[PATCH v2 03/16] ACPI: glue: Introduce acpi_find_child_by_adr()

Rafael J. Wysocki
2022-06-13T20:06:47Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Rearrange the ACPI device lookup code used internally by
acpi_find_child_device() so it can avoid extra checks after finding
one object with a matching _ADR and use it for defining
acpi_find_child_by_adr() that will allow the callers to find a given
ACPI device's child matching a given bus address without doing any
other checks in check_one_child().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---

v1 -> v2:
* Add R-by from Andy.

---
drivers/acpi/glue.c | 28 ++++++++++++++++++++++++----
include/acpi/acpi_bus.h | 2 ++
2 files changed, 26 insertions(+), 4 deletions(-)

Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -622,6 +622,8 @@ static inline int acpi_dma_configure(str
}
struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
u64 address, bool check_children);
+struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev,
+ acpi_bus_address adr);
int acpi_is_root_bridge(acpi_handle);
struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle);

Index: linux-pm/drivers/acpi/glue.c
===================================================================
--- linux-pm.orig/drivers/acpi/glue.c
+++ linux-pm/drivers/acpi/glue.c
@@ -119,6 +119,7 @@ struct find_child_walk_data {
struct acpi_device *adev;
u64 address;
int score;
+ bool check_sta;
bool check_children;
};

@@ -131,9 +132,13 @@ static int check_one_child(struct acpi_d
return 0;

if (!wd->adev) {
- /* This is the first matching object. Save it and continue. */
+ /*
+ * This is the first matching object, so save it. If it is not
+ * necessary to look for any other matching objects, stop the
+ * search.
+ */
wd->adev = adev;
- return 0;
+ return !(wd->check_sta || wd->check_children);
}

/*
@@ -169,12 +174,14 @@ static int check_one_child(struct acpi_d
return 0;
}

-struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
- u64 address, bool check_children)
+static struct acpi_device *acpi_find_child(struct acpi_device *parent,
+ u64 address, bool check_children,
+ bool check_sta)
{
struct find_child_walk_data wd = {
.address = address,
.check_children = check_children,
+ .check_sta = check_sta,
.adev = NULL,
.score = 0,
};
@@ -184,8 +191,21 @@ struct acpi_device *acpi_find_child_devi

return wd.adev;
}
+
+struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
+ u64 address, bool check_children)
+{
+ return acpi_find_child(parent, address, check_children, true);
+}
EXPORT_SYMBOL_GPL(acpi_find_child_device);

+struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev,
+ acpi_bus_address adr)
+{
+ return acpi_find_child(adev, adr, false, false);
+}
+EXPORT_SYMBOL_GPL(acpi_find_child_by_adr);
+
static void acpi_physnode_link_name(char *buf, unsigned int node_id)
{
if (node_id > 0)