OpenCloudOS-Kernel/drivers/net/can/dev.c

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/*
* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/kernel.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/workqueue.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/skb.h>
#include <linux/can/netlink.h>
#include <linux/can/led.h>
#include <linux/of.h>
#include <net/rtnetlink.h>
#define MOD_DESC "CAN device driver interface"
MODULE_DESCRIPTION(MOD_DESC);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
/* CAN DLC to real data length conversion helpers */
static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
8, 12, 16, 20, 24, 32, 48, 64};
/* get data length from can_dlc with sanitized can_dlc */
u8 can_dlc2len(u8 can_dlc)
{
return dlc2len[can_dlc & 0x0F];
}
EXPORT_SYMBOL_GPL(can_dlc2len);
static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
9, 9, 9, 9, /* 9 - 12 */
10, 10, 10, 10, /* 13 - 16 */
11, 11, 11, 11, /* 17 - 20 */
12, 12, 12, 12, /* 21 - 24 */
13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
/* map the sanitized data length to an appropriate data length code */
u8 can_len2dlc(u8 len)
{
if (unlikely(len > 64))
return 0xF;
return len2dlc[len];
}
EXPORT_SYMBOL_GPL(can_len2dlc);
#ifdef CONFIG_CAN_CALC_BITTIMING
#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
#define CAN_CALC_SYNC_SEG 1
/*
* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int can_update_sample_point(const struct can_bittiming_const *btc,
unsigned int sample_point_nominal, unsigned int tseg,
unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
unsigned int *sample_point_error_ptr)
{
unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
unsigned int sample_point, best_sample_point = 0;
unsigned int tseg1, tseg2;
int i;
for (i = 0; i <= 1; i++) {
tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
tseg1 = tseg - tseg2;
if (tseg1 > btc->tseg1_max) {
tseg1 = btc->tseg1_max;
tseg2 = tseg - tseg1;
}
sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
sample_point_error = abs(sample_point_nominal - sample_point);
if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
best_sample_point = sample_point;
best_sample_point_error = sample_point_error;
*tseg1_ptr = tseg1;
*tseg2_ptr = tseg2;
}
}
if (sample_point_error_ptr)
*sample_point_error_ptr = best_sample_point_error;
return best_sample_point;
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int bitrate; /* current bitrate */
unsigned int bitrate_error; /* difference between current and nominal value */
unsigned int best_bitrate_error = UINT_MAX;
unsigned int sample_point_error; /* difference between current and nominal value */
unsigned int best_sample_point_error = UINT_MAX;
unsigned int sample_point_nominal; /* nominal sample point */
unsigned int best_tseg = 0; /* current best value for tseg */
unsigned int best_brp = 0; /* current best value for brp */
unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
u64 v64;
/* Use CiA recommended sample points */
if (bt->sample_point) {
sample_point_nominal = bt->sample_point;
} else {
if (bt->bitrate > 800000)
sample_point_nominal = 750;
else if (bt->bitrate > 500000)
sample_point_nominal = 800;
else
sample_point_nominal = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* choose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
bitrate = priv->clock.freq / (brp * tsegall);
bitrate_error = abs(bt->bitrate - bitrate);
/* tseg brp biterror */
if (bitrate_error > best_bitrate_error)
continue;
/* reset sample point error if we have a better bitrate */
if (bitrate_error < best_bitrate_error)
best_sample_point_error = UINT_MAX;
can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
if (sample_point_error > best_sample_point_error)
continue;
best_sample_point_error = sample_point_error;
best_bitrate_error = bitrate_error;
best_tseg = tseg / 2;
best_brp = brp;
if (bitrate_error == 0 && sample_point_error == 0)
break;
}
if (best_bitrate_error) {
/* Error in one-tenth of a percent */
v64 = (u64)best_bitrate_error * 1000;
do_div(v64, bt->bitrate);
bitrate_error = (u32)v64;
if (bitrate_error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %d.%d%% too high\n",
bitrate_error / 10, bitrate_error % 10);
return -EDOM;
}
netdev_warn(dev, "bitrate error %d.%d%%\n",
bitrate_error / 10, bitrate_error % 10);
}
/* real sample point */
bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
&tseg1, &tseg2, NULL);
v64 = (u64)best_brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max) {
bt->sjw = 1;
} else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bitrate */
bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
return 0;
}
#else /* !CONFIG_CAN_CALC_BITTIMING */
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
netdev_err(dev, "bit-timing calculation not available\n");
return -EINVAL;
}
#endif /* CONFIG_CAN_CALC_BITTIMING */
/*
* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}
/* Checks the validity of predefined bitrate settings */
static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
const u32 *bitrate_const,
const unsigned int bitrate_const_cnt)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int i;
for (i = 0; i < bitrate_const_cnt; i++) {
if (bt->bitrate == bitrate_const[i])
break;
}
if (i >= priv->bitrate_const_cnt)
return -EINVAL;
return 0;
}
static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc,
const u32 *bitrate_const,
const unsigned int bitrate_const_cnt)
{
int err;
/*
* Depending on the given can_bittiming parameter structure the CAN
* timing parameters are calculated based on the provided bitrate OR
* alternatively the CAN timing parameters (tq, prop_seg, etc.) are
* provided directly which are then checked and fixed up.
*/
if (!bt->tq && bt->bitrate && btc)
err = can_calc_bittiming(dev, bt, btc);
else if (bt->tq && !bt->bitrate && btc)
err = can_fixup_bittiming(dev, bt, btc);
else if (!bt->tq && bt->bitrate && bitrate_const)
err = can_validate_bitrate(dev, bt, bitrate_const,
bitrate_const_cnt);
else
err = -EINVAL;
return err;
}
static void can_update_state_error_stats(struct net_device *dev,
enum can_state new_state)
{
struct can_priv *priv = netdev_priv(dev);
if (new_state <= priv->state)
return;
switch (new_state) {
case CAN_STATE_ERROR_WARNING:
priv->can_stats.error_warning++;
break;
case CAN_STATE_ERROR_PASSIVE:
priv->can_stats.error_passive++;
break;
case CAN_STATE_BUS_OFF:
priv->can_stats.bus_off++;
break;
default:
break;
}
}
static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
{
switch (state) {
case CAN_STATE_ERROR_ACTIVE:
return CAN_ERR_CRTL_ACTIVE;
case CAN_STATE_ERROR_WARNING:
return CAN_ERR_CRTL_TX_WARNING;
case CAN_STATE_ERROR_PASSIVE:
return CAN_ERR_CRTL_TX_PASSIVE;
default:
return 0;
}
}
static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
{
switch (state) {
case CAN_STATE_ERROR_ACTIVE:
return CAN_ERR_CRTL_ACTIVE;
case CAN_STATE_ERROR_WARNING:
return CAN_ERR_CRTL_RX_WARNING;
case CAN_STATE_ERROR_PASSIVE:
return CAN_ERR_CRTL_RX_PASSIVE;
default:
return 0;
}
}
void can_change_state(struct net_device *dev, struct can_frame *cf,
enum can_state tx_state, enum can_state rx_state)
{
struct can_priv *priv = netdev_priv(dev);
enum can_state new_state = max(tx_state, rx_state);
if (unlikely(new_state == priv->state)) {
netdev_warn(dev, "%s: oops, state did not change", __func__);
return;
}
netdev_dbg(dev, "New error state: %d\n", new_state);
can_update_state_error_stats(dev, new_state);
priv->state = new_state;
if (!cf)
return;
if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
cf->can_id |= CAN_ERR_BUSOFF;
return;
}
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] |= tx_state >= rx_state ?
can_tx_state_to_frame(dev, tx_state) : 0;
cf->data[1] |= tx_state <= rx_state ?
can_rx_state_to_frame(dev, rx_state) : 0;
}
EXPORT_SYMBOL_GPL(can_change_state);
/*
* Local echo of CAN messages
*
* CAN network devices *should* support a local echo functionality
* (see Documentation/networking/can.rst). To test the handling of CAN
* interfaces that do not support the local echo both driver types are
* implemented. In the case that the driver does not support the echo
* the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
* to perform the echo as a fallback solution.
*/
static void can_flush_echo_skb(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
int i;
for (i = 0; i < priv->echo_skb_max; i++) {
if (priv->echo_skb[i]) {
kfree_skb(priv->echo_skb[i]);
priv->echo_skb[i] = NULL;
stats->tx_dropped++;
stats->tx_aborted_errors++;
}
}
}
/*
* Put the skb on the stack to be looped backed locally lateron
*
* The function is typically called in the start_xmit function
* of the device driver. The driver must protect access to
* priv->echo_skb, if necessary.
*/
void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
unsigned int idx)
{
struct can_priv *priv = netdev_priv(dev);
BUG_ON(idx >= priv->echo_skb_max);
/* check flag whether this packet has to be looped back */
if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
(skb->protocol != htons(ETH_P_CAN) &&
skb->protocol != htons(ETH_P_CANFD))) {
kfree_skb(skb);
return;
}
if (!priv->echo_skb[idx]) {
skb = can_create_echo_skb(skb);
if (!skb)
return;
/* make settings for echo to reduce code in irq context */
skb->pkt_type = PACKET_BROADCAST;
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->dev = dev;
/* save this skb for tx interrupt echo handling */
priv->echo_skb[idx] = skb;
} else {
/* locking problem with netif_stop_queue() ?? */
netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
kfree_skb(skb);
}
}
EXPORT_SYMBOL_GPL(can_put_echo_skb);
/*
* Get the skb from the stack and loop it back locally
*
* The function is typically called when the TX done interrupt
* is handled in the device driver. The driver must protect
* access to priv->echo_skb, if necessary.
*/
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
{
struct can_priv *priv = netdev_priv(dev);
BUG_ON(idx >= priv->echo_skb_max);
if (priv->echo_skb[idx]) {
struct sk_buff *skb = priv->echo_skb[idx];
struct can_frame *cf = (struct can_frame *)skb->data;
u8 dlc = cf->can_dlc;
netif_rx(priv->echo_skb[idx]);
priv->echo_skb[idx] = NULL;
return dlc;
}
return 0;
}
EXPORT_SYMBOL_GPL(can_get_echo_skb);
/*
* Remove the skb from the stack and free it.
*
* The function is typically called when TX failed.
*/
void can_free_echo_skb(struct net_device *dev, unsigned int idx)
{
struct can_priv *priv = netdev_priv(dev);
BUG_ON(idx >= priv->echo_skb_max);
if (priv->echo_skb[idx]) {
can: dev: avoid calling kfree_skb() from interrupt context ikfree_skb() is Called in can_free_echo_skb(), which might be called from (TX Error) interrupt, which triggers the folloing warning: [ 1153.360705] ------------[ cut here ]------------ [ 1153.360715] WARNING: CPU: 0 PID: 31 at net/core/skbuff.c:563 skb_release_head_state+0xb9/0xd0() [ 1153.360772] Call Trace: [ 1153.360778] [<c167906f>] dump_stack+0x41/0x52 [ 1153.360782] [<c105bb7e>] warn_slowpath_common+0x7e/0xa0 [ 1153.360784] [<c158b909>] ? skb_release_head_state+0xb9/0xd0 [ 1153.360786] [<c158b909>] ? skb_release_head_state+0xb9/0xd0 [ 1153.360788] [<c105bc42>] warn_slowpath_null+0x22/0x30 [ 1153.360791] [<c158b909>] skb_release_head_state+0xb9/0xd0 [ 1153.360793] [<c158be90>] skb_release_all+0x10/0x30 [ 1153.360795] [<c158bf06>] kfree_skb+0x36/0x80 [ 1153.360799] [<f8486938>] ? can_free_echo_skb+0x28/0x40 [can_dev] [ 1153.360802] [<f8486938>] can_free_echo_skb+0x28/0x40 [can_dev] [ 1153.360805] [<f849a12c>] esd_pci402_interrupt+0x34c/0x57a [esd402] [ 1153.360809] [<c10a75b5>] handle_irq_event_percpu+0x35/0x180 [ 1153.360811] [<c10a7623>] ? handle_irq_event_percpu+0xa3/0x180 [ 1153.360813] [<c10a7731>] handle_irq_event+0x31/0x50 [ 1153.360816] [<c10a9c7f>] handle_fasteoi_irq+0x6f/0x120 [ 1153.360818] [<c10a9c10>] ? handle_edge_irq+0x110/0x110 [ 1153.360822] [<c1011b61>] handle_irq+0x71/0x90 [ 1153.360823] <IRQ> [<c168152c>] do_IRQ+0x3c/0xd0 [ 1153.360829] [<c1680b6c>] common_interrupt+0x2c/0x34 [ 1153.360834] [<c107d277>] ? finish_task_switch+0x47/0xf0 [ 1153.360836] [<c167c27b>] __schedule+0x35b/0x7e0 [ 1153.360839] [<c10a5334>] ? console_unlock+0x2c4/0x4d0 [ 1153.360842] [<c13df500>] ? n_tty_receive_buf_common+0x890/0x890 [ 1153.360845] [<c10707b6>] ? process_one_work+0x196/0x370 [ 1153.360847] [<c167c723>] schedule+0x23/0x60 [ 1153.360849] [<c1070de1>] worker_thread+0x161/0x460 [ 1153.360852] [<c1090fcf>] ? __wake_up_locked+0x1f/0x30 [ 1153.360854] [<c1070c80>] ? rescuer_thread+0x2f0/0x2f0 [ 1153.360856] [<c1074f01>] kthread+0xa1/0xc0 [ 1153.360859] [<c1680401>] ret_from_kernel_thread+0x21/0x30 [ 1153.360861] [<c1074e60>] ? kthread_create_on_node+0x110/0x110 [ 1153.360863] ---[ end trace 5ff83639cbb74b35 ]--- This patch replaces the kfree_skb() by dev_kfree_skb_any(). Signed-off-by: Thomas Körper <thomas.koerper@esd.eu> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-31 14:33:54 +08:00
dev_kfree_skb_any(priv->echo_skb[idx]);
priv->echo_skb[idx] = NULL;
}
}
EXPORT_SYMBOL_GPL(can_free_echo_skb);
/*
* CAN device restart for bus-off recovery
*/
static void can_restart(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
struct can_frame *cf;
int err;
BUG_ON(netif_carrier_ok(dev));
/*
* No synchronization needed because the device is bus-off and
* no messages can come in or go out.
*/
can_flush_echo_skb(dev);
/* send restart message upstream */
skb = alloc_can_err_skb(dev, &cf);
if (skb == NULL) {
err = -ENOMEM;
goto restart;
}
cf->can_id |= CAN_ERR_RESTARTED;
netif_rx(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
restart:
netdev_dbg(dev, "restarted\n");
priv->can_stats.restarts++;
/* Now restart the device */
err = priv->do_set_mode(dev, CAN_MODE_START);
netif_carrier_on(dev);
if (err)
netdev_err(dev, "Error %d during restart", err);
}
static void can_restart_work(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
can_restart(priv->dev);
}
int can_restart_now(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
/*
* A manual restart is only permitted if automatic restart is
* disabled and the device is in the bus-off state
*/
if (priv->restart_ms)
return -EINVAL;
if (priv->state != CAN_STATE_BUS_OFF)
return -EBUSY;
cancel_delayed_work_sync(&priv->restart_work);
can_restart(dev);
return 0;
}
/*
* CAN bus-off
*
* This functions should be called when the device goes bus-off to
* tell the netif layer that no more packets can be sent or received.
* If enabled, a timer is started to trigger bus-off recovery.
*/
void can_bus_off(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
netdev_dbg(dev, "bus-off\n");
netif_carrier_off(dev);
if (priv->restart_ms)
schedule_delayed_work(&priv->restart_work,
msecs_to_jiffies(priv->restart_ms));
}
EXPORT_SYMBOL_GPL(can_bus_off);
static void can_setup(struct net_device *dev)
{
dev->type = ARPHRD_CAN;
dev->mtu = CAN_MTU;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->tx_queue_len = 10;
/* New-style flags. */
dev->flags = IFF_NOARP;
dev->features = NETIF_F_HW_CSUM;
}
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
{
struct sk_buff *skb;
skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
sizeof(struct can_frame));
if (unlikely(!skb))
return NULL;
skb->protocol = htons(ETH_P_CAN);
skb->pkt_type = PACKET_BROADCAST;
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
*cf = skb_put(skb, sizeof(struct can_frame));
memset(*cf, 0, sizeof(struct can_frame));
return skb;
}
EXPORT_SYMBOL_GPL(alloc_can_skb);
struct sk_buff *alloc_canfd_skb(struct net_device *dev,
struct canfd_frame **cfd)
{
struct sk_buff *skb;
skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
sizeof(struct canfd_frame));
if (unlikely(!skb))
return NULL;
skb->protocol = htons(ETH_P_CANFD);
skb->pkt_type = PACKET_BROADCAST;
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
*cfd = skb_put(skb, sizeof(struct canfd_frame));
memset(*cfd, 0, sizeof(struct canfd_frame));
return skb;
}
EXPORT_SYMBOL_GPL(alloc_canfd_skb);
struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
{
struct sk_buff *skb;
skb = alloc_can_skb(dev, cf);
if (unlikely(!skb))
return NULL;
(*cf)->can_id = CAN_ERR_FLAG;
(*cf)->can_dlc = CAN_ERR_DLC;
return skb;
}
EXPORT_SYMBOL_GPL(alloc_can_err_skb);
/*
* Allocate and setup space for the CAN network device
*/
struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
{
struct net_device *dev;
struct can_priv *priv;
int size;
if (echo_skb_max)
size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
echo_skb_max * sizeof(struct sk_buff *);
else
size = sizeof_priv;
dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
if (!dev)
return NULL;
priv = netdev_priv(dev);
priv->dev = dev;
if (echo_skb_max) {
priv->echo_skb_max = echo_skb_max;
priv->echo_skb = (void *)priv +
ALIGN(sizeof_priv, sizeof(struct sk_buff *));
}
priv->state = CAN_STATE_STOPPED;
INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
return dev;
}
EXPORT_SYMBOL_GPL(alloc_candev);
/*
* Free space of the CAN network device
*/
void free_candev(struct net_device *dev)
{
free_netdev(dev);
}
EXPORT_SYMBOL_GPL(free_candev);
/*
* changing MTU and control mode for CAN/CANFD devices
*/
int can_change_mtu(struct net_device *dev, int new_mtu)
{
struct can_priv *priv = netdev_priv(dev);
/* Do not allow changing the MTU while running */
if (dev->flags & IFF_UP)
return -EBUSY;
/* allow change of MTU according to the CANFD ability of the device */
switch (new_mtu) {
case CAN_MTU:
/* 'CANFD-only' controllers can not switch to CAN_MTU */
if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
return -EINVAL;
priv->ctrlmode &= ~CAN_CTRLMODE_FD;
break;
case CANFD_MTU:
/* check for potential CANFD ability */
if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
!(priv->ctrlmode_static & CAN_CTRLMODE_FD))
return -EINVAL;
priv->ctrlmode |= CAN_CTRLMODE_FD;
break;
default:
return -EINVAL;
}
dev->mtu = new_mtu;
return 0;
}
EXPORT_SYMBOL_GPL(can_change_mtu);
/*
* Common open function when the device gets opened.
*
* This function should be called in the open function of the device
* driver.
*/
int open_candev(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
if (!priv->bittiming.bitrate) {
netdev_err(dev, "bit-timing not yet defined\n");
return -EINVAL;
}
/* For CAN FD the data bitrate has to be >= the arbitration bitrate */
if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
(!priv->data_bittiming.bitrate ||
(priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
netdev_err(dev, "incorrect/missing data bit-timing\n");
return -EINVAL;
}
/* Switch carrier on if device was stopped while in bus-off state */
if (!netif_carrier_ok(dev))
netif_carrier_on(dev);
return 0;
}
EXPORT_SYMBOL_GPL(open_candev);
#ifdef CONFIG_OF
/* Common function that can be used to understand the limitation of
* a transceiver when it provides no means to determine these limitations
* at runtime.
*/
void of_can_transceiver(struct net_device *dev)
{
struct device_node *dn;
struct can_priv *priv = netdev_priv(dev);
struct device_node *np = dev->dev.parent->of_node;
int ret;
dn = of_get_child_by_name(np, "can-transceiver");
if (!dn)
return;
ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
}
EXPORT_SYMBOL_GPL(of_can_transceiver);
#endif
/*
* Common close function for cleanup before the device gets closed.
*
* This function should be called in the close function of the device
* driver.
*/
void close_candev(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
cancel_delayed_work_sync(&priv->restart_work);
can_flush_echo_skb(dev);
}
EXPORT_SYMBOL_GPL(close_candev);
/*
* CAN netlink interface
*/
static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
[IFLA_CAN_STATE] = { .type = NLA_U32 },
[IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
[IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
[IFLA_CAN_RESTART] = { .type = NLA_U32 },
[IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
[IFLA_CAN_BITTIMING_CONST]
= { .len = sizeof(struct can_bittiming_const) },
[IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
[IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
[IFLA_CAN_DATA_BITTIMING]
= { .len = sizeof(struct can_bittiming) },
[IFLA_CAN_DATA_BITTIMING_CONST]
= { .len = sizeof(struct can_bittiming_const) },
};
static int can_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
bool is_can_fd = false;
/* Make sure that valid CAN FD configurations always consist of
* - nominal/arbitration bittiming
* - data bittiming
* - control mode with CAN_CTRLMODE_FD set
*/
if (!data)
return 0;
if (data[IFLA_CAN_CTRLMODE]) {
struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
}
if (is_can_fd) {
if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
return -EOPNOTSUPP;
}
if (data[IFLA_CAN_DATA_BITTIMING]) {
if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
return -EOPNOTSUPP;
}
return 0;
}
static int can_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct can_priv *priv = netdev_priv(dev);
int err;
/* We need synchronization with dev->stop() */
ASSERT_RTNL();
if (data[IFLA_CAN_BITTIMING]) {
struct can_bittiming bt;
/* Do not allow changing bittiming while running */
if (dev->flags & IFF_UP)
return -EBUSY;
/* Calculate bittiming parameters based on
* bittiming_const if set, otherwise pass bitrate
* directly via do_set_bitrate(). Bail out if neither
* is given.
*/
if (!priv->bittiming_const && !priv->do_set_bittiming)
return -EOPNOTSUPP;
memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
err = can_get_bittiming(dev, &bt,
priv->bittiming_const,
priv->bitrate_const,
priv->bitrate_const_cnt);
if (err)
return err;
if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
priv->bitrate_max);
return -EINVAL;
}
memcpy(&priv->bittiming, &bt, sizeof(bt));
if (priv->do_set_bittiming) {
/* Finally, set the bit-timing registers */
err = priv->do_set_bittiming(dev);
if (err)
return err;
}
}
if (data[IFLA_CAN_CTRLMODE]) {
struct can_ctrlmode *cm;
u32 ctrlstatic;
u32 maskedflags;
/* Do not allow changing controller mode while running */
if (dev->flags & IFF_UP)
return -EBUSY;
cm = nla_data(data[IFLA_CAN_CTRLMODE]);
ctrlstatic = priv->ctrlmode_static;
maskedflags = cm->flags & cm->mask;
/* check whether provided bits are allowed to be passed */
if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
return -EOPNOTSUPP;
/* do not check for static fd-non-iso if 'fd' is disabled */
if (!(maskedflags & CAN_CTRLMODE_FD))
ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
/* make sure static options are provided by configuration */
if ((maskedflags & ctrlstatic) != ctrlstatic)
return -EOPNOTSUPP;
/* clear bits to be modified and copy the flag values */
priv->ctrlmode &= ~cm->mask;
priv->ctrlmode |= maskedflags;
/* CAN_CTRLMODE_FD can only be set when driver supports FD */
if (priv->ctrlmode & CAN_CTRLMODE_FD)
dev->mtu = CANFD_MTU;
else
dev->mtu = CAN_MTU;
}
if (data[IFLA_CAN_RESTART_MS]) {
/* Do not allow changing restart delay while running */
if (dev->flags & IFF_UP)
return -EBUSY;
priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
}
if (data[IFLA_CAN_RESTART]) {
/* Do not allow a restart while not running */
if (!(dev->flags & IFF_UP))
return -EINVAL;
err = can_restart_now(dev);
if (err)
return err;
}
if (data[IFLA_CAN_DATA_BITTIMING]) {
struct can_bittiming dbt;
/* Do not allow changing bittiming while running */
if (dev->flags & IFF_UP)
return -EBUSY;
/* Calculate bittiming parameters based on
* data_bittiming_const if set, otherwise pass bitrate
* directly via do_set_bitrate(). Bail out if neither
* is given.
*/
if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
return -EOPNOTSUPP;
memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
sizeof(dbt));
err = can_get_bittiming(dev, &dbt,
priv->data_bittiming_const,
priv->data_bitrate_const,
priv->data_bitrate_const_cnt);
if (err)
return err;
if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
priv->bitrate_max);
return -EINVAL;
}
memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
if (priv->do_set_data_bittiming) {
/* Finally, set the bit-timing registers */
err = priv->do_set_data_bittiming(dev);
if (err)
return err;
}
}
if (data[IFLA_CAN_TERMINATION]) {
const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
const unsigned int num_term = priv->termination_const_cnt;
unsigned int i;
if (!priv->do_set_termination)
return -EOPNOTSUPP;
/* check whether given value is supported by the interface */
for (i = 0; i < num_term; i++) {
if (termval == priv->termination_const[i])
break;
}
if (i >= num_term)
return -EINVAL;
/* Finally, set the termination value */
err = priv->do_set_termination(dev, termval);
if (err)
return err;
priv->termination = termval;
}
return 0;
}
static size_t can_get_size(const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
size_t size = 0;
if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
size += nla_total_size(sizeof(struct can_bittiming));
if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
size += nla_total_size(sizeof(struct can_bittiming_const));
size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
size += nla_total_size(sizeof(struct can_berr_counter));
if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
size += nla_total_size(sizeof(struct can_bittiming));
if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
size += nla_total_size(sizeof(struct can_bittiming_const));
if (priv->termination_const) {
size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */
size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */
priv->termination_const_cnt);
}
if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */
size += nla_total_size(sizeof(*priv->bitrate_const) *
priv->bitrate_const_cnt);
if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */
size += nla_total_size(sizeof(*priv->data_bitrate_const) *
priv->data_bitrate_const_cnt);
size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
return size;
}
static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
struct can_ctrlmode cm = {.flags = priv->ctrlmode};
struct can_berr_counter bec;
enum can_state state = priv->state;
if (priv->do_get_state)
priv->do_get_state(dev, &state);
if ((priv->bittiming.bitrate &&
nla_put(skb, IFLA_CAN_BITTIMING,
sizeof(priv->bittiming), &priv->bittiming)) ||
(priv->bittiming_const &&
nla_put(skb, IFLA_CAN_BITTIMING_CONST,
sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
nla_put_u32(skb, IFLA_CAN_STATE, state) ||
nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
(priv->do_get_berr_counter &&
!priv->do_get_berr_counter(dev, &bec) &&
nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
(priv->data_bittiming.bitrate &&
nla_put(skb, IFLA_CAN_DATA_BITTIMING,
sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
(priv->data_bittiming_const &&
nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
sizeof(*priv->data_bittiming_const),
priv->data_bittiming_const)) ||
(priv->termination_const &&
(nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
nla_put(skb, IFLA_CAN_TERMINATION_CONST,
sizeof(*priv->termination_const) *
priv->termination_const_cnt,
priv->termination_const))) ||
(priv->bitrate_const &&
nla_put(skb, IFLA_CAN_BITRATE_CONST,
sizeof(*priv->bitrate_const) *
priv->bitrate_const_cnt,
priv->bitrate_const)) ||
(priv->data_bitrate_const &&
nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
sizeof(*priv->data_bitrate_const) *
priv->data_bitrate_const_cnt,
priv->data_bitrate_const)) ||
(nla_put(skb, IFLA_CAN_BITRATE_MAX,
sizeof(priv->bitrate_max),
&priv->bitrate_max))
)
return -EMSGSIZE;
return 0;
}
static size_t can_get_xstats_size(const struct net_device *dev)
{
return sizeof(struct can_device_stats);
}
static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
if (nla_put(skb, IFLA_INFO_XSTATS,
sizeof(priv->can_stats), &priv->can_stats))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int can_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
return -EOPNOTSUPP;
}
static void can_dellink(struct net_device *dev, struct list_head *head)
{
return;
}
static struct rtnl_link_ops can_link_ops __read_mostly = {
.kind = "can",
.maxtype = IFLA_CAN_MAX,
.policy = can_policy,
.setup = can_setup,
.validate = can_validate,
.newlink = can_newlink,
.changelink = can_changelink,
.dellink = can_dellink,
.get_size = can_get_size,
.fill_info = can_fill_info,
.get_xstats_size = can_get_xstats_size,
.fill_xstats = can_fill_xstats,
};
/*
* Register the CAN network device
*/
int register_candev(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
/* Ensure termination_const, termination_const_cnt and
* do_set_termination consistency. All must be either set or
* unset.
*/
if ((!priv->termination_const != !priv->termination_const_cnt) ||
(!priv->termination_const != !priv->do_set_termination))
return -EINVAL;
if (!priv->bitrate_const != !priv->bitrate_const_cnt)
return -EINVAL;
if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
return -EINVAL;
dev->rtnl_link_ops = &can_link_ops;
return register_netdev(dev);
}
EXPORT_SYMBOL_GPL(register_candev);
/*
* Unregister the CAN network device
*/
void unregister_candev(struct net_device *dev)
{
unregister_netdev(dev);
}
EXPORT_SYMBOL_GPL(unregister_candev);
/*
* Test if a network device is a candev based device
* and return the can_priv* if so.
*/
struct can_priv *safe_candev_priv(struct net_device *dev)
{
if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
return NULL;
return netdev_priv(dev);
}
EXPORT_SYMBOL_GPL(safe_candev_priv);
static __init int can_dev_init(void)
{
int err;
can_led_notifier_init();
err = rtnl_link_register(&can_link_ops);
if (!err)
printk(KERN_INFO MOD_DESC "\n");
return err;
}
module_init(can_dev_init);
static __exit void can_dev_exit(void)
{
rtnl_link_unregister(&can_link_ops);
can_led_notifier_exit();
}
module_exit(can_dev_exit);
MODULE_ALIAS_RTNL_LINK("can");