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Diffstat (limited to '')
| -rw-r--r-- | drivers/usb/dwc2/hcd_queue.c | 2099 |
1 files changed, 2099 insertions, 0 deletions
diff --git a/drivers/usb/dwc2/hcd_queue.c b/drivers/usb/dwc2/hcd_queue.c new file mode 100644 index 000000000..94af71e98 --- /dev/null +++ b/drivers/usb/dwc2/hcd_queue.c @@ -0,0 +1,2099 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) +/* + * hcd_queue.c - DesignWare HS OTG Controller host queuing routines + * + * Copyright (C) 2004-2013 Synopsys, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The names of the above-listed copyright holders may not be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * ALTERNATIVELY, this software may be distributed under the terms of the + * GNU General Public License ("GPL") as published by the Free Software + * Foundation; either version 2 of the License, or (at your option) any + * later version. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * This file contains the functions to manage Queue Heads and Queue + * Transfer Descriptors for Host mode + */ +#include <linux/gcd.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/dma-mapping.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/usb.h> + +#include <linux/usb/hcd.h> +#include <linux/usb/ch11.h> + +#include "core.h" +#include "hcd.h" + +/* Wait this long before releasing periodic reservation */ +#define DWC2_UNRESERVE_DELAY (msecs_to_jiffies(5)) + +/* If we get a NAK, wait this long before retrying */ +#define DWC2_RETRY_WAIT_DELAY (1 * NSEC_PER_MSEC) + +/** + * dwc2_periodic_channel_available() - Checks that a channel is available for a + * periodic transfer + * + * @hsotg: The HCD state structure for the DWC OTG controller + * + * Return: 0 if successful, negative error code otherwise + */ +static int dwc2_periodic_channel_available(struct dwc2_hsotg *hsotg) +{ + /* + * Currently assuming that there is a dedicated host channel for + * each periodic transaction plus at least one host channel for + * non-periodic transactions + */ + int status; + int num_channels; + + num_channels = hsotg->params.host_channels; + if ((hsotg->periodic_channels + hsotg->non_periodic_channels < + num_channels) && (hsotg->periodic_channels < num_channels - 1)) { + status = 0; + } else { + dev_dbg(hsotg->dev, + "%s: Total channels: %d, Periodic: %d, Non-periodic: %d\n", + __func__, num_channels, + hsotg->periodic_channels, hsotg->non_periodic_channels); + status = -ENOSPC; + } + + return status; +} + +/** + * dwc2_check_periodic_bandwidth() - Checks that there is sufficient bandwidth + * for the specified QH in the periodic schedule + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH containing periodic bandwidth required + * + * Return: 0 if successful, negative error code otherwise + * + * For simplicity, this calculation assumes that all the transfers in the + * periodic schedule may occur in the same (micro)frame + */ +static int dwc2_check_periodic_bandwidth(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + int status; + s16 max_claimed_usecs; + + status = 0; + + if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) { + /* + * High speed mode + * Max periodic usecs is 80% x 125 usec = 100 usec + */ + max_claimed_usecs = 100 - qh->host_us; + } else { + /* + * Full speed mode + * Max periodic usecs is 90% x 1000 usec = 900 usec + */ + max_claimed_usecs = 900 - qh->host_us; + } + + if (hsotg->periodic_usecs > max_claimed_usecs) { + dev_err(hsotg->dev, + "%s: already claimed usecs %d, required usecs %d\n", + __func__, hsotg->periodic_usecs, qh->host_us); + status = -ENOSPC; + } + + return status; +} + +/** + * pmap_schedule() - Schedule time in a periodic bitmap (pmap). + * + * @map: The bitmap representing the schedule; will be updated + * upon success. + * @bits_per_period: The schedule represents several periods. This is how many + * bits are in each period. It's assumed that the beginning + * of the schedule will repeat after its end. + * @periods_in_map: The number of periods in the schedule. + * @num_bits: The number of bits we need per period we want to reserve + * in this function call. + * @interval: How often we need to be scheduled for the reservation this + * time. 1 means every period. 2 means every other period. + * ...you get the picture? + * @start: The bit number to start at. Normally 0. Must be within + * the interval or we return failure right away. + * @only_one_period: Normally we'll allow picking a start anywhere within the + * first interval, since we can still make all repetition + * requirements by doing that. However, if you pass true + * here then we'll return failure if we can't fit within + * the period that "start" is in. + * + * The idea here is that we want to schedule time for repeating events that all + * want the same resource. The resource is divided into fixed-sized periods + * and the events want to repeat every "interval" periods. The schedule + * granularity is one bit. + * + * To keep things "simple", we'll represent our schedule with a bitmap that + * contains a fixed number of periods. This gets rid of a lot of complexity + * but does mean that we need to handle things specially (and non-ideally) if + * the number of the periods in the schedule doesn't match well with the + * intervals that we're trying to schedule. + * + * Here's an explanation of the scheme we'll implement, assuming 8 periods. + * - If interval is 1, we need to take up space in each of the 8 + * periods we're scheduling. Easy. + * - If interval is 2, we need to take up space in half of the + * periods. Again, easy. + * - If interval is 3, we actually need to fall back to interval 1. + * Why? Because we might need time in any period. AKA for the + * first 8 periods, we'll be in slot 0, 3, 6. Then we'll be + * in slot 1, 4, 7. Then we'll be in 2, 5. Then we'll be back to + * 0, 3, and 6. Since we could be in any frame we need to reserve + * for all of them. Sucks, but that's what you gotta do. Note that + * if we were instead scheduling 8 * 3 = 24 we'd do much better, but + * then we need more memory and time to do scheduling. + * - If interval is 4, easy. + * - If interval is 5, we again need interval 1. The schedule will be + * 0, 5, 2, 7, 4, 1, 6, 3, 0 + * - If interval is 6, we need interval 2. 0, 6, 4, 2. + * - If interval is 7, we need interval 1. + * - If interval is 8, we need interval 8. + * + * If you do the math, you'll see that we need to pretend that interval is + * equal to the greatest_common_divisor(interval, periods_in_map). + * + * Note that at the moment this function tends to front-pack the schedule. + * In some cases that's really non-ideal (it's hard to schedule things that + * need to repeat every period). In other cases it's perfect (you can easily + * schedule bigger, less often repeating things). + * + * Here's the algorithm in action (8 periods, 5 bits per period): + * |** | |** | |** | |** | | OK 2 bits, intv 2 at 0 + * |*****| ***|*****| ***|*****| ***|*****| ***| OK 3 bits, intv 3 at 2 + * |*****|* ***|*****| ***|*****|* ***|*****| ***| OK 1 bits, intv 4 at 5 + * |** |* |** | |** |* |** | | Remv 3 bits, intv 3 at 2 + * |*** |* |*** | |*** |* |*** | | OK 1 bits, intv 6 at 2 + * |**** |* * |**** | * |**** |* * |**** | * | OK 1 bits, intv 1 at 3 + * |**** |**** |**** | *** |**** |**** |**** | *** | OK 2 bits, intv 2 at 6 + * |*****|*****|*****| ****|*****|*****|*****| ****| OK 1 bits, intv 1 at 4 + * |*****|*****|*****| ****|*****|*****|*****| ****| FAIL 1 bits, intv 1 + * | ***|*****| ***| ****| ***|*****| ***| ****| Remv 2 bits, intv 2 at 0 + * | ***| ****| ***| ****| ***| ****| ***| ****| Remv 1 bits, intv 4 at 5 + * | **| ****| **| ****| **| ****| **| ****| Remv 1 bits, intv 6 at 2 + * | *| ** *| *| ** *| *| ** *| *| ** *| Remv 1 bits, intv 1 at 3 + * | *| *| *| *| *| *| *| *| Remv 2 bits, intv 2 at 6 + * | | | | | | | | | Remv 1 bits, intv 1 at 4 + * |** | |** | |** | |** | | OK 2 bits, intv 2 at 0 + * |*** | |** | |*** | |** | | OK 1 bits, intv 4 at 2 + * |*****| |** **| |*****| |** **| | OK 2 bits, intv 2 at 3 + * |*****|* |** **| |*****|* |** **| | OK 1 bits, intv 4 at 5 + * |*****|*** |** **| ** |*****|*** |** **| ** | OK 2 bits, intv 2 at 6 + * |*****|*****|** **| ****|*****|*****|** **| ****| OK 2 bits, intv 2 at 8 + * |*****|*****|*****| ****|*****|*****|*****| ****| OK 1 bits, intv 4 at 12 + * + * This function is pretty generic and could be easily abstracted if anything + * needed similar scheduling. + * + * Returns either -ENOSPC or a >= 0 start bit which should be passed to the + * unschedule routine. The map bitmap will be updated on a non-error result. + */ +static int pmap_schedule(unsigned long *map, int bits_per_period, + int periods_in_map, int num_bits, + int interval, int start, bool only_one_period) +{ + int interval_bits; + int to_reserve; + int first_end; + int i; + + if (num_bits > bits_per_period) + return -ENOSPC; + + /* Adjust interval as per description */ + interval = gcd(interval, periods_in_map); + + interval_bits = bits_per_period * interval; + to_reserve = periods_in_map / interval; + + /* If start has gotten us past interval then we can't schedule */ + if (start >= interval_bits) + return -ENOSPC; + + if (only_one_period) + /* Must fit within same period as start; end at begin of next */ + first_end = (start / bits_per_period + 1) * bits_per_period; + else + /* Can fit anywhere in the first interval */ + first_end = interval_bits; + + /* + * We'll try to pick the first repetition, then see if that time + * is free for each of the subsequent repetitions. If it's not + * we'll adjust the start time for the next search of the first + * repetition. + */ + while (start + num_bits <= first_end) { + int end; + + /* Need to stay within this period */ + end = (start / bits_per_period + 1) * bits_per_period; + + /* Look for num_bits us in this microframe starting at start */ + start = bitmap_find_next_zero_area(map, end, start, num_bits, + 0); + + /* + * We should get start >= end if we fail. We might be + * able to check the next microframe depending on the + * interval, so continue on (start already updated). + */ + if (start >= end) { + start = end; + continue; + } + + /* At this point we have a valid point for first one */ + for (i = 1; i < to_reserve; i++) { + int ith_start = start + interval_bits * i; + int ith_end = end + interval_bits * i; + int ret; + + /* Use this as a dumb "check if bits are 0" */ + ret = bitmap_find_next_zero_area( + map, ith_start + num_bits, ith_start, num_bits, + 0); + + /* We got the right place, continue checking */ + if (ret == ith_start) + continue; + + /* Move start up for next time and exit for loop */ + ith_start = bitmap_find_next_zero_area( + map, ith_end, ith_start, num_bits, 0); + if (ith_start >= ith_end) + /* Need a while new period next time */ + start = end; + else + start = ith_start - interval_bits * i; + break; + } + + /* If didn't exit the for loop with a break, we have success */ + if (i == to_reserve) + break; + } + + if (start + num_bits > first_end) + return -ENOSPC; + + for (i = 0; i < to_reserve; i++) { + int ith_start = start + interval_bits * i; + + bitmap_set(map, ith_start, num_bits); + } + + return start; +} + +/** + * pmap_unschedule() - Undo work done by pmap_schedule() + * + * @map: See pmap_schedule(). + * @bits_per_period: See pmap_schedule(). + * @periods_in_map: See pmap_schedule(). + * @num_bits: The number of bits that was passed to schedule. + * @interval: The interval that was passed to schedule. + * @start: The return value from pmap_schedule(). + */ +static void pmap_unschedule(unsigned long *map, int bits_per_period, + int periods_in_map, int num_bits, + int interval, int start) +{ + int interval_bits; + int to_release; + int i; + + /* Adjust interval as per description in pmap_schedule() */ + interval = gcd(interval, periods_in_map); + + interval_bits = bits_per_period * interval; + to_release = periods_in_map / interval; + + for (i = 0; i < to_release; i++) { + int ith_start = start + interval_bits * i; + + bitmap_clear(map, ith_start, num_bits); + } +} + +/** + * dwc2_get_ls_map() - Get the map used for the given qh + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + * + * We'll always get the periodic map out of our TT. Note that even if we're + * running the host straight in low speed / full speed mode it appears as if + * a TT is allocated for us, so we'll use it. If that ever changes we can + * add logic here to get a map out of "hsotg" if !qh->do_split. + * + * Returns: the map or NULL if a map couldn't be found. + */ +static unsigned long *dwc2_get_ls_map(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + unsigned long *map; + + /* Don't expect to be missing a TT and be doing low speed scheduling */ + if (WARN_ON(!qh->dwc_tt)) + return NULL; + + /* Get the map and adjust if this is a multi_tt hub */ + map = qh->dwc_tt->periodic_bitmaps; + if (qh->dwc_tt->usb_tt->multi) + map += DWC2_ELEMENTS_PER_LS_BITMAP * (qh->ttport - 1); + + return map; +} + +#ifdef DWC2_PRINT_SCHEDULE +/* + * cat_printf() - A printf() + strcat() helper + * + * This is useful for concatenating a bunch of strings where each string is + * constructed using printf. + * + * @buf: The destination buffer; will be updated to point after the printed + * data. + * @size: The number of bytes in the buffer (includes space for '\0'). + * @fmt: The format for printf. + * @...: The args for printf. + */ +static __printf(3, 4) +void cat_printf(char **buf, size_t *size, const char *fmt, ...) +{ + va_list args; + int i; + + if (*size == 0) + return; + + va_start(args, fmt); + i = vsnprintf(*buf, *size, fmt, args); + va_end(args); + + if (i >= *size) { + (*buf)[*size - 1] = '\0'; + *buf += *size; + *size = 0; + } else { + *buf += i; + *size -= i; + } +} + +/* + * pmap_print() - Print the given periodic map + * + * Will attempt to print out the periodic schedule. + * + * @map: See pmap_schedule(). + * @bits_per_period: See pmap_schedule(). + * @periods_in_map: See pmap_schedule(). + * @period_name: The name of 1 period, like "uFrame" + * @units: The name of the units, like "us". + * @print_fn: The function to call for printing. + * @print_data: Opaque data to pass to the print function. + */ +static void pmap_print(unsigned long *map, int bits_per_period, + int periods_in_map, const char *period_name, + const char *units, + void (*print_fn)(const char *str, void *data), + void *print_data) +{ + int period; + + for (period = 0; period < periods_in_map; period++) { + char tmp[64]; + char *buf = tmp; + size_t buf_size = sizeof(tmp); + int period_start = period * bits_per_period; + int period_end = period_start + bits_per_period; + int start = 0; + int count = 0; + bool printed = false; + int i; + + for (i = period_start; i < period_end + 1; i++) { + /* Handle case when ith bit is set */ + if (i < period_end && + bitmap_find_next_zero_area(map, i + 1, + i, 1, 0) != i) { + if (count == 0) + start = i - period_start; + count++; + continue; + } + + /* ith bit isn't set; don't care if count == 0 */ + if (count == 0) + continue; + + if (!printed) + cat_printf(&buf, &buf_size, "%s %d: ", + period_name, period); + else + cat_printf(&buf, &buf_size, ", "); + printed = true; + + cat_printf(&buf, &buf_size, "%d %s -%3d %s", start, + units, start + count - 1, units); + count = 0; + } + + if (printed) + print_fn(tmp, print_data); + } +} + +struct dwc2_qh_print_data { + struct dwc2_hsotg *hsotg; + struct dwc2_qh *qh; +}; + +/** + * dwc2_qh_print() - Helper function for dwc2_qh_schedule_print() + * + * @str: The string to print + * @data: A pointer to a struct dwc2_qh_print_data + */ +static void dwc2_qh_print(const char *str, void *data) +{ + struct dwc2_qh_print_data *print_data = data; + + dwc2_sch_dbg(print_data->hsotg, "QH=%p ...%s\n", print_data->qh, str); +} + +/** + * dwc2_qh_schedule_print() - Print the periodic schedule + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH to print. + */ +static void dwc2_qh_schedule_print(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + struct dwc2_qh_print_data print_data = { hsotg, qh }; + int i; + + /* + * The printing functions are quite slow and inefficient. + * If we don't have tracing turned on, don't run unless the special + * define is turned on. + */ + + if (qh->schedule_low_speed) { + unsigned long *map = dwc2_get_ls_map(hsotg, qh); + + dwc2_sch_dbg(hsotg, "QH=%p LS/FS trans: %d=>%d us @ %d us", + qh, qh->device_us, + DWC2_ROUND_US_TO_SLICE(qh->device_us), + DWC2_US_PER_SLICE * qh->ls_start_schedule_slice); + + if (map) { + dwc2_sch_dbg(hsotg, + "QH=%p Whole low/full speed map %p now:\n", + qh, map); + pmap_print(map, DWC2_LS_PERIODIC_SLICES_PER_FRAME, + DWC2_LS_SCHEDULE_FRAMES, "Frame ", "slices", + dwc2_qh_print, &print_data); + } + } + + for (i = 0; i < qh->num_hs_transfers; i++) { + struct dwc2_hs_transfer_time *trans_time = qh->hs_transfers + i; + int uframe = trans_time->start_schedule_us / + DWC2_HS_PERIODIC_US_PER_UFRAME; + int rel_us = trans_time->start_schedule_us % + DWC2_HS_PERIODIC_US_PER_UFRAME; + + dwc2_sch_dbg(hsotg, + "QH=%p HS trans #%d: %d us @ uFrame %d + %d us\n", + qh, i, trans_time->duration_us, uframe, rel_us); + } + if (qh->num_hs_transfers) { + dwc2_sch_dbg(hsotg, "QH=%p Whole high speed map now:\n", qh); + pmap_print(hsotg->hs_periodic_bitmap, + DWC2_HS_PERIODIC_US_PER_UFRAME, + DWC2_HS_SCHEDULE_UFRAMES, "uFrame", "us", + dwc2_qh_print, &print_data); + } +} +#else +static inline void dwc2_qh_schedule_print(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) {}; +#endif + +/** + * dwc2_ls_pmap_schedule() - Schedule a low speed QH + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + * @search_slice: We'll start trying to schedule at the passed slice. + * Remember that slices are the units of the low speed + * schedule (think 25us or so). + * + * Wraps pmap_schedule() with the right parameters for low speed scheduling. + * + * Normally we schedule low speed devices on the map associated with the TT. + * + * Returns: 0 for success or an error code. + */ +static int dwc2_ls_pmap_schedule(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh, + int search_slice) +{ + int slices = DIV_ROUND_UP(qh->device_us, DWC2_US_PER_SLICE); + unsigned long *map = dwc2_get_ls_map(hsotg, qh); + int slice; + + if (!map) + return -EINVAL; + + /* + * Schedule on the proper low speed map with our low speed scheduling + * parameters. Note that we use the "device_interval" here since + * we want the low speed interval and the only way we'd be in this + * function is if the device is low speed. + * + * If we happen to be doing low speed and high speed scheduling for the + * same transaction (AKA we have a split) we always do low speed first. + * That means we can always pass "false" for only_one_period (that + * parameters is only useful when we're trying to get one schedule to + * match what we already planned in the other schedule). + */ + slice = pmap_schedule(map, DWC2_LS_PERIODIC_SLICES_PER_FRAME, + DWC2_LS_SCHEDULE_FRAMES, slices, + qh->device_interval, search_slice, false); + + if (slice < 0) + return slice; + + qh->ls_start_schedule_slice = slice; + return 0; +} + +/** + * dwc2_ls_pmap_unschedule() - Undo work done by dwc2_ls_pmap_schedule() + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static void dwc2_ls_pmap_unschedule(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + int slices = DIV_ROUND_UP(qh->device_us, DWC2_US_PER_SLICE); + unsigned long *map = dwc2_get_ls_map(hsotg, qh); + + /* Schedule should have failed, so no worries about no error code */ + if (!map) + return; + + pmap_unschedule(map, DWC2_LS_PERIODIC_SLICES_PER_FRAME, + DWC2_LS_SCHEDULE_FRAMES, slices, qh->device_interval, + qh->ls_start_schedule_slice); +} + +/** + * dwc2_hs_pmap_schedule - Schedule in the main high speed schedule + * + * This will schedule something on the main dwc2 schedule. + * + * We'll start looking in qh->hs_transfers[index].start_schedule_us. We'll + * update this with the result upon success. We also use the duration from + * the same structure. + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + * @only_one_period: If true we will limit ourselves to just looking at + * one period (aka one 100us chunk). This is used if we have + * already scheduled something on the low speed schedule and + * need to find something that matches on the high speed one. + * @index: The index into qh->hs_transfers that we're working with. + * + * Returns: 0 for success or an error code. Upon success the + * dwc2_hs_transfer_time specified by "index" will be updated. + */ +static int dwc2_hs_pmap_schedule(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh, + bool only_one_period, int index) +{ + struct dwc2_hs_transfer_time *trans_time = qh->hs_transfers + index; + int us; + + us = pmap_schedule(hsotg->hs_periodic_bitmap, + DWC2_HS_PERIODIC_US_PER_UFRAME, + DWC2_HS_SCHEDULE_UFRAMES, trans_time->duration_us, + qh->host_interval, trans_time->start_schedule_us, + only_one_period); + + if (us < 0) + return us; + + trans_time->start_schedule_us = us; + return 0; +} + +/** + * dwc2_ls_pmap_unschedule() - Undo work done by dwc2_hs_pmap_schedule() + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + * @index: Transfer index + */ +static void dwc2_hs_pmap_unschedule(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh, int index) +{ + struct dwc2_hs_transfer_time *trans_time = qh->hs_transfers + index; + + pmap_unschedule(hsotg->hs_periodic_bitmap, + DWC2_HS_PERIODIC_US_PER_UFRAME, + DWC2_HS_SCHEDULE_UFRAMES, trans_time->duration_us, + qh->host_interval, trans_time->start_schedule_us); +} + +/** + * dwc2_uframe_schedule_split - Schedule a QH for a periodic split xfer. + * + * This is the most complicated thing in USB. We have to find matching time + * in both the global high speed schedule for the port and the low speed + * schedule for the TT associated with the given device. + * + * Being here means that the host must be running in high speed mode and the + * device is in low or full speed mode (and behind a hub). + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static int dwc2_uframe_schedule_split(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + int bytecount = qh->maxp_mult * qh->maxp; + int ls_search_slice; + int err = 0; + int host_interval_in_sched; + + /* + * The interval (how often to repeat) in the actual host schedule. + * See pmap_schedule() for gcd() explanation. + */ + host_interval_in_sched = gcd(qh->host_interval, + DWC2_HS_SCHEDULE_UFRAMES); + + /* + * We always try to find space in the low speed schedule first, then + * try to find high speed time that matches. If we don't, we'll bump + * up the place we start searching in the low speed schedule and try + * again. To start we'll look right at the beginning of the low speed + * schedule. + * + * Note that this will tend to front-load the high speed schedule. + * We may eventually want to try to avoid this by either considering + * both schedules together or doing some sort of round robin. + */ + ls_search_slice = 0; + + while (ls_search_slice < DWC2_LS_SCHEDULE_SLICES) { + int start_s_uframe; + int ssplit_s_uframe; + int second_s_uframe; + int rel_uframe; + int first_count; + int middle_count; + int end_count; + int first_data_bytes; + int other_data_bytes; + int i; + + if (qh->schedule_low_speed) { + err = dwc2_ls_pmap_schedule(hsotg, qh, ls_search_slice); + + /* + * If we got an error here there's no other magic we + * can do, so bail. All the looping above is only + * helpful to redo things if we got a low speed slot + * and then couldn't find a matching high speed slot. + */ + if (err) + return err; + } else { + /* Must be missing the tt structure? Why? */ + WARN_ON_ONCE(1); + } + + /* + * This will give us a number 0 - 7 if + * DWC2_LS_SCHEDULE_FRAMES == 1, or 0 - 15 if == 2, or ... + */ + start_s_uframe = qh->ls_start_schedule_slice / + DWC2_SLICES_PER_UFRAME; + + /* Get a number that's always 0 - 7 */ + rel_uframe = (start_s_uframe % 8); + + /* + * If we were going to start in uframe 7 then we would need to + * issue a start split in uframe 6, which spec says is not OK. + * Move on to the next full frame (assuming there is one). + * + * See 11.18.4 Host Split Transaction Scheduling Requirements + * bullet 1. + */ + if (rel_uframe == 7) { + if (qh->schedule_low_speed) + dwc2_ls_pmap_unschedule(hsotg, qh); + ls_search_slice = + (qh->ls_start_schedule_slice / + DWC2_LS_PERIODIC_SLICES_PER_FRAME + 1) * + DWC2_LS_PERIODIC_SLICES_PER_FRAME; + continue; + } + + /* + * For ISOC in: + * - start split (frame -1) + * - complete split w/ data (frame +1) + * - complete split w/ data (frame +2) + * - ... + * - complete split w/ data (frame +num_data_packets) + * - complete split w/ data (frame +num_data_packets+1) + * - complete split w/ data (frame +num_data_packets+2, max 8) + * ...though if frame was "0" then max is 7... + * + * For ISOC out we might need to do: + * - start split w/ data (frame -1) + * - start split w/ data (frame +0) + * - ... + * - start split w/ data (frame +num_data_packets-2) + * + * For INTERRUPT in we might need to do: + * - start split (frame -1) + * - complete split w/ data (frame +1) + * - complete split w/ data (frame +2) + * - complete split w/ data (frame +3, max 8) + * + * For INTERRUPT out we might need to do: + * - start split w/ data (frame -1) + * - complete split (frame +1) + * - complete split (frame +2) + * - complete split (frame +3, max 8) + * + * Start adjusting! + */ + ssplit_s_uframe = (start_s_uframe + + host_interval_in_sched - 1) % + host_interval_in_sched; + if (qh->ep_type == USB_ENDPOINT_XFER_ISOC && !qh->ep_is_in) + second_s_uframe = start_s_uframe; + else + second_s_uframe = start_s_uframe + 1; + + /* First data transfer might not be all 188 bytes. */ + first_data_bytes = 188 - + DIV_ROUND_UP(188 * (qh->ls_start_schedule_slice % + DWC2_SLICES_PER_UFRAME), + DWC2_SLICES_PER_UFRAME); + if (first_data_bytes > bytecount) + first_data_bytes = bytecount; + other_data_bytes = bytecount - first_data_bytes; + + /* + * For now, skip OUT xfers where first xfer is partial + * + * Main dwc2 code assumes: + * - INT transfers never get split in two. + * - ISOC transfers can always transfer 188 bytes the first + * time. + * + * Until that code is fixed, try again if the first transfer + * couldn't transfer everything. + * + * This code can be removed if/when the rest of dwc2 handles + * the above cases. Until it's fixed we just won't be able + * to schedule quite as tightly. + */ + if (!qh->ep_is_in && + (first_data_bytes != min_t(int, 188, bytecount))) { + dwc2_sch_dbg(hsotg, + "QH=%p avoiding broken 1st xfer (%d, %d)\n", + qh, first_data_bytes, bytecount); + if (qh->schedule_low_speed) + dwc2_ls_pmap_unschedule(hsotg, qh); + ls_search_slice = (start_s_uframe + 1) * + DWC2_SLICES_PER_UFRAME; + continue; + } + + /* Start by assuming transfers for the bytes */ + qh->num_hs_transfers = 1 + DIV_ROUND_UP(other_data_bytes, 188); + + /* + * Everything except ISOC OUT has extra transfers. Rules are + * complicated. See 11.18.4 Host Split Transaction Scheduling + * Requirements bullet 3. + */ + if (qh->ep_type == USB_ENDPOINT_XFER_INT) { + if (rel_uframe == 6) + qh->num_hs_transfers += 2; + else + qh->num_hs_transfers += 3; + + if (qh->ep_is_in) { + /* + * First is start split, middle/end is data. + * Allocate full data bytes for all data. + */ + first_count = 4; + middle_count = bytecount; + end_count = bytecount; + } else { + /* + * First is data, middle/end is complete. + * First transfer and second can have data. + * Rest should just have complete split. + */ + first_count = first_data_bytes; + middle_count = max_t(int, 4, other_data_bytes); + end_count = 4; + } + } else { + if (qh->ep_is_in) { + int last; + + /* Account for the start split */ + qh->num_hs_transfers++; + + /* Calculate "L" value from spec */ + last = rel_uframe + qh->num_hs_transfers + 1; + + /* Start with basic case */ + if (last <= 6) + qh->num_hs_transfers += 2; + else + qh->num_hs_transfers += 1; + + /* Adjust downwards */ + if (last >= 6 && rel_uframe == 0) + qh->num_hs_transfers--; + + /* 1st = start; rest can contain data */ + first_count = 4; + middle_count = min_t(int, 188, bytecount); + end_count = middle_count; + } else { + /* All contain data, last might be smaller */ + first_count = first_data_bytes; + middle_count = min_t(int, 188, + other_data_bytes); + end_count = other_data_bytes % 188; + } + } + + /* Assign durations per uFrame */ + qh->hs_transfers[0].duration_us = HS_USECS_ISO(first_count); + for (i = 1; i < qh->num_hs_transfers - 1; i++) + qh->hs_transfers[i].duration_us = + HS_USECS_ISO(middle_count); + if (qh->num_hs_transfers > 1) + qh->hs_transfers[qh->num_hs_transfers - 1].duration_us = + HS_USECS_ISO(end_count); + + /* + * Assign start us. The call below to dwc2_hs_pmap_schedule() + * will start with these numbers but may adjust within the same + * microframe. + */ + qh->hs_transfers[0].start_schedule_us = + ssplit_s_uframe * DWC2_HS_PERIODIC_US_PER_UFRAME; + for (i = 1; i < qh->num_hs_transfers; i++) + qh->hs_transfers[i].start_schedule_us = + ((second_s_uframe + i - 1) % + DWC2_HS_SCHEDULE_UFRAMES) * + DWC2_HS_PERIODIC_US_PER_UFRAME; + + /* Try to schedule with filled in hs_transfers above */ + for (i = 0; i < qh->num_hs_transfers; i++) { + err = dwc2_hs_pmap_schedule(hsotg, qh, true, i); + if (err) + break; + } + + /* If we scheduled all w/out breaking out then we're all good */ + if (i == qh->num_hs_transfers) + break; + + for (; i >= 0; i--) + dwc2_hs_pmap_unschedule(hsotg, qh, i); + + if (qh->schedule_low_speed) + dwc2_ls_pmap_unschedule(hsotg, qh); + + /* Try again starting in the next microframe */ + ls_search_slice = (start_s_uframe + 1) * DWC2_SLICES_PER_UFRAME; + } + + if (ls_search_slice >= DWC2_LS_SCHEDULE_SLICES) + return -ENOSPC; + + return 0; +} + +/** + * dwc2_uframe_schedule_hs - Schedule a QH for a periodic high speed xfer. + * + * Basically this just wraps dwc2_hs_pmap_schedule() to provide a clean + * interface. + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static int dwc2_uframe_schedule_hs(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + /* In non-split host and device time are the same */ + WARN_ON(qh->host_us != qh->device_us); + WARN_ON(qh->host_interval != qh->device_interval); + WARN_ON(qh->num_hs_transfers != 1); + + /* We'll have one transfer; init start to 0 before calling scheduler */ + qh->hs_transfers[0].start_schedule_us = 0; + qh->hs_transfers[0].duration_us = qh->host_us; + + return dwc2_hs_pmap_schedule(hsotg, qh, false, 0); +} + +/** + * dwc2_uframe_schedule_ls - Schedule a QH for a periodic low/full speed xfer. + * + * Basically this just wraps dwc2_ls_pmap_schedule() to provide a clean + * interface. + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static int dwc2_uframe_schedule_ls(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + /* In non-split host and device time are the same */ + WARN_ON(qh->host_us != qh->device_us); + WARN_ON(qh->host_interval != qh->device_interval); + WARN_ON(!qh->schedule_low_speed); + + /* Run on the main low speed schedule (no split = no hub = no TT) */ + return dwc2_ls_pmap_schedule(hsotg, qh, 0); +} + +/** + * dwc2_uframe_schedule - Schedule a QH for a periodic xfer. + * + * Calls one of the 3 sub-function depending on what type of transfer this QH + * is for. Also adds some printing. + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static int dwc2_uframe_schedule(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + int ret; + + if (qh->dev_speed == USB_SPEED_HIGH) + ret = dwc2_uframe_schedule_hs(hsotg, qh); + else if (!qh->do_split) + ret = dwc2_uframe_schedule_ls(hsotg, qh); + else + ret = dwc2_uframe_schedule_split(hsotg, qh); + + if (ret) + dwc2_sch_dbg(hsotg, "QH=%p Failed to schedule %d\n", qh, ret); + else + dwc2_qh_schedule_print(hsotg, qh); + + return ret; +} + +/** + * dwc2_uframe_unschedule - Undoes dwc2_uframe_schedule(). + * + * @hsotg: The HCD state structure for the DWC OTG controller. + * @qh: QH for the periodic transfer. + */ +static void dwc2_uframe_unschedule(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + int i; + + for (i = 0; i < qh->num_hs_transfers; i++) + dwc2_hs_pmap_unschedule(hsotg, qh, i); + + if (qh->schedule_low_speed) + dwc2_ls_pmap_unschedule(hsotg, qh); + + dwc2_sch_dbg(hsotg, "QH=%p Unscheduled\n", qh); +} + +/** + * dwc2_pick_first_frame() - Choose 1st frame for qh that's already scheduled + * + * Takes a qh that has already been scheduled (which means we know we have the + * bandwdith reserved for us) and set the next_active_frame and the + * start_active_frame. + * + * This is expected to be called on qh's that weren't previously actively + * running. It just picks the next frame that we can fit into without any + * thought about the past. + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for a periodic endpoint + * + */ +static void dwc2_pick_first_frame(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + u16 frame_number; + u16 earliest_frame; + u16 next_active_frame; + u16 relative_frame; + u16 interval; + + /* + * Use the real frame number rather than the cached value as of the + * last SOF to give us a little extra slop. + */ + frame_number = dwc2_hcd_get_frame_number(hsotg); + + /* + * We wouldn't want to start any earlier than the next frame just in + * case the frame number ticks as we're doing this calculation. + * + * NOTE: if we could quantify how long till we actually get scheduled + * we might be able to avoid the "+ 1" by looking at the upper part of + * HFNUM (the FRREM field). For now we'll just use the + 1 though. + */ + earliest_frame = dwc2_frame_num_inc(frame_number, 1); + next_active_frame = earliest_frame; + + /* Get the "no microframe schduler" out of the way... */ + if (!hsotg->params.uframe_sched) { + if (qh->do_split) + /* Splits are active at microframe 0 minus 1 */ + next_active_frame |= 0x7; + goto exit; + } + + if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) { + /* + * We're either at high speed or we're doing a split (which + * means we're talking high speed to a hub). In any case + * the first frame should be based on when the first scheduled + * event is. + */ + WARN_ON(qh->num_hs_transfers < 1); + + relative_frame = qh->hs_transfers[0].start_schedule_us / + DWC2_HS_PERIODIC_US_PER_UFRAME; + + /* Adjust interval as per high speed schedule */ + interval = gcd(qh->host_interval, DWC2_HS_SCHEDULE_UFRAMES); + + } else { + /* + * Low or full speed directly on dwc2. Just about the same + * as high speed but on a different schedule and with slightly + * different adjustments. Note that this works because when + * the host and device are both low speed then frames in the + * controller tick at low speed. + */ + relative_frame = qh->ls_start_schedule_slice / + DWC2_LS_PERIODIC_SLICES_PER_FRAME; + interval = gcd(qh->host_interval, DWC2_LS_SCHEDULE_FRAMES); + } + + /* Scheduler messed up if frame is past interval */ + WARN_ON(relative_frame >= interval); + + /* + * We know interval must divide (HFNUM_MAX_FRNUM + 1) now that we've + * done the gcd(), so it's safe to move to the beginning of the current + * interval like this. + * + * After this we might be before earliest_frame, but don't worry, + * we'll fix it... + */ + next_active_frame = (next_active_frame / interval) * interval; + + /* + * Actually choose to start at the frame number we've been + * scheduled for. + */ + next_active_frame = dwc2_frame_num_inc(next_active_frame, + relative_frame); + + /* + * We actually need 1 frame before since the next_active_frame is + * the frame number we'll be put on the ready list and we won't be on + * the bus until 1 frame later. + */ + next_active_frame = dwc2_frame_num_dec(next_active_frame, 1); + + /* + * By now we might actually be before the earliest_frame. Let's move + * up intervals until we're not. + */ + while (dwc2_frame_num_gt(earliest_frame, next_active_frame)) + next_active_frame = dwc2_frame_num_inc(next_active_frame, + interval); + +exit: + qh->next_active_frame = next_active_frame; + qh->start_active_frame = next_active_frame; + + dwc2_sch_vdbg(hsotg, "QH=%p First fn=%04x nxt=%04x\n", + qh, frame_number, qh->next_active_frame); +} + +/** + * dwc2_do_reserve() - Make a periodic reservation + * + * Try to allocate space in the periodic schedule. Depending on parameters + * this might use the microframe scheduler or the dumb scheduler. + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for the periodic transfer. + * + * Returns: 0 upon success; error upon failure. + */ +static int dwc2_do_reserve(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + int status; + + if (hsotg->params.uframe_sched) { + status = dwc2_uframe_schedule(hsotg, qh); + } else { + status = dwc2_periodic_channel_available(hsotg); + if (status) { + dev_info(hsotg->dev, + "%s: No host channel available for periodic transfer\n", + __func__); + return status; + } + + status = dwc2_check_periodic_bandwidth(hsotg, qh); + } + + if (status) { + dev_dbg(hsotg->dev, + "%s: Insufficient periodic bandwidth for periodic transfer\n", + __func__); + return status; + } + + if (!hsotg->params.uframe_sched) + /* Reserve periodic channel */ + hsotg->periodic_channels++; + + /* Update claimed usecs per (micro)frame */ + hsotg->periodic_usecs += qh->host_us; + + dwc2_pick_first_frame(hsotg, qh); + + return 0; +} + +/** + * dwc2_do_unreserve() - Actually release the periodic reservation + * + * This function actually releases the periodic bandwidth that was reserved + * by the given qh. + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for the periodic transfer. + */ +static void dwc2_do_unreserve(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + assert_spin_locked(&hsotg->lock); + + WARN_ON(!qh->unreserve_pending); + + /* No more unreserve pending--we're doing it */ + qh->unreserve_pending = false; + + if (WARN_ON(!list_empty(&qh->qh_list_entry))) + list_del_init(&qh->qh_list_entry); + + /* Update claimed usecs per (micro)frame */ + hsotg->periodic_usecs -= qh->host_us; + + if (hsotg->params.uframe_sched) { + dwc2_uframe_unschedule(hsotg, qh); + } else { + /* Release periodic channel reservation */ + hsotg->periodic_channels--; + } +} + +/** + * dwc2_unreserve_timer_fn() - Timer function to release periodic reservation + * + * According to the kernel doc for usb_submit_urb() (specifically the part about + * "Reserved Bandwidth Transfers"), we need to keep a reservation active as + * long as a device driver keeps submitting. Since we're using HCD_BH to give + * back the URB we need to give the driver a little bit of time before we + * release the reservation. This worker is called after the appropriate + * delay. + * + * @t: Address to a qh unreserve_work. + */ +static void dwc2_unreserve_timer_fn(struct timer_list *t) +{ + struct dwc2_qh *qh = from_timer(qh, t, unreserve_timer); + struct dwc2_hsotg *hsotg = qh->hsotg; + unsigned long flags; + + /* + * Wait for the lock, or for us to be scheduled again. We + * could be scheduled again if: + * - We started executing but didn't get the lock yet. + * - A new reservation came in, but cancel didn't take effect + * because we already started executing. + * - The timer has been kicked again. + * In that case cancel and wait for the next call. + */ + while (!spin_trylock_irqsave(&hsotg->lock, flags)) { + if (timer_pending(&qh->unreserve_timer)) + return; + } + + /* + * Might be no more unreserve pending if: + * - We started executing but didn't get the lock yet. + * - A new reservation came in, but cancel didn't take effect + * because we already started executing. + * + * We can't put this in the loop above because unreserve_pending needs + * to be accessed under lock, so we can only check it once we got the + * lock. + */ + if (qh->unreserve_pending) + dwc2_do_unreserve(hsotg, qh); + + spin_unlock_irqrestore(&hsotg->lock, flags); +} + +/** + * dwc2_check_max_xfer_size() - Checks that the max transfer size allowed in a + * host channel is large enough to handle the maximum data transfer in a single + * (micro)frame for a periodic transfer + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for a periodic endpoint + * + * Return: 0 if successful, negative error code otherwise + */ +static int dwc2_check_max_xfer_size(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + u32 max_xfer_size; + u32 max_channel_xfer_size; + int status = 0; + + max_xfer_size = qh->maxp * qh->maxp_mult; + max_channel_xfer_size = hsotg->params.max_transfer_size; + + if (max_xfer_size > max_channel_xfer_size) { + dev_err(hsotg->dev, + "%s: Periodic xfer length %d > max xfer length for channel %d\n", + __func__, max_xfer_size, max_channel_xfer_size); + status = -ENOSPC; + } + + return status; +} + +/** + * dwc2_schedule_periodic() - Schedules an interrupt or isochronous transfer in + * the periodic schedule + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for the periodic transfer. The QH should already contain the + * scheduling information. + * + * Return: 0 if successful, negative error code otherwise + */ +static int dwc2_schedule_periodic(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + int status; + + status = dwc2_check_max_xfer_size(hsotg, qh); + if (status) { + dev_dbg(hsotg->dev, + "%s: Channel max transfer size too small for periodic transfer\n", + __func__); + return status; + } + + /* Cancel pending unreserve; if canceled OK, unreserve was pending */ + if (del_timer(&qh->unreserve_timer)) + WARN_ON(!qh->unreserve_pending); + + /* + * Only need to reserve if there's not an unreserve pending, since if an + * unreserve is pending then by definition our old reservation is still + * valid. Unreserve might still be pending even if we didn't cancel if + * dwc2_unreserve_timer_fn() already started. Code in the timer handles + * that case. + */ + if (!qh->unreserve_pending) { + status = dwc2_do_reserve(hsotg, qh); + if (status) + return status; + } else { + /* + * It might have been a while, so make sure that frame_number + * is still good. Note: we could also try to use the similar + * dwc2_next_periodic_start() but that schedules much more + * tightly and we might need to hurry and queue things up. + */ + if (dwc2_frame_num_le(qh->next_active_frame, + hsotg->frame_number)) + dwc2_pick_first_frame(hsotg, qh); + } + + qh->unreserve_pending = 0; + + if (hsotg->params.dma_desc_enable) + /* Don't rely on SOF and start in ready schedule */ + list_add_tail(&qh->qh_list_entry, &hsotg->periodic_sched_ready); + else + /* Always start in inactive schedule */ + list_add_tail(&qh->qh_list_entry, + &hsotg->periodic_sched_inactive); + + return 0; +} + +/** + * dwc2_deschedule_periodic() - Removes an interrupt or isochronous transfer + * from the periodic schedule + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: QH for the periodic transfer + */ +static void dwc2_deschedule_periodic(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh) +{ + bool did_modify; + + assert_spin_locked(&hsotg->lock); + + /* + * Schedule the unreserve to happen in a little bit. Cases here: + * - Unreserve worker might be sitting there waiting to grab the lock. + * In this case it will notice it's been schedule again and will + * quit. + * - Unreserve worker might not be scheduled. + * + * We should never already be scheduled since dwc2_schedule_periodic() + * should have canceled the scheduled unreserve timer (hence the + * warning on did_modify). + * + * We add + 1 to the timer to guarantee that at least 1 jiffy has + * passed (otherwise if the jiffy counter might tick right after we + * read it and we'll get no delay). + */ + did_modify = mod_timer(&qh->unreserve_timer, + jiffies + DWC2_UNRESERVE_DELAY + 1); + WARN_ON(did_modify); + qh->unreserve_pending = 1; + + list_del_init(&qh->qh_list_entry); +} + +/** + * dwc2_wait_timer_fn() - Timer function to re-queue after waiting + * + * As per the spec, a NAK indicates that "a function is temporarily unable to + * transmit or receive data, but will eventually be able to do so without need + * of host intervention". + * + * That means that when we encounter a NAK we're supposed to retry. + * + * ...but if we retry right away (from the interrupt handler that saw the NAK) + * then we can end up with an interrupt storm (if the other side keeps NAKing + * us) because on slow enough CPUs it could take us longer to get out of the + * interrupt routine than it takes for the device to send another NAK. That + * leads to a constant stream of NAK interrupts and the CPU locks. + * + * ...so instead of retrying right away in the case of a NAK we'll set a timer + * to retry some time later. This function handles that timer and moves the + * qh back to the "inactive" list, then queues transactions. + * + * @t: Pointer to wait_timer in a qh. + * + * Return: HRTIMER_NORESTART to not automatically restart this timer. + */ +static enum hrtimer_restart dwc2_wait_timer_fn(struct hrtimer *t) +{ + struct dwc2_qh *qh = container_of(t, struct dwc2_qh, wait_timer); + struct dwc2_hsotg *hsotg = qh->hsotg; + unsigned long flags; + + spin_lock_irqsave(&hsotg->lock, flags); + + /* + * We'll set wait_timer_cancel to true if we want to cancel this + * operation in dwc2_hcd_qh_unlink(). + */ + if (!qh->wait_timer_cancel) { + enum dwc2_transaction_type tr_type; + + qh->want_wait = false; + + list_move(&qh->qh_list_entry, + &hsotg->non_periodic_sched_inactive); + + tr_type = dwc2_hcd_select_transactions(hsotg); + if (tr_type != DWC2_TRANSACTION_NONE) + dwc2_hcd_queue_transactions(hsotg, tr_type); + } + + spin_unlock_irqrestore(&hsotg->lock, flags); + return HRTIMER_NORESTART; +} + +/** + * dwc2_qh_init() - Initializes a QH structure + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: The QH to init + * @urb: Holds the information about the device/endpoint needed to initialize + * the QH + * @mem_flags: Flags for allocating memory. + */ +static void dwc2_qh_init(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh, + struct dwc2_hcd_urb *urb, gfp_t mem_flags) +{ + int dev_speed = dwc2_host_get_speed(hsotg, urb->priv); + u8 ep_type = dwc2_hcd_get_pipe_type(&urb->pipe_info); + bool ep_is_in = !!dwc2_hcd_is_pipe_in(&urb->pipe_info); + bool ep_is_isoc = (ep_type == USB_ENDPOINT_XFER_ISOC); + bool ep_is_int = (ep_type == USB_ENDPOINT_XFER_INT); + u32 hprt = dwc2_readl(hsotg, HPRT0); + u32 prtspd = (hprt & HPRT0_SPD_MASK) >> HPRT0_SPD_SHIFT; + bool do_split = (prtspd == HPRT0_SPD_HIGH_SPEED && + dev_speed != USB_SPEED_HIGH); + int maxp = dwc2_hcd_get_maxp(&urb->pipe_info); + int maxp_mult = dwc2_hcd_get_maxp_mult(&urb->pipe_info); + int bytecount = maxp_mult * maxp; + char *speed, *type; + + /* Initialize QH */ + qh->hsotg = hsotg; + timer_setup(&qh->unreserve_timer, dwc2_unreserve_timer_fn, 0); + hrtimer_init(&qh->wait_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + qh->wait_timer.function = &dwc2_wait_timer_fn; + qh->ep_type = ep_type; + qh->ep_is_in = ep_is_in; + + qh->data_toggle = DWC2_HC_PID_DATA0; + qh->maxp = maxp; + qh->maxp_mult = maxp_mult; + INIT_LIST_HEAD(&qh->qtd_list); + INIT_LIST_HEAD(&qh->qh_list_entry); + + qh->do_split = do_split; + qh->dev_speed = dev_speed; + + if (ep_is_int || ep_is_isoc) { + /* Compute scheduling parameters once and save them */ + int host_speed = do_split ? USB_SPEED_HIGH : dev_speed; + struct dwc2_tt *dwc_tt = dwc2_host_get_tt_info(hsotg, urb->priv, + mem_flags, + &qh->ttport); + int device_ns; + + qh->dwc_tt = dwc_tt; + + qh->host_us = NS_TO_US(usb_calc_bus_time(host_speed, ep_is_in, + ep_is_isoc, bytecount)); + device_ns = usb_calc_bus_time(dev_speed, ep_is_in, + ep_is_isoc, bytecount); + + if (do_split && dwc_tt) + device_ns += dwc_tt->usb_tt->think_time; + qh->device_us = NS_TO_US(device_ns); + + qh->device_interval = urb->interval; + qh->host_interval = urb->interval * (do_split ? 8 : 1); + + /* + * Schedule low speed if we're running the host in low or + * full speed OR if we've got a "TT" to deal with to access this + * device. + */ + qh->schedule_low_speed = prtspd != HPRT0_SPD_HIGH_SPEED || + dwc_tt; + + if (do_split) { + /* We won't know num transfers until we schedule */ + qh->num_hs_transfers = -1; + } else if (dev_speed == USB_SPEED_HIGH) { + qh->num_hs_transfers = 1; + } else { + qh->num_hs_transfers = 0; + } + + /* We'll schedule later when we have something to do */ + } + + switch (dev_speed) { + case USB_SPEED_LOW: + speed = "low"; + break; + case USB_SPEED_FULL: + speed = "full"; + break; + case USB_SPEED_HIGH: + speed = "high"; + break; + default: + speed = "?"; + break; + } + + switch (qh->ep_type) { + case USB_ENDPOINT_XFER_ISOC: + type = "isochronous"; + break; + case USB_ENDPOINT_XFER_INT: + type = "interrupt"; + break; + case USB_ENDPOINT_XFER_CONTROL: + type = "control"; + break; + case USB_ENDPOINT_XFER_BULK: + type = "bulk"; + break; + default: + type = "?"; + break; + } + + dwc2_sch_dbg(hsotg, "QH=%p Init %s, %s speed, %d bytes:\n", qh, type, + speed, bytecount); + dwc2_sch_dbg(hsotg, "QH=%p ...addr=%d, ep=%d, %s\n", qh, + dwc2_hcd_get_dev_addr(&urb->pipe_info), + dwc2_hcd_get_ep_num(&urb->pipe_info), + ep_is_in ? "IN" : "OUT"); + if (ep_is_int || ep_is_isoc) { + dwc2_sch_dbg(hsotg, + "QH=%p ...duration: host=%d us, device=%d us\n", + qh, qh->host_us, qh->device_us); + dwc2_sch_dbg(hsotg, "QH=%p ...interval: host=%d, device=%d\n", + qh, qh->host_interval, qh->device_interval); + if (qh->schedule_low_speed) + dwc2_sch_dbg(hsotg, "QH=%p ...low speed schedule=%p\n", + qh, dwc2_get_ls_map(hsotg, qh)); + } +} + +/** + * dwc2_hcd_qh_create() - Allocates and initializes a QH + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @urb: Holds the information about the device/endpoint needed + * to initialize the QH + * @mem_flags: Flags for allocating memory. + * + * Return: Pointer to the newly allocated QH, or NULL on error + */ +struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg, + struct dwc2_hcd_urb *urb, + gfp_t mem_flags) +{ + struct dwc2_qh *qh; + + if (!urb->priv) + return NULL; + + /* Allocate memory */ + qh = kzalloc(sizeof(*qh), mem_flags); + if (!qh) + return NULL; + + dwc2_qh_init(hsotg, qh, urb, mem_flags); + + if (hsotg->params.dma_desc_enable && + dwc2_hcd_qh_init_ddma(hsotg, qh, mem_flags) < 0) { + dwc2_hcd_qh_free(hsotg, qh); + return NULL; + } + + return qh; +} + +/** + * dwc2_hcd_qh_free() - Frees the QH + * + * @hsotg: HCD instance + * @qh: The QH to free + * + * QH should already be removed from the list. QTD list should already be empty + * if called from URB Dequeue. + * + * Must NOT be called with interrupt disabled or spinlock held + */ +void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + /* Make sure any unreserve work is finished. */ + if (del_timer_sync(&qh->unreserve_timer)) { + unsigned long flags; + + spin_lock_irqsave(&hsotg->lock, flags); + dwc2_do_unreserve(hsotg, qh); + spin_unlock_irqrestore(&hsotg->lock, flags); + } + + /* + * We don't have the lock so we can safely wait until the wait timer + * finishes. Of course, at this point in time we'd better have set + * wait_timer_active to false so if this timer was still pending it + * won't do anything anyway, but we want it to finish before we free + * memory. + */ + hrtimer_cancel(&qh->wait_timer); + + dwc2_host_put_tt_info(hsotg, qh->dwc_tt); + + if (qh->desc_list) + dwc2_hcd_qh_free_ddma(hsotg, qh); + else if (hsotg->unaligned_cache && qh->dw_align_buf) + kmem_cache_free(hsotg->unaligned_cache, qh->dw_align_buf); + + kfree(qh); +} + +/** + * dwc2_hcd_qh_add() - Adds a QH to either the non periodic or periodic + * schedule if it is not already in the schedule. If the QH is already in + * the schedule, no action is taken. + * + * @hsotg: The HCD state structure for the DWC OTG controller + * @qh: The QH to add + * + * Return: 0 if successful, negative error code otherwise + */ +int dwc2_hcd_qh_add(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + int status; + u32 intr_mask; + ktime_t delay; + + if (dbg_qh(qh)) + dev_vdbg(hsotg->dev, "%s()\n", __func__); + + if (!list_empty(&qh->qh_list_entry)) + /* QH already in a schedule */ + return 0; + + /* Add the new QH to the appropriate schedule */ + if (dwc2_qh_is_non_per(qh)) { + /* Schedule right away */ + qh->start_active_frame = hsotg->frame_number; + qh->next_active_frame = qh->start_active_frame; + + if (qh->want_wait) { + list_add_tail(&qh->qh_list_entry, + &hsotg->non_periodic_sched_waiting); + qh->wait_timer_cancel = false; + delay = ktime_set(0, DWC2_RETRY_WAIT_DELAY); + hrtimer_start(&qh->wait_timer, delay, HRTIMER_MODE_REL); + } else { + list_add_tail(&qh->qh_list_entry, + &hsotg->non_periodic_sched_inactive); + } + return 0; + } + + status = dwc2_schedule_periodic(hsotg, qh); + if (status) + return status; + if (!hsotg->periodic_qh_count) { + intr_mask = dwc2_readl(hsotg, GINTMSK); + intr_mask |= GINTSTS_SOF; + dwc2_writel(hsotg, intr_mask, GINTMSK); + } + hsotg->periodic_qh_count++; + + return 0; +} + +/** + * dwc2_hcd_qh_unlink() - Removes a QH from either the non-periodic or periodic + * schedule. Memory is not freed. + * + * @hsotg: The HCD state structure + * @qh: QH to remove from schedule + */ +void dwc2_hcd_qh_unlink(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh) +{ + u32 intr_mask; + + dev_vdbg(hsotg->dev, "%s()\n", __func__); + + /* If the wait_timer is pending, this will stop it from acting */ + qh->wait_timer_cancel = true; + + if (list_empty(&qh->qh_list_entry)) + /* QH is not in a schedule */ + return; + + if (dwc2_qh_is_non_per(qh)) { + if (hsotg->non_periodic_qh_ptr == &qh->qh_list_entry) + hsotg->non_periodic_qh_ptr = + hsotg->non_periodic_qh_ptr->next; + list_del_init(&qh->qh_list_entry); + return; + } + + dwc2_deschedule_periodic(hsotg, qh); + hsotg->periodic_qh_count--; + if (!hsotg->periodic_qh_count && + !hsotg->params.dma_desc_enable) { + intr_mask = dwc2_readl(hsotg, GINTMSK); + intr_mask &= ~GINTSTS_SOF; + dwc2_writel(hsotg, intr_mask, GINTMSK); + } +} + +/** + * dwc2_next_for_periodic_split() - Set next_active_frame midway thru a split. + * + * This is called for setting next_active_frame for periodic splits for all but + * the first packet of the split. Confusing? I thought so... + * + * Periodic splits are single low/full speed transfers that we end up splitting + * up into several high speed transfers. They always fit into one full (1 ms) + * frame but might be split over several microframes (125 us each). We to put + * each of the parts on a very specific high speed frame. + * + * This function figures out where the next active uFrame needs to be. + * + * @hsotg: The HCD state structure + * @qh: QH for the periodic transfer. + * @frame_number: The current frame number. + * + * Return: number missed by (or 0 if we didn't miss). + */ +static int dwc2_next_for_periodic_split(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh, u16 frame_number) +{ + u16 old_frame = qh->next_active_frame; + u16 prev_frame_number = dwc2_frame_num_dec(frame_number, 1); + int missed = 0; + u16 incr; + + /* + * See dwc2_uframe_schedule_split() for split scheduling. + * + * Basically: increment 1 normally, but 2 right after the start split + * (except for ISOC out). + */ + if (old_frame == qh->start_active_frame && + !(qh->ep_type == USB_ENDPOINT_XFER_ISOC && !qh->ep_is_in)) + incr = 2; + else + incr = 1; + + qh->next_active_frame = dwc2_frame_num_inc(old_frame, incr); + + /* + * Note that it's OK for frame_number to be 1 frame past + * next_active_frame. Remember that next_active_frame is supposed to + * be 1 frame _before_ when we want to be scheduled. If we're 1 frame + * past it just means schedule ASAP. + * + * It's _not_ OK, however, if we're more than one frame past. + */ + if (dwc2_frame_num_gt(prev_frame_number, qh->next_active_frame)) { + /* + * OOPS, we missed. That's actually pretty bad since + * the hub will be unhappy; try ASAP I guess. + */ + missed = dwc2_frame_num_dec(prev_frame_number, + qh->next_active_frame); + qh->next_active_frame = frame_number; + } + + return missed; +} + +/** + * dwc2_next_periodic_start() - Set next_active_frame for next transfer start + * + * This is called for setting next_active_frame for a periodic transfer for + * all cases other than midway through a periodic split. This will also update + * start_active_frame. + * + * Since we _always_ keep start_active_frame as the start of the previous + * transfer this is normally pretty easy: we just add our interval to + * start_active_frame and we've got our answer. + * + * The tricks come into play if we miss. In that case we'll look for the next + * slot we can fit into. + * + * @hsotg: The HCD state structure + * @qh: QH for the periodic transfer. + * @frame_number: The current frame number. + * + * Return: number missed by (or 0 if we didn't miss). + */ +static int dwc2_next_periodic_start(struct dwc2_hsotg *hsotg, + struct dwc2_qh *qh, u16 frame_number) +{ + int missed = 0; + u16 interval = qh->host_interval; + u16 prev_frame_number = dwc2_frame_num_dec(frame_number, 1); + + qh->start_active_frame = dwc2_frame_num_inc(qh->start_active_frame, + interval); + + /* + * The dwc2_frame_num_gt() function used below won't work terribly well + * with if we just incremented by a really large intervals since the + * frame counter only goes to 0x3fff. It's terribly unlikely that we + * will have missed in this case anyway. Just go to exit. If we want + * to try to do better we'll need to keep track of a bigger counter + * somewhere in the driver and handle overflows. + */ + if (interval >= 0x1000) + goto exit; + + /* + * Test for misses, which is when it's too late to schedule. + * + * A few things to note: + * - We compare against prev_frame_number since start_active_frame + * and next_active_frame are always 1 frame before we want things + * to be active and we assume we can still get scheduled in the + * current frame number. + * - It's possible for start_active_frame (now incremented) to be + * next_active_frame if we got an EO MISS (even_odd miss) which + * basically means that we detected there wasn't enough time for + * the last packet and dwc2_hc_set_even_odd_frame() rescheduled us + * at the last second. We want to make sure we don't schedule + * another transfer for the same frame. My test webcam doesn't seem + * terribly upset by missing a transfer but really doesn't like when + * we do two transfers in the same frame. + * - Some misses are expected. Specifically, in order to work + * perfectly dwc2 really needs quite spectacular interrupt latency + * requirements. It needs to be able to handle its interrupts + * completely within 125 us of them being asserted. That not only + * means that the dwc2 interrupt handler needs to be fast but it + * means that nothing else in the system has to block dwc2 for a long + * time. We can help with the dwc2 parts of this, but it's hard to + * guarantee that a system will have interrupt latency < 125 us, so + * we have to be robust to some misses. + */ + if (qh->start_active_frame == qh->next_active_frame || + dwc2_frame_num_gt(prev_frame_number, qh->start_active_frame)) { + u16 ideal_start = qh->start_active_frame; + int periods_in_map; + + /* + * Adjust interval as per gcd with map size. + * See pmap_schedule() for more details here. + */ + if (qh->do_split || qh->dev_speed == USB_SPEED_HIGH) + periods_in_map = DWC2_HS_SCHEDULE_UFRAMES; + else + periods_in_map = DWC2_LS_SCHEDULE_FRAMES; + interval = gcd(interval, periods_in_map); + + do { + qh->start_active_frame = dwc2_frame_num_inc( + qh->start_active_frame, interval); + } while (dwc2_frame_num_gt(prev_frame_number, + qh->start_active_frame)); + + missed = dwc2_frame_num_dec(qh->start_active_frame, + ideal_start); + } + +exit: + qh->next_active_frame = qh->start_active_frame; + + return missed; +} + +/* + * Deactivates a QH. For non-periodic QHs, removes the QH from the active + * non-periodic schedule. The QH is added to the inactive non-periodic + * schedule if any QTDs are still attached to the QH. + * + * For periodic QHs, the QH is removed from the periodic queued schedule. If + * there are any QTDs still attached to the QH, the QH is added to either the + * periodic inactive schedule or the periodic ready schedule and its next + * scheduled frame is calculated. The QH is placed in the ready schedule if + * the scheduled frame has been reached already. Otherwise it's placed in the + * inactive schedule. If there are no QTDs attached to the QH, the QH is + * completely removed from the periodic schedule. + */ +void dwc2_hcd_qh_deactivate(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh, + int sched_next_periodic_split) +{ + u16 old_frame = qh->next_active_frame; + u16 frame_number; + int missed; + + if (dbg_qh(qh)) + dev_vdbg(hsotg->dev, "%s()\n", __func__); + + if (dwc2_qh_is_non_per(qh)) { + dwc2_hcd_qh_unlink(hsotg, qh); + if (!list_empty(&qh->qtd_list)) + /* Add back to inactive/waiting non-periodic schedule */ + dwc2_hcd_qh_add(hsotg, qh); + return; + } + + /* + * Use the real frame number rather than the cached value as of the + * last SOF just to get us a little closer to reality. Note that + * means we don't actually know if we've already handled the SOF + * interrupt for this frame. + */ + frame_number = dwc2_hcd_get_frame_number(hsotg); + + if (sched_next_periodic_split) + missed = dwc2_next_for_periodic_split(hsotg, qh, frame_number); + else + missed = dwc2_next_periodic_start(hsotg, qh, frame_number); + + dwc2_sch_vdbg(hsotg, + "QH=%p next(%d) fn=%04x, sch=%04x=>%04x (%+d) miss=%d %s\n", + qh, sched_next_periodic_split, frame_number, old_frame, + qh->next_active_frame, + dwc2_frame_num_dec(qh->next_active_frame, old_frame), + missed, missed ? "MISS" : ""); + + if (list_empty(&qh->qtd_list)) { + dwc2_hcd_qh_unlink(hsotg, qh); + return; + } + + /* + * Remove from periodic_sched_queued and move to + * appropriate queue + * + * Note: we purposely use the frame_number from the "hsotg" structure + * since we know SOF interrupt will handle future frames. + */ + if (dwc2_frame_num_le(qh->next_active_frame, hsotg->frame_number)) + list_move_tail(&qh->qh_list_entry, + &hsotg->periodic_sched_ready); + else + list_move_tail(&qh->qh_list_entry, + &hsotg->periodic_sched_inactive); +} + +/** + * dwc2_hcd_qtd_init() - Initializes a QTD structure + * + * @qtd: The QTD to initialize + * @urb: The associated URB + */ +void dwc2_hcd_qtd_init(struct dwc2_qtd *qtd, struct dwc2_hcd_urb *urb) +{ + qtd->urb = urb; + if (dwc2_hcd_get_pipe_type(&urb->pipe_info) == + USB_ENDPOINT_XFER_CONTROL) { + /* + * The only time the QTD data toggle is used is on the data + * phase of control transfers. This phase always starts with + * DATA1. + */ + qtd->data_toggle = DWC2_HC_PID_DATA1; + qtd->control_phase = DWC2_CONTROL_SETUP; + } + + /* Start split */ + qtd->complete_split = 0; + qtd->isoc_split_pos = DWC2_HCSPLT_XACTPOS_ALL; + qtd->isoc_split_offset = 0; + qtd->in_process = 0; + + /* Store the qtd ptr in the urb to reference the QTD */ + urb->qtd = qtd; +} + +/** + * dwc2_hcd_qtd_add() - Adds a QTD to the QTD-list of a QH + * Caller must hold driver lock. + * + * @hsotg: The DWC HCD structure + * @qtd: The QTD to add + * @qh: Queue head to add qtd to + * + * Return: 0 if successful, negative error code otherwise + * + * If the QH to which the QTD is added is not currently scheduled, it is placed + * into the proper schedule based on its EP type. + */ +int dwc2_hcd_qtd_add(struct dwc2_hsotg *hsotg, struct dwc2_qtd *qtd, + struct dwc2_qh *qh) +{ + int retval; + + if (unlikely(!qh)) { + dev_err(hsotg->dev, "%s: Invalid QH\n", __func__); + retval = -EINVAL; + goto fail; + } + + retval = dwc2_hcd_qh_add(hsotg, qh); + if (retval) + goto fail; + + qtd->qh = qh; + list_add_tail(&qtd->qtd_list_entry, &qh->qtd_list); + + return 0; +fail: + return retval; +} |