* [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel
@ 2018-05-22 8:23 Pingfan Liu
2018-05-22 8:49 ` Pingfan Liu
2024-01-25 19:39 ` Christophe Leroy
0 siblings, 2 replies; 4+ messages in thread
From: Pingfan Liu @ 2018-05-22 8:23 UTC (permalink / raw)
To: linuxppc-dev
Cc: kexec, Benjamin Herrenschmidt, Michael Ellerman, Paul Mackerras,
Mahesh J Salgaonkar, Guilherme G . Piccoli, dyoung
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel
2018-05-22 8:23 [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel Pingfan Liu
@ 2018-05-22 8:49 ` Pingfan Liu
2024-01-25 19:39 ` Christophe Leroy
1 sibling, 0 replies; 4+ messages in thread
From: Pingfan Liu @ 2018-05-22 8:49 UTC (permalink / raw)
To: linuxppc-dev
Cc: kexec, Benjamin Herrenschmidt, Michael Ellerman, Paul Mackerras,
Mahesh J Salgaonkar, Guilherme G . Piccoli, Dave Young
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
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel
2018-05-22 8:23 [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel Pingfan Liu
2018-05-22 8:49 ` Pingfan Liu
@ 2024-01-25 19:39 ` Christophe Leroy
2024-01-30 7:28 ` Pingfan Liu
1 sibling, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2024-01-25 19:39 UTC (permalink / raw)
To: Pingfan Liu, linuxppc-dev
Cc: Mahesh J Salgaonkar, dyoung, kexec, Guilherme G . Piccoli
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,
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel
2024-01-25 19:39 ` Christophe Leroy
@ 2024-01-30 7:28 ` Pingfan Liu
0 siblings, 0 replies; 4+ messages in thread
From: Pingfan Liu @ 2024-01-30 7:28 UTC (permalink / raw)
To: Christophe Leroy
Cc: dyoung, linuxppc-dev, kexec, Pingfan Liu, Guilherme G . Piccoli
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
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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2018-05-22 8:23 [PATCH v6 (proposal)] powerpc/cpu: enable nr_cpus for crash kernel Pingfan Liu
2018-05-22 8:49 ` Pingfan Liu
2024-01-25 19:39 ` Christophe Leroy
2024-01-30 7:28 ` Pingfan Liu
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