--- /dev/null
+From d35bcd754a6a214a549af5476040da61085b44eb Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Thu, 14 Jan 2021 19:46:47 +0100
+Subject: ACPI: scan: Rearrange memory allocation in acpi_device_add()
+
+From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+
+[ Upstream commit c1013ff7a5472db637c56bb6237f8343398c03a7 ]
+
+The upfront allocation of new_bus_id is done to avoid allocating
+memory under acpi_device_lock, but it doesn't really help,
+because (1) it leads to many unnecessary memory allocations for
+_ADR devices, (2) kstrdup_const() is run under that lock anyway and
+(3) it complicates the code.
+
+Rearrange acpi_device_add() to allocate memory for a new struct
+acpi_device_bus_id instance only when necessary, eliminate a redundant
+local variable from it and reduce the number of labels in there.
+
+No intentional functional impact.
+
+Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Reviewed-by: Hans de Goede <hdegoede@redhat.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/acpi/scan.c | 57 +++++++++++++++++++++------------------------
+ 1 file changed, 26 insertions(+), 31 deletions(-)
+
+diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
+index bd58f0743cfc..9ec463da9a50 100644
+--- a/drivers/acpi/scan.c
++++ b/drivers/acpi/scan.c
+@@ -622,12 +622,23 @@ void acpi_bus_put_acpi_device(struct acpi_device *adev)
+ put_device(&adev->dev);
+ }
+
++static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
++{
++ struct acpi_device_bus_id *acpi_device_bus_id;
++
++ /* Find suitable bus_id and instance number in acpi_bus_id_list. */
++ list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
++ if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
++ return acpi_device_bus_id;
++ }
++ return NULL;
++}
++
+ int acpi_device_add(struct acpi_device *device,
+ void (*release)(struct device *))
+ {
++ struct acpi_device_bus_id *acpi_device_bus_id;
+ int result;
+- struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
+- int found = 0;
+
+ if (device->handle) {
+ acpi_status status;
+@@ -653,38 +664,26 @@ int acpi_device_add(struct acpi_device *device,
+ INIT_LIST_HEAD(&device->del_list);
+ mutex_init(&device->physical_node_lock);
+
+- new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
+- if (!new_bus_id) {
+- pr_err(PREFIX "Memory allocation error\n");
+- result = -ENOMEM;
+- goto err_detach;
+- }
+-
+ mutex_lock(&acpi_device_lock);
+- /*
+- * Find suitable bus_id and instance number in acpi_bus_id_list
+- * If failed, create one and link it into acpi_bus_id_list
+- */
+- 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))) {
+- acpi_device_bus_id->instance_no++;
+- found = 1;
+- kfree(new_bus_id);
+- break;
++
++ acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
++ if (acpi_device_bus_id) {
++ acpi_device_bus_id->instance_no++;
++ } else {
++ acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
++ GFP_KERNEL);
++ if (!acpi_device_bus_id) {
++ result = -ENOMEM;
++ goto err_unlock;
+ }
+- }
+- if (!found) {
+- acpi_device_bus_id = new_bus_id;
+ acpi_device_bus_id->bus_id =
+ kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
+ if (!acpi_device_bus_id->bus_id) {
+- pr_err(PREFIX "Memory allocation error for bus id\n");
++ kfree(acpi_device_bus_id);
+ result = -ENOMEM;
+- goto err_free_new_bus_id;
++ goto err_unlock;
+ }
+
+- acpi_device_bus_id->instance_no = 0;
+ 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);
+@@ -719,13 +718,9 @@ int acpi_device_add(struct acpi_device *device,
+ list_del(&device->node);
+ list_del(&device->wakeup_list);
+
+- err_free_new_bus_id:
+- if (!found)
+- kfree(new_bus_id);
+-
++ err_unlock:
+ mutex_unlock(&acpi_device_lock);
+
+- err_detach:
+ acpi_detach_data(device->handle, acpi_scan_drop_device);
+ return result;
+ }
+--
+2.30.1
+
--- /dev/null
+From aa7d5123c9f5a4b1f1deb0b82d4a6b997944cf88 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Mon, 22 Mar 2021 18:31:00 +0200
+Subject: ACPI: scan: Use unique number for instance_no
+
+From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+
+[ Upstream commit eb50aaf960e3bedfef79063411ffd670da94b84b ]
+
+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: e49bd2dd5a50 ("ACPI: use PNPID:instance_no as bus_id of ACPI device")
+Fixes: ca9dc8d42b30 ("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>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/acpi/internal.h | 6 +++++-
+ drivers/acpi/scan.c | 33 ++++++++++++++++++++++++++++-----
+ include/acpi/acpi_bus.h | 1 +
+ 3 files changed, 34 insertions(+), 6 deletions(-)
+
+diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
+index e6b10aad55d5..6ac1c6b04199 100644
+--- a/drivers/acpi/internal.h
++++ b/drivers/acpi/internal.h
+@@ -18,6 +18,8 @@
+ #ifndef _ACPI_INTERNAL_H_
+ #define _ACPI_INTERNAL_H_
+
++#include <linux/idr.h>
++
+ #define PREFIX "ACPI: "
+
+ int early_acpi_osi_init(void);
+@@ -97,9 +99,11 @@ 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;
+ };
+
+diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
+index 9ec463da9a50..57a213466721 100644
+--- a/drivers/acpi/scan.c
++++ b/drivers/acpi/scan.c
+@@ -481,9 +481,8 @@ 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);
+@@ -634,6 +633,21 @@ 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 *))
+ {
+@@ -668,7 +682,9 @@ 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);
+@@ -684,9 +700,16 @@ 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);
+diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
+index 67f4fce22209..3746d4ce4857 100644
+--- a/include/acpi/acpi_bus.h
++++ b/include/acpi/acpi_bus.h
+@@ -245,6 +245,7 @@ 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 */
+--
+2.30.1
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
