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ACPI: scan: Use unique number for instance_no

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The decrementation of acpi_device_bus_id->instance_no
in acpi_device_del() is incorrect, because it may cause
a duplicate instance number to be allocated next time
a device with the same acpi_device_bus_id is added.

Replace above mentioned approach by using IDA framework.

While at it, define the instance range to be [0, 4096).

Fixes: e49bd2dd5a ("ACPI: use PNPID:instance_no as bus_id of ACPI device")
Fixes: ca9dc8d42b ("ACPI / scan: Fix acpi_bus_id_list bookkeeping")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Andy Shevchenko 2021-03-22 18:31:00 +02:00 committed by Rafael J. Wysocki
parent 0d02ec6b31
commit eb50aaf960
3 changed files with 34 additions and 6 deletions
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6
drivers/acpi/internal.h
View File

@ -9,6 +9,8 @@
#ifndef _ACPI_INTERNAL_H_
#define _ACPI_INTERNAL_H_
#include <linux/idr.h>
#define PREFIX "ACPI: "
int early_acpi_osi_init(void);
@ -96,9 +98,11 @@ void acpi_scan_table_handler(u32 event, void *table, void *context);
extern struct list_head acpi_bus_id_list;
#define ACPI_MAX_DEVICE_INSTANCES 4096
struct acpi_device_bus_id {
const char *bus_id;
unsigned int instance_no;
struct ida instance_ida;
struct list_head node;
};

33
drivers/acpi/scan.c
View File

@ -479,9 +479,8 @@ static void acpi_device_del(struct acpi_device *device)
list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
if (!strcmp(acpi_device_bus_id->bus_id,
acpi_device_hid(device))) {
if (acpi_device_bus_id->instance_no > 0)
acpi_device_bus_id->instance_no--;
else {
ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no);
if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
list_del(&acpi_device_bus_id->node);
kfree_const(acpi_device_bus_id->bus_id);
kfree(acpi_device_bus_id);
@ -631,6 +630,21 @@ static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
return NULL;
}
static int acpi_device_set_name(struct acpi_device *device,
struct acpi_device_bus_id *acpi_device_bus_id)
{
struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
int result;
result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL);
if (result < 0)
return result;
device->pnp.instance_no = result;
dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
return 0;
}
int acpi_device_add(struct acpi_device *device,
void (*release)(struct device *))
{
@ -665,7 +679,9 @@ int acpi_device_add(struct acpi_device *device,
acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
if (acpi_device_bus_id) {
acpi_device_bus_id->instance_no++;
result = acpi_device_set_name(device, acpi_device_bus_id);
if (result)
goto err_unlock;
} else {
acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
GFP_KERNEL);
@ -681,9 +697,16 @@ int acpi_device_add(struct acpi_device *device,
goto err_unlock;
}
ida_init(&acpi_device_bus_id->instance_ida);
result = acpi_device_set_name(device, acpi_device_bus_id);
if (result) {
kfree(acpi_device_bus_id);
goto err_unlock;
}
list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
}
dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
if (device->parent)
list_add_tail(&device->node, &device->parent->children);

1
include/acpi/acpi_bus.h
View File

@ -233,6 +233,7 @@ struct acpi_pnp_type {
struct acpi_device_pnp {
acpi_bus_id bus_id; /* Object name */
int instance_no; /* Instance number of this object */
struct acpi_pnp_type type; /* ID type */
acpi_bus_address bus_address; /* _ADR */
char *unique_id; /* _UID */