This helper can be called after iommu_of_get_single_iommu() to
automatically extract the raw list of IDs. It can be used by drivers that
expect to have a list of simple u32 IDs for a single IOMMU instance.
The driver must provide a per-driver structure with a trailing flex array
to hold the IDs. This helper will allocate the structure, size the ids
flex array, and fill it in with data.
Driver's should follow a typical pattern in their probe_device:
struct tegra_smmu_device {
struct tegra_smmu *smmu;
unsigned int num_ids;
u32 ids[] __counted_by(num_ids);
};
smmu = iommu_of_get_single_iommu(pinf, &tegra_smmu_ops, 1,
struct tegra_smmu, iommu);
if (IS_ERR(smmu)) return ERR_CAST(smmu);
smmu_device = iommu_fw_alloc_per_device_ids(pinf, smmu_device);
if (IS_ERR(smmu_device)) return ERR_CAST(smmu_device);
[..]
dev_iommu_priv_set(dev, data);
return &iommu->iommu;
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/iommu.c | 21 ++++++++++++++
drivers/iommu/of_iommu.c | 21 +++++++++++++-
include/linux/iommu-driver.h | 56 ++++++++++++++++++++++++++++++++++++
3 files changed, 97 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ca411ad14c1182..caf14a53ed1952 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3067,6 +3067,27 @@ struct iommu_device *iommu_fw_finish_get_single(struct iommu_probe_info *pinf)
return pinf->cached_iommu;
}
+/*
+ * This function shouldn't be called directly without a pretty good reason,
+ * prefer to structure the driver to use iommu_fw_alloc_per_device_ids()
+ * instead.
+ */
+int iommu_fw_get_u32_ids(struct iommu_probe_info *pinf, u32 *ids)
+{
+ if (WARN_ON(!pinf->get_u32_ids))
+ return -EINVAL;
+
+ /*
+ * We pre-parse a small number if IDs and keep it on the stack. If that
+ * isn't enough then just reparse again.
+ */
+ if (pinf->num_ids > ARRAY_SIZE(pinf->cached_ids))
+ return pinf->get_u32_ids(pinf, ids);
+ memcpy(ids, pinf->cached_ids, pinf->num_ids * sizeof(*ids));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iommu_fw_get_u32_ids);
+
int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
const struct iommu_ops *ops)
{
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 8d5495f03dbbcb..6f6e442f899ded 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -332,10 +332,28 @@ static int parse_single_iommu(struct of_phandle_args *iommu_spec, void *_info)
iommu = parse_iommu(info, iommu_spec);
if (IS_ERR(iommu))
return PTR_ERR(iommu);
- info->pinf->num_ids++;
+ iommu_fw_cache_id(info->pinf, iommu_spec->args[0]);
return 0;
}
+static int parse_read_ids(struct of_phandle_args *iommu_spec, void *_info)
+{
+ struct parse_info *info = _info;
+ u32 *ids = info->priv;
+
+ *ids = iommu_spec->args[0];
+ info->priv = ids + 1;
+ return 0;
+}
+
+static int iommu_of_get_u32_ids(struct iommu_probe_info *pinf, u32 *ids)
+{
+ struct parse_info info = { .pinf = pinf, .priv = ids };
+
+ return of_iommu_for_each_id(pinf->dev, pinf->of_master_np,
+ pinf->of_map_id, parse_read_ids, &info);
+}
+
struct iommu_device *__iommu_of_get_single_iommu(struct iommu_probe_info *pinf,
const struct iommu_ops *ops,
int num_cells)
@@ -353,6 +371,7 @@ struct iommu_device *__iommu_of_get_single_iommu(struct iommu_probe_info *pinf,
pinf->of_map_id, parse_single_iommu, &info);
if (err)
return ERR_PTR(err);
+ pinf->get_u32_ids = iommu_of_get_u32_ids;
return iommu_fw_finish_get_single(pinf);
}
EXPORT_SYMBOL_GPL(__iommu_of_get_single_iommu);
diff --git a/include/linux/iommu-driver.h b/include/linux/iommu-driver.h
index 622d6ad9056ce0..632c7b4a389abe 100644
--- a/include/linux/iommu-driver.h
+++ b/include/linux/iommu-driver.h
@@ -40,7 +40,9 @@ struct iommu_probe_info {
struct iommu_device *cached_iommu;
struct device_node *of_master_np;
const u32 *of_map_id;
+ int (*get_u32_ids)(struct iommu_probe_info *pinf, u32 *ids);
unsigned int num_ids;
+ u32 cached_ids[8];
bool defer_setup : 1;
bool is_dma_configure : 1;
bool cached_single_iommu : 1;
@@ -123,6 +125,60 @@ static inline unsigned int iommu_of_num_ids(struct iommu_probe_info *pinf)
return pinf->num_ids;
}
+unsigned int iommu_of_num_ids(struct iommu_probe_info *pinf);
+int iommu_fw_get_u32_ids(struct iommu_probe_info *pinf, u32 *ids);
+
+static inline void iommu_fw_cache_id(struct iommu_probe_info *pinf, u32 id)
+{
+ if (pinf->num_ids < ARRAY_SIZE(pinf->cached_ids))
+ pinf->cached_ids[pinf->num_ids] = id;
+ pinf->num_ids++;
+}
+
+static inline void *
+__iommu_fw_alloc_per_device_ids(struct iommu_probe_info *pinf, void *mem,
+ unsigned int num_ids, unsigned int *num_ids_p,
+ u32 *ids_p)
+{
+ int ret;
+
+ if (!mem)
+ return ERR_PTR(-ENOMEM);
+
+ ret = iommu_fw_get_u32_ids(pinf, ids_p);
+ if (ret) {
+ kfree(mem);
+ return ERR_PTR(ret);
+ }
+
+ *num_ids_p = num_ids;
+ return mem;
+}
+
+/**
+ * iommu_fw_alloc_per_device_ids - Allocate a per-device struct with ids
+ * @pinf: The iommu_probe_info
+ * @drv_struct: Name of a variable to a pointer of the driver structure
+ *
+ * Called by a driver during probe this helper allocates and initializes the
+ * driver struct that embeds the ids array with the trailing members:
+ *
+ * unsigned int num_ids;
+ * u32 ids[] __counted_by(num_ids);
+ *
+ * The helper allocates the driver struct with the right size flex array,
+ * and initializes both members. Returns the driver struct or ERR_PTR.
+ */
+#define iommu_fw_alloc_per_device_ids(pinf, drv_struct) \
+ ({ \
+ unsigned int num_ids = iommu_of_num_ids(pinf); \
+ typeof(drv_struct) drv; \
+ \
+ drv = kzalloc(struct_size(drv, ids, num_ids), GFP_KERNEL); \
+ drv = __iommu_fw_alloc_per_device_ids( \
+ pinf, drv, num_ids, &drv->num_ids, drv->ids); \
+ })
+
/*
* Used temporarily to indicate drivers that have moved to the new probe method.
*/
--
2.42.0
