This function can be called by drivers in their probe function to return a
single iommu_device instance associated with the current probe.
All drivers need a way to get the iommu_device instance the FW says the
device should be using. Wrap the function with a macro that does the
container_of().
The driver indicates what instances it accepts by passing in its ops.
num_cells is provided to validate that the args are correctly sized.
This function is all that is required by drivers that only support a
single IOMMU instance and no IDs data. Driver's should follow a typical
pattern in their probe_device:
iommu = iommu_of_get_single_iommu(pinf, &rk_iommu_ops, -1,
struct rk_iommu, iommu);
if (IS_ERR(iommu)) return ERR_CAST(iommu);
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) return ERR_PTR(-ENOMEM);
[..]
dev_iommu_priv_set(dev, data);
return &iommu->iommu;
Signed-off-by: Jason Gunthorpe <j...@nvidia.com>
---
drivers/acpi/scan.c | 1 +
drivers/iommu/iommu.c | 52 ++++++++++++++++++++++
drivers/iommu/of_iommu.c | 59 +++++++++++++++++++++++++
include/linux/iommu-driver.h | 85 ++++++++++++++++++++++++++++++++++++
4 files changed, 197 insertions(+)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 9c13df632aa5e0..de36299c3b75bf 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1570,6 +1570,7 @@ static int acpi_iommu_configure_id(struct device *dev,
const u32 *id_in)
const struct iommu_ops *ops;
struct iommu_probe_info pinf = {
.dev = dev,
+ .is_dma_configure = true,
};
/* Serialise to make dev->iommu stable under our potential fwspec */
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 45e6543748fd46..ca411ad14c1182 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3015,6 +3015,58 @@ struct iommu_device *iommu_device_from_fwnode(struct
fwnode_handle *fwnode)
return NULL;
}
+/*
+ * Helper for FW interfaces to parse the fwnode into an iommu_driver. This
+ * caches past search results to avoid re-searching the linked list and
computes
+ * if the FW is describing a single or multi-instance ID list.
+ */
+struct iommu_device *
+iommu_device_from_fwnode_pinf(struct iommu_probe_info *pinf,
+ const struct iommu_ops *ops,
+ struct fwnode_handle *fwnode)
+{
+ struct iommu_device *iommu = pinf->cached_iommu;
+
+ if (!pinf->num_ids)
+ pinf->cached_single_iommu = true;
+
+ if (!iommu || iommu->fwnode != fwnode) {
+ iommu = iommu_device_from_fwnode(fwnode);
+ if (!iommu)
+ return ERR_PTR(
+ driver_deferred_probe_check_state(pinf->dev));
+ pinf->cached_iommu = iommu;
+ if (pinf->num_ids)
+ pinf->cached_single_iommu = false;
+ }
+
+ /* NULL ops is used for the -EPROBE_DEFER check, match everything */
+ if (ops && iommu->ops != ops) {
+ if (!pinf->num_ids)
+ return ERR_PTR(-ENODEV);
+ dev_err(pinf->dev,
+ FW_BUG
+ "One device in the FW has iommu's with different Linux
drivers, expecting %ps FW wants %ps.",
+ ops, iommu->ops);
+ return ERR_PTR(-EINVAL);
+ }
+ return iommu;
+}
+
+struct iommu_device *iommu_fw_finish_get_single(struct iommu_probe_info *pinf)
+{
+ if (WARN_ON(!pinf->num_ids || !pinf->cached_iommu))
+ return ERR_PTR(-EINVAL);
+ if (!pinf->cached_single_iommu) {
+ dev_err(pinf->dev,
+ FW_BUG
+ "The iommu driver %ps expects only one iommu instance,
the FW has more.\n",
+ pinf->cached_iommu->ops);
+ return ERR_PTR(-EINVAL);
+ }
+ return pinf->cached_iommu;
+}
+
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 20266a8edd5c71..37af32a6bc84e5 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -138,6 +138,9 @@ int of_iommu_configure(struct device *dev, struct
device_node *master_np,
{
struct iommu_probe_info pinf = {
.dev = dev,
+ .of_master_np = master_np,
+ .of_map_id = id,
+ .is_dma_configure = true,
};
struct iommu_fwspec *fwspec;
int err;
@@ -277,3 +280,59 @@ void of_iommu_get_resv_regions(struct device *dev, struct
list_head *list)
#endif
}
EXPORT_SYMBOL(of_iommu_get_resv_regions);
+
+struct parse_info {
+ struct iommu_probe_info *pinf;
+ const struct iommu_ops *ops;
+ int num_cells;
+};
+
+static struct iommu_device *parse_iommu(struct parse_info *info,
+ struct of_phandle_args *iommu_spec)
+{
+ if (!of_device_is_available(iommu_spec->np))
+ return ERR_PTR(-ENODEV);
+
+ if (info->num_cells != -1 && iommu_spec->args_count != info->num_cells)
{
+ dev_err(info->pinf->dev,
+ FW_BUG
+ "Driver %ps expects number of cells %u but DT has %u\n",
+ info->ops, info->num_cells, iommu_spec->args_count);
+ return ERR_PTR(-EINVAL);
+ }
+ return iommu_device_from_fwnode_pinf(info->pinf, info->ops,
+ &iommu_spec->np->fwnode);
+}
+
+static int parse_single_iommu(struct of_phandle_args *iommu_spec, void *_info)
+{
+ struct parse_info *info = _info;
+ struct iommu_device *iommu;
+
+ iommu = parse_iommu(info, iommu_spec);
+ if (IS_ERR(iommu))
+ return PTR_ERR(iommu);
+ info->pinf->num_ids++;
+ return 0;
+}
+
+struct iommu_device *__iommu_of_get_single_iommu(struct iommu_probe_info *pinf,
+ const struct iommu_ops *ops,
+ int num_cells)
+{
+ struct parse_info info = { .pinf = pinf,
+ .ops = ops,
+ .num_cells = num_cells };
+ int err;
+
+ if (!pinf->is_dma_configure || !pinf->of_master_np)
+ return ERR_PTR(-ENODEV);
+
+ iommu_fw_clear_cache(pinf);
+ err = of_iommu_for_each_id(pinf->dev, pinf->of_master_np,
+ pinf->of_map_id, parse_single_iommu, &info);
+ if (err)
+ return ERR_PTR(err);
+ 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 c572620d3069b4..597998a62b0dd6 100644
--- a/include/linux/iommu-driver.h
+++ b/include/linux/iommu-driver.h
@@ -13,25 +13,110 @@
#endif
#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+struct of_phandle_args;
struct fwnode_handle;
+struct iommu_device;
+struct iommu_ops;
+
+/*
+ * FIXME this is sort of like container_of_safe() that was removed, do we want
+ * to put it in the common header?
+ */
+#define container_of_err(ptr, type, member) \
+ ({ \
+ void *__mptr = (void *)(ptr); \
+ \
+ (offsetof(type, member) != 0 && IS_ERR(__mptr)) ? \
+ (type *)ERR_CAST(__mptr) : \
+ container_of(ptr, type, member); \
+ })
struct iommu_probe_info {
struct device *dev;
struct list_head *deferred_group_list;
+ struct iommu_device *cached_iommu;
+ struct device_node *of_master_np;
+ const u32 *of_map_id;
+ unsigned int num_ids;
bool defer_setup : 1;
+ bool is_dma_configure : 1;
+ bool cached_single_iommu : 1;
};
+static inline void iommu_fw_clear_cache(struct iommu_probe_info *pinf)
+{
+ pinf->num_ids = 0;
+ pinf->cached_single_iommu = true;
+}
+
int iommu_probe_device_pinf(struct iommu_probe_info *pinf);
struct iommu_device *iommu_device_from_fwnode(struct fwnode_handle *fwnode);
+struct iommu_device *
+iommu_device_from_fwnode_pinf(struct iommu_probe_info *pinf,
+ const struct iommu_ops *ops,
+ struct fwnode_handle *fwnode);
+struct iommu_device *iommu_fw_finish_get_single(struct iommu_probe_info *pinf);
#if IS_ENABLED(CONFIG_OF_IOMMU)
void of_iommu_get_resv_regions(struct device *dev, struct list_head *list);
+
+struct iommu_device *__iommu_of_get_single_iommu(struct iommu_probe_info *pinf,
+ const struct iommu_ops *ops,
+ int num_cells);
#else
static inline void of_iommu_get_resv_regions(struct device *dev,
struct list_head *list)
{
}
+static inline
+struct iommu_device *__iommu_of_get_single_iommu(struct iommu_probe_info *pinf,
+ const struct iommu_ops *ops,
+ int num_cells)
+{
+ return ERR_PTR(-ENODEV);
+}
#endif
+/**
+ * iommu_of_get_single_iommu - Return the driver's iommu instance
+ * @pinf: The iommu_probe_info
+ * @ops: The ops the iommu instance must have
+ * @num_cells: #iommu-cells value to enforce, -1 is no check
+ * @drv_struct: The driver struct containing the struct iommu_device
+ * @member: The name of the iommu_device member
+ *
+ * Parse the OF table describing the iommus and return a pointer to the
driver's
+ * iommu_device struct that the OF table points to. Check that the OF table is
+ * well formed with a single iommu for all the entries and that the table
refers
+ * to this iommu driver. Integrates a container_of() to simplify all users.
+ */
+#define iommu_of_get_single_iommu(pinf, ops, num_cells, drv_struct, member) \
+ container_of_err(__iommu_of_get_single_iommu(pinf, ops, num_cells), \
+ drv_struct, member)
+
+/**
+ * iommu_of_num_ids - Return the number of iommu associations the FW has
+ * @pinf: The iommu_probe_info
+ *
+ * For drivers using iommu_of_get_single_iommu() this will return the number
+ * of ids associated with the iommu instance. For other cases this will return
+ * the sum of all ids across all instances. Returns >= 1.
+ */
+static inline unsigned int iommu_of_num_ids(struct iommu_probe_info *pinf)
+{
+ return pinf->num_ids;
+}
+
+/*
+ * Used temporarily to indicate drivers that have moved to the new probe
method.
+ */
+static inline int iommu_dummy_of_xlate(struct device *dev,
+ struct of_phandle_args *args)
+{
+ return 0;
+}
+
#endif
--
2.42.0
