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authorMika Westerberg <mika.westerberg@linux.intel.com>2020-10-07 18:17:12 +0300
committerMika Westerberg <mika.westerberg@linux.intel.com>2020-11-11 10:20:16 +0300
commit5bf722df5d37e82fd252b1d3e37cde4eab355c1c (patch)
treed0e882493f665ba826cdc915c7494d0a883c090a /drivers/thunderbolt
parent407ac931aefda91ac90498c6b6e6893982173613 (diff)
thunderbolt: Make it possible to allocate one directional DMA tunnel
With DMA tunnels it is possible that the service using it does not require bi-directional paths so make RX and TX optional (but of course one of them needs to be set). Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/thunderbolt')
-rw-r--r--drivers/thunderbolt/tunnel.c50
1 files changed, 31 insertions, 19 deletions
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 829b6ccdd5d4..dcdf9c7a9cae 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -34,9 +34,6 @@
#define TB_DP_AUX_PATH_OUT 1
#define TB_DP_AUX_PATH_IN 2
-#define TB_DMA_PATH_OUT 0
-#define TB_DMA_PATH_IN 1
-
static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \
@@ -829,10 +826,10 @@ static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
* @nhi: Host controller port
* @dst: Destination null port which the other domain is connected to
* @transmit_ring: NHI ring number used to send packets towards the
- * other domain
+ * other domain. Set to %0 if TX path is not needed.
* @transmit_path: HopID used for transmitting packets
* @receive_ring: NHI ring number used to receive packets from the
- * other domain
+ * other domain. Set to %0 if RX path is not needed.
* @reveive_path: HopID used for receiving packets
*
* Return: Returns a tb_tunnel on success or NULL on failure.
@@ -843,10 +840,19 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
int receive_path)
{
struct tb_tunnel *tunnel;
+ size_t npaths = 0, i = 0;
struct tb_path *path;
u32 credits;
- tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA);
+ if (receive_ring)
+ npaths++;
+ if (transmit_ring)
+ npaths++;
+
+ if (WARN_ON(!npaths))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
if (!tunnel)
return NULL;
@@ -856,22 +862,28 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
credits = tb_dma_credits(nhi);
- path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, "DMA RX");
- if (!path) {
- tb_tunnel_free(tunnel);
- return NULL;
+ if (receive_ring) {
+ path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
+ "DMA RX");
+ if (!path) {
+ tb_tunnel_free(tunnel);
+ return NULL;
+ }
+ tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
+ credits);
+ tunnel->paths[i++] = path;
}
- tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
- credits);
- tunnel->paths[TB_DMA_PATH_IN] = path;
- path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0, "DMA TX");
- if (!path) {
- tb_tunnel_free(tunnel);
- return NULL;
+ if (transmit_ring) {
+ path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
+ "DMA TX");
+ if (!path) {
+ tb_tunnel_free(tunnel);
+ return NULL;
+ }
+ tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
+ tunnel->paths[i++] = path;
}
- tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
- tunnel->paths[TB_DMA_PATH_OUT] = path;
return tunnel;
}