[PATCH v4 1/2] acpi: Added acpi_subtable_proc to ACPI table parsers

From: Lukasz Anaczkowski
Date: Wed Sep 09 2015 - 09:48:15 EST


ACPI subtable parsing needs to be extended to allow two or more
handlers to be run in the same ACPI table walk, thus adding
acpi_subtable_proc structure which stores
() ACPI table id
() handler that processes table
() counter how many items has been processed
and passing it to acpi_parse_entries_array() and
acpi_table_parse_entries_array().

This is needed to fix CPU enumeration when APIC/X2APIC entries
are interleaved.

Signed-off-by: Lukasz Anaczkowski <lukasz.anaczkowski@xxxxxxxxx>
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Tested-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
drivers/acpi/tables.c | 91 +++++++++++++++++++++++++++++++++++++++++----------
include/linux/acpi.h | 19 +++++++++--
2 files changed, 89 insertions(+), 21 deletions(-)

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 2e19189..b2608fe 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -214,20 +214,37 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
}
}

-int __init
-acpi_parse_entries(char *id, unsigned long table_size,
- acpi_tbl_entry_handler handler,
+/**
+ * acpi_parse_entries_array - for each proc_num find a subtable with proc->id
+ * and run proc->handler on it. Assumption is that there's only
+ * single handler for particular entry id.
+ *
+ * @id: table id (for debugging purposes)
+ * @table_size: single entry size
+ * @table_header: where does the table start?
+ * @proc: array of acpi_subtable_proc struct containing entry id
+ * and associated handler with it
+ * @proc_num: how big proc is?
+ * @max_entries: how many entries can we process?
+ *
+ * On success returns sum of all matching entries for all proc handlers.
+ * Otherwise, -ENODEV or -EINVAL is returned.
+ */
+static int __init
+acpi_parse_entries_array(char *id, unsigned long table_size,
struct acpi_table_header *table_header,
- int entry_id, unsigned int max_entries)
+ struct acpi_subtable_proc *proc, int proc_num,
+ unsigned int max_entries)
{
struct acpi_subtable_header *entry;
- int count = 0;
unsigned long table_end;
+ int count = 0;
+ int i;

if (acpi_disabled)
return -ENODEV;

- if (!id || !handler)
+ if (!id)
return -EINVAL;

if (!table_size)
@@ -247,20 +264,27 @@ acpi_parse_entries(char *id, unsigned long table_size,

while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
table_end) {
- if (entry->type == entry_id
- && (!max_entries || count < max_entries)) {
- if (handler(entry, table_end))
+ if (max_entries && count >= max_entries)
+ break;
+
+ for (i = 0; i < proc_num; i++) {
+ if (entry->type != proc[i].id)
+ continue;
+ if (!proc->handler || proc[i].handler(entry, table_end))
return -EINVAL;

- count++;
+ proc->count++;
+ break;
}
+ if (i != proc_num)
+ count++;

/*
* 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("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
return -EINVAL;
}

@@ -270,17 +294,32 @@ acpi_parse_entries(char *id, unsigned long table_size,

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);
+ id, proc->id, count - max_entries, count);
}

return count;
}

int __init
-acpi_table_parse_entries(char *id,
+acpi_parse_entries(char *id,
+ unsigned long table_size,
+ acpi_tbl_entry_handler handler,
+ struct acpi_table_header *table_header,
+ int entry_id, unsigned int max_entries)
+{
+ struct acpi_subtable_proc proc = {
+ .id = entry_id,
+ .handler = handler,
+ };
+
+ return acpi_parse_entries_array(id, table_size, table_header,
+ &proc, 1, max_entries);
+}
+
+int __init
+acpi_table_parse_entries_array(char *id,
unsigned long table_size,
- int entry_id,
- acpi_tbl_entry_handler handler,
+ struct acpi_subtable_proc *proc, int proc_num,
unsigned int max_entries)
{
struct acpi_table_header *table_header = NULL;
@@ -291,7 +330,7 @@ acpi_table_parse_entries(char *id,
if (acpi_disabled)
return -ENODEV;

- if (!id || !handler)
+ if (!id)
return -EINVAL;

if (!strncmp(id, ACPI_SIG_MADT, 4))
@@ -303,14 +342,30 @@ acpi_table_parse_entries(char *id,
return -ENODEV;
}

- count = acpi_parse_entries(id, table_size, handler, table_header,
- entry_id, max_entries);
+ count = acpi_parse_entries_array(id, table_size, table_header,
+ proc, proc_num, max_entries);

early_acpi_os_unmap_memory((char *)table_header, tbl_size);
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_subtable_proc proc = {
+ .id = entry_id,
+ .handler = handler,
+ };
+
+ return acpi_table_parse_entries_array(id, table_size, &proc, 1,
+ max_entries);
+}
+
+int __init
acpi_table_parse_madt(enum acpi_madt_type id,
acpi_tbl_entry_handler handler, unsigned int max_entries)
{
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d2445fa..3dd741f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -135,6 +135,12 @@ static inline void acpi_initrd_override(void *data, size_t size)
(!entry) || (unsigned long)entry + sizeof(*entry) > end || \
((struct acpi_subtable_header *)entry)->length < sizeof(*entry))

+struct acpi_subtable_proc {
+ int id;
+ acpi_tbl_entry_handler handler;
+ int count;
+};
+
char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
void __acpi_unmap_table(char *map, unsigned long size);
int early_acpi_boot_init(void);
@@ -150,9 +156,16 @@ int __init acpi_parse_entries(char *id, unsigned long table_size,
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,
- unsigned int max_entries);
+ int entry_id,
+ acpi_tbl_entry_handler handler,
+ unsigned int max_entries);
+int __init acpi_table_parse_entries(char *id, unsigned long table_size,
+ int entry_id,
+ acpi_tbl_entry_handler handler,
+ unsigned int max_entries);
+int __init acpi_table_parse_entries_array(char *id, unsigned long table_size,
+ struct acpi_subtable_proc *proc, int proc_num,
+ unsigned int max_entries);
int acpi_table_parse_madt(enum acpi_madt_type id,
acpi_tbl_entry_handler handler,
unsigned int max_entries);
--
1.8.3.1

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