Messages in this thread | | | From | Sunil Kovvuri <> | Date | Wed, 3 May 2017 21:54:21 +0530 | Subject | Re: [PATCH] iommu/arm-smmu-v3: Poll for CMDQ drain completion more effectively |
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On Wed, May 3, 2017 at 9:29 PM, Will Deacon <will.deacon@arm.com> wrote: > 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
Thanks for the info.
Sunil.
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