| Message ID | 20180823213600.23426-1-alexandre.belloni@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] soc: fsl: qbman: qman_portal: defer probing when qman is not available | expand |
On 8/23/2018 5:36 PM, Alexandre Belloni wrote: > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > unmapped page. > > This leads to a crash when probing qman_portal as the init_pcfg function > calls qman_liodn_fixup that tries to read qman registers. > > Assume that qman didn't probe when the pool mask is 0. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > index a120002b630e..4fc80d2c8feb 100644 > --- a/drivers/soc/fsl/qbman/qman_portal.c > +++ b/drivers/soc/fsl/qbman/qman_portal.c > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > } > > pcfg->pools = qm_get_pools_sdqcr(); > + if (pcfg->pools == 0) > + return -EPROBE_DEFER; > > spin_lock(&qman_lock); > cpu = cpumask_next_zero(-1, &portal_cpus); Reviewed-by: Roy Pledge <roy.pledge@nxp.com>
On Fri, Aug 24, 2018 at 9:54 AM Roy Pledge <roy.pledge@nxp.com> wrote: > > On 8/23/2018 5:36 PM, Alexandre Belloni wrote: > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > > unmapped page. > > > > This leads to a crash when probing qman_portal as the init_pcfg function > > calls qman_liodn_fixup that tries to read qman registers. > > > > Assume that qman didn't probe when the pool mask is 0. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Series applied to the fix branch of soc/fsl. > > --- > > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > > index a120002b630e..4fc80d2c8feb 100644 > > --- a/drivers/soc/fsl/qbman/qman_portal.c > > +++ b/drivers/soc/fsl/qbman/qman_portal.c > > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > > } > > > > pcfg->pools = qm_get_pools_sdqcr(); > > + if (pcfg->pools == 0) > > + return -EPROBE_DEFER; > > > > spin_lock(&qman_lock); > > cpu = cpumask_next_zero(-1, &portal_cpus); > > Reviewed-by: Roy Pledge <roy.pledge@nxp.com> > >
Hi, On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni <alexandre.belloni@bootlin.com> wrote: > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > unmapped page. > > This leads to a crash when probing qman_portal as the init_pcfg function > calls qman_liodn_fixup that tries to read qman registers. > > Assume that qman didn't probe when the pool mask is 0. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > index a120002b630e..4fc80d2c8feb 100644 > --- a/drivers/soc/fsl/qbman/qman_portal.c > +++ b/drivers/soc/fsl/qbman/qman_portal.c > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > } > > pcfg->pools = qm_get_pools_sdqcr(); > + if (pcfg->pools == 0) > + return -EPROBE_DEFER; This is quite late in the probe, after a bunch of resources have been claimed. Note that the ioremaps above this are doing unwinds, and you'll end up doing duplicate ioremaps if you come in and probe again. You should probably unwind those allocations, or move them to devm_* or do this check earlier in the function. -Olof
On Tue, Sep 25, 2018 at 2:47 PM Olof Johansson <olof@lixom.net> wrote: > > Hi, > > > On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni > <alexandre.belloni@bootlin.com> wrote: > > > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > > unmapped page. > > > > This leads to a crash when probing qman_portal as the init_pcfg function > > calls qman_liodn_fixup that tries to read qman registers. > > > > Assume that qman didn't probe when the pool mask is 0. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > --- > > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > > index a120002b630e..4fc80d2c8feb 100644 > > --- a/drivers/soc/fsl/qbman/qman_portal.c > > +++ b/drivers/soc/fsl/qbman/qman_portal.c > > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > > } > > > > pcfg->pools = qm_get_pools_sdqcr(); > > + if (pcfg->pools == 0) > > + return -EPROBE_DEFER; > > This is quite late in the probe, after a bunch of resources have been claimed. > > Note that the ioremaps above this are doing unwinds, and you'll end up > doing duplicate ioremaps if you come in and probe again. > > You should probably unwind those allocations, or move them to devm_* > or do this check earlier in the function. Hi Roy, Is there any more straightforward indicator on if qman has been probed? So that we can check it at the begining of the probe? Regards, Leo
On 25/09/2018 21:45:56+0200, Olof Johansson wrote: > Hi, > > > On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni > <alexandre.belloni@bootlin.com> wrote: > > > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > > unmapped page. > > > > This leads to a crash when probing qman_portal as the init_pcfg function > > calls qman_liodn_fixup that tries to read qman registers. > > > > Assume that qman didn't probe when the pool mask is 0. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > --- > > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > > index a120002b630e..4fc80d2c8feb 100644 > > --- a/drivers/soc/fsl/qbman/qman_portal.c > > +++ b/drivers/soc/fsl/qbman/qman_portal.c > > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > > } > > > > pcfg->pools = qm_get_pools_sdqcr(); > > + if (pcfg->pools == 0) > > + return -EPROBE_DEFER; > > This is quite late in the probe, after a bunch of resources have been claimed. > > Note that the ioremaps above this are doing unwinds, and you'll end up > doing duplicate ioremaps if you come in and probe again. > > You should probably unwind those allocations, or move them to devm_* > or do this check earlier in the function. > The actual chance of having that happen is quite small (this was coming from a non working DT) and I mainly wanted to avoid a crash so the platform could still boot. I would think moving to devm_ would be the right thing to do.
On Wed, Sep 26, 2018 at 4:28 AM Alexandre Belloni <alexandre.belloni@bootlin.com> wrote: > > On 25/09/2018 21:45:56+0200, Olof Johansson wrote: > > Hi, > > > > > > On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni > > <alexandre.belloni@bootlin.com> wrote: > > > > > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > > > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > > > unmapped page. > > > > > > This leads to a crash when probing qman_portal as the init_pcfg function > > > calls qman_liodn_fixup that tries to read qman registers. > > > > > > Assume that qman didn't probe when the pool mask is 0. > > > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > > --- > > > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > > > index a120002b630e..4fc80d2c8feb 100644 > > > --- a/drivers/soc/fsl/qbman/qman_portal.c > > > +++ b/drivers/soc/fsl/qbman/qman_portal.c > > > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > > > } > > > > > > pcfg->pools = qm_get_pools_sdqcr(); > > > + if (pcfg->pools == 0) > > > + return -EPROBE_DEFER; > > > > This is quite late in the probe, after a bunch of resources have been claimed. > > > > Note that the ioremaps above this are doing unwinds, and you'll end up > > doing duplicate ioremaps if you come in and probe again. > > > > You should probably unwind those allocations, or move them to devm_* > > or do this check earlier in the function. > > > > The actual chance of having that happen is quite small (this was coming > from a non working DT) and I mainly wanted to avoid a crash so the > platform could still boot. I would think moving to devm_ would be the > right thing to do. Even if it is not failing with the upstreamed device trees, it is still good to harden the driver for possible issues. Moving to devm_ is definitely a right thing to do. But I also think checking if the qman is already probed should be the first thing to do before starting to allocate resources and etc and rolling back later. Probably we can move the qm_get_pools_sdqcr() to the begining of the probe to determine if qman is probed as it doesn't seem to depend on any of the setups done right now. Regards, Leo
On Wed, Sep 26, 2018 at 1:15 PM Li Yang <leoyang.li@nxp.com> wrote: > > On Wed, Sep 26, 2018 at 4:28 AM Alexandre Belloni > <alexandre.belloni@bootlin.com> wrote: > > > > On 25/09/2018 21:45:56+0200, Olof Johansson wrote: > > > Hi, > > > > > > > > > On Thu, Aug 23, 2018 at 11:36 PM Alexandre Belloni > > > <alexandre.belloni@bootlin.com> wrote: > > > > > > > > If the qman driver (qman_ccsr) doesn't probe or fail to probe before > > > > qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an > > > > unmapped page. > > > > > > > > This leads to a crash when probing qman_portal as the init_pcfg function > > > > calls qman_liodn_fixup that tries to read qman registers. > > > > > > > > Assume that qman didn't probe when the pool mask is 0. > > > > > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > > > --- > > > > drivers/soc/fsl/qbman/qman_portal.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c > > > > index a120002b630e..4fc80d2c8feb 100644 > > > > --- a/drivers/soc/fsl/qbman/qman_portal.c > > > > +++ b/drivers/soc/fsl/qbman/qman_portal.c > > > > @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) > > > > } > > > > > > > > pcfg->pools = qm_get_pools_sdqcr(); > > > > + if (pcfg->pools == 0) > > > > + return -EPROBE_DEFER; > > > > > > This is quite late in the probe, after a bunch of resources have been claimed. > > > > > > Note that the ioremaps above this are doing unwinds, and you'll end up > > > doing duplicate ioremaps if you come in and probe again. > > > > > > You should probably unwind those allocations, or move them to devm_* > > > or do this check earlier in the function. > > > > > > > The actual chance of having that happen is quite small (this was coming > > from a non working DT) and I mainly wanted to avoid a crash so the > > platform could still boot. I would think moving to devm_ would be the > > right thing to do. > > Even if it is not failing with the upstreamed device trees, it is > still good to harden the driver for possible issues. Moving to devm_ > is definitely a right thing to do. But I also think checking if the > qman is already probed should be the first thing to do before starting > to allocate resources and etc and rolling back later. Probably we can > move the qm_get_pools_sdqcr() to the begining of the probe to > determine if qman is probed as it doesn't seem to depend on any of the > setups done right now. I just find out Laurentiu also included the following patches in his SMMU patch series (although not neccessarily related to SMMU) which also fix the same problem. I think they are more straightforward and can deal with the case that qman failed to probe. So we can take these to fix this problem instead in 4.19. https://patchwork.kernel.org/patch/10616021/ https://patchwork.kernel.org/patch/10616019/ https://patchwork.kernel.org/patch/10615971/ Regards, Leo
diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c index a120002b630e..4fc80d2c8feb 100644 --- a/drivers/soc/fsl/qbman/qman_portal.c +++ b/drivers/soc/fsl/qbman/qman_portal.c @@ -277,6 +277,8 @@ static int qman_portal_probe(struct platform_device *pdev) } pcfg->pools = qm_get_pools_sdqcr(); + if (pcfg->pools == 0) + return -EPROBE_DEFER; spin_lock(&qman_lock); cpu = cpumask_next_zero(-1, &portal_cpus);
If the qman driver (qman_ccsr) doesn't probe or fail to probe before qman_portal, qm_ccsr_start will be either NULL or a stale pointer to an unmapped page. This leads to a crash when probing qman_portal as the init_pcfg function calls qman_liodn_fixup that tries to read qman registers. Assume that qman didn't probe when the pool mask is 0. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- drivers/soc/fsl/qbman/qman_portal.c | 2 ++ 1 file changed, 2 insertions(+)