4.4-stable review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven geert+renesas@glider.be
[ Upstream commit 46583e8c48c5a094ba28060615b3a7c8c576690f ]
When attaching a device to an IOMMU group with CONFIG_DEBUG_ATOMIC_SLEEP=y:
BUG: sleeping function called from invalid context at mm/slab.h:421 in_atomic(): 1, irqs_disabled(): 128, pid: 61, name: kworker/1:1 ... Call trace: ... arm_lpae_alloc_pgtable+0x114/0x184 arm_64_lpae_alloc_pgtable_s1+0x2c/0x128 arm_32_lpae_alloc_pgtable_s1+0x40/0x6c alloc_io_pgtable_ops+0x60/0x88 ipmmu_attach_device+0x140/0x334
ipmmu_attach_device() takes a spinlock, while arm_lpae_alloc_pgtable() allocates memory using GFP_KERNEL. Originally, the ipmmu-vmsa driver had its own custom page table allocation implementation using GFP_ATOMIC, hence the spinlock was fine.
Fix this by replacing the spinlock by a mutex, like the arm-smmu driver does.
Fixes: f20ed39f53145e45 ("iommu/ipmmu-vmsa: Use the ARM LPAE page table allocator") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/ipmmu-vmsa.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
--- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -44,7 +44,7 @@ struct ipmmu_vmsa_domain { struct io_pgtable_ops *iop;
unsigned int context_id; - spinlock_t lock; /* Protects mappings */ + struct mutex mutex; /* Protects mappings */ };
struct ipmmu_vmsa_archdata { @@ -464,7 +464,7 @@ static struct iommu_domain *ipmmu_domain if (!domain) return NULL;
- spin_lock_init(&domain->lock); + mutex_init(&domain->mutex);
return &domain->io_domain; } @@ -488,7 +488,6 @@ static int ipmmu_attach_device(struct io struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu; struct ipmmu_vmsa_device *mmu = archdata->mmu; struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain); - unsigned long flags; unsigned int i; int ret = 0;
@@ -497,7 +496,7 @@ static int ipmmu_attach_device(struct io return -ENXIO; }
- spin_lock_irqsave(&domain->lock, flags); + mutex_lock(&domain->mutex);
if (!domain->mmu) { /* The domain hasn't been used yet, initialize it. */ @@ -513,7 +512,7 @@ static int ipmmu_attach_device(struct io ret = -EINVAL; }
- spin_unlock_irqrestore(&domain->lock, flags); + mutex_unlock(&domain->mutex);
if (ret < 0) return ret;