[PATCH v2 03/17] iommu/of: Use -ENODEV consistently in of_iommu_configure()

Jason Gunthorpe
2023-11-15T14:07:14Z

Instead of returning 1 and trying to handle positive error codes just
stick to the convention of returning -ENODEV. Remove references to ops
from of_iommu_configure(), a NULL ops will already generate an error code.

There is no reason to check dev->bus, if err=0 at this point then the
called configure functions thought there was an iommu and we should try to
probe it. Remove it.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/of_iommu.c | 48 +++++++++++++---------------------------
1 file changed, 15 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index b47dcb66cde98d..a68a4d1dc0725c 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -17,8 +17,6 @@
#include <linux/slab.h>
#include <linux/fsl/mc.h>

-#define NO_IOMMU 1
-
static int of_iommu_xlate(struct device *dev,
struct of_phandle_args *iommu_spec)
{
@@ -29,7 +27,7 @@ static int of_iommu_xlate(struct device *dev,
ops = iommu_ops_from_fwnode(fwnode);
if ((ops && !ops->of_xlate) ||
!of_device_is_available(iommu_spec->np))
- return NO_IOMMU;
+ return -ENODEV;

ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
if (ret)
@@ -61,7 +59,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
"iommu-map-mask", &iommu_spec.np,
iommu_spec.args);
if (err)
- return err == -ENODEV ? NO_IOMMU : err;
+ return err;

err = of_iommu_xlate(dev, &iommu_spec);
of_node_put(iommu_spec.np);
@@ -72,7 +70,7 @@ static int of_iommu_configure_dev(struct device_node *master_np,
struct device *dev)
{
struct of_phandle_args iommu_spec;
- int err = NO_IOMMU, idx = 0;
+ int err = -ENODEV, idx = 0;

while (!of_parse_phandle_with_args(master_np, "iommus",
"#iommu-cells",
@@ -117,9 +115,8 @@ static int of_iommu_configure_device(struct device_node *master_np,
int of_iommu_configure(struct device *dev, struct device_node *master_np,
const u32 *id)
{
- const struct iommu_ops *ops = NULL;
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
- int err = NO_IOMMU;
+ int err;

if (!master_np)
return -ENODEV;
@@ -150,34 +147,19 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np,
err = of_iommu_configure_device(master_np, dev, id);
}

- /*
- * Two success conditions can be represented by non-negative err here:
- * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
- * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
- * <0 : any actual error
- */
- if (!err) {
- /* The fwspec pointer changed, read it again */
- fwspec = dev_iommu_fwspec_get(dev);
- ops = fwspec->ops;
- }
- /*
- * If we have reason to believe the IOMMU driver missed the initial
- * probe for dev, replay it to get things in order.
- */
- if (!err && dev->bus)
- err = iommu_probe_device(dev);
-
- /* Ignore all other errors apart from EPROBE_DEFER */
- if (err < 0) {
- if (err == -EPROBE_DEFER)
- return err;
- dev_dbg(dev, "Adding to IOMMU failed: %pe\n", ERR_PTR(err));
+ if (err == -ENODEV || err == -EPROBE_DEFER)
return err;
- }
- if (!ops)
- return -ENODEV;
+ if (err)
+ goto err_log;
+
+ err = iommu_probe_device(dev);
+ if (err)
+ goto err_log;
return 0;
+
+err_log:
+ dev_dbg(dev, "Adding to IOMMU failed: %pe\n", ERR_PTR(err));
+ return err;
}

static enum iommu_resv_type __maybe_unused