[v1 PATCH 1/4] RISC-V: Add RISC-V specific arch_match_cpu_phys_id

[v1 PATCH 1/4] RISC-V: Add RISC-V specific arch_match_cpu_phys_id

[Atish Patra]

OF/DT core has a hook for architecture specific logical cpuid to hartid
mapping. By implementing this, we can pass the logical cpu id to cpu
node parsing functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/smp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 0c41d07e..94db7266 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -70,6 +70,11 @@ void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
 	for_each_cpu(cpu, in)
 		cpumask_set_cpu(cpuid_to_hartid_map(cpu), out);
 }
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return phys_id == cpuid_to_hartid_map(cpu);
+}
 /* Unsupported */
 int setup_profiling_timer(unsigned int multiplier)
 {
-- 
2.21.0

[v1 PATCH 2/4] RISC-V: Fix of_get_cpu_node usage

[Atish Patra]

of_get_cpu_node expects a logical cpu id not a hartid.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/cpu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index cf2fca12..c8d2a322 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -136,8 +136,7 @@ static void c_stop(struct seq_file *m, void *v)
 static int c_show(struct seq_file *m, void *v)
 {
 	unsigned long cpu_id = (unsigned long)v - 1;
-	struct device_node *node = of_get_cpu_node(cpuid_to_hartid_map(cpu_id),
-						   NULL);
+	struct device_node *node = of_get_cpu_node(cpu_id, NULL);
 	const char *compat, *isa, *mmu;
 
 	seq_printf(m, "processor\t: %lu\n", cpu_id);
-- 
2.21.0

[v1 PATCH 3/4] RISC-V: Implement nosmp commandline option.

[Atish Patra]

nosmp command line option sets max_cpus to zero. No secondary harts
will boot if this is enabled. But present cpu mask will still point to
all possible masks.

Fix present cpu mask for nosmp usecase.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/smpboot.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index df353199..609475c5 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -49,6 +49,17 @@ void __init smp_prepare_boot_cpu(void)
 
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
+	int cpuid;
+
+	/* This covers non-smp usecase mandated by "nosmp" option */
+	if (max_cpus == 0)
+		return;
+
+	for_each_possible_cpu(cpuid) {
+		if (cpuid == smp_processor_id())
+			continue;
+		set_cpu_present(cpuid, true);
+	}
 }
 
 void __init setup_smp(void)
@@ -76,7 +87,6 @@ void __init setup_smp(void)
 
 		cpuid_to_hartid_map(cpuid) = hart;
 		set_cpu_possible(cpuid, true);
-		set_cpu_present(cpuid, true);
 		cpuid++;
 	}
 
-- 
2.21.0

[v1 PATCH 4/4] RISC-V: Support nr_cpus command line option.

[Atish Patra]

If nr_cpus command line option is set, maximum possible cpu should be
set to that value.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/smpboot.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 609475c5..a8fe590c 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -86,11 +86,19 @@ void __init setup_smp(void)
 		}
 
 		cpuid_to_hartid_map(cpuid) = hart;
-		set_cpu_possible(cpuid, true);
 		cpuid++;
 	}
 
 	BUG_ON(!found_boot_cpu);
+
+	if (cpuid > nr_cpu_ids)
+		pr_warn("Total number of cpus [%d] are greater than configured via nr_cpus [%d]\n",
+			cpuid, nr_cpu_ids);
+
+	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
+		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
+			set_cpu_possible(cpuid, true);
+	}
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
-- 
2.21.0

Re: [v1 PATCH 4/4] RISC-V: Support nr_cpus command line option.

[Damien Le Moal]

On 2019/03/20 7:20, Atish Patra wrote:
> If nr_cpus command line option is set, maximum possible cpu should be
> set to that value.
> 
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
>  arch/riscv/kernel/smpboot.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
> index 609475c5..a8fe590c 100644
> --- a/arch/riscv/kernel/smpboot.c
> +++ b/arch/riscv/kernel/smpboot.c
> @@ -86,11 +86,19 @@ void __init setup_smp(void)
>  		}
>  
>  		cpuid_to_hartid_map(cpuid) = hart;
> -		set_cpu_possible(cpuid, true);

This looks weird: the code being changed does not match what patch 3/4 did.

>  		cpuid++;
>  	}
>  
>  	BUG_ON(!found_boot_cpu);
> +
> +	if (cpuid > nr_cpu_ids)
> +		pr_warn("Total number of cpus [%d] are greater than configured via nr_cpus [%d]\n",

"The total number of cpus [%d] is greater than nr_cpus option value [%d]\n"

> +			cpuid, nr_cpu_ids);
> +
> +	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
> +		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
> +			set_cpu_possible(cpuid, true);
> +	}
>  }
>  
>  int __cpu_up(unsigned int cpu, struct task_struct *tidle)
> 


-- 
Damien Le Moal
Western Digital Research

Re: [v1 PATCH 4/4] RISC-V: Support nr_cpus command line option.

[Damien Le Moal]

On 2019/03/20 8:56, Damien Le Moal wrote:
> On 2019/03/20 7:20, Atish Patra wrote:
>> If nr_cpus command line option is set, maximum possible cpu should be
>> set to that value.
>>
>> Signed-off-by: Atish Patra <atish.patra@wdc.com>
>> ---
>>  arch/riscv/kernel/smpboot.c | 10 +++++++++-
>>  1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
>> index 609475c5..a8fe590c 100644
>> --- a/arch/riscv/kernel/smpboot.c
>> +++ b/arch/riscv/kernel/smpboot.c
>> @@ -86,11 +86,19 @@ void __init setup_smp(void)
>>  		}
>>  
>>  		cpuid_to_hartid_map(cpuid) = hart;
>> -		set_cpu_possible(cpuid, true);
> 
> This looks weird: the code being changed does not match what patch 3/4 did.

Arg... Ignore this one. My bad. Morning here, I need more coffee :)

> 
>>  		cpuid++;
>>  	}
>>  
>>  	BUG_ON(!found_boot_cpu);
>> +
>> +	if (cpuid > nr_cpu_ids)
>> +		pr_warn("Total number of cpus [%d] are greater than configured via nr_cpus [%d]\n",
> 
> "The total number of cpus [%d] is greater than nr_cpus option value [%d]\n"
> 
>> +			cpuid, nr_cpu_ids);
>> +
>> +	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
>> +		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
>> +			set_cpu_possible(cpuid, true);
>> +	}
>>  }
>>  
>>  int __cpu_up(unsigned int cpu, struct task_struct *tidle)
>>
> 
> 


-- 
Damien Le Moal
Western Digital Research

Re: [v1 PATCH 4/4] RISC-V: Support nr_cpus command line option.

[Atish Patra]

On 3/19/19 4:58 PM, Damien Le Moal wrote:
> On 2019/03/20 8:56, Damien Le Moal wrote:
>> On 2019/03/20 7:20, Atish Patra wrote:
>>> If nr_cpus command line option is set, maximum possible cpu should be
>>> set to that value.
>>>
>>> Signed-off-by: Atish Patra <atish.patra@wdc.com>
>>> ---
>>>   arch/riscv/kernel/smpboot.c | 10 +++++++++-
>>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
>>> index 609475c5..a8fe590c 100644
>>> --- a/arch/riscv/kernel/smpboot.c
>>> +++ b/arch/riscv/kernel/smpboot.c
>>> @@ -86,11 +86,19 @@ void __init setup_smp(void)
>>>   		}
>>>   
>>>   		cpuid_to_hartid_map(cpuid) = hart;
>>> -		set_cpu_possible(cpuid, true);
>>
>> This looks weird: the code being changed does not match what patch 3/4 did.
> 
> Arg... Ignore this one. My bad. Morning here, I need more coffee :)
> 
:).

>>
>>>   		cpuid++;
>>>   	}
>>>   
>>>   	BUG_ON(!found_boot_cpu);
>>> +
>>> +	if (cpuid > nr_cpu_ids)
>>> +		pr_warn("Total number of cpus [%d] are greater than configured via nr_cpus [%d]\n",
>>
>> "The total number of cpus [%d] is greater than nr_cpus option value [%d]\n"
>>

ok. I will fix it in v2.

Regards,
Atish
>>> +			cpuid, nr_cpu_ids);
>>> +
>>> +	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
>>> +		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
>>> +			set_cpu_possible(cpuid, true);
>>> +	}
>>>   }
>>>   
>>>   int __cpu_up(unsigned int cpu, struct task_struct *tidle)
>>>
>>
>>
> 
>