From: Tom Murphy <[email protected]>
---
This patch allows the IOMMU API path in the AMD driver to be called from an
atomic context.
This is useful for anyone building a driver which needs to call the IOMMU API
while holding a spinlock.
drivers/iommu/amd_iommu.c | 14 ++++++++------
drivers/iommu/amd_iommu_types.h | 2 +-
2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 0c910a8..642afc9 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2904,7 +2904,7 @@ static void protection_domain_free(struct
protection_domain *domain)
static int protection_domain_init(struct protection_domain *domain)
{
spin_lock_init(&domain->lock);
- mutex_init(&domain->api_lock);
+ spin_lock_init(&domain->api_lock);
domain->id = domain_id_alloc();
if (!domain->id)
return -ENOMEM;
@@ -3088,6 +3088,7 @@ static int amd_iommu_map(struct iommu_domain *dom,
unsigned long iova,
phys_addr_t paddr, size_t page_size, int iommu_prot)
{
struct protection_domain *domain = to_pdomain(dom);
+ unsigned long flags;
int prot = 0;
int ret;
@@ -3099,9 +3100,9 @@ static int amd_iommu_map(struct iommu_domain *dom,
unsigned long iova,
if (iommu_prot & IOMMU_WRITE)
prot |= IOMMU_PROT_IW;
- mutex_lock(&domain->api_lock);
- ret = iommu_map_page(domain, iova, paddr, page_size, prot, GFP_KERNEL);
- mutex_unlock(&domain->api_lock);
+ spin_lock_irqsave(&domain->api_lock, flags);
+ ret = iommu_map_page(domain, iova, paddr, page_size, prot, GFP_ATOMIC);
+ spin_unlock_irqrestore(&domain->api_lock, flags);
return ret;
}
@@ -3110,14 +3111,15 @@ static size_t amd_iommu_unmap(struct iommu_domain *dom,
unsigned long iova,
size_t page_size)
{
struct protection_domain *domain = to_pdomain(dom);
+ unsigned long flags;
size_t unmap_size;
if (domain->mode == PAGE_MODE_NONE)
return -EINVAL;
- mutex_lock(&domain->api_lock);
+ spin_lock_irqsave(&domain->api_lock, flags);
unmap_size = iommu_unmap_page(domain, iova, page_size);
- mutex_unlock(&domain->api_lock);
+ spin_unlock_irqrestore(&domain->api_lock, flags);
domain_flush_tlb_pde(domain);
domain_flush_complete(domain);
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 0d91785..a9077a5 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -444,7 +444,7 @@ struct protection_domain {
struct iommu_domain domain; /* generic domain handle used by
iommu core code */
spinlock_t lock; /* mostly used to lock the page table*/
- struct mutex api_lock; /* protect page tables in the iommu-api path */
+ spinlock_t api_lock; /* protect page tables in the iommu-api path */
u16 id; /* the domain id written to the device table */
int mode; /* paging mode (0-6 levels) */
u64 *pt_root; /* page table root pointer */
--
2.7.4
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