* [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry
@ 2021-08-10 4:53 Aneesh Kumar K.V
2021-08-10 5:17 ` Christophe Leroy
0 siblings, 1 reply; 5+ messages in thread
From: Aneesh Kumar K.V @ 2021-08-10 4:53 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V
Similar to x86/s390 add a debugfs file to tune tlb_single_page_flush_ceiling.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
index aefc100d79a7..5cca0fe130e7 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -17,6 +17,7 @@
#include <asm/trace.h>
#include <asm/cputhreads.h>
#include <asm/plpar_wrappers.h>
+#include <asm/debugfs.h>
#include "internal.h"
@@ -1524,3 +1525,50 @@ void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
EXPORT_SYMBOL_GPL(do_h_rpt_invalidate_prt);
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
+static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[32];
+ unsigned int len;
+
+ len = sprintf(buf, "%ld\n", tlb_single_page_flush_ceiling);
+ return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t tlbflush_write_file(struct file *file,
+ const char __user *user_buf, size_t count, loff_t *ppos)
+{
+ char buf[32];
+ ssize_t len;
+ int ceiling;
+
+ len = min(count, sizeof(buf) - 1);
+ if (copy_from_user(buf, user_buf, len))
+ return -EFAULT;
+
+ buf[len] = '\0';
+ if (kstrtoint(buf, 0, &ceiling))
+ return -EINVAL;
+
+ if (ceiling < 0)
+ return -EINVAL;
+
+ tlb_single_page_flush_ceiling = ceiling;
+ return count;
+}
+
+static const struct file_operations fops_tlbflush = {
+ .read = tlbflush_read_file,
+ .write = tlbflush_write_file,
+ .llseek = default_llseek,
+};
+
+static int __init create_tlb_single_page_flush_ceiling(void)
+{
+ debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
+ powerpc_debugfs_root, NULL, &fops_tlbflush);
+ return 0;
+}
+late_initcall(create_tlb_single_page_flush_ceiling);
+
--
2.31.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry
2021-08-10 4:53 [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry Aneesh Kumar K.V
@ 2021-08-10 5:17 ` Christophe Leroy
2021-08-12 7:28 ` Michael Ellerman
0 siblings, 1 reply; 5+ messages in thread
From: Christophe Leroy @ 2021-08-10 5:17 UTC (permalink / raw)
To: Aneesh Kumar K.V, linuxppc-dev, mpe
Le 10/08/2021 à 06:53, Aneesh Kumar K.V a écrit :
> Similar to x86/s390 add a debugfs file to tune tlb_single_page_flush_ceiling.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
> arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++
> 1 file changed, 48 insertions(+)
>
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
> index aefc100d79a7..5cca0fe130e7 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -17,6 +17,7 @@
> #include <asm/trace.h>
> #include <asm/cputhreads.h>
> #include <asm/plpar_wrappers.h>
> +#include <asm/debugfs.h>
>
> #include "internal.h"
>
> @@ -1524,3 +1525,50 @@ void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
> EXPORT_SYMBOL_GPL(do_h_rpt_invalidate_prt);
>
> #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> +
> +static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + char buf[32];
> + unsigned int len;
> +
> + len = sprintf(buf, "%ld\n", tlb_single_page_flush_ceiling);
> + return simple_read_from_buffer(user_buf, count, ppos, buf, len);
> +}
> +
> +static ssize_t tlbflush_write_file(struct file *file,
> + const char __user *user_buf, size_t count, loff_t *ppos)
> +{
> + char buf[32];
> + ssize_t len;
> + int ceiling;
> +
> + len = min(count, sizeof(buf) - 1);
> + if (copy_from_user(buf, user_buf, len))
> + return -EFAULT;
> +
> + buf[len] = '\0';
> + if (kstrtoint(buf, 0, &ceiling))
> + return -EINVAL;
> +
> + if (ceiling < 0)
> + return -EINVAL;
> +
> + tlb_single_page_flush_ceiling = ceiling;
> + return count;
> +}
> +
> +static const struct file_operations fops_tlbflush = {
> + .read = tlbflush_read_file,
> + .write = tlbflush_write_file,
> + .llseek = default_llseek,
> +};
> +
> +static int __init create_tlb_single_page_flush_ceiling(void)
> +{
> + debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
> + powerpc_debugfs_root, NULL, &fops_tlbflush);
Could you just use debugfs_create_u32() instead of re-implementing simple read and write ?
Or at least use DEFINE_DEBUGFS_ATTRIBUTE() if you need something a bit more elaborated ?
> + return 0;
> +}
> +late_initcall(create_tlb_single_page_flush_ceiling);
> +
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry
2021-08-10 5:17 ` Christophe Leroy
@ 2021-08-12 7:28 ` Michael Ellerman
2021-08-12 8:13 ` Aneesh Kumar K.V
0 siblings, 1 reply; 5+ messages in thread
From: Michael Ellerman @ 2021-08-12 7:28 UTC (permalink / raw)
To: Christophe Leroy, Aneesh Kumar K.V, linuxppc-dev
Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 10/08/2021 à 06:53, Aneesh Kumar K.V a écrit :
>> Similar to x86/s390 add a debugfs file to tune tlb_single_page_flush_ceiling.
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>> ---
>> arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++
>> 1 file changed, 48 insertions(+)
>>
>> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
>> index aefc100d79a7..5cca0fe130e7 100644
>> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
>> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
>> @@ -17,6 +17,7 @@
...
>> +
>> +static int __init create_tlb_single_page_flush_ceiling(void)
>> +{
>> + debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
>> + powerpc_debugfs_root, NULL, &fops_tlbflush);
>
> Could you just use debugfs_create_u32() instead of re-implementing simple read and write ?
Yeah AFAICS that should work fine.
It could probably even be a u16?
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry
2021-08-12 7:28 ` Michael Ellerman
@ 2021-08-12 8:13 ` Aneesh Kumar K.V
2021-08-12 12:14 ` Michael Ellerman
0 siblings, 1 reply; 5+ messages in thread
From: Aneesh Kumar K.V @ 2021-08-12 8:13 UTC (permalink / raw)
To: Michael Ellerman, Christophe Leroy, linuxppc-dev
On 8/12/21 12:58 PM, Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>> Le 10/08/2021 à 06:53, Aneesh Kumar K.V a écrit :
>>> Similar to x86/s390 add a debugfs file to tune tlb_single_page_flush_ceiling.
>>>
>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>> ---
>>> arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++
>>> 1 file changed, 48 insertions(+)
>>>
>>> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
>>> index aefc100d79a7..5cca0fe130e7 100644
>>> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
>>> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
>>> @@ -17,6 +17,7 @@
> ...
>>> +
>>> +static int __init create_tlb_single_page_flush_ceiling(void)
>>> +{
>>> + debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
>>> + powerpc_debugfs_root, NULL, &fops_tlbflush);
>>
>> Could you just use debugfs_create_u32() instead of re-implementing simple read and write ?
>
> Yeah AFAICS that should work fine.
>
> It could probably even be a u16?
>
I was looking at switching all that to u64. Should i fallback to u16,
considering a tlb_signle_page_flush_ceiling value larger that 2**16
doesn't make sense?
-aneesh
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry
2021-08-12 8:13 ` Aneesh Kumar K.V
@ 2021-08-12 12:14 ` Michael Ellerman
0 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2021-08-12 12:14 UTC (permalink / raw)
To: Aneesh Kumar K.V, Christophe Leroy, linuxppc-dev
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> On 8/12/21 12:58 PM, Michael Ellerman wrote:
>> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>>> Le 10/08/2021 à 06:53, Aneesh Kumar K.V a écrit :
>>>> Similar to x86/s390 add a debugfs file to tune tlb_single_page_flush_ceiling.
>>>>
>>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>>> ---
>>>> arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++
>>>> 1 file changed, 48 insertions(+)
>>>>
>>>> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
>>>> index aefc100d79a7..5cca0fe130e7 100644
>>>> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
>>>> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
>>>> @@ -17,6 +17,7 @@
>> ...
>>>> +
>>>> +static int __init create_tlb_single_page_flush_ceiling(void)
>>>> +{
>>>> + debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR,
>>>> + powerpc_debugfs_root, NULL, &fops_tlbflush);
>>>
>>> Could you just use debugfs_create_u32() instead of re-implementing simple read and write ?
>>
>> Yeah AFAICS that should work fine.
>>
>> It could probably even be a u16?
>
> I was looking at switching all that to u64. Should i fallback to u16,
> considering a tlb_signle_page_flush_ceiling value larger that 2**16
> doesn't make sense?
Hmm, if we make it u16 and someone writes a value >= 2^16 it just
truncates the value to 0, which is a bit unfortunate.
So maybe just make it u32, that way if someone writes a stupidly large
value it stays large.
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-08-10 4:53 [PATCH] powerpc/book3s64/radix: make tlb_single_page_flush_ceiling a debugfs entry Aneesh Kumar K.V
2021-08-10 5:17 ` Christophe Leroy
2021-08-12 7:28 ` Michael Ellerman
2021-08-12 8:13 ` Aneesh Kumar K.V
2021-08-12 12:14 ` Michael Ellerman
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