* Re: [PATCH -next] arm64: Export __cpu_logical_map
[not found] <20200724030433.22287-1-wangkefeng.wang@huawei.com>
@ 2020-07-24 3:08 ` Kefeng Wang
2020-07-24 8:16 ` Anshuman Khandual
` (2 more replies)
0 siblings, 3 replies; 18+ messages in thread
From: Kefeng Wang @ 2020-07-24 3:08 UTC (permalink / raw)
To: Catalin Marinas, Will Deacon, Mikko Perttunen, Sumit Gupta, Viresh Kumar
Cc: Hulk Robot, linux-kernel@vger.kernel.org List, linux-arm-kernel
+maillist
On 2020/7/24 11:04, Kefeng Wang wrote:
> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>
> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> __cpu_logical_map to fix build issue.
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> arch/arm64/kernel/setup.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index c793276ec7ad9..3aea05fbb9998 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> arch_initcall(reserve_memblock_reserved_regions);
>
> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> +EXPORT_SYMBOL(__cpu_logical_map);
>
> void __init setup_arch(char **cmdline_p)
> {
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 3:08 ` [PATCH -next] arm64: Export __cpu_logical_map Kefeng Wang
@ 2020-07-24 8:16 ` Anshuman Khandual
2020-07-24 9:13 ` Mark Rutland
` (2 more replies)
2020-07-24 9:43 ` Christoph Hellwig
2020-07-24 13:10 ` Sudeep Holla
2 siblings, 3 replies; 18+ messages in thread
From: Anshuman Khandual @ 2020-07-24 8:16 UTC (permalink / raw)
To: Kefeng Wang, Catalin Marinas, Will Deacon, Mikko Perttunen,
Sumit Gupta, Viresh Kumar
Cc: Hulk Robot, linux-kernel@vger.kernel.org List, linux-arm-kernel
On 07/24/2020 08:38 AM, Kefeng Wang wrote:
> +maillist
This does not seem to be a correct method of posting any patch.
>
> On 2020/7/24 11:04, Kefeng Wang wrote:
>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>
>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>> __cpu_logical_map to fix build issue.
Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds
this particular driver is present just on linux-next. But as expected,
the driver does not use __cpu_logical_map directly but instead accesses
it via cpu_logical_map() wrapper. Wondering, how did you even trigger
the modpost error ?
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>> arch/arm64/kernel/setup.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
>> index c793276ec7ad9..3aea05fbb9998 100644
>> --- a/arch/arm64/kernel/setup.c
>> +++ b/arch/arm64/kernel/setup.c
>> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
>> arch_initcall(reserve_memblock_reserved_regions);
>> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
>> +EXPORT_SYMBOL(__cpu_logical_map);
>> void __init setup_arch(char **cmdline_p)
>> {
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 8:16 ` Anshuman Khandual
@ 2020-07-24 9:13 ` Mark Rutland
2020-07-24 9:35 ` Catalin Marinas
2020-07-24 9:16 ` Kefeng Wang
2020-07-24 9:30 ` Catalin Marinas
2 siblings, 1 reply; 18+ messages in thread
From: Mark Rutland @ 2020-07-24 9:13 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Catalin Marinas, Sumit Gupta,
Will Deacon, linux-arm-kernel
On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
>
> On 07/24/2020 08:38 AM, Kefeng Wang wrote:
> > +maillist
>
> This does not seem to be a correct method of posting any patch.
>
> >
> > On 2020/7/24 11:04, Kefeng Wang wrote:
> >> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>
>
> >>
> >> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> >> __cpu_logical_map to fix build issue.
>
> Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds
> this particular driver is present just on linux-next. But as expected,
> the driver does not use __cpu_logical_map directly but instead accesses
> it via cpu_logical_map() wrapper. Wondering, how did you even trigger
> the modpost error ?
The wrapper in <asm/smp.h> is:
| /*
| * Logical CPU mapping.
| */
| extern u64 __cpu_logical_map[NR_CPUS];
| #define cpu_logical_map(cpu) __cpu_logical_map[cpu]
... and use of that would blow up as described.
> >>
> >> Reported-by: Hulk Robot <hulkci@huawei.com>
> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> >> ---
> >> arch/arm64/kernel/setup.c | 1 +
> >> 1 file changed, 1 insertion(+)
> >>
> >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> >> index c793276ec7ad9..3aea05fbb9998 100644
> >> --- a/arch/arm64/kernel/setup.c
> >> +++ b/arch/arm64/kernel/setup.c
> >> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> >> arch_initcall(reserve_memblock_reserved_regions);
> >> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> >> +EXPORT_SYMBOL(__cpu_logical_map);
If modules are using cpu_logical_map(), this looks sane ot me, but I
wonder if we should instead turn cpu_logical_map() into a C wrapper in
smp.c, or at least mark __cpu_logical_map as __ro_after_init lest
someone have the bright idea to fiddle with it.
Mark.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 8:16 ` Anshuman Khandual
2020-07-24 9:13 ` Mark Rutland
@ 2020-07-24 9:16 ` Kefeng Wang
2020-07-24 9:30 ` Catalin Marinas
2 siblings, 0 replies; 18+ messages in thread
From: Kefeng Wang @ 2020-07-24 9:16 UTC (permalink / raw)
To: Anshuman Khandual, Catalin Marinas, Will Deacon, Mikko Perttunen,
Sumit Gupta, Viresh Kumar
Cc: Hulk Robot, linux-kernel@vger.kernel.org List, linux-arm-kernel
On 2020/7/24 16:16, Anshuman Khandual wrote:
> On 07/24/2020 08:38 AM, Kefeng Wang wrote:
>> +maillist
> This does not seem to be a correct method of posting any patch.
sorry, forget to cc mailist when git send-email
>> On 2020/7/24 11:04, Kefeng Wang wrote:
>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>
>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>> __cpu_logical_map to fix build issue.
> Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds
> this particular driver is present just on linux-next. But as expected,
> the driver does not use __cpu_logical_map directly but instead accesses
> it via cpu_logical_map() wrapper. Wondering, how did you even trigger
> the modpost error ?
arch/arm64/include/asm/smp.h:#define cpu_logical_map(cpu)
__cpu_logical_map[cpu]
Will see the error when using allmodconfig to build.
>
>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>>> ---
>>> arch/arm64/kernel/setup.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
>>> index c793276ec7ad9..3aea05fbb9998 100644
>>> --- a/arch/arm64/kernel/setup.c
>>> +++ b/arch/arm64/kernel/setup.c
>>> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
>>> arch_initcall(reserve_memblock_reserved_regions);
>>> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
>>> +EXPORT_SYMBOL(__cpu_logical_map);
>>> void __init setup_arch(char **cmdline_p)
>>> {
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
> .
>
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 8:16 ` Anshuman Khandual
2020-07-24 9:13 ` Mark Rutland
2020-07-24 9:16 ` Kefeng Wang
@ 2020-07-24 9:30 ` Catalin Marinas
2020-07-24 10:36 ` Anshuman Khandual
2 siblings, 1 reply; 18+ messages in thread
From: Catalin Marinas @ 2020-07-24 9:30 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Sumit Gupta, Will Deacon,
linux-arm-kernel
On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
> On 07/24/2020 08:38 AM, Kefeng Wang wrote:
> > On 2020/7/24 11:04, Kefeng Wang wrote:
> >> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> >>
> >> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> >> __cpu_logical_map to fix build issue.
>
> Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds
> this particular driver is present just on linux-next. But as expected,
> the driver does not use __cpu_logical_map directly but instead accesses
> it via cpu_logical_map() wrapper. Wondering, how did you even trigger
> the modpost error ?
Since the wrapper is a macro, it just expands to __cpu_logical_map[].
> >> Reported-by: Hulk Robot <hulkci@huawei.com>
> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> >> ---
> >> arch/arm64/kernel/setup.c | 1 +
> >> 1 file changed, 1 insertion(+)
> >>
> >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> >> index c793276ec7ad9..3aea05fbb9998 100644
> >> --- a/arch/arm64/kernel/setup.c
> >> +++ b/arch/arm64/kernel/setup.c
> >> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> >> arch_initcall(reserve_memblock_reserved_regions);
> >> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> >> +EXPORT_SYMBOL(__cpu_logical_map);
> >> void __init setup_arch(char **cmdline_p)
> >> {
I can see the Tegra cpuidle also using cpu_logical_map(), though it
can't be built as a module, unlike the cpufreq one. I think the patch
makes sense.
--
Catalin
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 9:13 ` Mark Rutland
@ 2020-07-24 9:35 ` Catalin Marinas
2020-07-24 10:33 ` Anshuman Khandual
0 siblings, 1 reply; 18+ messages in thread
From: Catalin Marinas @ 2020-07-24 9:35 UTC (permalink / raw)
To: Mark Rutland
Cc: Kefeng Wang, Anshuman Khandual, Viresh Kumar,
linux-kernel@vger.kernel.org List, Mikko Perttunen, Hulk Robot,
Sumit Gupta, Will Deacon, linux-arm-kernel
On Fri, Jul 24, 2020 at 10:13:52AM +0100, Mark Rutland wrote:
> On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
> > On 07/24/2020 08:38 AM, Kefeng Wang wrote:
> > >> Reported-by: Hulk Robot <hulkci@huawei.com>
> > >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> > >> ---
> > >> arch/arm64/kernel/setup.c | 1 +
> > >> 1 file changed, 1 insertion(+)
> > >>
> > >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> > >> index c793276ec7ad9..3aea05fbb9998 100644
> > >> --- a/arch/arm64/kernel/setup.c
> > >> +++ b/arch/arm64/kernel/setup.c
> > >> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> > >> arch_initcall(reserve_memblock_reserved_regions);
> > >> u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> > >> +EXPORT_SYMBOL(__cpu_logical_map);
>
> If modules are using cpu_logical_map(), this looks sane ot me, but I
> wonder if we should instead turn cpu_logical_map() into a C wrapper in
> smp.c, or at least mark __cpu_logical_map as __ro_after_init lest
> someone have the bright idea to fiddle with it.
I'd go for a C wrapper and also change a couple of instances where we
assign a value directly to cpu_logical_map(cpu).
--
Catalin
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 3:08 ` [PATCH -next] arm64: Export __cpu_logical_map Kefeng Wang
2020-07-24 8:16 ` Anshuman Khandual
@ 2020-07-24 9:43 ` Christoph Hellwig
2020-07-24 13:10 ` Sudeep Holla
2 siblings, 0 replies; 18+ messages in thread
From: Christoph Hellwig @ 2020-07-24 9:43 UTC (permalink / raw)
To: Kefeng Wang
Cc: Catalin Marinas, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Viresh Kumar, Sumit Gupta,
Will Deacon, linux-arm-kernel
On Fri, Jul 24, 2020 at 11:08:03AM +0800, Kefeng Wang wrote:
> +maillist
>
> On 2020/7/24 11:04, Kefeng Wang wrote:
> > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> >
> > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > __cpu_logical_map to fix build issue.
> >
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> > ---
> > arch/arm64/kernel/setup.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> > index c793276ec7ad9..3aea05fbb9998 100644
> > --- a/arch/arm64/kernel/setup.c
> > +++ b/arch/arm64/kernel/setup.c
> > @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> > arch_initcall(reserve_memblock_reserved_regions);
> > u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> > +EXPORT_SYMBOL(__cpu_logical_map);
EXPORT_SYMBOL_GPL, please. Also consider turning the wrapper into
an out of line function instead of exporting the data structure.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 9:35 ` Catalin Marinas
@ 2020-07-24 10:33 ` Anshuman Khandual
0 siblings, 0 replies; 18+ messages in thread
From: Anshuman Khandual @ 2020-07-24 10:33 UTC (permalink / raw)
To: Catalin Marinas, Mark Rutland
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Sumit Gupta, Will Deacon,
linux-arm-kernel
On 07/24/2020 03:05 PM, Catalin Marinas wrote:
> On Fri, Jul 24, 2020 at 10:13:52AM +0100, Mark Rutland wrote:
>> On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
>>> On 07/24/2020 08:38 AM, Kefeng Wang wrote:
>>>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>>>>> ---
>>>>> � arch/arm64/kernel/setup.c | 1 +
>>>>> � 1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
>>>>> index c793276ec7ad9..3aea05fbb9998 100644
>>>>> --- a/arch/arm64/kernel/setup.c
>>>>> +++ b/arch/arm64/kernel/setup.c
>>>>> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
>>>>> � arch_initcall(reserve_memblock_reserved_regions);
>>>>> � � u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
>>>>> +EXPORT_SYMBOL(__cpu_logical_map);
>>
>> If modules are using cpu_logical_map(), this looks sane ot me, but I
>> wonder if we should instead turn cpu_logical_map() into a C wrapper in
>> smp.c, or at least mark __cpu_logical_map as __ro_after_init lest
>> someone have the bright idea to fiddle with it.
>
> I'd go for a C wrapper and also change a couple of instances where we
> assign a value directly to cpu_logical_map(cpu).
Probably also create a set_cpu_logical_map(cpu, hwid) for those instances
as well.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 9:30 ` Catalin Marinas
@ 2020-07-24 10:36 ` Anshuman Khandual
0 siblings, 0 replies; 18+ messages in thread
From: Anshuman Khandual @ 2020-07-24 10:36 UTC (permalink / raw)
To: Catalin Marinas
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Sumit Gupta, Will Deacon,
linux-arm-kernel
On 07/24/2020 03:00 PM, Catalin Marinas wrote:
> On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
>> On 07/24/2020 08:38 AM, Kefeng Wang wrote:
>>> On 2020/7/24 11:04, Kefeng Wang wrote:
>>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>>>
>>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>>> __cpu_logical_map to fix build issue.
>> Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds
>> this particular driver is present just on linux-next. But as expected,
>> the driver does not use __cpu_logical_map directly but instead accesses
>> it via cpu_logical_map() wrapper. Wondering, how did you even trigger
>> the modpost error ?
> Since the wrapper is a macro, it just expands to __cpu_logical_map[].
>
Ahh, right. Existing cpu_logical_map() is not a true wrapper and it
makes sense to convert that into one.
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 3:08 ` [PATCH -next] arm64: Export __cpu_logical_map Kefeng Wang
2020-07-24 8:16 ` Anshuman Khandual
2020-07-24 9:43 ` Christoph Hellwig
@ 2020-07-24 13:10 ` Sudeep Holla
2020-07-25 2:00 ` Kefeng Wang
2020-07-26 11:46 ` Sumit Gupta
2 siblings, 2 replies; 18+ messages in thread
From: Sudeep Holla @ 2020-07-24 13:10 UTC (permalink / raw)
To: Kefeng Wang
Cc: Catalin Marinas, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Viresh Kumar, Sudeep Holla,
Sumit Gupta, Will Deacon, linux-arm-kernel
On Fri, Jul 24, 2020 at 11:08:03AM +0800, Kefeng Wang wrote:
> +maillist
>
> On 2020/7/24 11:04, Kefeng Wang wrote:
> > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> >
> > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > __cpu_logical_map to fix build issue.
> >
I wonder why like other instances in the drivers, the mpidr is not get
directly from the cpu. The cpufreq_driver->init call happens when the cpu
is being brought online and is executed on the required cpu IIUC.
read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
Though we may not add physical hotplug anytime soon, less dependency
on this cpu_logical_map is better given that we can resolve this without
the need to access the map.
--
Regards,
Sudeep
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^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 13:10 ` Sudeep Holla
@ 2020-07-25 2:00 ` Kefeng Wang
2020-07-26 11:46 ` Sumit Gupta
1 sibling, 0 replies; 18+ messages in thread
From: Kefeng Wang @ 2020-07-25 2:00 UTC (permalink / raw)
To: Sudeep Holla
Cc: Anshuman Khandual, Catalin Marinas,
linux-kernel@vger.kernel.org List, Mikko Perttunen, hch,
Hulk Robot, Viresh Kumar, Sumit Gupta, Will Deacon,
linux-arm-kernel
On 2020/7/24 21:10, Sudeep Holla wrote:
> On Fri, Jul 24, 2020 at 11:08:03AM +0800, Kefeng Wang wrote:
>> +maillist
>>
>> On 2020/7/24 11:04, Kefeng Wang wrote:
>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>>
>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>> __cpu_logical_map to fix build issue.
>>>
> I wonder why like other instances in the drivers, the mpidr is not get
> directly from the cpu. The cpufreq_driver->init call happens when the cpu
> is being brought online and is executed on the required cpu IIUC.
>
> read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> Though we may not add physical hotplug anytime soon, less dependency
> on this cpu_logical_map is better given that we can resolve this without
> the need to access the map.
Hi all, thanks for all comments.
As Sudeep said, I will using read_cpuid_mpidr() directly in
tegra194-cpufreq to
fix the build issue, and later we also would turn cpu_logical_map()
into a C wrapper.
If that's ok, I will send a new build-fix patch firstly, thanks.
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-24 13:10 ` Sudeep Holla
2020-07-25 2:00 ` Kefeng Wang
@ 2020-07-26 11:46 ` Sumit Gupta
2020-07-27 16:05 ` Sudeep Holla
1 sibling, 1 reply; 18+ messages in thread
From: Sumit Gupta @ 2020-07-26 11:46 UTC (permalink / raw)
To: Sudeep Holla, Kefeng Wang
Cc: Catalin Marinas, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Bibek Basu, Viresh Kumar,
Sumit Gupta, Will Deacon, linux-arm-kernel
>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>>
>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>> __cpu_logical_map to fix build issue.
>>>
>
> I wonder why like other instances in the drivers, the mpidr is not get
> directly from the cpu. The cpufreq_driver->init call happens when the cpu
> is being brought online and is executed on the required cpu IIUC.
>
Yes, this occurs during hotplug case.
But in the case of system boot, 'cpufreq_driver->init' is called later
during cpufreq platform driver's probe. The value of CPU in
'policy->cpu' can be different from the current CPU. That's why
read_cpuid_mpidr() can't be used.
> read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> Though we may not add physical hotplug anytime soon, less dependency
> on this cpu_logical_map is better given that we can resolve this without
> the need to access the map.
>
> --
> Regards,
> Sudeep
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-26 11:46 ` Sumit Gupta
@ 2020-07-27 16:05 ` Sudeep Holla
2020-08-01 12:16 ` Sumit Gupta
0 siblings, 1 reply; 18+ messages in thread
From: Sudeep Holla @ 2020-07-27 16:05 UTC (permalink / raw)
To: Sumit Gupta
Cc: Kefeng Wang, Catalin Marinas, Sudeep Holla,
linux-kernel@vger.kernel.org List, Mikko Perttunen, Hulk Robot,
Bibek Basu, Viresh Kumar, Will Deacon, linux-arm-kernel
On Sun, Jul 26, 2020 at 05:16:27PM +0530, Sumit Gupta wrote:
> > > > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> > > >
> > > > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > > > __cpu_logical_map to fix build issue.
> > > >
> >
> > I wonder why like other instances in the drivers, the mpidr is not get
> > directly from the cpu. The cpufreq_driver->init call happens when the cpu
> > is being brought online and is executed on the required cpu IIUC.
> >
> Yes, this occurs during hotplug case.
> But in the case of system boot, 'cpufreq_driver->init' is called later
> during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
> can be different from the current CPU. That's why read_cpuid_mpidr() can't
> be used.
>
Fair enough, why not do cross call like in set_target ? Since it is one-off
in init, I don't see any issue when you are doing it runtime for set_target.
> > read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> > Though we may not add physical hotplug anytime soon, less dependency
> > on this cpu_logical_map is better given that we can resolve this without
> > the need to access the map.
> >
To be honest, we have tried to remove all the dependency on cluster id
in generic code as it is not well defined. This one is tegra specific
driver so should be fine. But I am still bit nervous to export
cpu_logical_map as we have no clue what that would mean for physical
hotplug.
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-07-27 16:05 ` Sudeep Holla
@ 2020-08-01 12:16 ` Sumit Gupta
2020-08-10 7:49 ` Sudeep Holla
0 siblings, 1 reply; 18+ messages in thread
From: Sumit Gupta @ 2020-08-01 12:16 UTC (permalink / raw)
To: Sudeep Holla
Cc: Kefeng Wang, Catalin Marinas, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Bibek Basu, Thierry Reding,
Viresh Kumar, linux-tegra, Sumit Gupta, Jon Hunter, Will Deacon,
linux-arm-kernel
>>>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>>>>
>>>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>>>> __cpu_logical_map to fix build issue.
>>>>>
>>>
>>> I wonder why like other instances in the drivers, the mpidr is not get
>>> directly from the cpu. The cpufreq_driver->init call happens when the cpu
>>> is being brought online and is executed on the required cpu IIUC.
>>>
>> Yes, this occurs during hotplug case.
>> But in the case of system boot, 'cpufreq_driver->init' is called later
>> during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
>> can be different from the current CPU. That's why read_cpuid_mpidr() can't
>> be used.
>>
>
> Fair enough, why not do cross call like in set_target ? Since it is one-off
> in init, I don't see any issue when you are doing it runtime for set_target.
>
>>> read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
>>> Though we may not add physical hotplug anytime soon, less dependency
>>> on this cpu_logical_map is better given that we can resolve this without
>>> the need to access the map.
>>>
>
> To be honest, we have tried to remove all the dependency on cluster id
> in generic code as it is not well defined. This one is tegra specific
> driver so should be fine. But I am still bit nervous to export
> cpu_logical_map as we have no clue what that would mean for physical
> hotplug.
>
As suggested, I have done below change to get the cluster number using
read_cpuid_mpidr(). Please review and suggest if this looks ok?
I will send formal patch if the change is fine.
Thanks,
Sumit
----
diff --git a/drivers/cpufreq/tegra194-cpufreq.c
b/drivers/cpufreq/tegra194-cpufreq.c
index bae527e..06f5ccf 100644
--- a/drivers/cpufreq/tegra194-cpufreq.c
+++ b/drivers/cpufreq/tegra194-cpufreq.c
@@ -56,9 +56,11 @@ struct read_counters_work {
static struct workqueue_struct *read_counters_wq;
-static enum cluster get_cpu_cluster(u8 cpu)
+static void get_cpu_cluster(void *cluster)
{
- return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
+ u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
+
+ *((uint32_t *) cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
}
/*
@@ -186,8 +188,10 @@ static unsigned int tegra194_get_speed(u32 cpu)
static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
{
struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
- int cl = get_cpu_cluster(policy->cpu);
u32 cpu;
+ u32 cl;
+
+ smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
>
> --
> Regards,
> Sudeep
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-08-01 12:16 ` Sumit Gupta
@ 2020-08-10 7:49 ` Sudeep Holla
2020-08-10 10:19 ` Catalin Marinas
0 siblings, 1 reply; 18+ messages in thread
From: Sudeep Holla @ 2020-08-10 7:49 UTC (permalink / raw)
To: Sumit Gupta
Cc: Kefeng Wang, Catalin Marinas, Sudeep Holla,
linux-kernel@vger.kernel.org List, Mikko Perttunen, Hulk Robot,
Bibek Basu, Thierry Reding, Viresh Kumar, linux-tegra,
Jon Hunter, Will Deacon, linux-arm-kernel
On Sat, Aug 01, 2020 at 05:46:43PM +0530, Sumit Gupta wrote:
>
> > > > > > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> > > > > >
> > > > > > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > > > > > __cpu_logical_map to fix build issue.
> > > > > >
> > > >
> > > > I wonder why like other instances in the drivers, the mpidr is not get
> > > > directly from the cpu. The cpufreq_driver->init call happens when the cpu
> > > > is being brought online and is executed on the required cpu IIUC.
> > > >
> > > Yes, this occurs during hotplug case.
> > > But in the case of system boot, 'cpufreq_driver->init' is called later
> > > during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
> > > can be different from the current CPU. That's why read_cpuid_mpidr() can't
> > > be used.
> > >
> >
> > Fair enough, why not do cross call like in set_target ? Since it is one-off
> > in init, I don't see any issue when you are doing it runtime for set_target.
> >
> > > > read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> > > > Though we may not add physical hotplug anytime soon, less dependency
> > > > on this cpu_logical_map is better given that we can resolve this without
> > > > the need to access the map.
> > > >
> >
> > To be honest, we have tried to remove all the dependency on cluster id
> > in generic code as it is not well defined. This one is tegra specific
> > driver so should be fine. But I am still bit nervous to export
> > cpu_logical_map as we have no clue what that would mean for physical
> > hotplug.
> >
> As suggested, I have done below change to get the cluster number using
> read_cpuid_mpidr(). Please review and suggest if this looks ok?
> I will send formal patch if the change is fine.
>
> Thanks,
> Sumit
>
> ----
>
> diff --git a/drivers/cpufreq/tegra194-cpufreq.c
> b/drivers/cpufreq/tegra194-cpufreq.c
> index bae527e..06f5ccf 100644
> --- a/drivers/cpufreq/tegra194-cpufreq.c
> +++ b/drivers/cpufreq/tegra194-cpufreq.c
> @@ -56,9 +56,11 @@ struct read_counters_work {
>
> static struct workqueue_struct *read_counters_wq;
>
> -static enum cluster get_cpu_cluster(u8 cpu)
> +static void get_cpu_cluster(void *cluster)
> {
> - return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
> + u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
> +
> + *((uint32_t *) cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> }
>
> /*
> @@ -186,8 +188,10 @@ static unsigned int tegra194_get_speed(u32 cpu)
> static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
> {
> struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
> - int cl = get_cpu_cluster(policy->cpu);
> u32 cpu;
> + u32 cl;
> +
> + smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
Thanks for this, looks good to me. You can add:
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-08-10 7:49 ` Sudeep Holla
@ 2020-08-10 10:19 ` Catalin Marinas
2020-08-10 12:11 ` Sudeep Holla
2020-08-11 19:44 ` Sumit Gupta
0 siblings, 2 replies; 18+ messages in thread
From: Catalin Marinas @ 2020-08-10 10:19 UTC (permalink / raw)
To: Sudeep Holla
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Bibek Basu, Thierry Reding,
linux-tegra, Sumit Gupta, Jon Hunter, Will Deacon,
linux-arm-kernel
On Mon, Aug 10, 2020 at 08:49:56AM +0100, Sudeep Holla wrote:
> On Sat, Aug 01, 2020 at 05:46:43PM +0530, Sumit Gupta wrote:
> > > > > > > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> > > > > > >
> > > > > > > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > > > > > > __cpu_logical_map to fix build issue.
> > > > > > >
> > > > >
> > > > > I wonder why like other instances in the drivers, the mpidr is not get
> > > > > directly from the cpu. The cpufreq_driver->init call happens when the cpu
> > > > > is being brought online and is executed on the required cpu IIUC.
> > > >
> > > > Yes, this occurs during hotplug case.
> > > > But in the case of system boot, 'cpufreq_driver->init' is called later
> > > > during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
> > > > can be different from the current CPU. That's why read_cpuid_mpidr() can't
> > > > be used.
> > >
> > > Fair enough, why not do cross call like in set_target ? Since it is one-off
> > > in init, I don't see any issue when you are doing it runtime for set_target.
> > >
> > > > > read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> > > > > Though we may not add physical hotplug anytime soon, less dependency
> > > > > on this cpu_logical_map is better given that we can resolve this without
> > > > > the need to access the map.
> > >
> > > To be honest, we have tried to remove all the dependency on cluster id
> > > in generic code as it is not well defined. This one is tegra specific
> > > driver so should be fine. But I am still bit nervous to export
> > > cpu_logical_map as we have no clue what that would mean for physical
> > > hotplug.
> >
> > As suggested, I have done below change to get the cluster number using
> > read_cpuid_mpidr(). Please review and suggest if this looks ok?
> > I will send formal patch if the change is fine.
> >
> > diff --git a/drivers/cpufreq/tegra194-cpufreq.c
> > b/drivers/cpufreq/tegra194-cpufreq.c
> > index bae527e..06f5ccf 100644
> > --- a/drivers/cpufreq/tegra194-cpufreq.c
> > +++ b/drivers/cpufreq/tegra194-cpufreq.c
> > @@ -56,9 +56,11 @@ struct read_counters_work {
> >
> > static struct workqueue_struct *read_counters_wq;
> >
> > -static enum cluster get_cpu_cluster(u8 cpu)
> > +static void get_cpu_cluster(void *cluster)
> > {
> > - return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
> > + u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
> > +
> > + *((uint32_t *) cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> > }
> >
> > /*
> > @@ -186,8 +188,10 @@ static unsigned int tegra194_get_speed(u32 cpu)
> > static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
> > {
> > struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
> > - int cl = get_cpu_cluster(policy->cpu);
> > u32 cpu;
> > + u32 cl;
> > +
> > + smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
>
> Thanks for this, looks good to me. You can add:
>
> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
I already merged Kefeng's __cpu_logical_map fix (commit eaecca9e7710)
but if the above goes in, I can drop the EXPORT_SYMBOL part (and keep
the rest as it's a good refactoring).
--
Catalin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-08-10 10:19 ` Catalin Marinas
@ 2020-08-10 12:11 ` Sudeep Holla
2020-08-11 19:44 ` Sumit Gupta
1 sibling, 0 replies; 18+ messages in thread
From: Sudeep Holla @ 2020-08-10 12:11 UTC (permalink / raw)
To: Catalin Marinas
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Bibek Basu, Thierry Reding,
linux-tegra, Sumit Gupta, Jon Hunter, Will Deacon,
linux-arm-kernel
On Mon, Aug 10, 2020 at 11:19:55AM +0100, Catalin Marinas wrote:
> On Mon, Aug 10, 2020 at 08:49:56AM +0100, Sudeep Holla wrote:
> > On Sat, Aug 01, 2020 at 05:46:43PM +0530, Sumit Gupta wrote:
> > > > > > > > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> > > > > > > >
> > > > > > > > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > > > > > > > __cpu_logical_map to fix build issue.
> > > > > > > >
> > > > > >
> > > > > > I wonder why like other instances in the drivers, the mpidr is not get
> > > > > > directly from the cpu. The cpufreq_driver->init call happens when the cpu
> > > > > > is being brought online and is executed on the required cpu IIUC.
> > > > >
> > > > > Yes, this occurs during hotplug case.
> > > > > But in the case of system boot, 'cpufreq_driver->init' is called later
> > > > > during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
> > > > > can be different from the current CPU. That's why read_cpuid_mpidr() can't
> > > > > be used.
> > > >
> > > > Fair enough, why not do cross call like in set_target ? Since it is one-off
> > > > in init, I don't see any issue when you are doing it runtime for set_target.
> > > >
> > > > > > read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
> > > > > > Though we may not add physical hotplug anytime soon, less dependency
> > > > > > on this cpu_logical_map is better given that we can resolve this without
> > > > > > the need to access the map.
> > > >
> > > > To be honest, we have tried to remove all the dependency on cluster id
> > > > in generic code as it is not well defined. This one is tegra specific
> > > > driver so should be fine. But I am still bit nervous to export
> > > > cpu_logical_map as we have no clue what that would mean for physical
> > > > hotplug.
> > >
> > > As suggested, I have done below change to get the cluster number using
> > > read_cpuid_mpidr(). Please review and suggest if this looks ok?
> > > I will send formal patch if the change is fine.
> > >
> > > diff --git a/drivers/cpufreq/tegra194-cpufreq.c
> > > b/drivers/cpufreq/tegra194-cpufreq.c
> > > index bae527e..06f5ccf 100644
> > > --- a/drivers/cpufreq/tegra194-cpufreq.c
> > > +++ b/drivers/cpufreq/tegra194-cpufreq.c
> > > @@ -56,9 +56,11 @@ struct read_counters_work {
> > >
> > > static struct workqueue_struct *read_counters_wq;
> > >
> > > -static enum cluster get_cpu_cluster(u8 cpu)
> > > +static void get_cpu_cluster(void *cluster)
> > > {
> > > - return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
> > > + u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
> > > +
> > > + *((uint32_t *) cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> > > }
> > >
> > > /*
> > > @@ -186,8 +188,10 @@ static unsigned int tegra194_get_speed(u32 cpu)
> > > static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
> > > {
> > > struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
> > > - int cl = get_cpu_cluster(policy->cpu);
> > > u32 cpu;
> > > + u32 cl;
> > > +
> > > + smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
> >
> > Thanks for this, looks good to me. You can add:
> >
> > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
>
> I already merged Kefeng's __cpu_logical_map fix (commit eaecca9e7710)
> but if the above goes in, I can drop the EXPORT_SYMBOL part (and keep
> the rest as it's a good refactoring).
>
OK, I will keep an eye on this and we can drop export once this is merged.
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH -next] arm64: Export __cpu_logical_map
2020-08-10 10:19 ` Catalin Marinas
2020-08-10 12:11 ` Sudeep Holla
@ 2020-08-11 19:44 ` Sumit Gupta
1 sibling, 0 replies; 18+ messages in thread
From: Sumit Gupta @ 2020-08-11 19:44 UTC (permalink / raw)
To: Catalin Marinas, Sudeep Holla
Cc: Kefeng Wang, Viresh Kumar, linux-kernel@vger.kernel.org List,
Mikko Perttunen, Hulk Robot, Bibek Basu, Thierry Reding,
linux-tegra, Jon Hunter, Will Deacon, linux-arm-kernel
>>>>>>>> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
>>>>>>>>
>>>>>>>> ARM64 tegra194-cpufreq driver use cpu_logical_map, export
>>>>>>>> __cpu_logical_map to fix build issue.
>>>>>>>>
>>>>>>
>>>>>> I wonder why like other instances in the drivers, the mpidr is not get
>>>>>> directly from the cpu. The cpufreq_driver->init call happens when the cpu
>>>>>> is being brought online and is executed on the required cpu IIUC.
>>>>>
>>>>> Yes, this occurs during hotplug case.
>>>>> But in the case of system boot, 'cpufreq_driver->init' is called later
>>>>> during cpufreq platform driver's probe. The value of CPU in 'policy->cpu'
>>>>> can be different from the current CPU. That's why read_cpuid_mpidr() can't
>>>>> be used.
>>>>
>>>> Fair enough, why not do cross call like in set_target ? Since it is one-off
>>>> in init, I don't see any issue when you are doing it runtime for set_target.
>>>>
>>>>>> read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
>>>>>> Though we may not add physical hotplug anytime soon, less dependency
>>>>>> on this cpu_logical_map is better given that we can resolve this without
>>>>>> the need to access the map.
>>>>
>>>> To be honest, we have tried to remove all the dependency on cluster id
>>>> in generic code as it is not well defined. This one is tegra specific
>>>> driver so should be fine. But I am still bit nervous to export
>>>> cpu_logical_map as we have no clue what that would mean for physical
>>>> hotplug.
>>>
>>> As suggested, I have done below change to get the cluster number using
>>> read_cpuid_mpidr(). Please review and suggest if this looks ok?
>>> I will send formal patch if the change is fine.
>>>
>>> diff --git a/drivers/cpufreq/tegra194-cpufreq.c
>>> b/drivers/cpufreq/tegra194-cpufreq.c
>>> index bae527e..06f5ccf 100644
>>> --- a/drivers/cpufreq/tegra194-cpufreq.c
>>> +++ b/drivers/cpufreq/tegra194-cpufreq.c
>>> @@ -56,9 +56,11 @@ struct read_counters_work {
>>>
>>> static struct workqueue_struct *read_counters_wq;
>>>
>>> -static enum cluster get_cpu_cluster(u8 cpu)
>>> +static void get_cpu_cluster(void *cluster)
>>> {
>>> - return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
>>> + u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
>>> +
>>> + *((uint32_t *) cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>>> }
>>>
>>> /*
>>> @@ -186,8 +188,10 @@ static unsigned int tegra194_get_speed(u32 cpu)
>>> static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
>>> {
>>> struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
>>> - int cl = get_cpu_cluster(policy->cpu);
>>> u32 cpu;
>>> + u32 cl;
>>> +
>>> + smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
>>
>> Thanks for this, looks good to me. You can add:
>>
>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
>
> I already merged Kefeng's __cpu_logical_map fix (commit eaecca9e7710)
> but if the above goes in, I can drop the EXPORT_SYMBOL part (and keep
> the rest as it's a good refactoring).
>
I have posted the formal patch.
Thanks,
Sumit
> --
> Catalin
>
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^ permalink raw reply [flat|nested] 18+ messages in thread
end of thread, other threads:[~2020-08-11 19:46 UTC | newest]
Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <20200724030433.22287-1-wangkefeng.wang@huawei.com>
2020-07-24 3:08 ` [PATCH -next] arm64: Export __cpu_logical_map Kefeng Wang
2020-07-24 8:16 ` Anshuman Khandual
2020-07-24 9:13 ` Mark Rutland
2020-07-24 9:35 ` Catalin Marinas
2020-07-24 10:33 ` Anshuman Khandual
2020-07-24 9:16 ` Kefeng Wang
2020-07-24 9:30 ` Catalin Marinas
2020-07-24 10:36 ` Anshuman Khandual
2020-07-24 9:43 ` Christoph Hellwig
2020-07-24 13:10 ` Sudeep Holla
2020-07-25 2:00 ` Kefeng Wang
2020-07-26 11:46 ` Sumit Gupta
2020-07-27 16:05 ` Sudeep Holla
2020-08-01 12:16 ` Sumit Gupta
2020-08-10 7:49 ` Sudeep Holla
2020-08-10 10:19 ` Catalin Marinas
2020-08-10 12:11 ` Sudeep Holla
2020-08-11 19:44 ` Sumit Gupta
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