From 5bf722df5d37e82fd252b1d3e37cde4eab355c1c Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 7 Oct 2020 18:17:12 +0300 Subject: 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 Acked-by: Yehezkel Bernat Reviewed-by: Greg Kroah-Hartman --- drivers/thunderbolt/tunnel.c | 50 +++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 19 deletions(-) (limited to 'drivers/thunderbolt/tunnel.c') 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; } -- cgit v1.2.3