| Message ID | 3b26ce04e8ecb5e47f028fe5cae48e5235e68420.1736550979.git.nicolinc@nvidia.com |
|---|---|
| State | New |
| Headers | show |
| Series | iommu: Add MSI mapping support with nested SMMU | expand |
On Thu, Jan 23, 2025 at 09:54:38AM +0000, Tian, Kevin wrote: > > From: Nicolin Chen <nicolinc@nvidia.com> > > Sent: Saturday, January 11, 2025 11:32 AM > > > > @@ -224,8 +224,10 @@ struct iommu_domain { > > phys_addr_t msi_addr); > > #endif > > > > - void *fault_data; > > - union { > > + union { /* Pointer usable by owner of the domain */ > > + struct iommufd_hw_pagetable *iommufd_hwpt; /* iommufd > > */ > > + }; > > + union { /* Fault handler */ > > hmm is it better to rename it as "void *private;" and let the caller > do type conversion? I like the type safety, the union can hold other in-kernel users with their proper types and this discourages drivers from inventing weird things.. Jason
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 423fdfa6b3bb..b6526d734f30 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -224,8 +224,10 @@ struct iommu_domain { phys_addr_t msi_addr); #endif - void *fault_data; - union { + union { /* Pointer usable by owner of the domain */ + struct iommufd_hw_pagetable *iommufd_hwpt; /* iommufd */ + }; + union { /* Fault handler */ struct { iommu_fault_handler_t handler; void *handler_token; diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index 1fe804e28a86..06aa83a75e94 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -431,7 +431,7 @@ int iommufd_fault_iopf_handler(struct iopf_group *group) struct iommufd_hw_pagetable *hwpt; struct iommufd_fault *fault; - hwpt = group->attach_handle->domain->fault_data; + hwpt = group->attach_handle->domain->iommufd_hwpt; fault = hwpt->fault; mutex_lock(&fault->mutex); diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index ce03c3804651..f7c0d7b214b6 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -402,10 +402,10 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) } hwpt->fault = fault; hwpt->domain->iopf_handler = iommufd_fault_iopf_handler; - hwpt->domain->fault_data = hwpt; refcount_inc(&fault->obj.users); iommufd_put_object(ucmd->ictx, &fault->obj); } + hwpt->domain->iommufd_hwpt = hwpt; cmd->out_hwpt_id = hwpt->obj.id; rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
A "fault_data" was added exclusively for the iommufd_fault_iopf_handler() used by IOPF/PRI use cases, along with the attach_handle. Now, the iommufd version of sw_msi function will resue the attach_handle and fault_data for a non-fault case. Rename "fault_data" to "iommufd_hwpt" so as not to confine it to a "fault" case. Move it into a union to be the iommufd private pointer. A following patch will move the iova_cookie to the union for dma-iommu too, after the iommufd_sw_msi implementation is added. Since we have two unions now, add some simple comments for readability. Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> --- include/linux/iommu.h | 6 ++++-- drivers/iommu/iommufd/fault.c | 2 +- drivers/iommu/iommufd/hw_pagetable.c | 2 +- 3 files changed, 6 insertions(+), 4 deletions(-)