[PATCH 13/19] ACPI / table: Add new function to get table entries

Hanjun Guo
2014-07-24T13:00:19Z

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().

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
drivers/acpi/tables.c | 70 +++++++++++++++++++++++++++++++++++--------------
include/linux/acpi.h | 4 +++
2 files changed, 54 insertions(+), 20 deletions(-)

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 8bb8159..e6455c9 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -229,17 +229,14 @@ 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;
@@ -247,13 +244,11 @@ 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;
}

@@ -268,31 +263,66 @@ acpi_table_parse_entries(char *id,
table_end) {
if (entry->type == entry_id
&& (!max_entries || count++ < max_entries))
- if (handler(entry, table_end))
+ if (handler(entry, table_end)) {
+ count = -EINVAL;
goto err;
+ }

/*
* 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);
+ pr_err("[0x%02x] Invalid zero length\n", entry_id);
+ count = -EINVAL;
goto err;
}

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);
+ pr_warn("[0x%02x] ignored %i entries of %i found\n",
+ entry_id, count - max_entries, count);
}

- early_acpi_os_unmap_memory((char *)table_header, tbl_size);
- return count;
err:
+ return count;
+}
+
+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 ad6c30f..95540e7 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -124,6 +124,10 @@ 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,
--
1.7.9.5