@@ -391,7 +391,7 @@ struct arm_smmu_domain {
struct arm_smmu_cfg root_cfg;
phys_addr_t output_mask;
- struct mutex lock;
+ spinlock_t lock;
};
static DEFINE_SPINLOCK(arm_smmu_devices_lock);
@@ -884,7 +884,7 @@ static int arm_smmu_domain_init(struct iommu_domain *domain)
goto out_free_domain;
smmu_domain->root_cfg.pgd = pgd;
- mutex_init(&smmu_domain->lock);
+ spin_lock_init(&smmu_domain->lock);
domain->priv = smmu_domain;
return 0;
@@ -1116,7 +1116,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
* Sanity check the domain. We don't currently support domains
* that cross between different SMMU chains.
*/
- mutex_lock(&smmu_domain->lock);
+ spin_lock(&smmu_domain->lock);
if (!smmu_domain->leaf_smmu) {
/* Now that we have a master, we can finalise the domain */
ret = arm_smmu_init_domain_context(domain, dev);
@@ -1131,7 +1131,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
dev_name(device_smmu->dev));
goto err_unlock;
}
- mutex_unlock(&smmu_domain->lock);
+ spin_unlock(&smmu_domain->lock);
/* Looks ok, so add the device to the domain */
master = find_smmu_master(smmu_domain->leaf_smmu, dev->of_node);
@@ -1141,7 +1141,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
return arm_smmu_domain_add_master(smmu_domain, master);
err_unlock:
- mutex_unlock(&smmu_domain->lock);
+ spin_unlock(&smmu_domain->lock);
return ret;
}
@@ -1188,7 +1188,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
if (pmd_none(*pmd)) {
/* Allocate a new set of tables */
- pgtable_t table = alloc_page(PGALLOC_GFP);
+ pgtable_t table = alloc_page(GFP_ATOMIC|__GFP_ZERO);
if (!table)
return -ENOMEM;
@@ -1290,7 +1290,7 @@ static int arm_smmu_alloc_init_pmd(struct arm_smmu_device *smmu, pud_t *pud,
#ifndef __PAGETABLE_PMD_FOLDED
if (pud_none(*pud)) {
- pmd = pmd_alloc_one(NULL, addr);
+ pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);
if (!pmd)
return -ENOMEM;
@@ -1322,7 +1322,7 @@ static int arm_smmu_alloc_init_pud(struct arm_smmu_device *smmu, pgd_t *pgd,
#ifndef __PAGETABLE_PUD_FOLDED
if (pgd_none(*pgd)) {
- pud = pud_alloc_one(NULL, addr);
+ pud = (pud_t *)get_zeroed_page(GFP_ATOMIC);
if (!pud)
return -ENOMEM;
@@ -1376,7 +1376,7 @@ static int arm_smmu_handle_mapping(struct arm_smmu_domain *smmu_domain,
if (paddr & ~output_mask)
return -ERANGE;
- mutex_lock(&smmu_domain->lock);
+ spin_lock(&smmu_domain->lock);
pgd += pgd_index(iova);
end = iova + size;
do {
@@ -1392,7 +1392,7 @@ static int arm_smmu_handle_mapping(struct arm_smmu_domain *smmu_domain,
} while (pgd++, iova != end);
out_unlock:
- mutex_unlock(&smmu_domain->lock);
+ spin_unlock(&smmu_domain->lock);
/* Ensure new page tables are visible to the hardware walker */
if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
This is a note to let you know that I have just added a patch titled iommu/arm-smmu: really fix page table locking to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 78112054034b05b0aa75584ebc93873d45781114 Mon Sep 17 00:00:00 2001 From: Will Deacon <will.deacon@arm.com> Date: Tue, 4 Feb 2014 22:12:42 +0000 Subject: iommu/arm-smmu: really fix page table locking commit c9d09e2748eaa55cac2af274574baa6368189bc1 upstream. Commit a44a9791e778 ("iommu/arm-smmu: use mutex instead of spinlock for locking page tables") replaced the page table spinlock with a mutex, to allow blocking allocations to satisfy lazy mapping requests. Unfortunately, it turns out that IOMMU mappings are created from atomic context (e.g. spinlock held during a dma_map), so this change doesn't really help us in practice. This patch is a partial revert of the offending commit, bringing back the original spinlock but replacing our page table allocations for any levels below the pgd (which is allocated during domain init) with GFP_ATOMIC instead of GFP_KERNEL. Reported-by: Andreas Herrmann <andreas.herrmann@calxeda.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/iommu/arm-smmu.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) -- 1.9.0