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authorLinus Torvalds2022-03-21 12:28:13 -0700
committerLinus Torvalds2022-03-21 12:28:13 -0700
commit3fd33273a4675e819544ccbbf8d769e14672666b (patch)
treede1dc2f55a4d6f6445ac622eb67ed89103574403 /drivers/iommu
parenteaa54b1458ca84092e513d554dd6d234245e6bef (diff)
parent83aa52ffed5d35a08e24452d0471e1684075cdf8 (diff)
Merge tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PASID support from Thomas Gleixner: "Reenable ENQCMD/PASID support: - Simplify the PASID handling to allocate the PASID once, associate it to the mm of a process and free it on mm_exit(). The previous attempt of refcounted PASIDs and dynamic alloc()/free() turned out to be error prone and too complex. The PASID space is 20bits, so the case of resource exhaustion is a pure academic concern. - Populate the PASID MSR on demand via #GP to avoid racy updates via IPIs. - Reenable ENQCMD and let objtool check for the forbidden usage of ENQCMD in the kernel. - Update the documentation for Shared Virtual Addressing accordingly" * tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation/x86: Update documentation for SVA (Shared Virtual Addressing) tools/objtool: Check for use of the ENQCMD instruction in the kernel x86/cpufeatures: Re-enable ENQCMD x86/traps: Demand-populate PASID MSR via #GP sched: Define and initialize a flag to identify valid PASID in the task x86/fpu: Clear PASID when copying fpstate iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit kernel/fork: Initialize mm's PASID iommu/ioasid: Introduce a helper to check for valid PASIDs mm: Change CONFIG option for mm->pasid field iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/Kconfig6
-rw-r--r--drivers/iommu/Makefile2
-rw-r--r--drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c5
-rw-r--r--drivers/iommu/intel/Kconfig2
-rw-r--r--drivers/iommu/intel/iommu.c4
-rw-r--r--drivers/iommu/intel/svm.c9
-rw-r--r--drivers/iommu/ioasid.c39
-rw-r--r--drivers/iommu/iommu-sva-lib.c39
-rw-r--r--drivers/iommu/iommu-sva-lib.h7
9 files changed, 27 insertions, 86 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 3eb68fa1b8cc..c79a0df090c0 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -144,8 +144,8 @@ config IOMMU_DMA
select IRQ_MSI_IOMMU
select NEED_SG_DMA_LENGTH
-# Shared Virtual Addressing library
-config IOMMU_SVA_LIB
+# Shared Virtual Addressing
+config IOMMU_SVA
bool
select IOASID
@@ -379,7 +379,7 @@ config ARM_SMMU_V3
config ARM_SMMU_V3_SVA
bool "Shared Virtual Addressing support for the ARM SMMUv3"
depends on ARM_SMMU_V3
- select IOMMU_SVA_LIB
+ select IOMMU_SVA
select MMU_NOTIFIER
help
Support for sharing process address spaces with devices using the
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index bc7f730edbb0..44475a9b3eea 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -27,6 +27,6 @@ obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
-obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o io-pgfault.o
+obj-$(CONFIG_IOMMU_SVA) += iommu-sva-lib.o io-pgfault.o
obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
obj-$(CONFIG_APPLE_DART) += apple-dart.o
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index a737ba5f727e..22ddd05bbdcd 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -340,14 +340,12 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
bond->smmu_mn = arm_smmu_mmu_notifier_get(smmu_domain, mm);
if (IS_ERR(bond->smmu_mn)) {
ret = PTR_ERR(bond->smmu_mn);
- goto err_free_pasid;
+ goto err_free_bond;
}
list_add(&bond->list, &master->bonds);
return &bond->sva;
-err_free_pasid:
- iommu_sva_free_pasid(mm);
err_free_bond:
kfree(bond);
return ERR_PTR(ret);
@@ -377,7 +375,6 @@ void arm_smmu_sva_unbind(struct iommu_sva *handle)
if (refcount_dec_and_test(&bond->refs)) {
list_del(&bond->list);
arm_smmu_mmu_notifier_put(bond->smmu_mn);
- iommu_sva_free_pasid(bond->mm);
kfree(bond);
}
mutex_unlock(&sva_lock);
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 247d0f2d5fdf..39a06d245f12 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -52,7 +52,7 @@ config INTEL_IOMMU_SVM
select PCI_PRI
select MMU_NOTIFIER
select IOASID
- select IOMMU_SVA_LIB
+ select IOMMU_SVA
help
Shared Virtual Memory (SVM) provides a facility for devices
to access DMA resources through process address space by
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 5b196cfe9ed2..1ce1741a7fa4 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4781,7 +4781,7 @@ attach_failed:
link_failed:
spin_unlock_irqrestore(&device_domain_lock, flags);
if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
- ioasid_put(domain->default_pasid);
+ ioasid_free(domain->default_pasid);
return ret;
}
@@ -4811,7 +4811,7 @@ static void aux_domain_remove_dev(struct dmar_domain *domain,
spin_unlock_irqrestore(&device_domain_lock, flags);
if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
- ioasid_put(domain->default_pasid);
+ ioasid_free(domain->default_pasid);
}
static int prepare_domain_attach_device(struct iommu_domain *domain,
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 5b5d69b04fcc..51ac2096b3da 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -514,11 +514,6 @@ static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm,
return iommu_sva_alloc_pasid(mm, PASID_MIN, max_pasid - 1);
}
-static void intel_svm_free_pasid(struct mm_struct *mm)
-{
- iommu_sva_free_pasid(mm);
-}
-
static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
struct device *dev,
struct mm_struct *mm,
@@ -662,8 +657,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
kfree(svm);
}
}
- /* Drop a PASID reference and free it if no reference. */
- intel_svm_free_pasid(mm);
}
out:
return ret;
@@ -1047,8 +1040,6 @@ struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void
}
sva = intel_svm_bind_mm(iommu, dev, mm, flags);
- if (IS_ERR_OR_NULL(sva))
- intel_svm_free_pasid(mm);
mutex_unlock(&pasid_mutex);
return sva;
diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index 06fee7416816..a786c034907c 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c
@@ -2,7 +2,7 @@
/*
* I/O Address Space ID allocator. There is one global IOASID space, split into
* subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
- * free IOASIDs with ioasid_alloc and ioasid_put.
+ * free IOASIDs with ioasid_alloc() and ioasid_free().
*/
#include <linux/ioasid.h>
#include <linux/module.h>
@@ -15,7 +15,6 @@ struct ioasid_data {
struct ioasid_set *set;
void *private;
struct rcu_head rcu;
- refcount_t refs;
};
/*
@@ -315,7 +314,6 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
data->set = set;
data->private = private;
- refcount_set(&data->refs, 1);
/*
* Custom allocator needs allocator data to perform platform specific
@@ -348,35 +346,11 @@ exit_free:
EXPORT_SYMBOL_GPL(ioasid_alloc);
/**
- * ioasid_get - obtain a reference to the IOASID
- * @ioasid: the ID to get
- */
-void ioasid_get(ioasid_t ioasid)
-{
- struct ioasid_data *ioasid_data;
-
- spin_lock(&ioasid_allocator_lock);
- ioasid_data = xa_load(&active_allocator->xa, ioasid);
- if (ioasid_data)
- refcount_inc(&ioasid_data->refs);
- else
- WARN_ON(1);
- spin_unlock(&ioasid_allocator_lock);
-}
-EXPORT_SYMBOL_GPL(ioasid_get);
-
-/**
- * ioasid_put - Release a reference to an ioasid
+ * ioasid_free - Free an ioasid
* @ioasid: the ID to remove
- *
- * Put a reference to the IOASID, free it when the number of references drops to
- * zero.
- *
- * Return: %true if the IOASID was freed, %false otherwise.
*/
-bool ioasid_put(ioasid_t ioasid)
+void ioasid_free(ioasid_t ioasid)
{
- bool free = false;
struct ioasid_data *ioasid_data;
spin_lock(&ioasid_allocator_lock);
@@ -386,10 +360,6 @@ bool ioasid_put(ioasid_t ioasid)
goto exit_unlock;
}
- free = refcount_dec_and_test(&ioasid_data->refs);
- if (!free)
- goto exit_unlock;
-
active_allocator->ops->free(ioasid, active_allocator->ops->pdata);
/* Custom allocator needs additional steps to free the xa element */
if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) {
@@ -399,9 +369,8 @@ bool ioasid_put(ioasid_t ioasid)
exit_unlock:
spin_unlock(&ioasid_allocator_lock);
- return free;
}
-EXPORT_SYMBOL_GPL(ioasid_put);
+EXPORT_SYMBOL_GPL(ioasid_free);
/**
* ioasid_find - Find IOASID data
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index bd41405d34e9..106506143896 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -18,8 +18,7 @@ static DECLARE_IOASID_SET(iommu_sva_pasid);
*
* Try to allocate a PASID for this mm, or take a reference to the existing one
* provided it fits within the [@min, @max] range. On success the PASID is
- * available in mm->pasid, and must be released with iommu_sva_free_pasid().
- * @min must be greater than 0, because 0 indicates an unused mm->pasid.
+ * available in mm->pasid and will be available for the lifetime of the mm.
*
* Returns 0 on success and < 0 on error.
*/
@@ -33,38 +32,24 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
return -EINVAL;
mutex_lock(&iommu_sva_lock);
- if (mm->pasid) {
- if (mm->pasid >= min && mm->pasid <= max)
- ioasid_get(mm->pasid);
- else
+ /* Is a PASID already associated with this mm? */
+ if (pasid_valid(mm->pasid)) {
+ if (mm->pasid < min || mm->pasid >= max)
ret = -EOVERFLOW;
- } else {
- pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
- if (pasid == INVALID_IOASID)
- ret = -ENOMEM;
- else
- mm->pasid = pasid;
+ goto out;
}
+
+ pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
+ if (!pasid_valid(pasid))
+ ret = -ENOMEM;
+ else
+ mm_pasid_set(mm, pasid);
+out:
mutex_unlock(&iommu_sva_lock);
return ret;
}
EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
-/**
- * iommu_sva_free_pasid - Release the mm's PASID
- * @mm: the mm
- *
- * Drop one reference to a PASID allocated with iommu_sva_alloc_pasid()
- */
-void iommu_sva_free_pasid(struct mm_struct *mm)
-{
- mutex_lock(&iommu_sva_lock);
- if (ioasid_put(mm->pasid))
- mm->pasid = 0;
- mutex_unlock(&iommu_sva_lock);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_free_pasid);
-
/* ioasid_find getter() requires a void * argument */
static bool __mmget_not_zero(void *mm)
{
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 031155010ca8..8909ea1094e3 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -9,7 +9,6 @@
#include <linux/mm_types.h>
int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
-void iommu_sva_free_pasid(struct mm_struct *mm);
struct mm_struct *iommu_sva_find(ioasid_t pasid);
/* I/O Page fault */
@@ -17,7 +16,7 @@ struct device;
struct iommu_fault;
struct iopf_queue;
-#ifdef CONFIG_IOMMU_SVA_LIB
+#ifdef CONFIG_IOMMU_SVA
int iommu_queue_iopf(struct iommu_fault *fault, void *cookie);
int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev);
@@ -28,7 +27,7 @@ struct iopf_queue *iopf_queue_alloc(const char *name);
void iopf_queue_free(struct iopf_queue *queue);
int iopf_queue_discard_partial(struct iopf_queue *queue);
-#else /* CONFIG_IOMMU_SVA_LIB */
+#else /* CONFIG_IOMMU_SVA */
static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
{
return -ENODEV;
@@ -64,5 +63,5 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
{
return -ENODEV;
}
-#endif /* CONFIG_IOMMU_SVA_LIB */
+#endif /* CONFIG_IOMMU_SVA */
#endif /* _IOMMU_SVA_LIB_H */