Device drivers typically use ACPI _HIDs/_CIDs listed in struct device_driver
acpi_match_table to match devices. However, for generic drivers, we do not
want to list _HID for all supported devices. Also, certain classes of devices
do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS,
which specifies PCI-defined class code (i.e. base-class, subclass and
programming interface). This patch adds support for matching ACPI devices using
the _CLS method.
To support loadable module, current design uses _HID or _CID to match device's
modalias. With the new way of matching with _CLS this would requires modification
to the current ACPI modalias key to include _CLS. This patch appends PCI-defined
class-code to the existing ACPI modalias as following.
acpi:<HID>:<CID1>:<CID2>:..:<CIDn>:<bbsspp>:
E.g:
# cat /sys/devices/platform/AMDI0600:00/modalias
acpi:AMDI0600:010601:
where bb is th base-class code, ss is te sub-class code, and pp is the
programming interface code
Since there would not be _HID/_CID in the ACPI matching table of the driver,
this patch adds a field to acpi_device_id to specify the matching _CLS.
static const struct acpi_device_id ahci_acpi_match[] = {
{ ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
{},
};
In this case, the corresponded entry in modules.alias file would be:
alias acpi*:010601:* ahci_platform
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
drivers/acpi/scan.c | 36 ++++++++++++++++++++++++++++++++----
include/acpi/acnames.h | 1 +
include/acpi/actypes.h | 4 +++-
include/linux/acpi.h | 14 ++++++++++++++
include/linux/mod_devicetable.h | 2 ++
scripts/mod/devicetable-offsets.c | 2 ++
scripts/mod/file2alias.c | 32 ++++++++++++++++++++++++++++++--
7 files changed, 84 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c03cadb..d8551cd 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -900,6 +900,29 @@ static void acpi_device_remove_files(struct acpi_device *dev)
ACPI Bus operations
-------------------------------------------------------------------------- */
+static bool __acpi_match_device_cls(const struct acpi_device_id *id,
+ struct acpi_hardware_id *hwid)
+{
+ int i, msk, byte_shift;
+ char buf[3];
+
+ if (!id->cls)
+ return false;
+
+ /* Apply class-code bitmask, before checking each class-code byte */
+ for (i = 1; i <= 3; i++) {
+ byte_shift = 8 * (3 - i);
+ msk = (id->cls_msk >> byte_shift) & 0xFF;
+ if (!msk)
+ continue;
+
+ sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
+ if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
+ return false;
+ }
+ return true;
+}
+
static const struct acpi_device_id *__acpi_match_device(
struct acpi_device *device, const struct acpi_device_id *ids)
{
@@ -913,11 +936,14 @@ static const struct acpi_device_id *__acpi_match_device(
if (!device->status.present)
return NULL;
- for (id = ids; id->id[0]; id++)
- list_for_each_entry(hwid, &device->pnp.ids, list)
- if (!strcmp((char *) id->id, hwid->id))
+ for (id = ids; id->id[0] || id->cls; id++) {
+ list_for_each_entry(hwid, &device->pnp.ids, list) {
+ if (id->id[0] && !strcmp((char *) id->id, hwid->id))
return id;
-
+ else if (__acpi_match_device_cls(id, hwid))
+ return id;
+ }
+ }
return NULL;
}
@@ -2032,6 +2058,8 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
if (info->valid & ACPI_VALID_UID)
pnp->unique_id = kstrdup(info->unique_id.string,
GFP_KERNEL);
+ if (info->valid & ACPI_VALID_CLS)
+ acpi_add_id(pnp, info->cls.string);
kfree(info);
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 273de70..b52c0dc 100644
--- a/include/acpi/acnames.h
+++ b/include/acpi/acnames.h
@@ -51,6 +51,7 @@
#define METHOD_NAME__BBN "_BBN"
#define METHOD_NAME__CBA "_CBA"
#define METHOD_NAME__CID "_CID"
+#define METHOD_NAME__CLS "_CLS"
#define METHOD_NAME__CRS "_CRS"
#define METHOD_NAME__DDN "_DDN"
#define METHOD_NAME__HID "_HID"
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index b034f10..ab3dac8 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -1148,7 +1148,7 @@ struct acpi_device_info {
u32 name; /* ACPI object Name */
acpi_object_type type; /* ACPI object Type */
u8 param_count; /* If a method, required parameter count */
- u8 valid; /* Indicates which optional fields are valid */
+ u16 valid; /* Indicates which optional fields are valid */
u8 flags; /* Miscellaneous info */
u8 highest_dstates[4]; /* _sx_d values: 0xFF indicates not valid */
u8 lowest_dstates[5]; /* _sx_w values: 0xFF indicates not valid */
@@ -1157,6 +1157,7 @@ struct acpi_device_info {
struct acpi_pnp_device_id hardware_id; /* _HID value */
struct acpi_pnp_device_id unique_id; /* _UID value */
struct acpi_pnp_device_id subsystem_id; /* _SUB value */
+ struct acpi_pnp_device_id cls; /* _CLS value */
struct acpi_pnp_device_id_list compatible_id_list; /* _CID list <must be last> */
};
@@ -1174,6 +1175,7 @@ struct acpi_device_info {
#define ACPI_VALID_CID 0x20
#define ACPI_VALID_SXDS 0x40
#define ACPI_VALID_SXWS 0x80
+#define ACPI_VALID_CLS 0x100
/* Flags for _STA return value (current_status above) */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index de4e86f..3d1e5dd 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -57,6 +57,19 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev)
#define ACPI_COMPANION_SET(dev, adev) ACPI_COMPANION(dev) = (adev)
#define ACPI_HANDLE(dev) acpi_device_handle(ACPI_COMPANION(dev))
+/**
+ * ACPI_DEVICE_CLASS - macro used to describe an ACPI device with
+ * the PCI-defined class-code information
+ *
+ * @_cls : the class, subclass, prog-if triple for this device
+ * @_msk : the class mask for this device
+ *
+ * This macro is used to create a struct acpi_device_id that matches a
+ * specific PCI class. The .id and .driver_data fields will be left
+ * initialized with the default value.
+ */
+#define ACPI_DEVICE_CLASS(_cls, _msk) .cls = (_cls), .cls_msk = (_msk),
+
static inline void acpi_preset_companion(struct device *dev,
struct acpi_device *parent, u64 addr)
{
@@ -459,6 +472,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *);
#define ACPI_COMPANION(dev) (NULL)
#define ACPI_COMPANION_SET(dev, adev) do { } while (0)
#define ACPI_HANDLE(dev) (NULL)
+#define ACPI_DEVICE_CLASS(_cls, _msk) .cls = (0), .cls_msk = (0),
struct fwnode_handle;
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index e530533..2ed31b8 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -189,6 +189,8 @@ struct css_device_id {
struct acpi_device_id {
__u8 id[ACPI_ID_LEN];
kernel_ulong_t driver_data;
+ __u32 cls;
+ __u32 cls_msk;
};
#define PNP_ID_LEN 8
diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index f282516..8987160 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -63,6 +63,8 @@ int main(void)
DEVID(acpi_device_id);
DEVID_FIELD(acpi_device_id, id);
+ DEVID_FIELD(acpi_device_id, cls);
+ DEVID_FIELD(acpi_device_id, cls_msk);
DEVID(pnp_device_id);
DEVID_FIELD(pnp_device_id, id);
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index e614ef6..704d597 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -511,12 +511,40 @@ static int do_serio_entry(const char *filename,
}
ADD_TO_DEVTABLE("serio", serio_device_id, do_serio_entry);
-/* looks like: "acpi:ACPI0003 or acpi:PNP0C0B" or "acpi:LNXVIDEO" */
+/* looks like: "acpi:ACPI0003" or "acpi:PNP0C0B" or "acpi:LNXVIDEO" or
+ * "acpi:bbsspp" (bb=base-class, ss=sub-class, pp=prog-if)
+ *
+ * NOTE: Each driver should use one of the following : _HID, _CIDs
+ * or _CLS. Also, bb, ss, and pp can be substituted with ??
+ * as don't care byte.
+ */
static int do_acpi_entry(const char *filename,
void *symval, char *alias)
{
DEF_FIELD_ADDR(symval, acpi_device_id, id);
- sprintf(alias, "acpi*:%s:*", *id);
+ DEF_FIELD_ADDR(symval, acpi_device_id, cls);
+ DEF_FIELD_ADDR(symval, acpi_device_id, cls_msk);
+
+ if (id && strlen((const char *)*id))
+ sprintf(alias, "acpi*:%s:*", *id);
+ else if (cls) {
+ int i, byte_shift, cnt = 0;
+ unsigned int msk;
+
+ sprintf(&alias[cnt], "acpi*:");
+ cnt = 6;
+ for (i = 1; i <= 3; i++) {
+ byte_shift = 8 * (3-i);
+ msk = (*cls_msk >> byte_shift) & 0xFF;
+ if (msk)
+ sprintf(&alias[cnt], "%02x",
+ (*cls >> byte_shift) & 0xFF);
+ else
+ sprintf(&alias[cnt], "??");
+ cnt += 2;
+ }
+ sprintf(&alias[cnt], ":*");
+ }
return 1;
}
ADD_TO_DEVTABLE("acpi", acpi_device_id, do_acpi_entry);
--
2.1.0
--
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