@@ -21,6 +21,42 @@
#include <linux/limits.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
+#include <linux/device.h>
+
+static DEFINE_MUTEX(iommus_lock);
+static LIST_HEAD(iommus_list);
+
+void iommu_add(struct iommu *iommu)
+{
+ INIT_LIST_HEAD(&iommu->list);
+ mutex_lock(&iommus_lock);
+ list_add_tail(&iommu->list, &iommus_list);
+ mutex_unlock(&iommus_lock);
+}
+
+void iommu_del(struct iommu *iommu)
+{
+ INIT_LIST_HEAD(&iommu->list);
+ mutex_lock(&iommus_lock);
+ list_del(&iommu->list);
+ mutex_unlock(&iommus_lock);
+}
+
+static struct iommu *of_find_iommu_by_node(struct device_node *np)
+{
+ struct iommu *iommu;
+
+ mutex_lock(&iommus_lock);
+ list_for_each_entry(iommu, &iommus_list, list) {
+ if (iommu->dev->of_node == np) {
+ mutex_unlock(&iommus_lock);
+ return iommu;
+ }
+ }
+ mutex_unlock(&iommus_lock);
+
+ return NULL;
+}
/**
* of_get_dma_window - Parse *dma-window property and returns 0 if found.
@@ -3,10 +3,18 @@
#ifdef CONFIG_OF_IOMMU
+struct iommu {
+ struct list_head list;
+ struct device *dev;
+};
+
extern int of_get_dma_window(struct device_node *dn, const char *prefix,
int index, unsigned long *busno, dma_addr_t *addr,
size_t *size);
+void iommu_add(struct iommu *iommu);
+void iommu_del(struct iommu *iommu);
+
#else
static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
@@ -16,6 +24,14 @@ static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
return -EINVAL;
}
+static inline void iommu_add(struct iommu *iommu)
+{
+}
+
+static inline void iommu_del(struct iommu *iommu)
+{
+}
+
#endif /* CONFIG_OF_IOMMU */
#endif /* __OF_IOMMU_H */
This enables to find an populated IOMMU device via a device node. This can be used to see if an dependee IOMMU is populated or not to keep correct device population order. Client devices need to wait an IOMMU to be populated. Suggested by Thierry Reding and copied his example code. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Thierry Reding <thierry.reding@gmail.com> --- drivers/iommu/of_iommu.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 16 ++++++++++++++++ 2 files changed, 52 insertions(+)