Re: [PATCH 2/6 v2] iommu: of: make of_pci_map_rid() available for other devices too

From: Robin Murphy
Date: Tue Apr 17 2018 - 12:53:02 EST


On 17/04/18 11:21, Nipun Gupta wrote:
iommu-map property is also used by devices with fsl-mc. This
patch moves the of_pci_map_rid to generic location, so that it
can be used by other busses too.

Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>
---
drivers/iommu/of_iommu.c | 106 +++++++++++++++++++++++++++++++++++++++++++++--

Doesn't this break "msi-parent" parsing for !CONFIG_OF_IOMMU? I guess you don't want fsl-mc to have to depend on PCI, but this looks like a step in the wrong direction.

I'm not entirely sure where of_map_rid() fits best, but from a quick look around the least-worst option might be drivers/of/of_address.c, unless Rob and Frank have a better idea of where generic DT-based ID translation routines could live?

drivers/of/irq.c | 6 +--
drivers/pci/of.c | 101 --------------------------------------------
include/linux/of_iommu.h | 11 +++++
include/linux/of_pci.h | 10 -----
5 files changed, 117 insertions(+), 117 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 5c36a8b..4e7712f 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -138,6 +138,106 @@ static int of_iommu_xlate(struct device *dev,
return ops->of_xlate(dev, iommu_spec);
}
+/**
+ * of_map_rid - Translate a requester ID through a downstream mapping.
+ * @np: root complex device node.
+ * @rid: device requester ID to map.
+ * @map_name: property name of the map to use.
+ * @map_mask_name: optional property name of the mask to use.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Given a device requester ID, look up the appropriate implementation-defined
+ * platform ID and/or the target device which receives transactions on that
+ * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
+ * @id_out may be NULL if only the other is required. If @target points to
+ * a non-NULL device node pointer, only entries targeting that node will be
+ * matched; if it points to a NULL value, it will receive the device node of
+ * the first matching target phandle, with a reference held.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_rid(struct device_node *np, u32 rid,
+ const char *map_name, const char *map_mask_name,
+ struct device_node **target, u32 *id_out)
+{
+ u32 map_mask, masked_rid;
+ int map_len;
+ const __be32 *map = NULL;
+
+ if (!np || !map_name || (!target && !id_out))
+ return -EINVAL;
+
+ map = of_get_property(np, map_name, &map_len);
+ if (!map) {
+ if (target)
+ return -ENODEV;
+ /* Otherwise, no map implies no translation */
+ *id_out = rid;
+ return 0;
+ }
+
+ if (!map_len || map_len % (4 * sizeof(*map))) {
+ pr_err("%pOF: Error: Bad %s length: %d\n", np,
+ map_name, map_len);
+ return -EINVAL;
+ }
+
+ /* The default is to select all bits. */
+ map_mask = 0xffffffff;
+
+ /*
+ * Can be overridden by "{iommu,msi}-map-mask" property.
+ */
+ if (map_mask_name)
+ of_property_read_u32(np, map_mask_name, &map_mask);
+
+ masked_rid = map_mask & rid;
+ for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
+ struct device_node *phandle_node;
+ u32 rid_base = be32_to_cpup(map + 0);
+ u32 phandle = be32_to_cpup(map + 1);
+ u32 out_base = be32_to_cpup(map + 2);
+ u32 rid_len = be32_to_cpup(map + 3);
+
+ if (rid_base & ~map_mask) {
+ pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
+ np, map_name, map_name,
+ map_mask, rid_base);
+ return -EFAULT;
+ }
+
+ if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
+ continue;
+
+ phandle_node = of_find_node_by_phandle(phandle);
+ if (!phandle_node)
+ return -ENODEV;
+
+ if (target) {
+ if (*target)
+ of_node_put(phandle_node);
+ else
+ *target = phandle_node;
+
+ if (*target != phandle_node)
+ continue;
+ }
+
+ if (id_out)
+ *id_out = masked_rid - rid_base + out_base;
+
+ pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
+ np, map_name, map_mask, rid_base, out_base,
+ rid_len, rid, masked_rid - rid_base + out_base);
+ return 0;
+ }
+
+ pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
+ np, map_name, rid, target && *target ? *target : NULL);
+ return -EFAULT;
+}
+
struct of_pci_iommu_alias_info {
struct device *dev;
struct device_node *np;
@@ -149,9 +249,9 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
struct of_phandle_args iommu_spec = { .args_count = 1 };
int err;
- err = of_pci_map_rid(info->np, alias, "iommu-map",
- "iommu-map-mask", &iommu_spec.np,
- iommu_spec.args);
+ err = of_map_rid(info->np, alias, "iommu-map",
+ "iommu-map-mask", &iommu_spec.np,
+ iommu_spec.args);

Super-nit: Apparently I missed rewrapping this to 2 lines in d87beb749281, but if it's being touched again, that would be nice ;)

Robin.

if (err)
return err == -ENODEV ? NO_IOMMU : err;
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 02ad93a..b72eeec 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -22,7 +22,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
-#include <linux/of_pci.h>
+#include <linux/of_iommu.h>
#include <linux/string.h>
#include <linux/slab.h>
@@ -588,8 +588,8 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
* "msi-map" property.
*/
for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
- if (!of_pci_map_rid(parent_dev->of_node, rid_in, "msi-map",
- "msi-map-mask", np, &rid_out))
+ if (!of_map_rid(parent_dev->of_node, rid_in, "msi-map",
+ "msi-map-mask", np, &rid_out))
break;
return rid_out;
}
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index a28355c..d2cebbe 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -362,107 +362,6 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
#endif /* CONFIG_OF_ADDRESS */
-/**
- * of_pci_map_rid - Translate a requester ID through a downstream mapping.
- * @np: root complex device node.
- * @rid: PCI requester ID to map.
- * @map_name: property name of the map to use.
- * @map_mask_name: optional property name of the mask to use.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
- *
- * Given a PCI requester ID, look up the appropriate implementation-defined
- * platform ID and/or the target device which receives transactions on that
- * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
- * @id_out may be NULL if only the other is required. If @target points to
- * a non-NULL device node pointer, only entries targeting that node will be
- * matched; if it points to a NULL value, it will receive the device node of
- * the first matching target phandle, with a reference held.
- *
- * Return: 0 on success or a standard error code on failure.
- */
-int of_pci_map_rid(struct device_node *np, u32 rid,
- const char *map_name, const char *map_mask_name,
- struct device_node **target, u32 *id_out)
-{
- u32 map_mask, masked_rid;
- int map_len;
- const __be32 *map = NULL;
-
- if (!np || !map_name || (!target && !id_out))
- return -EINVAL;
-
- map = of_get_property(np, map_name, &map_len);
- if (!map) {
- if (target)
- return -ENODEV;
- /* Otherwise, no map implies no translation */
- *id_out = rid;
- return 0;
- }
-
- if (!map_len || map_len % (4 * sizeof(*map))) {
- pr_err("%pOF: Error: Bad %s length: %d\n", np,
- map_name, map_len);
- return -EINVAL;
- }
-
- /* The default is to select all bits. */
- map_mask = 0xffffffff;
-
- /*
- * Can be overridden by "{iommu,msi}-map-mask" property.
- * If of_property_read_u32() fails, the default is used.
- */
- if (map_mask_name)
- of_property_read_u32(np, map_mask_name, &map_mask);
-
- masked_rid = map_mask & rid;
- for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
- struct device_node *phandle_node;
- u32 rid_base = be32_to_cpup(map + 0);
- u32 phandle = be32_to_cpup(map + 1);
- u32 out_base = be32_to_cpup(map + 2);
- u32 rid_len = be32_to_cpup(map + 3);
-
- if (rid_base & ~map_mask) {
- pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
- np, map_name, map_name,
- map_mask, rid_base);
- return -EFAULT;
- }
-
- if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
- continue;
-
- phandle_node = of_find_node_by_phandle(phandle);
- if (!phandle_node)
- return -ENODEV;
-
- if (target) {
- if (*target)
- of_node_put(phandle_node);
- else
- *target = phandle_node;
-
- if (*target != phandle_node)
- continue;
- }
-
- if (id_out)
- *id_out = masked_rid - rid_base + out_base;
-
- pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
- np, map_name, map_mask, rid_base, out_base,
- rid_len, rid, masked_rid - rid_base + out_base);
- return 0;
- }
-
- pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
- np, map_name, rid, target && *target ? *target : NULL);
- return -EFAULT;
-}
-
#if IS_ENABLED(CONFIG_OF_IRQ)
/**
* of_irq_parse_pci - Resolve the interrupt for a PCI device
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index 4fa654e..432b53c 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -15,6 +15,10 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix,
extern const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np);
+int of_map_rid(struct device_node *np, u32 rid,
+ const char *map_name, const char *map_mask_name,
+ struct device_node **target, u32 *id_out);
+
#else
static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
@@ -30,6 +34,13 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
return NULL;
}
+static inline int of_map_rid(struct device_node *np, u32 rid,
+ const char *map_name, const char *map_mask_name,
+ struct device_node **target, u32 *id_out)
+{
+ return -EINVAL;
+}
+
#endif /* CONFIG_OF_IOMMU */
extern struct of_device_id __iommu_of_table;
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 091033a..a23b44a 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -17,9 +17,6 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
int of_get_pci_domain_nr(struct device_node *node);
int of_pci_get_max_link_speed(struct device_node *node);
void of_pci_check_probe_only(void);
-int of_pci_map_rid(struct device_node *np, u32 rid,
- const char *map_name, const char *map_mask_name,
- struct device_node **target, u32 *id_out);
#else
static inline struct device_node *of_pci_find_child_device(struct device_node *parent,
unsigned int devfn)
@@ -44,13 +41,6 @@ static inline int of_pci_get_devfn(struct device_node *np)
return -1;
}
-static inline int of_pci_map_rid(struct device_node *np, u32 rid,
- const char *map_name, const char *map_mask_name,
- struct device_node **target, u32 *id_out)
-{
- return -EINVAL;
-}
-
static inline int
of_pci_get_max_link_speed(struct device_node *node)
{