diff mbox

[v5,02/18] ACPI / table: Add new function to get table entries

Message ID 1413553034-20956-3-git-send-email-hanjun.guo@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Hanjun Guo Oct. 17, 2014, 1:36 p.m. UTC 
From: Ashwin Chaugule <ashwin.chaugule@linaro.org>

The acpi_table_parse() function has a callback that
passes a pointer to a table_header. Add a new function
which takes this pointer and parses its entries. This
eliminates the need to re-traverse all the tables for
each call. e.g. as in acpi_table_parse_madt() which is
normally called after acpi_table_parse().

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
 include/linux/acpi.h  |    4 +++
 2 files changed, 51 insertions(+), 20 deletions(-)

Comments

Rafael J. Wysocki Nov. 24, 2014, 1:27 a.m. UTC | #1 
On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> 
> The acpi_table_parse() function has a callback that
> passes a pointer to a table_header. Add a new function
> which takes this pointer and parses its entries. This
> eliminates the need to re-traverse all the tables for
> each call. e.g. as in acpi_table_parse_madt() which is
> normally called after acpi_table_parse().
> 
> Acked-by: Grant Likely <grant.likely@linaro.org>
> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
>  include/linux/acpi.h  |    4 +++
>  2 files changed, 51 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index 6d5a6cd..21ae521 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
>  
>  
>  int __init
> -acpi_table_parse_entries(char *id,
> -			     unsigned long table_size,
> -			     int entry_id,
> -			     acpi_tbl_entry_handler handler,
> -			     unsigned int max_entries)
> +acpi_parse_entries(unsigned long table_size,
> +		acpi_tbl_entry_handler handler,
> +		struct acpi_table_header *table_header,
> +		int entry_id, unsigned int max_entries)
>  {
> -	struct acpi_table_header *table_header = NULL;
>  	struct acpi_subtable_header *entry;
> -	unsigned int count = 0;
> +	int count = 0;
>  	unsigned long table_end;
> -	acpi_size tbl_size;
>  
>  	if (acpi_disabled)
>  		return -ENODEV;
> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
>  	if (!handler)
>  		return -EINVAL;
>  
> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
> -	else
> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
> +	if (!table_size)
> +		return -EINVAL;
>  
>  	if (!table_header) {
> -		pr_warn("%4.4s not present\n", id);
> +		pr_warn("Table header not present\n");

The message doesn't make sense any more if the table signature is not printed.

>  		return -ENODEV;
>  	}
>  
> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
>  		if (entry->type == entry_id
>  		    && (!max_entries || count++ < max_entries))
>  			if (handler(entry, table_end))
> -				goto err;
> +				return -EINVAL;
>  
>  		/*
>  		 * If entry->length is 0, break from this loop to avoid
>  		 * infinite loop.
>  		 */
>  		if (entry->length == 0) {
> -			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
> -			goto err;
> +			pr_err("[0x%02x] Invalid zero length\n", entry_id);

Same here.

> +			return -EINVAL;
>  		}
>  
>  		entry = (struct acpi_subtable_header *)
>  		    ((unsigned long)entry + entry->length);
>  	}
> +
>  	if (max_entries && count > max_entries) {
>  		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
> -			id, entry_id, count - max_entries, count);
> +			table_header->signature, entry_id, count - max_entries,
> +			count);
>  	}
>  
> -	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
>  	return count;
> -err:
> +}
> +
> +int __init
> +acpi_table_parse_entries(char *id,
> +			 unsigned long table_size,
> +			 int entry_id,
> +			 acpi_tbl_entry_handler handler,
> +			 unsigned int max_entries)
> +{
> +	struct acpi_table_header *table_header = NULL;
> +	acpi_size tbl_size;
> +	int count;
> +
> +	if (acpi_disabled)
> +		return -ENODEV;
> +
> +	if (!handler)
> +		return -EINVAL;
> +
> +	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
> +		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
> +	else
> +		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);


	u32 instance = 0;

	if (!strncmp(id, ACPI_SIG_MADT, 4))
		instance = acpi_apic_instance;

	acpi_get_table_with_size(id, instance, &table_header, &tbl_size);

Pretty please.

> +
> +	if (!table_header) {
> +		pr_warn("%4.4s not present\n", id);
> +		return -ENODEV;
> +	}
> +
> +	count = acpi_parse_entries(table_size, handler, table_header,
> +			entry_id, max_entries);
> +
>  	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
> -	return -EINVAL;
> +	return count;
>  }
>  
>  int __init
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 807cbc4..36d5012 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -123,6 +123,10 @@ int acpi_numa_init (void);
>  
>  int acpi_table_init (void);
>  int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
> +int __init acpi_parse_entries(unsigned long table_size,
> +			      acpi_tbl_entry_handler handler,
> +			      struct acpi_table_header *table_header,
> +			      int entry_id, unsigned int max_entries);
>  int __init acpi_table_parse_entries(char *id, unsigned long table_size,
>  				    int entry_id,
>  				    acpi_tbl_entry_handler handler,
>
Hanjun Guo Nov. 24, 2014, 11:03 a.m. UTC | #2 
On 2014-11-24 9:27, Rafael J. Wysocki wrote:
> On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
>> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>>
>> The acpi_table_parse() function has a callback that
>> passes a pointer to a table_header. Add a new function
>> which takes this pointer and parses its entries. This
>> eliminates the need to re-traverse all the tables for
>> each call. e.g. as in acpi_table_parse_madt() which is
>> normally called after acpi_table_parse().
>>
>> Acked-by: Grant Likely <grant.likely@linaro.org>
>> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
>>  include/linux/acpi.h  |    4 +++
>>  2 files changed, 51 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
>> index 6d5a6cd..21ae521 100644
>> --- a/drivers/acpi/tables.c
>> +++ b/drivers/acpi/tables.c
>> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
>>  
>>  
>>  int __init
>> -acpi_table_parse_entries(char *id,
>> -			     unsigned long table_size,
>> -			     int entry_id,
>> -			     acpi_tbl_entry_handler handler,
>> -			     unsigned int max_entries)
>> +acpi_parse_entries(unsigned long table_size,
>> +		acpi_tbl_entry_handler handler,
>> +		struct acpi_table_header *table_header,
>> +		int entry_id, unsigned int max_entries)
>>  {
>> -	struct acpi_table_header *table_header = NULL;
>>  	struct acpi_subtable_header *entry;
>> -	unsigned int count = 0;
>> +	int count = 0;
>>  	unsigned long table_end;
>> -	acpi_size tbl_size;
>>  
>>  	if (acpi_disabled)
>>  		return -ENODEV;
>> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
>>  	if (!handler)
>>  		return -EINVAL;
>>  
>> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
>> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
>> -	else
>> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
>> +	if (!table_size)
>> +		return -EINVAL;
>>  
>>  	if (!table_header) {
>> -		pr_warn("%4.4s not present\n", id);
>> +		pr_warn("Table header not present\n");
> 
> The message doesn't make sense any more if the table signature is not printed.
> 
>>  		return -ENODEV;
>>  	}
>>  
>> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
>>  		if (entry->type == entry_id
>>  		    && (!max_entries || count++ < max_entries))
>>  			if (handler(entry, table_end))
>> -				goto err;
>> +				return -EINVAL;
>>  
>>  		/*
>>  		 * If entry->length is 0, break from this loop to avoid
>>  		 * infinite loop.
>>  		 */
>>  		if (entry->length == 0) {
>> -			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
>> -			goto err;
>> +			pr_err("[0x%02x] Invalid zero length\n", entry_id);
> 
> Same here.

How about remove the message and return directly?

> 
>> +			return -EINVAL;
>>  		}
>>  
>>  		entry = (struct acpi_subtable_header *)
>>  		    ((unsigned long)entry + entry->length);
>>  	}
>> +
>>  	if (max_entries && count > max_entries) {
>>  		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
>> -			id, entry_id, count - max_entries, count);
>> +			table_header->signature, entry_id, count - max_entries,
>> +			count);
>>  	}
>>  
>> -	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
>>  	return count;
>> -err:
>> +}
>> +
>> +int __init
>> +acpi_table_parse_entries(char *id,
>> +			 unsigned long table_size,
>> +			 int entry_id,
>> +			 acpi_tbl_entry_handler handler,
>> +			 unsigned int max_entries)
>> +{
>> +	struct acpi_table_header *table_header = NULL;
>> +	acpi_size tbl_size;
>> +	int count;
>> +
>> +	if (acpi_disabled)
>> +		return -ENODEV;
>> +
>> +	if (!handler)
>> +		return -EINVAL;
>> +
>> +	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
>> +		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
>> +	else
>> +		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
> 
> 
> 	u32 instance = 0;
> 
> 	if (!strncmp(id, ACPI_SIG_MADT, 4))
> 		instance = acpi_apic_instance;
> 
> 	acpi_get_table_with_size(id, instance, &table_header, &tbl_size);
> 
> Pretty please.

Yes, much better! I will update the patch.

Thanks
Hanjun
Rafael J. Wysocki Nov. 24, 2014, 2:51 p.m. UTC | #3 
On Monday, November 24, 2014 07:03:54 PM Hanjun Guo wrote:
> On 2014-11-24 9:27, Rafael J. Wysocki wrote:
> > On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
> >> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> >>
> >> The acpi_table_parse() function has a callback that
> >> passes a pointer to a table_header. Add a new function
> >> which takes this pointer and parses its entries. This
> >> eliminates the need to re-traverse all the tables for
> >> each call. e.g. as in acpi_table_parse_madt() which is
> >> normally called after acpi_table_parse().
> >>
> >> Acked-by: Grant Likely <grant.likely@linaro.org>
> >> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> >> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> >> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> >> ---
> >>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
> >>  include/linux/acpi.h  |    4 +++
> >>  2 files changed, 51 insertions(+), 20 deletions(-)
> >>
> >> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> >> index 6d5a6cd..21ae521 100644
> >> --- a/drivers/acpi/tables.c
> >> +++ b/drivers/acpi/tables.c
> >> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
> >>  
> >>  
> >>  int __init
> >> -acpi_table_parse_entries(char *id,
> >> -			     unsigned long table_size,
> >> -			     int entry_id,
> >> -			     acpi_tbl_entry_handler handler,
> >> -			     unsigned int max_entries)
> >> +acpi_parse_entries(unsigned long table_size,
> >> +		acpi_tbl_entry_handler handler,
> >> +		struct acpi_table_header *table_header,
> >> +		int entry_id, unsigned int max_entries)
> >>  {
> >> -	struct acpi_table_header *table_header = NULL;
> >>  	struct acpi_subtable_header *entry;
> >> -	unsigned int count = 0;
> >> +	int count = 0;
> >>  	unsigned long table_end;
> >> -	acpi_size tbl_size;
> >>  
> >>  	if (acpi_disabled)
> >>  		return -ENODEV;
> >> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
> >>  	if (!handler)
> >>  		return -EINVAL;
> >>  
> >> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
> >> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
> >> -	else
> >> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
> >> +	if (!table_size)
> >> +		return -EINVAL;
> >>  
> >>  	if (!table_header) {
> >> -		pr_warn("%4.4s not present\n", id);
> >> +		pr_warn("Table header not present\n");
> > 
> > The message doesn't make sense any more if the table signature is not printed.
> > 
> >>  		return -ENODEV;
> >>  	}
> >>  
> >> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
> >>  		if (entry->type == entry_id
> >>  		    && (!max_entries || count++ < max_entries))
> >>  			if (handler(entry, table_end))
> >> -				goto err;
> >> +				return -EINVAL;
> >>  
> >>  		/*
> >>  		 * If entry->length is 0, break from this loop to avoid
> >>  		 * infinite loop.
> >>  		 */
> >>  		if (entry->length == 0) {
> >> -			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
> >> -			goto err;
> >> +			pr_err("[0x%02x] Invalid zero length\n", entry_id);
> > 
> > Same here.
> 
> How about remove the message and return directly?

We could do that, but for what reason?  Is the message not useful?
Hanjun Guo Nov. 25, 2014, 3:38 a.m. UTC | #4 
On 2014/11/24 22:51, Rafael J. Wysocki wrote:
> On Monday, November 24, 2014 07:03:54 PM Hanjun Guo wrote:
>> On 2014-11-24 9:27, Rafael J. Wysocki wrote:
>>> On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
>>>> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>>>>
>>>> The acpi_table_parse() function has a callback that
>>>> passes a pointer to a table_header. Add a new function
>>>> which takes this pointer and parses its entries. This
>>>> eliminates the need to re-traverse all the tables for
>>>> each call. e.g. as in acpi_table_parse_madt() which is
>>>> normally called after acpi_table_parse().
>>>>
>>>> Acked-by: Grant Likely <grant.likely@linaro.org>
>>>> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>>>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>>>> ---
>>>>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
>>>>  include/linux/acpi.h  |    4 +++
>>>>  2 files changed, 51 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
>>>> index 6d5a6cd..21ae521 100644
>>>> --- a/drivers/acpi/tables.c
>>>> +++ b/drivers/acpi/tables.c
>>>> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
>>>>  
>>>>  
>>>>  int __init
>>>> -acpi_table_parse_entries(char *id,
>>>> -			     unsigned long table_size,
>>>> -			     int entry_id,
>>>> -			     acpi_tbl_entry_handler handler,
>>>> -			     unsigned int max_entries)
>>>> +acpi_parse_entries(unsigned long table_size,
>>>> +		acpi_tbl_entry_handler handler,
>>>> +		struct acpi_table_header *table_header,
>>>> +		int entry_id, unsigned int max_entries)
>>>>  {
>>>> -	struct acpi_table_header *table_header = NULL;
>>>>  	struct acpi_subtable_header *entry;
>>>> -	unsigned int count = 0;
>>>> +	int count = 0;
>>>>  	unsigned long table_end;
>>>> -	acpi_size tbl_size;
>>>>  
>>>>  	if (acpi_disabled)
>>>>  		return -ENODEV;
>>>> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
>>>>  	if (!handler)
>>>>  		return -EINVAL;
>>>>  
>>>> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
>>>> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
>>>> -	else
>>>> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
>>>> +	if (!table_size)
>>>> +		return -EINVAL;
>>>>  
>>>>  	if (!table_header) {
>>>> -		pr_warn("%4.4s not present\n", id);
>>>> +		pr_warn("Table header not present\n");
>>> The message doesn't make sense any more if the table signature is not printed.

For this message, since no table id is passed, and this message is printed in
acpi_table_parse_entries() before this function is called, I think we can check
the table_header before call this function and remove the printed message here.

>>>
>>>>  		return -ENODEV;
>>>>  	}
>>>>  
>>>> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
>>>>  		if (entry->type == entry_id
>>>>  		    && (!max_entries || count++ < max_entries))
>>>>  			if (handler(entry, table_end))
>>>> -				goto err;
>>>> +				return -EINVAL;
>>>>  
>>>>  		/*
>>>>  		 * If entry->length is 0, break from this loop to avoid
>>>>  		 * infinite loop.
>>>>  		 */
>>>>  		if (entry->length == 0) {
>>>> -			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
>>>> -			goto err;
>>>> +			pr_err("[0x%02x] Invalid zero length\n", entry_id);

For this one, since the table_header is valid now, we can keep it with:

- pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
+ pr_err("[%4.4s:0x%02x] Invalid zero length\n", table_header->signature, entry_id);

>>> Same here.
>> How about remove the message and return directly?
> We could do that, but for what reason?  Is the message not useful?

I agree with you, the message is useful I think, how about the comments above?

Thanks
Hanjun
Rafael J. Wysocki Nov. 25, 2014, 9:20 p.m. UTC | #5 
On Tuesday, November 25, 2014 11:38:05 AM Hanjun Guo wrote:
> On 2014/11/24 22:51, Rafael J. Wysocki wrote:
> > On Monday, November 24, 2014 07:03:54 PM Hanjun Guo wrote:
> >> On 2014-11-24 9:27, Rafael J. Wysocki wrote:
> >>> On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
> >>>> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> >>>>
> >>>> The acpi_table_parse() function has a callback that
> >>>> passes a pointer to a table_header. Add a new function
> >>>> which takes this pointer and parses its entries. This
> >>>> eliminates the need to re-traverse all the tables for
> >>>> each call. e.g. as in acpi_table_parse_madt() which is
> >>>> normally called after acpi_table_parse().
> >>>>
> >>>> Acked-by: Grant Likely <grant.likely@linaro.org>
> >>>> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
> >>>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> >>>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> >>>> ---
> >>>>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
> >>>>  include/linux/acpi.h  |    4 +++
> >>>>  2 files changed, 51 insertions(+), 20 deletions(-)
> >>>>
> >>>> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> >>>> index 6d5a6cd..21ae521 100644
> >>>> --- a/drivers/acpi/tables.c
> >>>> +++ b/drivers/acpi/tables.c
> >>>> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
> >>>>  
> >>>>  
> >>>>  int __init
> >>>> -acpi_table_parse_entries(char *id,
> >>>> -			     unsigned long table_size,
> >>>> -			     int entry_id,
> >>>> -			     acpi_tbl_entry_handler handler,
> >>>> -			     unsigned int max_entries)
> >>>> +acpi_parse_entries(unsigned long table_size,
> >>>> +		acpi_tbl_entry_handler handler,
> >>>> +		struct acpi_table_header *table_header,
> >>>> +		int entry_id, unsigned int max_entries)
> >>>>  {
> >>>> -	struct acpi_table_header *table_header = NULL;
> >>>>  	struct acpi_subtable_header *entry;
> >>>> -	unsigned int count = 0;
> >>>> +	int count = 0;
> >>>>  	unsigned long table_end;
> >>>> -	acpi_size tbl_size;
> >>>>  
> >>>>  	if (acpi_disabled)
> >>>>  		return -ENODEV;
> >>>> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
> >>>>  	if (!handler)
> >>>>  		return -EINVAL;
> >>>>  
> >>>> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
> >>>> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
> >>>> -	else
> >>>> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
> >>>> +	if (!table_size)
> >>>> +		return -EINVAL;
> >>>>  
> >>>>  	if (!table_header) {
> >>>> -		pr_warn("%4.4s not present\n", id);
> >>>> +		pr_warn("Table header not present\n");
> >>> The message doesn't make sense any more if the table signature is not printed.
> 
> For this message, since no table id is passed, and this message is printed in
> acpi_table_parse_entries() before this function is called, I think we can check
> the table_header before call this function and remove the printed message here.

table_header needs to be checked against NULL in the caller and the message
printed from there to my eyes.

> >>>
> >>>>  		return -ENODEV;
> >>>>  	}
> >>>>  
> >>>> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
> >>>>  		if (entry->type == entry_id
> >>>>  		    && (!max_entries || count++ < max_entries))
> >>>>  			if (handler(entry, table_end))
> >>>> -				goto err;
> >>>> +				return -EINVAL;
> >>>>  
> >>>>  		/*
> >>>>  		 * If entry->length is 0, break from this loop to avoid
> >>>>  		 * infinite loop.
> >>>>  		 */
> >>>>  		if (entry->length == 0) {
> >>>> -			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
> >>>> -			goto err;
> >>>> +			pr_err("[0x%02x] Invalid zero length\n", entry_id);
> 
> For this one, since the table_header is valid now, we can keep it with:

Fine by me.

> - pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
> + pr_err("[%4.4s:0x%02x] Invalid zero length\n", table_header->signature, entry_id);
> 
> >>> Same here.
> >> How about remove the message and return directly?
> > We could do that, but for what reason?  Is the message not useful?
> 
> I agree with you, the message is useful I think, how about the comments above?

Please see above.
Hanjun Guo Nov. 26, 2014, 1:42 a.m. UTC | #6 
On 2014/11/26 5:20, Rafael J. Wysocki wrote:
> On Tuesday, November 25, 2014 11:38:05 AM Hanjun Guo wrote:
>> On 2014/11/24 22:51, Rafael J. Wysocki wrote:
>>> On Monday, November 24, 2014 07:03:54 PM Hanjun Guo wrote:
>>>> On 2014-11-24 9:27, Rafael J. Wysocki wrote:
>>>>> On Friday, October 17, 2014 09:36:58 PM Hanjun Guo wrote:
>>>>>> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>>>>>>
>>>>>> The acpi_table_parse() function has a callback that
>>>>>> passes a pointer to a table_header. Add a new function
>>>>>> which takes this pointer and parses its entries. This
>>>>>> eliminates the need to re-traverse all the tables for
>>>>>> each call. e.g. as in acpi_table_parse_madt() which is
>>>>>> normally called after acpi_table_parse().
>>>>>>
>>>>>> Acked-by: Grant Likely <grant.likely@linaro.org>
>>>>>> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>>>>>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>>>>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>>>>>> ---
>>>>>>  drivers/acpi/tables.c |   67 ++++++++++++++++++++++++++++++++++---------------
>>>>>>  include/linux/acpi.h  |    4 +++
>>>>>>  2 files changed, 51 insertions(+), 20 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
>>>>>> index 6d5a6cd..21ae521 100644
>>>>>> --- a/drivers/acpi/tables.c
>>>>>> +++ b/drivers/acpi/tables.c
>>>>>> @@ -192,17 +192,14 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
>>>>>>  
>>>>>>  
>>>>>>  int __init
>>>>>> -acpi_table_parse_entries(char *id,
>>>>>> -			     unsigned long table_size,
>>>>>> -			     int entry_id,
>>>>>> -			     acpi_tbl_entry_handler handler,
>>>>>> -			     unsigned int max_entries)
>>>>>> +acpi_parse_entries(unsigned long table_size,
>>>>>> +		acpi_tbl_entry_handler handler,
>>>>>> +		struct acpi_table_header *table_header,
>>>>>> +		int entry_id, unsigned int max_entries)
>>>>>>  {
>>>>>> -	struct acpi_table_header *table_header = NULL;
>>>>>>  	struct acpi_subtable_header *entry;
>>>>>> -	unsigned int count = 0;
>>>>>> +	int count = 0;
>>>>>>  	unsigned long table_end;
>>>>>> -	acpi_size tbl_size;
>>>>>>  
>>>>>>  	if (acpi_disabled)
>>>>>>  		return -ENODEV;
>>>>>> @@ -210,13 +207,11 @@ acpi_table_parse_entries(char *id,
>>>>>>  	if (!handler)
>>>>>>  		return -EINVAL;
>>>>>>  
>>>>>> -	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
>>>>>> -		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
>>>>>> -	else
>>>>>> -		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
>>>>>> +	if (!table_size)
>>>>>> +		return -EINVAL;
>>>>>>  
>>>>>>  	if (!table_header) {
>>>>>> -		pr_warn("%4.4s not present\n", id);
>>>>>> +		pr_warn("Table header not present\n");
>>>>> The message doesn't make sense any more if the table signature is not printed.
>> For this message, since no table id is passed, and this message is printed in
>> acpi_table_parse_entries() before this function is called, I think we can check
>> the table_header before call this function and remove the printed message here.
> table_header needs to be checked against NULL in the caller and the message
> printed from there to my eyes.

ok, I think table id should pass to this function, I will rework this patch
and resend.

Thanks
Hanjun
diff mbox

Patch

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 6d5a6cd..21ae521 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -192,17 +192,14 @@  void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
 
 
 int __init
-acpi_table_parse_entries(char *id,
-			     unsigned long table_size,
-			     int entry_id,
-			     acpi_tbl_entry_handler handler,
-			     unsigned int max_entries)
+acpi_parse_entries(unsigned long table_size,
+		acpi_tbl_entry_handler handler,
+		struct acpi_table_header *table_header,
+		int entry_id, unsigned int max_entries)
 {
-	struct acpi_table_header *table_header = NULL;
 	struct acpi_subtable_header *entry;
-	unsigned int count = 0;
+	int count = 0;
 	unsigned long table_end;
-	acpi_size tbl_size;
 
 	if (acpi_disabled)
 		return -ENODEV;
@@ -210,13 +207,11 @@  acpi_table_parse_entries(char *id,
 	if (!handler)
 		return -EINVAL;
 
-	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
-		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
-	else
-		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
+	if (!table_size)
+		return -EINVAL;
 
 	if (!table_header) {
-		pr_warn("%4.4s not present\n", id);
+		pr_warn("Table header not present\n");
 		return -ENODEV;
 	}
 
@@ -232,30 +227,62 @@  acpi_table_parse_entries(char *id,
 		if (entry->type == entry_id
 		    && (!max_entries || count++ < max_entries))
 			if (handler(entry, table_end))
-				goto err;
+				return -EINVAL;
 
 		/*
 		 * If entry->length is 0, break from this loop to avoid
 		 * infinite loop.
 		 */
 		if (entry->length == 0) {
-			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
-			goto err;
+			pr_err("[0x%02x] Invalid zero length\n", entry_id);
+			return -EINVAL;
 		}
 
 		entry = (struct acpi_subtable_header *)
 		    ((unsigned long)entry + entry->length);
 	}
+
 	if (max_entries && count > max_entries) {
 		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
-			id, entry_id, count - max_entries, count);
+			table_header->signature, entry_id, count - max_entries,
+			count);
 	}
 
-	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
 	return count;
-err:
+}
+
+int __init
+acpi_table_parse_entries(char *id,
+			 unsigned long table_size,
+			 int entry_id,
+			 acpi_tbl_entry_handler handler,
+			 unsigned int max_entries)
+{
+	struct acpi_table_header *table_header = NULL;
+	acpi_size tbl_size;
+	int count;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	if (!handler)
+		return -EINVAL;
+
+	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
+		acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
+	else
+		acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
+
+	if (!table_header) {
+		pr_warn("%4.4s not present\n", id);
+		return -ENODEV;
+	}
+
+	count = acpi_parse_entries(table_size, handler, table_header,
+			entry_id, max_entries);
+
 	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
-	return -EINVAL;
+	return count;
 }
 
 int __init
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 807cbc4..36d5012 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -123,6 +123,10 @@  int acpi_numa_init (void);
 
 int acpi_table_init (void);
 int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
+int __init acpi_parse_entries(unsigned long table_size,
+			      acpi_tbl_entry_handler handler,
+			      struct acpi_table_header *table_header,
+			      int entry_id, unsigned int max_entries);
 int __init acpi_table_parse_entries(char *id, unsigned long table_size,
 				    int entry_id,
 				    acpi_tbl_entry_handler handler,