From: tchalamarla@caviumnetworks•com (Tirumalesh Chalamarla)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V4] iommu/arm-smmu-v2: Workaround for ThunderX errata#27704
Date: Fri, 4 Mar 2016 10:09:02 -0800 [thread overview]
Message-ID: <56D9CF3E.7080607@caviumnetworks.com> (raw)
In-Reply-To: <20160304160221.GC7886@arm.com>
On 03/04/2016 08:02 AM, Will Deacon wrote:
> On Thu, Mar 03, 2016 at 07:44:03PM -0800, Tirumalesh Chalamarla wrote:
>> Due to Errata#27704 CN88xx SMMUv2,supports only shared ASID and VMID
>> namespaces; specifically within a given node SMMU0 and SMMU1 share,
>> as does SMMU2 and SMMU3.
>>
>> This patch make sures ASID and VMID space is unique across cavium SMMUv2.
>>
>> changes from V3:
>> - Removed redundent variable.
>
> [...]
>
>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
>> index 247a469..bfe38f3 100644
>> --- a/drivers/iommu/arm-smmu.c
>> +++ b/drivers/iommu/arm-smmu.c
>> @@ -326,6 +326,11 @@ struct arm_smmu_device {
>>
>> struct list_head list;
>> struct rb_root masters;
>> + /*
>> + *The following fields are specific to Cavium, Thunder
>> + */
>> + u32 cavium_id_base;
>> +
>> };
>>
>> struct arm_smmu_cfg {
>> @@ -335,8 +340,8 @@ struct arm_smmu_cfg {
>> };
>> #define INVALID_IRPTNDX 0xff
>>
>> -#define ARM_SMMU_CB_ASID(cfg) ((cfg)->cbndx)
>> -#define ARM_SMMU_CB_VMID(cfg) ((cfg)->cbndx + 1)
>> +#define ARM_SMMU_CB_ASID(smmu, cfg) ((u16)(smmu)->cavium_id_base + (cfg)->cbndx)
>> +#define ARM_SMMU_CB_VMID(smmu, cfg) ((u16)(smmu)->cavium_id_base + (cfg)->cbndx + 1)
>>
>> enum arm_smmu_domain_stage {
>> ARM_SMMU_DOMAIN_S1 = 0,
>> @@ -364,6 +369,8 @@ struct arm_smmu_option_prop {
>> const char *prop;
>> };
>>
>> +static u32 cavium_smmu_context_count;
>
> I thought you were going to make this an atomic_t?
well i moved variable handling inside atomic context.
with atomic_t i still needed 2 operations like read and add
it seems atomic_add_return is not sufficient.
in any case i thought why not use the atomic context that is already
there. if you feel the use of atomic_t is more natural, i will resend
again.
Thanks,
Tirumalesh.
>
> Will
>
next prev parent reply other threads:[~2016-03-04 18:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-04 3:44 [PATCH V4] iommu/arm-smmu-v2: Workaround for ThunderX errata#27704 Tirumalesh Chalamarla
2016-03-04 16:02 ` Will Deacon
2016-03-04 18:09 ` Tirumalesh Chalamarla [this message]
2016-03-04 18:16 ` Tirumalesh Chalamarla
-- strict thread matches above, loose matches on Subject: below --
2016-03-04 18:39 Tirumalesh Chalamarla
2016-03-04 20:59 ` Will Deacon
2016-03-04 21:35 ` Tirumalesh Chalamarla
2016-03-04 21:56 Tirumalesh Chalamarla
2016-03-24 17:36 ` Chalamarla, Tirumalesh
2016-03-24 17:51 ` Will Deacon
2016-03-24 18:29 ` Chalamarla, Tirumalesh
2016-03-28 18:57 ` Radha Mohan
2016-03-28 19:25 ` Radha Mohan
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