On Wed, 2015-08-05 at 17:18 +0200, Joerg Roedel wrote:
> From: Joerg Roedel <[email protected]>
>
> Instead of searching in the domain array for already
> allocated domain ids, keep track of them explicitly.
>
> Signed-off-by: Joerg Roedel <[email protected]>
> ---
> drivers/iommu/intel-iommu.c | 51
> +++++++++++++++++++++++----------------------
> 1 file changed, 26 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 0649b94..c3c5167 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -378,6 +378,9 @@ struct dmar_domain {
> DECLARE_BITMAP(iommu_bmp, DMAR_UNITS_SUPPORTED);
> /* bitmap of iommus this domain uses*/
>
> + u16 iommu_did[DMAR_UNITS_SUPPORTED];
> + /* Domain ids per IOMMU */
Maybe a spec reference here to justify u16 that the 2.3 vt-d spec only
supports up to 16bit domain IDs.
> +
> struct list_head devices; /* all devices' list */
> struct iova_domain iovad; /* iova's that belong to this domain */
>
> @@ -1543,11 +1546,13 @@ static int iommu_init_domains(struct intel_iommu
> *iommu)
> }
>
> /*
> - * if Caching mode is set, then invalid translations are tagged
> - * with domainid 0. Hence we need to pre-allocate it.
> + * If Caching mode is set, then invalid translations are tagged
> + * with domain-id 0, hence we need to pre-allocate it. We also
> + * use domain-id 0 as a marker for non-allocated domain-id, so
> + * make sure it is not used for a real domain.
> */
> - if (cap_caching_mode(iommu->cap))
> - set_bit(0, iommu->domain_ids);
> + set_bit(0, iommu->domain_ids);
> +
> return 0;
> }
>
> @@ -1560,9 +1565,10 @@ static void disable_dmar_iommu(struct intel_iommu
> *iommu)
> for_each_set_bit(i, iommu->domain_ids, cap_ndoms(iommu->cap)) {
> /*
> * Domain id 0 is reserved for invalid translation
> - * if hardware supports caching mode.
> + * if hardware supports caching mode and used as
> + * a non-allocated marker.
> */
> - if (cap_caching_mode(iommu->cap) && i == 0)
> + if (i == 0)
> continue;
>
> domain = iommu->domains[i];
> @@ -1624,6 +1630,7 @@ static int __iommu_attach_domain(struct dmar_domain
> *domain,
> if (num < ndomains) {
> set_bit(num, iommu->domain_ids);
> iommu->domains[num] = domain;
> + domain->iommu_did[iommu->seq_id] = num;
> } else {
> num = -ENOSPC;
> }
> @@ -1650,12 +1657,10 @@ static int iommu_attach_vm_domain(struct dmar_domain
> *domain,
> struct intel_iommu *iommu)
> {
> int num;
> - unsigned long ndomains;
>
> - ndomains = cap_ndoms(iommu->cap);
> - for_each_set_bit(num, iommu->domain_ids, ndomains)
> - if (iommu->domains[num] == domain)
> - return num;
> + num = domain->iommu_did[iommu->seq_id];
> + if (num)
> + return num;
>
> return __iommu_attach_domain(domain, iommu);
> }
> @@ -1664,22 +1669,17 @@ static void iommu_detach_domain(struct dmar_domain
> *domain,
> struct intel_iommu *iommu)
> {
> unsigned long flags;
> - int num, ndomains;
> + int num;
>
> spin_lock_irqsave(&iommu->lock, flags);
> - if (domain_type_is_vm_or_si(domain)) {
> - ndomains = cap_ndoms(iommu->cap);
> - for_each_set_bit(num, iommu->domain_ids, ndomains) {
> - if (iommu->domains[num] == domain) {
> - clear_bit(num, iommu->domain_ids);
> - iommu->domains[num] = NULL;
> - break;
> - }
> - }
> - } else {
> - clear_bit(domain->id, iommu->domain_ids);
> - iommu->domains[domain->id] = NULL;
> - }
> +
> + num = domain->iommu_did[iommu->seq_id];
> +
> + WARN_ON(num == 0);
Return -ENODEV and let the caller decide if that's an error? Then we
could safely call this over all all iommus.
> +
> + clear_bit(num, iommu->domain_ids);
> + iommu->domains[num] = NULL;
> +
> spin_unlock_irqrestore(&iommu->lock, flags);
> }
>
> @@ -1708,6 +1708,7 @@ static int domain_detach_iommu(struct dmar_domain
> *domain,
> if (test_and_clear_bit(iommu->seq_id, domain->iommu_bmp)) {
> count = --domain->iommu_count;
> domain_update_iommu_cap(domain);
> + domain->iommu_did[iommu->seq_id] = 0;
> }
> spin_unlock_irqrestore(&domain->iommu_lock, flags);
>
--
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