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thunderbolt: Introduce tb_switch_next_cap()

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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>
This commit is contained in:
Mika Westerberg 2020-06-29 20:21:07 +03:00
parent 3c8b228d43
commit 6de057ef91
2 changed files with 64 additions and 30 deletions
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93
drivers/thunderbolt/cap.c
View File

@ -132,6 +132,50 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
return ret;
}
/**
* 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
@ -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;
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;
}

1
drivers/thunderbolt/tb.h
View File

@ -822,6 +822,7 @@ int tb_port_get_link_speed(struct tb_port *port);
int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap);
int tb_switch_next_cap(struct tb_switch *sw, unsigned int offset);
int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);
int tb_port_next_cap(struct tb_port *port, unsigned int offset);
bool tb_port_is_enabled(struct tb_port *port);