thunderbolt: Make tb_switch_alloc() return ERR_PTR()

In order to detect possible connections to other domains we need to be
able to find out why tb_switch_alloc() fails so make it return ERR_PTR()
instead. This allows the caller to differentiate between errors such as
-ENOMEM which comes from the kernel and for instance -EIO which comes
from the hardware when trying to access the possible switch.

Convert all the current call sites to handle this properly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index 805958e53c583305c2855efa65e2630d85d6c88f..d1f6ec89763c3e17a83cb687eddfbc287ec91d9e 100644 (file)
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -468,7 +468,7 @@ static void add_switch(struct tb_switch *parent_sw, u64 route,
        pm_runtime_get_sync(&parent_sw->dev);
 
        sw = tb_switch_alloc(parent_sw->tb, &parent_sw->dev, route);
-       if (!sw)
+       if (IS_ERR(sw))
                goto out;
 
        sw->uuid = kmemdup(uuid, sizeof(*uuid), GFP_KERNEL);
@@ -1848,8 +1848,8 @@ static int icm_start(struct tb *tb)
                tb->root_switch = tb_switch_alloc_safe_mode(tb, &tb->dev, 0);
        else
                tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
-       if (!tb->root_switch)
-               return -ENODEV;
+       if (IS_ERR(tb->root_switch))
+               return PTR_ERR(tb->root_switch);
 
        /*
         * NVM upgrade has not been tested on Apple systems and they

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index ecf53d986a5cadba917697fdca8f730c3c17f6b6..460f2bcad40a84b59542fc97aa62bcb56b6dad5b 100644 (file)
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1450,30 +1450,32 @@ static int tb_switch_get_generation(struct tb_switch *sw)
  * separately. The returned switch should be released by calling
  * tb_switch_put().
  *
- * Return: Pointer to the allocated switch or %NULL in case of failure
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of
+ * failure.
  */
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
                                  u64 route)
 {
        struct tb_switch *sw;
        int upstream_port;
-       int i, cap, depth;
+       int i, ret, depth;
 
        /* Make sure we do not exceed maximum topology limit */
        depth = tb_route_length(route);
        if (depth > TB_SWITCH_MAX_DEPTH)
-               return NULL;
+               return ERR_PTR(-EADDRNOTAVAIL);
 
        upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
        if (upstream_port < 0)
-               return NULL;
+               return ERR_PTR(upstream_port);
 
        sw = kzalloc(sizeof(*sw), GFP_KERNEL);
        if (!sw)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        sw->tb = tb;
-       if (tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5))
+       ret = tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5);
+       if (ret)
                goto err_free_sw_ports;
 
        tb_dbg(tb, "current switch config:\n");
@@ -1489,8 +1491,10 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
        /* initialize ports */
        sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
                                GFP_KERNEL);
-       if (!sw->ports)
+       if (!sw->ports) {
+               ret = -ENOMEM;
                goto err_free_sw_ports;
+       }
 
        for (i = 0; i <= sw->config.max_port_number; i++) {
                /* minimum setup for tb_find_cap and tb_drom_read to work */
@@ -1500,16 +1504,16 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 
        sw->generation = tb_switch_get_generation(sw);
 
-       cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
-       if (cap < 0) {
+       ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
+       if (ret < 0) {
                tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
                goto err_free_sw_ports;
        }
-       sw->cap_plug_events = cap;
+       sw->cap_plug_events = ret;
 
-       cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
-       if (cap > 0)
-               sw->cap_lc = cap;
+       ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
+       if (ret > 0)
+               sw->cap_lc = ret;
 
        /* Root switch is always authorized */
        if (!route)
@@ -1528,7 +1532,7 @@ err_free_sw_ports:
        kfree(sw->ports);
        kfree(sw);
 
-       return NULL;
+       return ERR_PTR(ret);
 }
 
 /**
@@ -1543,7 +1547,7 @@ err_free_sw_ports:
  *
  * The returned switch must be released by calling tb_switch_put().
  *
- * Return: Pointer to the allocated switch or %NULL in case of failure
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of failure
  */
 struct tb_switch *
 tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
@@ -1552,7 +1556,7 @@ tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
 
        sw = kzalloc(sizeof(*sw), GFP_KERNEL);
        if (!sw)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        sw->tb = tb;
        sw->config.depth = tb_route_length(route);

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 8a97a4e19638d18205c79e845f932c90f5f26b21..c5e82c4dcb649a1d60153a2e38f997b465365fa2 100644 (file)
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -148,7 +148,7 @@ static void tb_scan_port(struct tb_port *port)
        }
        sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
                             tb_downstream_route(port));
-       if (!sw)
+       if (IS_ERR(sw))
                return;
 
        if (tb_switch_configure(sw)) {
@@ -533,8 +533,8 @@ static int tb_start(struct tb *tb)
        int ret;
 
        tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
-       if (!tb->root_switch)
-               return -ENOMEM;
+       if (IS_ERR(tb->root_switch))
+               return PTR_ERR(tb->root_switch);
 
        /*
         * ICM firmware upgrade needs running firmware and in native