[PATCH v5 5/7] iommu/exynos: Rework and fix internal locking
From: Marek Szyprowski <hidden>
Date: 2016-10-20 07:23:51
Also in:
linux-iommu, linux-samsung-soc, lkml
Subsystem:
exynos sysmmu (iommu) driver, iommu subsystem, the rest · Maintainers:
Marek Szyprowski, Joerg Roedel, Will Deacon, Linus Torvalds
This patch reworks locking in the exynos_iommu_attach/detach_device functions to ensure that all entries of the sysmmu_drvdata and exynos_iommu_owner structure are updated under the respective spinlocks, while runtime pm functions are called without any spinlocks held. Signed-off-by: Marek Szyprowski <redacted> --- drivers/iommu/exynos-iommu.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 28e570b53672..a959443e6f33 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c@@ -731,10 +731,12 @@ static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain) spin_lock_irqsave(&domain->lock, flags); list_for_each_entry_safe(data, next, &domain->clients, domain_node) { + spin_lock(&data->lock); __sysmmu_disable(data); data->pgtable = 0; data->domain = NULL; list_del_init(&data->domain_node); + spin_unlock(&data->lock); } spin_unlock_irqrestore(&domain->lock, flags);
@@ -772,17 +774,22 @@ static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain, if (!has_sysmmu(dev) || owner->domain != iommu_domain) return; + list_for_each_entry(data, &owner->controllers, owner_node) { + __sysmmu_disable(data); + pm_runtime_put(data->sysmmu); + } + spin_lock_irqsave(&domain->lock, flags); list_for_each_entry_safe(data, next, &domain->clients, domain_node) { - __sysmmu_disable(data); + spin_lock(&data->lock); data->pgtable = 0; data->domain = NULL; list_del_init(&data->domain_node); - pm_runtime_put(data->sysmmu); + spin_unlock(&data->lock); } + owner->domain = NULL; spin_unlock_irqrestore(&domain->lock, flags); - owner->domain = NULL; dev_dbg(dev, "%s: Detached IOMMU with pgtable %pa\n", __func__, &pagetable);
@@ -803,18 +810,22 @@ static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain, if (owner->domain) exynos_iommu_detach_device(owner->domain, dev); + spin_lock_irqsave(&domain->lock, flags); list_for_each_entry(data, &owner->controllers, owner_node) { + spin_lock(&data->lock); data->pgtable = pagetable; data->domain = domain; + list_add_tail(&data->domain_node, &domain->clients); + spin_unlock(&data->lock); + } + owner->domain = iommu_domain; + spin_unlock_irqrestore(&domain->lock, flags); + + list_for_each_entry(data, &owner->controllers, owner_node) { pm_runtime_get_sync(data->sysmmu); __sysmmu_enable(data); - - spin_lock_irqsave(&domain->lock, flags); - list_add_tail(&data->domain_node, &domain->clients); - spin_unlock_irqrestore(&domain->lock, flags); } - owner->domain = iommu_domain; dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa\n", __func__, &pagetable);
--
1.9.1