| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 13 Dec 2016 17:27:17 +0100
From: "Niklas Söderlund" <niklas.soderlund@...natech.se>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
Simon Horman <horms+renesas@...ge.net.au>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
Linux-Renesas <linux-renesas-soc@...r.kernel.org>,
linux-pm@...r.kernel.org
Subject: Re: [PATCHv2 1/5] sh_eth: add generic wake-on-lan support via magic
packet
Hi Geert,
Thanks for feedback and testing!
On 2016-12-13 14:03:52 +0100, Geert Uytterhoeven wrote:
> CC linux-pm
I think you forgot to CC linux-pm :-)
>
> On Mon, Dec 12, 2016 at 5:09 PM, Niklas Söderlund
> <niklas.soderlund+renesas@...natech.se> wrote:
> > Add generic functionality to support Wake-on-Lan using MagicPacket which
> > are supported by at least a few versions of sh_eth. Only add
> > functionality for WoL, no specific sh_eth version are marked to support
> > WoL yet.
> >
> > WoL is enabled in the suspend callback by setting MagicPacket detection
> > and disabling all interrupts expect MagicPacket. In the resume path the
> > driver needs to reset the hardware to rearm the WoL logic, this prevents
> > the driver from simply restoring the registers and to take advantage of
> > that sh_eth was not suspended to reduce resume time. To reset the
> > hardware the driver close and reopens the device just like it would do
> > in a normal suspend/resume scenario without WoL enabled, but it both
> > close and open the device in the resume callback since the device needs
> > to be open for WoL to work.
> >
> > One quirk needed for WoL is that the module clock needs to be prevented
> > from being switched off by Runtime PM. To keep the clock alive the
> > suspend callback need to call clk_enable() directly to increase the
> > usage count of the clock. Then when Runtime PM decreases the clock usage
> > count it won't reach 0 and be switched off.
> >
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@...natech.se>
>
> Thanks for the update!
>
> I've verified WoL is working on r8a7791/koelsch and r8a7740/armadillo.
>
> However, if I look at /sys/kernel/debug/wakeup_sources, "active_count" and
> "event_count" for the Ethernet device do not increase when using WoL, while
> they do for the GPIO keyboard when using the keyboard for wake up.
> So something seems to be missing from a bookkeeping point of view.
Cool, now I know why some net drivers call pm_wakeup_event() if the
wakeup source was WoL :-) I added this to sh_eth and now the bookkeeping
seems to work as you describe, "active_count" and "event_count" are
incremented while waking up from WoL. I will include this in the next
version, thanks for reporting I had no idea to check for this.
>
> Interestingly, "wakeup_count" does not increase for both?
> Has this been broken recently?
I had a quick look at this and the 'wakeup_count' is increased in
wakeup_source_report_event() which is in the call path from
pm_wakeup_event().
pm_wakeup_event()
__pm_wakeup_event()
wakeup_source_report_event()
static void wakeup_source_report_event(struct wakeup_source *ws)
{
ws->event_count++;
/* This is racy, but the counter is approximate anyway. */
if (events_check_enabled)
ws->wakeup_count++;
if (!ws->active)
wakeup_source_activate(ws);
}
So maybe 'wakeup_count' is not incremented due to the race with
events_check_enabled? But then again I'm new to PM so I might miss
something obvious. I'm also not sure if I can do anything in this series
to improve the behavior of 'wakeup_count' for sh_eth?
>
> > ---
> > drivers/net/ethernet/renesas/sh_eth.c | 112 +++++++++++++++++++++++++++++++---
> > drivers/net/ethernet/renesas/sh_eth.h | 3 +
> > 2 files changed, 107 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
> > index 05b0dc5..87640b9 100644
> > --- a/drivers/net/ethernet/renesas/sh_eth.c
> > +++ b/drivers/net/ethernet/renesas/sh_eth.c
> > @@ -2199,6 +2199,33 @@ static int sh_eth_set_ringparam(struct net_device *ndev,
> > return 0;
> > }
> >
> > +static void sh_eth_get_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
> > +{
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > +
> > + wol->supported = 0;
> > + wol->wolopts = 0;
> > +
> > + if (mdp->cd->magic && mdp->clk) {
> > + wol->supported = WAKE_MAGIC;
> > + wol->wolopts = mdp->wol_enabled ? WAKE_MAGIC : 0;
> > + }
> > +}
> > +
> > +static int sh_eth_set_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
> > +{
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > +
> > + if (!mdp->cd->magic || !mdp->clk || wol->wolopts & ~WAKE_MAGIC)
> > + return -EOPNOTSUPP;
> > +
> > + mdp->wol_enabled = !!(wol->wolopts & WAKE_MAGIC);
> > +
> > + device_set_wakeup_enable(&mdp->pdev->dev, mdp->wol_enabled);
> > +
> > + return 0;
> > +}
> > +
> > static const struct ethtool_ops sh_eth_ethtool_ops = {
> > .get_regs_len = sh_eth_get_regs_len,
> > .get_regs = sh_eth_get_regs,
> > @@ -2213,6 +2240,8 @@ static const struct ethtool_ops sh_eth_ethtool_ops = {
> > .set_ringparam = sh_eth_set_ringparam,
> > .get_link_ksettings = sh_eth_get_link_ksettings,
> > .set_link_ksettings = sh_eth_set_link_ksettings,
> > + .get_wol = sh_eth_get_wol,
> > + .set_wol = sh_eth_set_wol,
> > };
> >
> > /* network device open function */
> > @@ -3017,6 +3046,11 @@ static int sh_eth_drv_probe(struct platform_device *pdev)
> > goto out_release;
> > }
> >
> > + /* Get clock, if not found that's OK but Wake-On-Lan is unavailable */
> > + mdp->clk = devm_clk_get(&pdev->dev, NULL);
> > + if (IS_ERR(mdp->clk))
> > + mdp->clk = NULL;
> > +
> > ndev->base_addr = res->start;
> >
> > spin_lock_init(&mdp->lock);
> > @@ -3111,6 +3145,9 @@ static int sh_eth_drv_probe(struct platform_device *pdev)
> > if (ret)
> > goto out_napi_del;
> >
> > + if (mdp->cd->magic && mdp->clk)
> > + device_set_wakeup_capable(&pdev->dev, 1);
> > +
> > /* print device information */
> > netdev_info(ndev, "Base address at 0x%x, %pM, IRQ %d.\n",
> > (u32)ndev->base_addr, ndev->dev_addr, ndev->irq);
> > @@ -3150,15 +3187,67 @@ static int sh_eth_drv_remove(struct platform_device *pdev)
> >
> > #ifdef CONFIG_PM
> > #ifdef CONFIG_PM_SLEEP
> > +static int sh_eth_wol_setup(struct net_device *ndev)
> > +{
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > +
> > + /* Only allow ECI interrupts */
> > + synchronize_irq(ndev->irq);
> > + napi_disable(&mdp->napi);
> > + sh_eth_write(ndev, DMAC_M_ECI, EESIPR);
> > +
> > + /* Enable MagicPacket */
> > + sh_eth_modify(ndev, ECMR, 0, ECMR_PMDE);
> > +
> > + /* Increased clock usage so device won't be suspended */
> > + clk_enable(mdp->clk);
> > +
> > + return enable_irq_wake(ndev->irq);
> > +}
> > +
> > +static int sh_eth_wol_restore(struct net_device *ndev)
> > +{
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > + int ret;
> > +
> > + napi_enable(&mdp->napi);
> > +
> > + /* Disable MagicPacket */
> > + sh_eth_modify(ndev, ECMR, ECMR_PMDE, 0);
> > +
> > + /* The device need to be reset to restore MagicPacket logic
> > + * for next wakeup. If we close and open the device it will
> > + * both be reset and all registers restored. This is what
> > + * happens during suspend and resume without WoL enabled.
> > + */
> > + ret = sh_eth_close(ndev);
> > + if (ret < 0)
> > + return ret;
> > + ret = sh_eth_open(ndev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Restore clock usage count */
> > + clk_disable(mdp->clk);
> > +
> > + return disable_irq_wake(ndev->irq);
> > +}
> > +
> > static int sh_eth_suspend(struct device *dev)
> > {
> > struct net_device *ndev = dev_get_drvdata(dev);
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > int ret = 0;
> >
> > - if (netif_running(ndev)) {
> > - netif_device_detach(ndev);
> > + if (!netif_running(ndev))
> > + return 0;
> > +
> > + netif_device_detach(ndev);
> > +
> > + if (mdp->wol_enabled)
> > + ret = sh_eth_wol_setup(ndev);
> > + else
> > ret = sh_eth_close(ndev);
> > - }
> >
> > return ret;
> > }
> > @@ -3166,14 +3255,21 @@ static int sh_eth_suspend(struct device *dev)
> > static int sh_eth_resume(struct device *dev)
> > {
> > struct net_device *ndev = dev_get_drvdata(dev);
> > + struct sh_eth_private *mdp = netdev_priv(ndev);
> > int ret = 0;
> >
> > - if (netif_running(ndev)) {
> > + if (!netif_running(ndev))
> > + return 0;
> > +
> > + if (mdp->wol_enabled)
> > + ret = sh_eth_wol_restore(ndev);
> > + else
> > ret = sh_eth_open(ndev);
> > - if (ret < 0)
> > - return ret;
> > - netif_device_attach(ndev);
> > - }
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > + netif_device_attach(ndev);
> >
> > return ret;
> > }
> > diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
> > index d050f37..4ceed00 100644
> > --- a/drivers/net/ethernet/renesas/sh_eth.h
> > +++ b/drivers/net/ethernet/renesas/sh_eth.h
> > @@ -493,6 +493,7 @@ struct sh_eth_cpu_data {
> > unsigned shift_rd0:1; /* shift Rx descriptor word 0 right by 16 */
> > unsigned rmiimode:1; /* EtherC has RMIIMODE register */
> > unsigned rtrate:1; /* EtherC has RTRATE register */
> > + unsigned magic:1; /* EtherC has ECMR.PMDE and ECSR.MPD */
> > };
> >
> > struct sh_eth_private {
> > @@ -501,6 +502,7 @@ struct sh_eth_private {
> > const u16 *reg_offset;
> > void __iomem *addr;
> > void __iomem *tsu_addr;
> > + struct clk *clk;
> > u32 num_rx_ring;
> > u32 num_tx_ring;
> > dma_addr_t rx_desc_dma;
> > @@ -529,6 +531,7 @@ struct sh_eth_private {
> > unsigned no_ether_link:1;
> > unsigned ether_link_active_low:1;
> > unsigned is_opened:1;
> > + unsigned wol_enabled:1;
> > };
> >
> > static inline void sh_eth_soft_swap(char *src, int len)
> > --
> > 2.10.2
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
--
Regards,
Niklas Söderlund
Powered by blists - more mailing lists