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thunderbolt: Make it possible to allocate one directional DMA tunnel

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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>
This commit is contained in:
Mika Westerberg 2020-10-07 18:17:12 +03:00
parent 407ac931ae
commit 5bf722df5d
1 changed files with 31 additions and 19 deletions
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50
drivers/thunderbolt/tunnel.c
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@ -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;
}