boot core are forced to be onlined. This restriction will be lifted in a later patch with extra effort. Signed-off-by: Pingfan Liu <piliu@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> Cc: Wen Xiong <wenxiong@us.ibm.com> Cc: Baoquan He <bhe@redhat.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: kexec@lists.infradead.org To: linuxppc-dev@lists.ozlabs.org --- arch/powerpc/kernel/prom.c | 25 +++++---- arch/powerpc/kernel/setup-common.c | 87 +++++++++++++++++++++++------- 2 files changed, 85 insertions(+), 27 deletions(-)