From 7ee20d0afb69dfc79ef50d184d4b571f9064f9ba Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Thu, 8 Sep 2022 13:17:26 +0300 Subject: thunderbolt: Allow specifying custom credits for DMA tunnels The default ones should be find but this allows the user to tweak the credits to get more performance out of the P2P connection. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/tunnel.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/thunderbolt/tunnel.c') diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index dd3b5613ad2c..3bf2628a5dcd 100644 --- a/drivers/thunderbolt/tunnel.c +++ b/drivers/thunderbolt/tunnel.c @@ -41,9 +41,14 @@ * Number of credits we try to allocate for each DMA path if not limited * by the host router baMaxHI. */ -#define TB_DMA_CREDITS 14U +#define TB_DMA_CREDITS 14 /* Minimum number of credits for DMA path */ -#define TB_MIN_DMA_CREDITS 1U +#define TB_MIN_DMA_CREDITS 1 + +static unsigned int dma_credits = TB_DMA_CREDITS; +module_param(dma_credits, uint, 0444); +MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: " + __MODULE_STRING(TB_DMA_CREDITS) ")"); static bool bw_alloc_mode = true; module_param(bw_alloc_mode, bool, 0444); @@ -95,7 +100,7 @@ static unsigned int tb_available_credits(const struct tb_port *port, pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0; if (tb_acpi_is_xdomain_allowed()) { - spare = min_not_zero(sw->max_dma_credits, TB_DMA_CREDITS); + spare = min_not_zero(sw->max_dma_credits, dma_credits); /* Add some credits for potential second DMA tunnel */ spare += TB_MIN_DMA_CREDITS; } else { @@ -1472,7 +1477,7 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi, tunnel->dst_port = dst; tunnel->deinit = tb_dma_deinit; - credits = min_not_zero(TB_DMA_CREDITS, nhi->sw->max_dma_credits); + credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits); if (receive_ring > 0) { path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, -- cgit v1.2.3