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

[Rafael J. Wysocki]

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 at 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 at linaro.org>
> >> Signed-off-by: Ashwin Chaugule <ashwin.chaugule at linaro.org>
> >> Signed-off-by: Tomasz Nowicki <tomasz.nowicki at linaro.org>
> >> Signed-off-by: Hanjun Guo <hanjun.guo at 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?

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.