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authorJacob Pan <jacob.jun.pan@linux.intel.com>2023-08-09 20:47:55 +0800
committerJoerg Roedel <jroedel@suse.de>2023-08-09 17:44:36 +0200
commit2dcebc7ddce7ffd4015824227c7623558b89d721 (patch)
treeb5dc2480b3c4bda81aff2cd474e6db5c2fdac3d7 /drivers/iommu
parent4298780126c298f20ae4bc8676591eaf8c48767e (diff)
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iommu: Move global PASID allocation from SVA to core
Intel ENQCMD requires a single PASID to be shared between multiple devices, as the PASID is stored in a single MSR register per-process and userspace can use only that one PASID. This means that the PASID allocation for any ENQCMD using device driver must always come from a shared global pool, regardless of what kind of domain the PASID will be used with. Split the code for the global PASID allocator into iommu_alloc/free_global_pasid() so that drivers can attach non-SVA domains to PASIDs as well. This patch moves global PASID allocation APIs from SVA to IOMMU APIs. Reserved PASIDs, currently only RID_PASID, are excluded from the global PASID allocation. It is expected that device drivers will use the allocated PASIDs to attach to appropriate IOMMU domains for use. Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Link: https://lore.kernel.org/r/20230802212427.1497170-3-jacob.jun.pan@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iommu-sva.c29
-rw-r--r--drivers/iommu/iommu.c28
2 files changed, 38 insertions, 19 deletions
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 05c0fb2acbc4..b78671a8a914 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -10,34 +10,30 @@
#include "iommu-sva.h"
static DEFINE_MUTEX(iommu_sva_lock);
-static DEFINE_IDA(iommu_global_pasid_ida);
/* Allocate a PASID for the mm within range (inclusive) */
-static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
+static int iommu_sva_alloc_pasid(struct mm_struct *mm, struct device *dev)
{
+ ioasid_t pasid;
int ret = 0;
- if (min == IOMMU_PASID_INVALID ||
- max == IOMMU_PASID_INVALID ||
- min == 0 || max < min)
- return -EINVAL;
-
if (!arch_pgtable_dma_compat(mm))
return -EBUSY;
mutex_lock(&iommu_sva_lock);
/* Is a PASID already associated with this mm? */
if (mm_valid_pasid(mm)) {
- if (mm->pasid < min || mm->pasid > max)
+ if (mm->pasid >= dev->iommu->max_pasids)
ret = -EOVERFLOW;
goto out;
}
- ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
- if (ret < 0)
+ pasid = iommu_alloc_global_pasid(dev);
+ if (pasid == IOMMU_PASID_INVALID) {
+ ret = -ENOSPC;
goto out;
-
- mm->pasid = ret;
+ }
+ mm->pasid = pasid;
ret = 0;
out:
mutex_unlock(&iommu_sva_lock);
@@ -64,15 +60,10 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
{
struct iommu_domain *domain;
struct iommu_sva *handle;
- ioasid_t max_pasids;
int ret;
- max_pasids = dev->iommu->max_pasids;
- if (!max_pasids)
- return ERR_PTR(-EOPNOTSUPP);
-
/* Allocate mm->pasid if necessary. */
- ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1);
+ ret = iommu_sva_alloc_pasid(mm, dev);
if (ret)
return ERR_PTR(ret);
@@ -217,5 +208,5 @@ void mm_pasid_drop(struct mm_struct *mm)
if (likely(!mm_valid_pasid(mm)))
return;
- ida_free(&iommu_global_pasid_ida, mm->pasid);
+ iommu_free_global_pasid(mm->pasid);
}
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index caaf563d38ae..d199d144460c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -39,6 +39,7 @@
static struct kset *iommu_group_kset;
static DEFINE_IDA(iommu_group_ida);
+static DEFINE_IDA(iommu_global_pasid_ida);
static unsigned int iommu_def_domain_type __read_mostly;
static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT);
@@ -3400,3 +3401,30 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
return domain;
}
+
+ioasid_t iommu_alloc_global_pasid(struct device *dev)
+{
+ int ret;
+
+ /* max_pasids == 0 means that the device does not support PASID */
+ if (!dev->iommu->max_pasids)
+ return IOMMU_PASID_INVALID;
+
+ /*
+ * max_pasids is set up by vendor driver based on number of PASID bits
+ * supported but the IDA allocation is inclusive.
+ */
+ ret = ida_alloc_range(&iommu_global_pasid_ida, IOMMU_FIRST_GLOBAL_PASID,
+ dev->iommu->max_pasids - 1, GFP_KERNEL);
+ return ret < 0 ? IOMMU_PASID_INVALID : ret;
+}
+EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid);
+
+void iommu_free_global_pasid(ioasid_t pasid)
+{
+ if (WARN_ON(pasid == IOMMU_PASID_INVALID))
+ return;
+
+ ida_free(&iommu_global_pasid_ida, pasid);
+}
+EXPORT_SYMBOL_GPL(iommu_free_global_pasid);