From: Gil Fine gil.fine@linux.intel.com
[ Upstream commit 582e70b0d3a412d15389a3c9c07a44791b311715 ]
USB4 v2 Connection Manager guide (section 6.1.2.3) suggests to reserve bandwidth in a sligthly different manner. It suggests to keep minimum of 1500 Mb/s for each path that carry a bulk traffic. Here we change the bandwidth reservations to comply to the above for USB 3.x and PCIe protocols over Gen 4 link, taking weights into account (that's 1500 Mb/s for PCIe and 3000 Mb/s for USB 3.x).
For Gen 3 and below we use the existing reservation.
Signed-off-by: Gil Fine gil.fine@linux.intel.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Qin Wan qin.wan@hp.com Signed-off-by: Alexandru Gagniuc alexandru.gagniuc@hp.com --- drivers/thunderbolt/tb.c | 11 ++++++ drivers/thunderbolt/tunnel.c | 66 ++++++++++++++++++++++++++++++++++-- drivers/thunderbolt/tunnel.h | 2 ++ 3 files changed, 76 insertions(+), 3 deletions(-)
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c index e37fb1081420..183225bdbbf5 100644 --- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -602,6 +602,7 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port, /* Find the minimum available bandwidth over all links */ tb_for_each_port_on_path(src_port, dst_port, port) { int link_speed, link_width, up_bw, down_bw; + int pci_reserved_up, pci_reserved_down;
if (!tb_port_is_null(port)) continue; @@ -695,6 +696,16 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port, up_bw -= usb3_consumed_up; down_bw -= usb3_consumed_down;
+ /* + * If there is anything reserved for PCIe bulk traffic + * take it into account here too. + */ + if (tb_tunnel_reserved_pci(port, &pci_reserved_up, + &pci_reserved_down)) { + up_bw -= pci_reserved_up; + down_bw -= pci_reserved_down; + } + if (up_bw < *available_up) *available_up = up_bw; if (down_bw < *available_down) diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index b81344c6c06a..e296ab5d657b 100644 --- a/drivers/thunderbolt/tunnel.c +++ b/drivers/thunderbolt/tunnel.c @@ -31,7 +31,7 @@ #define TB_USB3_PATH_UP 1
#define TB_USB3_PRIORITY 3 -#define TB_USB3_WEIGHT 3 +#define TB_USB3_WEIGHT 2
/* DP adapters use HopID 8 for AUX and 9 for Video */ #define TB_DP_AUX_TX_HOPID 8 @@ -61,6 +61,15 @@ #define TB_DMA_PRIORITY 5 #define TB_DMA_WEIGHT 1
+/* + * Reserve additional bandwidth for USB 3.x and PCIe bulk traffic + * according to USB4 v2 Connection Manager guide. This ends up reserving + * 1500 Mb/s for PCIe and 3000 Mb/s for USB 3.x taking weights into + * account. + */ +#define USB4_V2_PCI_MIN_BANDWIDTH (1500 * TB_PCI_WEIGHT) +#define USB4_V2_USB3_MIN_BANDWIDTH (1500 * TB_USB3_WEIGHT) + 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: " @@ -150,11 +159,11 @@ static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable) { + struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw); int ret;
/* Only supported of both routers are at least USB4 v2 */ - if (usb4_switch_version(tunnel->src_port->sw) < 2 || - usb4_switch_version(tunnel->dst_port->sw) < 2) + if (tb_port_get_link_generation(port) < 4) return 0;
ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable); @@ -370,6 +379,51 @@ struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up, return NULL; }
+/** + * tb_tunnel_reserved_pci() - Amount of bandwidth to reserve for PCIe + * @port: Lane 0 adapter + * @reserved_up: Upstream bandwidth in Mb/s to reserve + * @reserved_down: Downstream bandwidth in Mb/s to reserve + * + * Can be called to any connected lane 0 adapter to find out how much + * bandwidth needs to be left in reserve for possible PCIe bulk traffic. + * Returns true if there is something to be reserved and writes the + * amount to @reserved_down/@reserved_up. Otherwise returns false and + * does not touch the parameters. + */ +bool tb_tunnel_reserved_pci(struct tb_port *port, int *reserved_up, + int *reserved_down) +{ + if (WARN_ON_ONCE(!port->remote)) + return false; + + if (!tb_acpi_may_tunnel_pcie()) + return false; + + if (tb_port_get_link_generation(port) < 4) + return false; + + /* Must have PCIe adapters */ + if (tb_is_upstream_port(port)) { + if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_UP)) + return false; + if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_DOWN)) + return false; + } else { + if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_DOWN)) + return false; + if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_UP)) + return false; + } + + *reserved_up = USB4_V2_PCI_MIN_BANDWIDTH; + *reserved_down = USB4_V2_PCI_MIN_BANDWIDTH; + + tb_port_dbg(port, "reserving %u/%u Mb/s for PCIe\n", *reserved_up, + *reserved_down); + return true; +} + static bool tb_dp_is_usb4(const struct tb_switch *sw) { /* Titan Ridge DP adapters need the same treatment as USB4 */ @@ -1747,6 +1801,7 @@ static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate) static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up, int *consumed_down) { + struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw); int pcie_weight = tb_acpi_may_tunnel_pcie() ? TB_PCI_WEIGHT : 0;
/* @@ -1758,6 +1813,11 @@ static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel, *consumed_down = tunnel->allocated_down * (TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;
+ if (tb_port_get_link_generation(port) >= 4) { + *consumed_up = max(*consumed_up, USB4_V2_USB3_MIN_BANDWIDTH); + *consumed_down = max(*consumed_down, USB4_V2_USB3_MIN_BANDWIDTH); + } + return 0; }
diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h index 750ebb570d99..b4cff5482112 100644 --- a/drivers/thunderbolt/tunnel.h +++ b/drivers/thunderbolt/tunnel.h @@ -80,6 +80,8 @@ struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down, bool alloc_hopid); struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up, struct tb_port *down); +bool tb_tunnel_reserved_pci(struct tb_port *port, int *reserved_up, + int *reserved_down); struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in, bool alloc_hopid); struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,