Messages in this thread | | | Date | Wed, 3 May 2017 16:59:20 +0100 | From | Will Deacon <> | Subject | Re: [PATCH] iommu/arm-smmu-v3: Poll for CMDQ drain completion more effectively |
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On Wed, May 03, 2017 at 09:24:13PM +0530, Sunil Kovvuri wrote: > On Wed, May 3, 2017 at 9:07 PM, Will Deacon <will.deacon@arm.com> wrote: > > On Wed, May 03, 2017 at 06:49:09PM +0530, Sunil Kovvuri wrote: > >> On Thu, Apr 27, 2017 at 4:43 PM, <sunil.kovvuri@gmail.com> wrote: > >> > From: Sunil Goutham <sgoutham@cavium.com> > >> > > >> > Modified polling on CMDQ consumer similar to how polling is done for TLB SYNC > >> > completion in SMMUv2 driver. Code changes are done with reference to > >> > > >> > 8513c8930069 iommu/arm-smmu: Poll for TLB sync completion more effectively > >> > > >> > Poll timeout has been increased which addresses issue of 100us timeout not > >> > sufficient, when command queue is full with TLB invalidation commands. > >> > > >> > Signed-off-by: Sunil Goutham <sgoutham@cavium.com> > >> > Signed-off-by: Geetha <gakula@cavium.com> > >> > --- > >> > drivers/iommu/arm-smmu-v3.c | 15 ++++++++++++--- > >> > 1 file changed, 12 insertions(+), 3 deletions(-) > >> > > >> > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > >> > index d412bdd..34599d4 100644 > >> > --- a/drivers/iommu/arm-smmu-v3.c > >> > +++ b/drivers/iommu/arm-smmu-v3.c > >> > @@ -379,6 +379,9 @@ > >> > #define CMDQ_SYNC_0_CS_NONE (0UL << CMDQ_SYNC_0_CS_SHIFT) > >> > #define CMDQ_SYNC_0_CS_SEV (2UL << CMDQ_SYNC_0_CS_SHIFT) > >> > > >> > +#define CMDQ_DRAIN_TIMEOUT_US 1000 > >> > +#define CMDQ_SPIN_COUNT 10 > >> > + > >> > /* Event queue */ > >> > #define EVTQ_ENT_DWORDS 4 > >> > #define EVTQ_MAX_SZ_SHIFT 7 > >> > @@ -737,7 +740,8 @@ static void queue_inc_prod(struct arm_smmu_queue *q) > >> > */ > >> > static int queue_poll_cons(struct arm_smmu_queue *q, bool drain, bool wfe) > >> > { > >> > - ktime_t timeout = ktime_add_us(ktime_get(), ARM_SMMU_POLL_TIMEOUT_US); > >> > + ktime_t timeout = ktime_add_us(ktime_get(), CMDQ_DRAIN_TIMEOUT_US); > >> > + unsigned int spin_cnt, delay = 1; > >> > > >> > while (queue_sync_cons(q), (drain ? !queue_empty(q) : queue_full(q))) { > >> > if (ktime_compare(ktime_get(), timeout) > 0) > >> > @@ -746,8 +750,13 @@ static int queue_poll_cons(struct arm_smmu_queue *q, bool drain, bool wfe) > >> > if (wfe) { > >> > wfe(); > >> > } else { > >> > - cpu_relax(); > >> > - udelay(1); > >> > + for (spin_cnt = 0; > >> > + spin_cnt < CMDQ_SPIN_COUNT; spin_cnt++) { > >> > + cpu_relax(); > >> > + continue; > >> > + } > >> > + udelay(delay); > >> > + delay *= 2; > >> > } > >> > } > >> > > >> > -- > >> > 2.7.4 > >> > > >> > >> Sorry for the ignorance. > >> Is there a patchwork where I can check current status of ARM IOMMU > >> related patches ? > >> > >> And is this patch accepted, if not any comments / feedback ? > > > > Please be patient: the merge window is open and it's not been long since you > > posted the patch, which looks pretty bonkers at first glance. > > > > Will > > Look at this > https://lkml.org/lkml/2017/4/3/605 > The same thing, i pinged after a week and you said you already picked it up. > All I am asking is how do i know the current status, how many days > would normally > be considered being patient ?
At least wait until the merge window is over if it's not a fix, or keep an eye on the relevant branches (see below).
> Instead of troubling you, is there a patchwork where i can check the status ?
No, but I pick patches up on my iommu/devel branch here:
https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/
and at some point they appear on for-joerg/arm-smmu/updates, which I send to Joerg (who is the iommu maintainer). He then puts them into linux-next before they get sent for inclusion in mainline during the next merge window.
Will
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