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WSL2-Linux-Kernel/drivers/usb/dwc2/hcd_queue.c

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// 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*1E6L
/**
* 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;
}
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