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authorMika Westerberg <mika.westerberg@linux.intel.com>2020-06-29 20:21:07 +0300
committerMika Westerberg <mika.westerberg@linux.intel.com>2020-09-03 12:21:07 +0300
commit6de057ef915f167dc6518910de3675ab061d2a50 (patch)
treebb6e759ca6fd908e4d8aedbc7c08dcdab9ab6105 /drivers/thunderbolt/cap.c
parent3c8b228d4371d0556d3d333d63df90172c2c7355 (diff)
downloadlinux-6de057ef915f167dc6518910de3675ab061d2a50.tar.xz
thunderbolt: Introduce tb_switch_next_cap()
This is similar to tb_port_next_cap() but instead allows walking capability list of a switch (router). Convert tb_switch_find_cap() and tb_switch_find_vse_cap() to use this as well. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt/cap.c')
-rw-r--r--drivers/thunderbolt/cap.c93
1 files changed, 63 insertions, 30 deletions
diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c
index c45b3a488412..6f571e912cf2 100644
--- a/drivers/thunderbolt/cap.c
+++ b/drivers/thunderbolt/cap.c
@@ -133,6 +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
@@ -143,21 +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;
}
@@ -174,37 +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;
-
- offset = tb_switch_find_cap(sw, TB_SWITCH_CAP_VSE);
- if (offset < 0)
- return offset;
+ int offset = 0;
- 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;
}