Re: [PATCHv4 1/3] powerpc, cpu: partially unbind the mapping between cpu logical id and its seq in dt
On Tue, Mar 13, 2018 at 10:58 AM, Benjamin Herrenschmidt
wrote:
> On Mon, 2018-03-12 at 12:43 +0800, Pingfan Liu 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, boot-cpu
>> will always be mapped into the range [0,threads_per_core).
>
> I'm ok with the idea but not fan of the implementation:
>
>> Signed-off-by: Pingfan Liu
>> ---
>> arch/powerpc/include/asm/smp.h | 1 +
>> arch/powerpc/kernel/prom.c | 25 ++---
>> arch/powerpc/kernel/setup-common.c | 21 +
>> 3 files changed, 36 insertions(+), 11 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
>> index fac963e..1299100 100644
>> --- a/arch/powerpc/include/asm/smp.h
>> +++ b/arch/powerpc/include/asm/smp.h
>> @@ -30,6 +30,7 @@
>> #include
>>
>> extern int boot_cpuid;
>> +extern int boot_cpuhwid;
>> extern int spinning_secondaries;
>>
>> extern void cpu_die(void);
>> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
>> index da67606..d0ebb25 100644
>> --- a/arch/powerpc/kernel/prom.c
>> +++ b/arch/powerpc/kernel/prom.c
>> @@ -315,8 +315,7 @@ 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)
>> @@ -341,8 +340,11 @@ static int __init early_init_dt_scan_cpus(unsigned long
>> node,
>> if (fdt_version(initial_boot_params) >= 2) {
>> 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
>> + * the range of [0, thread_per_core)
>> + */
>> + boot_cpuid = i;
>> + found = true;
>> }
>
> Call it boot_thread_id
>
But I think boot_cpuid has the meaning of global index, while the
thread_id has the meaning of index in a core.
>> } else {
>> /*
>> @@ -351,8 +353,10 @@ static int __init early_init_dt_scan_cpus(unsigned long
>> node,
>>* off secondary threads.
>>*/
>> if (of_get_flat_dt_prop(node,
>> - "linux,boot-cpu", NULL) != NULL)
>> - found = boot_cpu_count;
>> + "linux,boot-cpu", NULL) != NULL) {
>> + boot_cpuid = i;
>> + found = true;
>> + }
>> }
>> #ifdef CONFIG_SMP
>> /* logical cpu id is always 0 on UP kernels */
>> @@ -361,13 +365,12 @@ 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;
>> - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
>> + boot_cpuhwid = be32_to_cpu(intserv[boot_cpuid]);
>> + DBG("boot cpu: logical %d physical %d\n", boot_cpuid, boot_cpuhwid);
>> + set_hard_smp_processor_id(boot_cpuid, boot_cpuhwid);
>>
>> /*
>>* 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 66f7cc6..1a67344 100644
>> --- a/arch/powerpc/kernel/setup-common.c
>> +++ b/arch/powerpc/kernel/setup-common.c
>> @@ -86,6 +86,7 @@ struct machdep_calls *machine_id;
>> EXPORT_SYMBOL(machine_id);
>>
>> int boot_cpuid = -1;
>> +int boot_cpuhwid = -1;
>> EXPORT_SYMBOL_GPL(boot_cpuid);
>>
>> /*
>> @@ -459,11 +460,17 @@ static void __init cpu_init_thread_core_maps(int tpc)
>> void __init smp_setup_cpu_maps(void)
>> {
>> struct device_node *dn;
>> + struct device_node *boot_dn = NULL;
>> + bool handling_bootdn = true;
>> int cpu = 0;
>> int nthreads = 1;
>>
>> DBG("smp_setup_cpu_maps()\n");
>>
>> +again:
>> + /* E.g. kexec will not boot from the 1st core. So firstly loop to find
>> out
>> + * the dn of boot-cpu, and map them on
Re: [PATCHv4 1/3] powerpc, cpu: partially unbind the mapping between cpu logical id and its seq in dt
Hi Pingfan, Thank you for the patch! Yet something to improve: [auto build test ERROR on v4.16-rc4] [also build test ERROR on next-20180309] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Pingfan-Liu/powerpc-cpu-partially-unbind-the-mapping-between-cpu-logical-id-and-its-seq-in-dt/20180313-034420 config: powerpc-pq2fads_defconfig (attached as .config) compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=powerpc All errors (new ones prefixed by >>): >> arch/powerpc/kernel/prom.c:79:23: error: 'boot_cpu_count' defined but not >> used [-Werror=unused-variable] static int __initdata boot_cpu_count; ^~ cc1: all warnings being treated as errors vim +/boot_cpu_count +79 arch/powerpc/kernel/prom.c 9b6b563c Paul Mackerras 2005-10-06 71 9b6b563c Paul Mackerras 2005-10-06 72 #ifdef CONFIG_PPC64 28897731 Olof Johansson 2006-04-12 73 int __initdata iommu_is_off; 9b6b563c Paul Mackerras 2005-10-06 74 int __initdata iommu_force_on; cf00a8d1 Paul Mackerras 2005-10-31 75 unsigned long tce_alloc_start, tce_alloc_end; cd3db0c4 Benjamin Herrenschmidt 2010-07-06 76 u64 ppc64_rma_size; 9b6b563c Paul Mackerras 2005-10-06 77 #endif 03bf469a Benjamin Herrenschmidt 2011-05-11 78 static phys_addr_t first_memblock_size; 7ac87abb Matt Evans 2011-05-25 @79 static int __initdata boot_cpu_count; 9b6b563c Paul Mackerras 2005-10-06 80 :: The code at line 79 was first introduced by commit :: 7ac87abb8166b99584149fcfb2efef5773a078e9 powerpc: Fix early boot accounting of CPUs :: TO: Matt Evans :: CC: Benjamin Herrenschmidt --- 0-DAY kernel test infrastructureOpen Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation .config.gz Description: application/gzip ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCHv4 1/3] powerpc, cpu: partially unbind the mapping between cpu logical id and its seq in dt
On Mon, 2018-03-12 at 12:43 +0800, Pingfan Liu 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, boot-cpu
> will always be mapped into the range [0,threads_per_core).
I'm ok with the idea but not fan of the implementation:
> Signed-off-by: Pingfan Liu
> ---
> arch/powerpc/include/asm/smp.h | 1 +
> arch/powerpc/kernel/prom.c | 25 ++---
> arch/powerpc/kernel/setup-common.c | 21 +
> 3 files changed, 36 insertions(+), 11 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
> index fac963e..1299100 100644
> --- a/arch/powerpc/include/asm/smp.h
> +++ b/arch/powerpc/include/asm/smp.h
> @@ -30,6 +30,7 @@
> #include
>
> extern int boot_cpuid;
> +extern int boot_cpuhwid;
> extern int spinning_secondaries;
>
> extern void cpu_die(void);
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index da67606..d0ebb25 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -315,8 +315,7 @@ 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)
> @@ -341,8 +340,11 @@ static int __init early_init_dt_scan_cpus(unsigned long
> node,
> if (fdt_version(initial_boot_params) >= 2) {
> 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
> + * the range of [0, thread_per_core)
> + */
> + boot_cpuid = i;
> + found = true;
> }
Call it boot_thread_id
> } else {
> /*
> @@ -351,8 +353,10 @@ static int __init early_init_dt_scan_cpus(unsigned long
> node,
>* off secondary threads.
>*/
> if (of_get_flat_dt_prop(node,
> - "linux,boot-cpu", NULL) != NULL)
> - found = boot_cpu_count;
> + "linux,boot-cpu", NULL) != NULL) {
> + boot_cpuid = i;
> + found = true;
> + }
> }
> #ifdef CONFIG_SMP
> /* logical cpu id is always 0 on UP kernels */
> @@ -361,13 +365,12 @@ 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;
> - set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
> + boot_cpuhwid = be32_to_cpu(intserv[boot_cpuid]);
> + DBG("boot cpu: logical %d physical %d\n", boot_cpuid, boot_cpuhwid);
> + set_hard_smp_processor_id(boot_cpuid, boot_cpuhwid);
>
> /*
>* 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 66f7cc6..1a67344 100644
> --- a/arch/powerpc/kernel/setup-common.c
> +++ b/arch/powerpc/kernel/setup-common.c
> @@ -86,6 +86,7 @@ struct machdep_calls *machine_id;
> EXPORT_SYMBOL(machine_id);
>
> int boot_cpuid = -1;
> +int boot_cpuhwid = -1;
> EXPORT_SYMBOL_GPL(boot_cpuid);
>
> /*
> @@ -459,11 +460,17 @@ static void __init cpu_init_thread_core_maps(int tpc)
> void __init smp_setup_cpu_maps(void)
> {
> struct device_node *dn;
> + struct device_node *boot_dn = NULL;
> + bool handling_bootdn = true;
> int cpu = 0;
> int nthreads = 1;
>
> DBG("smp_setup_cpu_maps()\n");
>
> +again:
> + /* E.g. kexec will not boot from the 1st core. So firstly loop to find
> out
> + * the dn of boot-cpu, and map them onto [0, nthreads)
> + */
> for_each_node_by_type(dn, "cpu") {
> const __be32 *intserv;
> __be32 cpu_be;
> @@ -488,6 +495,16 @@ void __init smp_setup_cpu_maps(void)
>
> nthreads = len / sizeof(int);
>
> + if (handling
[PATCHv4 1/3] powerpc, cpu: partially unbind the mapping between cpu logical id and its seq in dt
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, boot-cpu
will always be mapped into the range [0,threads_per_core).
Signed-off-by: Pingfan Liu
---
arch/powerpc/include/asm/smp.h | 1 +
arch/powerpc/kernel/prom.c | 25 ++---
arch/powerpc/kernel/setup-common.c | 21 +
3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index fac963e..1299100 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -30,6 +30,7 @@
#include
extern int boot_cpuid;
+extern int boot_cpuhwid;
extern int spinning_secondaries;
extern void cpu_die(void);
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index da67606..d0ebb25 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -315,8 +315,7 @@ 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)
@@ -341,8 +340,11 @@ static int __init early_init_dt_scan_cpus(unsigned long
node,
if (fdt_version(initial_boot_params) >= 2) {
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
+* the range of [0, thread_per_core)
+*/
+ boot_cpuid = i;
+ found = true;
}
} else {
/*
@@ -351,8 +353,10 @@ static int __init early_init_dt_scan_cpus(unsigned long
node,
* off secondary threads.
*/
if (of_get_flat_dt_prop(node,
- "linux,boot-cpu", NULL) != NULL)
- found = boot_cpu_count;
+ "linux,boot-cpu", NULL) != NULL) {
+ boot_cpuid = i;
+ found = true;
+ }
}
#ifdef CONFIG_SMP
/* logical cpu id is always 0 on UP kernels */
@@ -361,13 +365,12 @@ 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;
- set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
+ boot_cpuhwid = be32_to_cpu(intserv[boot_cpuid]);
+ DBG("boot cpu: logical %d physical %d\n", boot_cpuid, boot_cpuhwid);
+ set_hard_smp_processor_id(boot_cpuid, boot_cpuhwid);
/*
* 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 66f7cc6..1a67344 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -86,6 +86,7 @@ struct machdep_calls *machine_id;
EXPORT_SYMBOL(machine_id);
int boot_cpuid = -1;
+int boot_cpuhwid = -1;
EXPORT_SYMBOL_GPL(boot_cpuid);
/*
@@ -459,11 +460,17 @@ static void __init cpu_init_thread_core_maps(int tpc)
void __init smp_setup_cpu_maps(void)
{
struct device_node *dn;
+ struct device_node *boot_dn = NULL;
+ bool handling_bootdn = true;
int cpu = 0;
int nthreads = 1;
DBG("smp_setup_cpu_maps()\n");
+again:
+ /* E.g. kexec will not boot from the 1st core. So firstly loop to find
out
+* the dn of boot-cpu, and map them onto [0, nthreads)
+*/
for_each_node_by_type(dn, "cpu") {
const __be32 *intserv;
__be32 cpu_be;
@@ -488,6 +495,16 @@ void __init smp_setup_cpu_maps(void)
nthreads = len / sizeof(int);
+ if (handling_bootdn) {
+ if (boot_cpuid < nthreads &&
+ be32_to_cpu(intserv[boot_cpuid]) ==
boot_cpuhwid) {
+ boot_dn = dn;
+ }
+ if (boot_dn == NULL)
+
