From: Mustapha Ghaddar <mghad...@amd.com> [WHY & HOW] - make link_dp_dpia_bw.c available for linux. - add the verify link peak bw - clean up code and comment format.
Reviewed-by: Jun Lei <jun....@amd.com> Acked-by: Qingqing Zhuo <qingqing.z...@amd.com> Signed-off-by: Mustapha Ghaddar <mghad...@amd.com> --- drivers/gpu/drm/amd/display/dc/dc_link.h | 12 + .../dc/link/protocols/link_dp_dpia_bw.c | 413 ++++++++++++++++++ .../dc/link/protocols/link_dp_dpia_bw.h | 29 -- 3 files changed, 425 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h index fcaf27a877ef..cecd807f5ed8 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_link.h +++ b/drivers/gpu/drm/amd/display/dc/dc_link.h @@ -558,6 +558,18 @@ void dc_link_set_usb4_req_bw_req(struct dc_link *link, int req_bw); */ void dc_link_get_usb4_req_bw_resp(struct dc_link *link, uint8_t bw, uint8_t result); +/* + * Handle the USB4 BW Allocation related functionality here: + * Plug => Try to allocate max bw from timing parameters supported by the sink + * Unplug => de-allocate bw + * + * @link: pointer to the dc_link struct instance + * @peak_bw: Peak bw used by the link/sink + * + * return: allocated bw else return 0 + */ +int dc_link_dp_dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int peak_bw); + /* TODO: this is not meant to be exposed to DM. Should switch to stream update * interface i.e stream_update->dsc_config */ diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c index 801a95b34e8c..f69e681b3b5b 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c @@ -26,3 +26,416 @@ /*********************************************************************/ // USB4 DPIA BANDWIDTH ALLOCATION LOGIC /*********************************************************************/ +#include "dc.h" +#include "dc_link.h" +#include "link_dp_dpia_bw.h" +#include "drm_dp_helper_dc.h" +#include "link_dpcd.h" + +#define Kbps_TO_Gbps (1000 * 1000) + +// ------------------------------------------------------------------ +// PRIVATE FUNCTIONS +// ------------------------------------------------------------------ +/* + * Always Check the following: + * - Is it USB4 link? + * - Is HPD HIGH? + * - Is BW Allocation Support Mode enabled on DP-Tx? + */ +static bool get_bw_alloc_proceed_flag(struct dc_link *tmp) +{ + return (tmp && DISPLAY_ENDPOINT_USB4_DPIA == tmp->ep_type + && tmp->hpd_status + && tmp->dpia_bw_alloc_config.bw_alloc_enabled); +} +static void reset_bw_alloc_struct(struct dc_link *link) +{ + link->dpia_bw_alloc_config.bw_alloc_enabled = false; + link->dpia_bw_alloc_config.sink_verified_bw = 0; + link->dpia_bw_alloc_config.sink_max_bw = 0; + link->dpia_bw_alloc_config.estimated_bw = 0; + link->dpia_bw_alloc_config.bw_granularity = 0; + link->dpia_bw_alloc_config.response_ready = false; +} +static uint8_t get_bw_granularity(struct dc_link *link) +{ + uint8_t bw_granularity = 0; + + core_link_read_dpcd( + link, + DP_BW_GRANULALITY, + &bw_granularity, + sizeof(uint8_t)); + + switch (bw_granularity & 0x3) { + case 0: + bw_granularity = 4; + break; + case 1: + default: + bw_granularity = 2; + break; + } + + return bw_granularity; +} +static int get_estimated_bw(struct dc_link *link) +{ + uint8_t bw_estimated_bw = 0; + + if (core_link_read_dpcd( + link, + ESTIMATED_BW, + &bw_estimated_bw, + sizeof(uint8_t)) != DC_OK) + dm_output_to_console("%s: AUX W/R ERROR @ 0x%x\n", __func__, ESTIMATED_BW); + + return bw_estimated_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); +} +static bool allocate_usb4_bw(int *stream_allocated_bw, int bw_needed, struct dc_link *link) +{ + if (bw_needed > 0) + *stream_allocated_bw += bw_needed; + + return true; +} +static bool deallocate_usb4_bw(int *stream_allocated_bw, int bw_to_dealloc, struct dc_link *link) +{ + bool ret = false; + + if (*stream_allocated_bw > 0) { + *stream_allocated_bw -= bw_to_dealloc; + ret = true; + } else { + //Do nothing for now + ret = true; + } + + // Unplug so reset values + if (!link->hpd_status) + reset_bw_alloc_struct(link); + + return ret; +} +/* + * Read all New BW alloc configuration ex: estimated_bw, allocated_bw, + * granuality, Driver_ID, CM_Group, & populate the BW allocation structs + * for host router and dpia + */ +static void init_usb4_bw_struct(struct dc_link *link) +{ + // Init the known values + link->dpia_bw_alloc_config.bw_granularity = get_bw_granularity(link); + link->dpia_bw_alloc_config.estimated_bw = get_estimated_bw(link); +} +static uint8_t get_lowest_dpia_index(struct dc_link *link) +{ + const struct dc *dc_struct = link->dc; + uint8_t idx = 0xFF; + + for (int i = 0; i < MAX_PIPES * 2; ++i) { + + if (!dc_struct->links[i] || + dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) + continue; + + if (idx > dc_struct->links[i]->link_index) + idx = dc_struct->links[i]->link_index; + } + + return idx; +} +/* + * Get the Max Available BW or Max Estimated BW for each Host Router + * + * @link: pointer to the dc_link struct instance + * @type: ESTIMATD BW or MAX AVAILABLE BW + * + * return: response_ready flag from dc_link struct + */ +static int get_host_router_total_bw(struct dc_link *link, uint8_t type) +{ + const struct dc *dc_struct = link->dc; + uint8_t lowest_dpia_index = get_lowest_dpia_index(link); + uint8_t idx = (link->link_index - lowest_dpia_index) / 2, idx_temp = 0; + struct dc_link *link_temp; + int total_bw = 0; + + for (int i = 0; i < MAX_PIPES * 2; ++i) { + + if (!dc_struct->links[i] || dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) + continue; + + link_temp = dc_struct->links[i]; + if (!link_temp || !link_temp->hpd_status) + continue; + + idx_temp = (link_temp->link_index - lowest_dpia_index) / 2; + + if (idx_temp == idx) { + + if (type == HOST_ROUTER_BW_ESTIMATED) + total_bw += link_temp->dpia_bw_alloc_config.estimated_bw; + else if (type == HOST_ROUTER_BW_ALLOCATED) + total_bw += link_temp->dpia_bw_alloc_config.sink_allocated_bw; + } + } + + return total_bw; +} +/* + * Cleanup function for when the dpia is unplugged to reset struct + * and perform any required clean up + * + * @link: pointer to the dc_link struct instance + * + * return: none + */ +static bool dpia_bw_alloc_unplug(struct dc_link *link) +{ + bool ret = false; + + if (!link) + return true; + + return deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, + link->dpia_bw_alloc_config.sink_allocated_bw, link); +} +static void dc_link_set_usb4_req_bw_req(struct dc_link *link, int req_bw) +{ + uint8_t requested_bw; + uint32_t temp; + + // 1. Add check for this corner case #1 + if (req_bw > link->dpia_bw_alloc_config.estimated_bw) + req_bw = link->dpia_bw_alloc_config.estimated_bw; + + temp = req_bw * link->dpia_bw_alloc_config.bw_granularity; + requested_bw = temp / Kbps_TO_Gbps; + + // Always make sure to add more to account for floating points + if (temp % Kbps_TO_Gbps) + ++requested_bw; + + // 2. Add check for this corner case #2 + req_bw = requested_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + if (req_bw == link->dpia_bw_alloc_config.sink_allocated_bw) + return; + + if (core_link_write_dpcd( + link, + REQUESTED_BW, + &requested_bw, + sizeof(uint8_t)) != DC_OK) + dm_output_to_console("%s: AUX W/R ERROR @ 0x%x\n", __func__, REQUESTED_BW); + else + link->dpia_bw_alloc_config.response_ready = false; // Reset flag +} +/* + * Return the response_ready flag from dc_link struct + * + * @link: pointer to the dc_link struct instance + * + * return: response_ready flag from dc_link struct + */ +static bool get_cm_response_ready_flag(struct dc_link *link) +{ + return link->dpia_bw_alloc_config.response_ready; +} +// ------------------------------------------------------------------ +// PUBLIC FUNCTIONS +// ------------------------------------------------------------------ +bool set_dptx_usb4_bw_alloc_support(struct dc_link *link) +{ + bool ret = false; + uint8_t response = 0, + bw_support_dpia = 0, + bw_support_cm = 0; + + if (!(link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA && link->hpd_status)) + goto out; + + if (core_link_read_dpcd( + link, + DP_TUNNELING_CAPABILITIES, + &response, + sizeof(uint8_t)) != DC_OK) + dm_output_to_console("%s: AUX W/R ERROR @ 0x%x\n", __func__, DP_TUNNELING_CAPABILITIES); + + bw_support_dpia = (response >> 7) & 1; + + if (core_link_read_dpcd( + link, + USB4_DRIVER_BW_CAPABILITY, + &response, + sizeof(uint8_t)) != DC_OK) + dm_output_to_console("%s: AUX W/R ERROR @ 0x%x\n", __func__, DP_TUNNELING_CAPABILITIES); + + bw_support_cm = (response >> 7) & 1; + + /* Send request acknowledgment to Turn ON DPTX support */ + if (bw_support_cm && bw_support_dpia) { + + response = 0x80; + if (core_link_write_dpcd( + link, + DPTX_BW_ALLOCATION_MODE_CONTROL, + &response, + sizeof(uint8_t)) != DC_OK) + dm_output_to_console("%s: AUX W/R ERROR @ 0x%x\n", + "**** FAILURE Enabling DPtx BW Allocation Mode Support ***\n", + __func__, DP_TUNNELING_CAPABILITIES); + else { + + // SUCCESS Enabled DPtx BW Allocation Mode Support + link->dpia_bw_alloc_config.bw_alloc_enabled = true; + dm_output_to_console("**** SUCCESS Enabling DPtx BW Allocation Mode Support ***\n"); + + ret = true; + init_usb4_bw_struct(link); + } + } + +out: + return ret; +} +void dc_link_get_usb4_req_bw_resp(struct dc_link *link, uint8_t bw, uint8_t result) +{ + if (!get_bw_alloc_proceed_flag((link))) + return; + + switch (result) { + + case DPIA_BW_REQ_FAILED: + + dm_output_to_console("%s: *** *** BW REQ FAILURE for DP-TX Request *** ***\n", __func__); + + // Update the new Estimated BW value updated by CM + link->dpia_bw_alloc_config.estimated_bw = + bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + + dc_link_set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.estimated_bw); + link->dpia_bw_alloc_config.response_ready = false; + + /* + * If FAIL then it is either: + * 1. Due to DP-Tx trying to allocate more than available i.e. it failed locally + * => get estimated and allocate that + * 2. Due to the fact that DP-Tx tried to allocated ESTIMATED BW and failed then + * CM will have to update 0xE0023 with new ESTIMATED BW value. + */ + break; + + case DPIA_BW_REQ_SUCCESS: + + dm_output_to_console("%s: *** BW REQ SUCCESS for DP-TX Request ***\n", __func__); + + // 1. SUCCESS 1st time before any Pruning is done + // 2. SUCCESS after prev. FAIL before any Pruning is done + // 3. SUCCESS after Pruning is done but before enabling link + + int needed = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + + // 1. + if (!link->dpia_bw_alloc_config.sink_allocated_bw) { + + allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, needed, link); + link->dpia_bw_alloc_config.sink_verified_bw = + link->dpia_bw_alloc_config.sink_allocated_bw; + + // SUCCESS from first attempt + if (link->dpia_bw_alloc_config.sink_allocated_bw > + link->dpia_bw_alloc_config.sink_max_bw) + link->dpia_bw_alloc_config.sink_verified_bw = + link->dpia_bw_alloc_config.sink_max_bw; + } + // 3. + else if (link->dpia_bw_alloc_config.sink_allocated_bw) { + + // Find out how much do we need to de-alloc + if (link->dpia_bw_alloc_config.sink_allocated_bw > needed) + deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, + link->dpia_bw_alloc_config.sink_allocated_bw - needed, link); + else + allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, + needed - link->dpia_bw_alloc_config.sink_allocated_bw, link); + } + + // 4. If this is the 2nd sink then any unused bw will be reallocated to master DPIA + // => check if estimated_bw changed + + link->dpia_bw_alloc_config.response_ready = true; + break; + + case DPIA_EST_BW_CHANGED: + + dm_output_to_console("%s: *** ESTIMATED BW CHANGED for DP-TX Request ***\n", __func__); + + int available = 0, estimated = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + int host_router_total_estimated_bw = get_host_router_total_bw(link, HOST_ROUTER_BW_ESTIMATED); + + // 1. If due to unplug of other sink + if (estimated == host_router_total_estimated_bw) { + + // First update the estimated & max_bw fields + if (link->dpia_bw_alloc_config.estimated_bw < estimated) { + available = estimated - link->dpia_bw_alloc_config.estimated_bw; + link->dpia_bw_alloc_config.estimated_bw = estimated; + } + } + // 2. If due to realloc bw btw 2 dpia due to plug OR realloc unused Bw + else { + + // We took from another unplugged/problematic sink to give to us + if (link->dpia_bw_alloc_config.estimated_bw < estimated) + available = estimated - link->dpia_bw_alloc_config.estimated_bw; + + // We lost estimated bw usually due to plug event of other dpia + link->dpia_bw_alloc_config.estimated_bw = estimated; + } + break; + + case DPIA_BW_ALLOC_CAPS_CHANGED: + + dm_output_to_console("%s: *** BW ALLOC CAPABILITY CHANGED for DP-TX Request ***\n", __func__); + link->dpia_bw_alloc_config.bw_alloc_enabled = false; + break; + } +} +int dc_link_dp_dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int peak_bw) +{ + int ret = 0; + uint8_t timeout = 10; + + if (!(link && DISPLAY_ENDPOINT_USB4_DPIA == link->ep_type + && link->dpia_bw_alloc_config.bw_alloc_enabled)) + goto out; + + //1. Hot Plug + if (link->hpd_status && peak_bw > 0) { + + // If DP over USB4 then we need to check BW allocation + link->dpia_bw_alloc_config.sink_max_bw = peak_bw; + dc_link_set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.sink_max_bw); + + do { + if (!timeout > 0) + timeout--; + else + break; + udelay(10 * 1000); + } while (!get_cm_response_ready_flag(link)); + + if (!timeout) + ret = 0;// ERROR TIMEOUT waiting for response for allocating bw + else if (link->dpia_bw_alloc_config.sink_allocated_bw > 0) + ret = get_host_router_total_bw(link, HOST_ROUTER_BW_ALLOCATED); + } + //2. Cold Unplug + else if (!link->hpd_status) + dpia_bw_alloc_unplug(link); + +out: + return ret; +} diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h index 832a6dd2c5fa..c2c3049adcd1 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h @@ -44,33 +44,4 @@ enum bw_type { */ bool set_dptx_usb4_bw_alloc_support(struct dc_link *link); -/* - * Return the response_ready flag from dc_link struct - * - * @link: pointer to the dc_link struct instance - * - * return: response_ready flag from dc_link struct - */ -bool get_cm_response_ready_flag(struct dc_link *link); - -/* - * Get the Max Available BW or Max Estimated BW for each Host Router - * - * @link: pointer to the dc_link struct instance - * @type: ESTIMATD BW or MAX AVAILABLE BW - * - * return: response_ready flag from dc_link struct - */ -int get_host_router_total_bw(struct dc_link *link, uint8_t type); - -/* - * Cleanup function for when the dpia is unplugged to reset struct - * and perform any required clean up - * - * @link: pointer to the dc_link struct instance - * - * return: none - */ -bool dpia_bw_alloc_unplug(struct dc_link *link); - #endif /* DC_INC_LINK_DP_DPIA_BW_H_ */ -- 2.25.1