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

From: [email-masked] (Hanjun Guo)
Date: Mon, 24 Nov 2014 19:03:54 +0800

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 <[email-masked]>
>>
>> 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 <[email-masked]>
>> Signed-off-by: Ashwin Chaugule <[email-masked]>
>> Signed-off-by: Tomasz Nowicki <[email-masked]>
>> Signed-off-by: Hanjun Guo <[email-masked]>
>> ---
>>  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