linux/linux-5.4.31/drivers/thunderbolt/tunnel.c

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2024-01-30 10:43:28 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt driver - Tunneling support
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
* Copyright (C) 2019, Intel Corporation
*/
#include <linux/slab.h>
#include <linux/list.h>
#include "tunnel.h"
#include "tb.h"
/* PCIe adapters use always HopID of 8 for both directions */
#define TB_PCI_HOPID 8
#define TB_PCI_PATH_DOWN 0
#define TB_PCI_PATH_UP 1
/* DP adapters use HopID 8 for AUX and 9 for Video */
#define TB_DP_AUX_TX_HOPID 8
#define TB_DP_AUX_RX_HOPID 8
#define TB_DP_VIDEO_HOPID 9
#define TB_DP_VIDEO_PATH_OUT 0
#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" };
#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \
do { \
struct tb_tunnel *__tunnel = (tunnel); \
level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt, \
tb_route(__tunnel->src_port->sw), \
__tunnel->src_port->port, \
tb_route(__tunnel->dst_port->sw), \
__tunnel->dst_port->port, \
tb_tunnel_names[__tunnel->type], \
## arg); \
} while (0)
#define tb_tunnel_WARN(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
#define tb_tunnel_warn(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
#define tb_tunnel_info(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
#define tb_tunnel_dbg(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
enum tb_tunnel_type type)
{
struct tb_tunnel *tunnel;
tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
if (!tunnel)
return NULL;
tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
if (!tunnel->paths) {
tb_tunnel_free(tunnel);
return NULL;
}
INIT_LIST_HEAD(&tunnel->list);
tunnel->tb = tb;
tunnel->npaths = npaths;
tunnel->type = type;
return tunnel;
}
static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
{
int res;
res = tb_pci_port_enable(tunnel->src_port, activate);
if (res)
return res;
if (tb_port_is_pcie_up(tunnel->dst_port))
return tb_pci_port_enable(tunnel->dst_port, activate);
return 0;
}
static void tb_pci_init_path(struct tb_path *path)
{
path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
path->egress_shared_buffer = TB_PATH_NONE;
path->ingress_fc_enable = TB_PATH_ALL;
path->ingress_shared_buffer = TB_PATH_NONE;
path->priority = 3;
path->weight = 1;
path->drop_packages = 0;
path->nfc_credits = 0;
path->hops[0].initial_credits = 7;
path->hops[1].initial_credits = 16;
}
/**
* tb_tunnel_discover_pci() - Discover existing PCIe tunnels
* @tb: Pointer to the domain structure
* @down: PCIe downstream adapter
*
* If @down adapter is active, follows the tunnel to the PCIe upstream
* adapter and back. Returns the discovered tunnel or %NULL if there was
* no tunnel.
*/
struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
{
struct tb_tunnel *tunnel;
struct tb_path *path;
if (!tb_pci_port_is_enabled(down))
return NULL;
tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
if (!tunnel)
return NULL;
tunnel->activate = tb_pci_activate;
tunnel->src_port = down;
/*
* Discover both paths even if they are not complete. We will
* clean them up by calling tb_tunnel_deactivate() below in that
* case.
*/
path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
&tunnel->dst_port, "PCIe Up");
if (!path) {
/* Just disable the downstream port */
tb_pci_port_enable(down, false);
goto err_free;
}
tunnel->paths[TB_PCI_PATH_UP] = path;
tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
"PCIe Down");
if (!path)
goto err_deactivate;
tunnel->paths[TB_PCI_PATH_DOWN] = path;
tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
/* Validate that the tunnel is complete */
if (!tb_port_is_pcie_up(tunnel->dst_port)) {
tb_port_warn(tunnel->dst_port,
"path does not end on a PCIe adapter, cleaning up\n");
goto err_deactivate;
}
if (down != tunnel->src_port) {
tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
goto err_deactivate;
}
if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
tb_tunnel_warn(tunnel,
"tunnel is not fully activated, cleaning up\n");
goto err_deactivate;
}
tb_tunnel_dbg(tunnel, "discovered\n");
return tunnel;
err_deactivate:
tb_tunnel_deactivate(tunnel);
err_free:
tb_tunnel_free(tunnel);
return NULL;
}
/**
* tb_tunnel_alloc_pci() - allocate a pci tunnel
* @tb: Pointer to the domain structure
* @up: PCIe upstream adapter port
* @down: PCIe downstream adapter port
*
* Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
* TB_TYPE_PCIE_DOWN.
*
* Return: Returns a tb_tunnel on success or NULL on failure.
*/
struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
struct tb_port *down)
{
struct tb_tunnel *tunnel;
struct tb_path *path;
tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
if (!tunnel)
return NULL;
tunnel->activate = tb_pci_activate;
tunnel->src_port = down;
tunnel->dst_port = up;
path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
"PCIe Down");
if (!path) {
tb_tunnel_free(tunnel);
return NULL;
}
tb_pci_init_path(path);
tunnel->paths[TB_PCI_PATH_DOWN] = path;
path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
"PCIe Up");
if (!path) {
tb_tunnel_free(tunnel);
return NULL;
}
tb_pci_init_path(path);
tunnel->paths[TB_PCI_PATH_UP] = path;
return tunnel;
}
static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
{
struct tb_port *out = tunnel->dst_port;
struct tb_port *in = tunnel->src_port;
u32 in_dp_cap, out_dp_cap;
int ret;
/*
* Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
* newer generation hardware.
*/
if (in->sw->generation < 2 || out->sw->generation < 2)
return 0;
/* Read both DP_LOCAL_CAP registers */
ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
in->cap_adap + TB_DP_LOCAL_CAP, 1);
if (ret)
return ret;
ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
out->cap_adap + TB_DP_LOCAL_CAP, 1);
if (ret)
return ret;
/* Write IN local caps to OUT remote caps */
ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
out->cap_adap + TB_DP_REMOTE_CAP, 1);
if (ret)
return ret;
return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
in->cap_adap + TB_DP_REMOTE_CAP, 1);
}
static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
{
int ret;
if (active) {
struct tb_path **paths;
int last;
paths = tunnel->paths;
last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
tb_dp_port_set_hops(tunnel->src_port,
paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
tb_dp_port_set_hops(tunnel->dst_port,
paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
} else {
tb_dp_port_hpd_clear(tunnel->src_port);
tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
if (tb_port_is_dpout(tunnel->dst_port))
tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
}
ret = tb_dp_port_enable(tunnel->src_port, active);
if (ret)
return ret;
if (tb_port_is_dpout(tunnel->dst_port))
return tb_dp_port_enable(tunnel->dst_port, active);
return 0;
}
static void tb_dp_init_aux_path(struct tb_path *path)
{
int i;
path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
path->egress_shared_buffer = TB_PATH_NONE;
path->ingress_fc_enable = TB_PATH_ALL;
path->ingress_shared_buffer = TB_PATH_NONE;
path->priority = 2;
path->weight = 1;
for (i = 0; i < path->path_length; i++)
path->hops[i].initial_credits = 1;
}
static void tb_dp_init_video_path(struct tb_path *path, bool discover)
{
u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
path->egress_fc_enable = TB_PATH_NONE;
path->egress_shared_buffer = TB_PATH_NONE;
path->ingress_fc_enable = TB_PATH_NONE;
path->ingress_shared_buffer = TB_PATH_NONE;
path->priority = 1;
path->weight = 1;
if (discover) {
path->nfc_credits = nfc_credits & TB_PORT_NFC_CREDITS_MASK;
} else {
u32 max_credits;
max_credits = (nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
TB_PORT_MAX_CREDITS_SHIFT;
/* Leave some credits for AUX path */
path->nfc_credits = min(max_credits - 2, 12U);
}
}
/**
* tb_tunnel_discover_dp() - Discover existing Display Port tunnels
* @tb: Pointer to the domain structure
* @in: DP in adapter
*
* If @in adapter is active, follows the tunnel to the DP out adapter
* and back. Returns the discovered tunnel or %NULL if there was no
* tunnel.
*
* Return: DP tunnel or %NULL if no tunnel found.
*/
struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
{
struct tb_tunnel *tunnel;
struct tb_port *port;
struct tb_path *path;
if (!tb_dp_port_is_enabled(in))
return NULL;
tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
if (!tunnel)
return NULL;
tunnel->init = tb_dp_xchg_caps;
tunnel->activate = tb_dp_activate;
tunnel->src_port = in;
path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
&tunnel->dst_port, "Video");
if (!path) {
/* Just disable the DP IN port */
tb_dp_port_enable(in, false);
goto err_free;
}
tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
if (!path)
goto err_deactivate;
tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
&port, "AUX RX");
if (!path)
goto err_deactivate;
tunnel->paths[TB_DP_AUX_PATH_IN] = path;
tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
/* Validate that the tunnel is complete */
if (!tb_port_is_dpout(tunnel->dst_port)) {
tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
goto err_deactivate;
}
if (!tb_dp_port_is_enabled(tunnel->dst_port))
goto err_deactivate;
if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
goto err_deactivate;
if (port != tunnel->src_port) {
tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
goto err_deactivate;
}
tb_tunnel_dbg(tunnel, "discovered\n");
return tunnel;
err_deactivate:
tb_tunnel_deactivate(tunnel);
err_free:
tb_tunnel_free(tunnel);
return NULL;
}
/**
* tb_tunnel_alloc_dp() - allocate a Display Port tunnel
* @tb: Pointer to the domain structure
* @in: DP in adapter port
* @out: DP out adapter port
*
* Allocates a tunnel between @in and @out that is capable of tunneling
* Display Port traffic.
*
* Return: Returns a tb_tunnel on success or NULL on failure.
*/
struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
struct tb_port *out)
{
struct tb_tunnel *tunnel;
struct tb_path **paths;
struct tb_path *path;
if (WARN_ON(!in->cap_adap || !out->cap_adap))
return NULL;
tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
if (!tunnel)
return NULL;
tunnel->init = tb_dp_xchg_caps;
tunnel->activate = tb_dp_activate;
tunnel->src_port = in;
tunnel->dst_port = out;
paths = tunnel->paths;
path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
1, "Video");
if (!path)
goto err_free;
tb_dp_init_video_path(path, false);
paths[TB_DP_VIDEO_PATH_OUT] = path;
path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
TB_DP_AUX_TX_HOPID, 1, "AUX TX");
if (!path)
goto err_free;
tb_dp_init_aux_path(path);
paths[TB_DP_AUX_PATH_OUT] = path;
path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
TB_DP_AUX_RX_HOPID, 1, "AUX RX");
if (!path)
goto err_free;
tb_dp_init_aux_path(path);
paths[TB_DP_AUX_PATH_IN] = path;
return tunnel;
err_free:
tb_tunnel_free(tunnel);
return NULL;
}
static u32 tb_dma_credits(struct tb_port *nhi)
{
u32 max_credits;
max_credits = (nhi->config.nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
TB_PORT_MAX_CREDITS_SHIFT;
return min(max_credits, 13U);
}
static int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
{
struct tb_port *nhi = tunnel->src_port;
u32 credits;
credits = active ? tb_dma_credits(nhi) : 0;
return tb_port_set_initial_credits(nhi, credits);
}
static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
unsigned int efc, u32 credits)
{
int i;
path->egress_fc_enable = efc;
path->ingress_fc_enable = TB_PATH_ALL;
path->egress_shared_buffer = TB_PATH_NONE;
path->ingress_shared_buffer = isb;
path->priority = 5;
path->weight = 1;
path->clear_fc = true;
for (i = 0; i < path->path_length; i++)
path->hops[i].initial_credits = credits;
}
/**
* tb_tunnel_alloc_dma() - allocate a DMA tunnel
* @tb: Pointer to the domain structure
* @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
* @transmit_path: HopID used for transmitting packets
* @receive_ring: NHI ring number used to receive packets from the
* other domain
* @reveive_path: HopID used for receiving packets
*
* Return: Returns a tb_tunnel on success or NULL on failure.
*/
struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
struct tb_port *dst, int transmit_ring,
int transmit_path, int receive_ring,
int receive_path)
{
struct tb_tunnel *tunnel;
struct tb_path *path;
u32 credits;
tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA);
if (!tunnel)
return NULL;
tunnel->activate = tb_dma_activate;
tunnel->src_port = nhi;
tunnel->dst_port = dst;
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;
}
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;
}
tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
tunnel->paths[TB_DMA_PATH_OUT] = path;
return tunnel;
}
/**
* tb_tunnel_free() - free a tunnel
* @tunnel: Tunnel to be freed
*
* Frees a tunnel. The tunnel does not need to be deactivated.
*/
void tb_tunnel_free(struct tb_tunnel *tunnel)
{
int i;
if (!tunnel)
return;
for (i = 0; i < tunnel->npaths; i++) {
if (tunnel->paths[i])
tb_path_free(tunnel->paths[i]);
}
kfree(tunnel->paths);
kfree(tunnel);
}
/**
* tb_tunnel_is_invalid - check whether an activated path is still valid
* @tunnel: Tunnel to check
*/
bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
{
int i;
for (i = 0; i < tunnel->npaths; i++) {
WARN_ON(!tunnel->paths[i]->activated);
if (tb_path_is_invalid(tunnel->paths[i]))
return true;
}
return false;
}
/**
* tb_tunnel_restart() - activate a tunnel after a hardware reset
* @tunnel: Tunnel to restart
*
* Return: 0 on success and negative errno in case if failure
*/
int tb_tunnel_restart(struct tb_tunnel *tunnel)
{
int res, i;
tb_tunnel_dbg(tunnel, "activating\n");
/*
* Make sure all paths are properly disabled before enabling
* them again.
*/
for (i = 0; i < tunnel->npaths; i++) {
if (tunnel->paths[i]->activated) {
tb_path_deactivate(tunnel->paths[i]);
tunnel->paths[i]->activated = false;
}
}
if (tunnel->init) {
res = tunnel->init(tunnel);
if (res)
return res;
}
for (i = 0; i < tunnel->npaths; i++) {
res = tb_path_activate(tunnel->paths[i]);
if (res)
goto err;
}
if (tunnel->activate) {
res = tunnel->activate(tunnel, true);
if (res)
goto err;
}
return 0;
err:
tb_tunnel_warn(tunnel, "activation failed\n");
tb_tunnel_deactivate(tunnel);
return res;
}
/**
* tb_tunnel_activate() - activate a tunnel
* @tunnel: Tunnel to activate
*
* Return: Returns 0 on success or an error code on failure.
*/
int tb_tunnel_activate(struct tb_tunnel *tunnel)
{
int i;
for (i = 0; i < tunnel->npaths; i++) {
if (tunnel->paths[i]->activated) {
tb_tunnel_WARN(tunnel,
"trying to activate an already activated tunnel\n");
return -EINVAL;
}
}
return tb_tunnel_restart(tunnel);
}
/**
* tb_tunnel_deactivate() - deactivate a tunnel
* @tunnel: Tunnel to deactivate
*/
void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
{
int i;
tb_tunnel_dbg(tunnel, "deactivating\n");
if (tunnel->activate)
tunnel->activate(tunnel, false);
for (i = 0; i < tunnel->npaths; i++) {
if (tunnel->paths[i] && tunnel->paths[i]->activated)
tb_path_deactivate(tunnel->paths[i]);
}
}