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path: root/drivers/thunderbolt/cap.c
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Diffstat (limited to 'drivers/thunderbolt/cap.c')
-rw-r--r--drivers/thunderbolt/cap.c136
1 files changed, 94 insertions, 42 deletions
diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c
index 19db6cdc5b70..6f571e912cf2 100644
--- a/drivers/thunderbolt/cap.c
+++ b/drivers/thunderbolt/cap.c
@@ -15,14 +15,6 @@
#define VSE_CAP_OFFSET_MAX 0xffff
#define TMU_ACCESS_EN BIT(20)
-struct tb_cap_any {
- union {
- struct tb_cap_basic basic;
- struct tb_cap_extended_short extended_short;
- struct tb_cap_extended_long extended_long;
- };
-} __packed;
-
static int tb_port_enable_tmu(struct tb_port *port, bool enable)
{
struct tb_switch *sw = port->sw;
@@ -67,23 +59,50 @@ static void tb_port_dummy_read(struct tb_port *port)
}
}
+/**
+ * tb_port_next_cap() - Return next capability in the linked list
+ * @port: Port to find the capability for
+ * @offset: Previous capability offset (%0 for start)
+ *
+ * Returns dword offset of the next capability in port config space
+ * capability list and returns it. Passing %0 returns the first entry in
+ * the capability list. If no next capability is found returns %0. In case
+ * of failure returns negative errno.
+ */
+int tb_port_next_cap(struct tb_port *port, unsigned int offset)
+{
+ struct tb_cap_any header;
+ int ret;
+
+ if (!offset)
+ return port->config.first_cap_offset;
+
+ ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);
+ if (ret)
+ return ret;
+
+ return header.basic.next;
+}
+
static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
{
- u32 offset = 1;
+ int offset = 0;
do {
struct tb_cap_any header;
int ret;
+ offset = tb_port_next_cap(port, offset);
+ if (offset < 0)
+ return offset;
+
ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);
if (ret)
return ret;
if (header.basic.cap == cap)
return offset;
-
- offset = header.basic.next;
- } while (offset);
+ } while (offset > 0);
return -ENOENT;
}
@@ -114,6 +133,50 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
}
/**
+ * tb_switch_next_cap() - Return next capability in the linked list
+ * @sw: Switch to find the capability for
+ * @offset: Previous capability offset (%0 for start)
+ *
+ * Finds dword offset of the next capability in router config space
+ * capability list and returns it. Passing %0 returns the first entry in
+ * the capability list. If no next capability is found returns %0. In case
+ * of failure returns negative errno.
+ */
+int tb_switch_next_cap(struct tb_switch *sw, unsigned int offset)
+{
+ struct tb_cap_any header;
+ int ret;
+
+ if (!offset)
+ return sw->config.first_cap_offset;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 2);
+ if (ret)
+ return ret;
+
+ switch (header.basic.cap) {
+ case TB_SWITCH_CAP_TMU:
+ ret = header.basic.next;
+ break;
+
+ case TB_SWITCH_CAP_VSE:
+ if (!header.extended_short.length)
+ ret = header.extended_long.next;
+ else
+ ret = header.extended_short.next;
+ break;
+
+ default:
+ tb_sw_dbg(sw, "unknown capability %#x at %#x\n",
+ header.basic.cap, offset);
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret >= VSE_CAP_OFFSET_MAX ? 0 : ret;
+}
+
+/**
* tb_switch_find_cap() - Find switch capability
* @sw Switch to find the capability for
* @cap: Capability to look
@@ -124,21 +187,23 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
*/
int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
{
- int offset = sw->config.first_cap_offset;
+ int offset = 0;
- while (offset > 0 && offset < CAP_OFFSET_MAX) {
+ do {
struct tb_cap_any header;
int ret;
+ offset = tb_switch_next_cap(sw, offset);
+ if (offset < 0)
+ return offset;
+
ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1);
if (ret)
return ret;
if (header.basic.cap == cap)
return offset;
-
- offset = header.basic.next;
- }
+ } while (offset);
return -ENOENT;
}
@@ -155,37 +220,24 @@ int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
*/
int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec)
{
- struct tb_cap_any header;
- int offset;
+ int offset = 0;
- offset = tb_switch_find_cap(sw, TB_SWITCH_CAP_VSE);
- if (offset < 0)
- return offset;
-
- while (offset > 0 && offset < VSE_CAP_OFFSET_MAX) {
+ do {
+ struct tb_cap_any header;
int ret;
- ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 2);
+ offset = tb_switch_next_cap(sw, offset);
+ if (offset < 0)
+ return offset;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1);
if (ret)
return ret;
- /*
- * Extended vendor specific capabilities come in two
- * flavors: short and long. The latter is used when
- * offset is over 0xff.
- */
- if (offset >= CAP_OFFSET_MAX) {
- if (header.extended_long.vsec_id == vsec)
- return offset;
- offset = header.extended_long.next;
- } else {
- if (header.extended_short.vsec_id == vsec)
- return offset;
- if (!header.extended_short.length)
- return -ENOENT;
- offset = header.extended_short.next;
- }
- }
+ if (header.extended_short.cap == TB_SWITCH_CAP_VSE &&
+ header.extended_short.vsec_id == vsec)
+ return offset;
+ } while (offset);
return -ENOENT;
}