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coresight: Fix support for sparsely populated ports
On some systems the firmware may not describe all the ports connected to a component (e.g, for security reasons). This could be especially problematic for "funnels" where we could end up in modifying memory beyond the allocated space for refcounts. e.g, for a funnel with input ports listed 0, 3, 5, nr_inport = 3. However the we could access refcnts[5] while checking for references, like : [ 526.110401] ================================================================== [ 526.117988] BUG: KASAN: slab-out-of-bounds in funnel_enable+0x54/0x1b0 [ 526.124706] Read of size 4 at addr ffffff8135f9549c by task bash/1114 [ 526.131324] [ 526.132886] CPU: 3 PID: 1114 Comm: bash Tainted: G S 5.4.25 #232 [ 526.140397] Hardware name: Qualcomm Technologies, Inc. SC7180 IDP (DT) [ 526.147113] Call trace: [ 526.149653] dump_backtrace+0x0/0x188 [ 526.153431] show_stack+0x20/0x2c [ 526.156852] dump_stack+0xdc/0x144 [ 526.160370] print_address_description+0x3c/0x494 [ 526.165211] __kasan_report+0x144/0x168 [ 526.169170] kasan_report+0x10/0x18 [ 526.172769] check_memory_region+0x1a4/0x1b4 [ 526.177164] __kasan_check_read+0x18/0x24 [ 526.181292] funnel_enable+0x54/0x1b0 [ 526.185072] coresight_enable_path+0x104/0x198 [ 526.189649] coresight_enable+0x118/0x26c ... [ 526.237782] Allocated by task 280: [ 526.241298] __kasan_kmalloc+0xf0/0x1ac [ 526.245249] kasan_kmalloc+0xc/0x14 [ 526.248849] __kmalloc+0x28c/0x3b4 [ 526.252361] coresight_register+0x88/0x250 [ 526.256587] funnel_probe+0x15c/0x228 [ 526.260365] dynamic_funnel_probe+0x20/0x2c [ 526.264679] amba_probe+0xbc/0x158 [ 526.268193] really_probe+0x144/0x408 [ 526.271970] driver_probe_device+0x70/0x140 ... [ 526.316810] [ 526.318364] Freed by task 0: [ 526.321344] (stack is not available) [ 526.325024] [ 526.326580] The buggy address belongs to the object at ffffff8135f95480 [ 526.326580] which belongs to the cache kmalloc-128 of size 128 [ 526.339439] The buggy address is located 28 bytes inside of [ 526.339439] 128-byte region [ffffff8135f95480, ffffff8135f95500) [ 526.351399] The buggy address belongs to the page: [ 526.356342] page:ffffffff04b7e500 refcount:1 mapcount:0 mapping:ffffff814b00c380 index:0x0 compound_mapcount: 0 [ 526.366711] flags: 0x4000000000010200(slab|head) [ 526.371475] raw: 4000000000010200 ffffffff05034008 ffffffff0501eb08 ffffff814b00c380 [ 526.379435] raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000 [ 526.387393] page dumped because: kasan: bad access detected [ 526.393128] [ 526.394681] Memory state around the buggy address: [ 526.399619] ffffff8135f95380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.407046] ffffff8135f95400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.414473] >ffffff8135f95480: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.421900] ^ [ 526.426029] ffffff8135f95500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.433456] ffffff8135f95580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 526.440883] ================================================================== To keep the code simple, we now track the maximum number of possible input/output connections to/from this component @ nr_inport and nr_outport in platform_data, respectively. Thus the output connections could be sparse and code is adjusted to skip the unspecified connections. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Tested-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20200518180242.7916-13-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Suzuki K Poulose
Greg Kroah-Hartman
parent
1c33c65cfe
commit
d375b356e6
@ -87,6 +87,7 @@ static void of_coresight_get_ports_legacy(const struct device_node *node,
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int *nr_inport, int *nr_outport)
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{
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struct device_node *ep = NULL;
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struct of_endpoint endpoint;
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int in = 0, out = 0;
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do {
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@ -94,10 +95,16 @@ static void of_coresight_get_ports_legacy(const struct device_node *node,
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if (!ep)
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break;
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if (of_coresight_legacy_ep_is_input(ep))
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in++;
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else
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out++;
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if (of_graph_parse_endpoint(ep, &endpoint))
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continue;
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if (of_coresight_legacy_ep_is_input(ep)) {
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in = (endpoint.port + 1 > in) ?
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endpoint.port + 1 : in;
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} else {
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out = (endpoint.port + 1) > out ?
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endpoint.port + 1 : out;
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}
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} while (ep);
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@ -137,9 +144,16 @@ of_coresight_count_ports(struct device_node *port_parent)
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{
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int i = 0;
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struct device_node *ep = NULL;
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struct of_endpoint endpoint;
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while ((ep = of_graph_get_next_endpoint(port_parent, ep))) {
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/* Defer error handling to parsing */
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if (of_graph_parse_endpoint(ep, &endpoint))
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continue;
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if (endpoint.port + 1 > i)
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i = endpoint.port + 1;
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}
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while ((ep = of_graph_get_next_endpoint(port_parent, ep)))
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i++;
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return i;
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}
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@ -191,14 +205,12 @@ static int of_coresight_get_cpu(struct device *dev)
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* Parses the local port, remote device name and the remote port.
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*
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* Returns :
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* 1 - If the parsing is successful and a connection record
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* was created for an output connection.
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* 0 - If the parsing completed without any fatal errors.
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* -Errno - Fatal error, abort the scanning.
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*/
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static int of_coresight_parse_endpoint(struct device *dev,
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struct device_node *ep,
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struct coresight_connection *conn)
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struct coresight_platform_data *pdata)
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{
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int ret = 0;
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struct of_endpoint endpoint, rendpoint;
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@ -206,6 +218,7 @@ static int of_coresight_parse_endpoint(struct device *dev,
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struct device_node *rep = NULL;
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struct device *rdev = NULL;
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struct fwnode_handle *rdev_fwnode;
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struct coresight_connection *conn;
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do {
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/* Parse the local port details */
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@ -232,6 +245,13 @@ static int of_coresight_parse_endpoint(struct device *dev,
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break;
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}
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conn = &pdata->conns[endpoint.port];
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if (conn->child_fwnode) {
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dev_warn(dev, "Duplicate output port %d\n",
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endpoint.port);
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ret = -EINVAL;
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break;
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}
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conn->outport = endpoint.port;
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/*
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* Hold the refcount to the target device. This could be
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@ -244,7 +264,6 @@ static int of_coresight_parse_endpoint(struct device *dev,
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conn->child_fwnode = fwnode_handle_get(rdev_fwnode);
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conn->child_port = rendpoint.port;
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/* Connection record updated */
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ret = 1;
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} while (0);
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of_node_put(rparent);
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@ -258,7 +277,6 @@ static int of_get_coresight_platform_data(struct device *dev,
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struct coresight_platform_data *pdata)
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{
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int ret = 0;
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struct coresight_connection *conn;
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struct device_node *ep = NULL;
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const struct device_node *parent = NULL;
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bool legacy_binding = false;
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@ -287,8 +305,6 @@ static int of_get_coresight_platform_data(struct device *dev,
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dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
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}
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conn = pdata->conns;
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/* Iterate through each output port to discover topology */
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while ((ep = of_graph_get_next_endpoint(parent, ep))) {
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/*
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@ -300,15 +316,9 @@ static int of_get_coresight_platform_data(struct device *dev,
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if (legacy_binding && of_coresight_legacy_ep_is_input(ep))
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continue;
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ret = of_coresight_parse_endpoint(dev, ep, conn);
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switch (ret) {
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case 1:
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conn++; /* Fall through */
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case 0:
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break;
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default:
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ret = of_coresight_parse_endpoint(dev, ep, pdata);
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if (ret)
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return ret;
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}
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}
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return 0;
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@ -647,6 +657,16 @@ static int acpi_coresight_parse_link(struct acpi_device *adev,
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* coresight_remove_match().
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*/
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conn->child_fwnode = fwnode_handle_get(&r_adev->fwnode);
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} else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
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/*
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* We are only interested in the port number
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* for the input ports at this component.
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* Store the port number in child_port.
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*/
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conn->child_port = fields[0].integer.value;
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} else {
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/* Invalid direction */
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return -EINVAL;
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}
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return dir;
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@ -692,10 +712,20 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev,
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return dir;
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if (dir == ACPI_CORESIGHT_LINK_MASTER) {
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pdata->nr_outport++;
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if (ptr->outport > pdata->nr_outport)
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pdata->nr_outport = ptr->outport;
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ptr++;
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} else {
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pdata->nr_inport++;
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WARN_ON(pdata->nr_inport == ptr->child_port);
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/*
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* We do not track input port connections for a device.
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* However we need the highest port number described,
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* which can be recorded now and reuse this connection
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* record for an output connection. Hence, do not move
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* the ptr for input connections
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*/
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if (ptr->child_port > pdata->nr_inport)
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pdata->nr_inport = ptr->child_port;
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}
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}
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@ -704,8 +734,13 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev,
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return rc;
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/* Copy the connection information to the final location */
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for (i = 0; i < pdata->nr_outport; i++)
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pdata->conns[i] = conns[i];
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for (i = 0; conns + i < ptr; i++) {
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int port = conns[i].outport;
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/* Duplicate output port */
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WARN_ON(pdata->conns[port].child_fwnode);
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pdata->conns[port] = conns[i];
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}
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devm_kfree(&adev->dev, conns);
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return 0;
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@ -1053,6 +1053,9 @@ static int coresight_orphan_match(struct device *dev, void *data)
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for (i = 0; i < i_csdev->pdata->nr_outport; i++) {
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conn = &i_csdev->pdata->conns[i];
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/* Skip the port if FW doesn't describe it */
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if (!conn->child_fwnode)
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continue;
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/* We have found at least one orphan connection */
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if (conn->child_dev == NULL) {
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/* Does it match this newly added device? */
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@ -1091,6 +1094,8 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev)
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for (i = 0; i < csdev->pdata->nr_outport; i++) {
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struct coresight_connection *conn = &csdev->pdata->conns[i];
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if (!conn->child_fwnode)
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continue;
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conn->child_dev =
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coresight_find_csdev_by_fwnode(conn->child_fwnode);
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if (conn->child_dev) {
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@ -1126,7 +1131,7 @@ static int coresight_remove_match(struct device *dev, void *data)
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for (i = 0; i < iterator->pdata->nr_outport; i++) {
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conn = &iterator->pdata->conns[i];
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if (conn->child_dev == NULL)
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if (conn->child_dev == NULL || conn->child_fwnode == NULL)
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continue;
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if (csdev->dev.fwnode == conn->child_fwnode) {
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@ -100,10 +100,12 @@ union coresight_dev_subtype {
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};
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/**
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* struct coresight_platform_data - data harvested from the DT specification
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* @nr_inport: number of input ports for this component.
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* @nr_outport: number of output ports for this component.
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* @conns: Array of nr_outport connections from this component
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* struct coresight_platform_data - data harvested from the firmware
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* specification.
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*
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* @nr_inport: Number of elements for the input connections.
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* @nr_outport: Number of elements for the output connections.
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* @conns: Sparse array of nr_outport connections from this component.
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*/
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struct coresight_platform_data {
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int nr_inport;
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