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

[Nipun Gupta]

> -Original Message-
> From: Robin Murphy [mailto:robin.mur...@arm.com]
> Sent: Tuesday, April 17, 2018 10:23 PM
> To: Nipun Gupta <nipun.gu...@nxp.com>; robh...@kernel.org;
> frowand.l...@gmail.com
> Cc: will.dea...@arm.com; mark.rutl...@arm.com; catalin.mari...@arm.com;
> h...@lst.de; gre...@linuxfoundation.org; j...@8bytes.org;
> m.szyprow...@samsung.com; shawn...@kernel.org; bhelg...@google.com;
> iommu@lists.linux-foundation.org; linux-ker...@vger.kernel.org;
> devicet...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; linuxppc-
> d...@lists.ozlabs.org; linux-...@vger.kernel.org; Bharat Bhushan
> <bharat.bhus...@nxp.com>; stuyo...@gmail.com; Laurentiu Tudor
> <laurentiu.tu...@nxp.com>; Leo Li <leoyang...@nxp.com>
> Subject: Re: [PATCH 2/6 v2] iommu: of: make of_pci_map_rid() available for
> other devices too
> 
> 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.gu...@nxp.com>
> > ---
> >   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.

Thanks for pointing out.
Agree, this will break "msi-parent" parsing for !CONFIG_OF_IOMMU case.

> 
> 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(-)
> >

[...]

> >   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", _spec.np,
> > -iommu_spec.args);
> > +   err = of_map_rid(info->np, alias, "iommu-map",
> > +"iommu-map-mask", _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 ;)

Sure.. I'll take care of this in the next version :)

Regards,
Nipun
___
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

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

[Bharat Bhushan]

> -Original Message-
> From: Robin Murphy [mailto:robin.mur...@arm.com]
> Sent: Tuesday, April 17, 2018 10:23 PM
> To: Nipun Gupta <nipun.gu...@nxp.com>; robh...@kernel.org;
> frowand.l...@gmail.com
> Cc: will.dea...@arm.com; mark.rutl...@arm.com; catalin.mari...@arm.com;
> h...@lst.de; gre...@linuxfoundation.org; j...@8bytes.org;
> m.szyprow...@samsung.com; shawn...@kernel.org; bhelg...@google.com;
> iommu@lists.linux-foundation.org; linux-ker...@vger.kernel.org;
> devicet...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; linuxppc-
> d...@lists.ozlabs.org; linux-...@vger.kernel.org; Bharat Bhushan
> <bharat.bhus...@nxp.com>; stuyo...@gmail.com; Laurentiu Tudor
> <laurentiu.tu...@nxp.com>; Leo Li <leoyang...@nxp.com>
> Subject: Re: [PATCH 2/6 v2] iommu: of: make of_pci_map_rid() available for
> other devices too
> 
> 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.

Nipun, please clarify that only function name is changed and rest of body is 
same.

> >
> > Signed-off-by: Nipun Gupta <nipun.gu...@nxp.com>
> > ---
> >   drivers/iommu/of_iommu.c | 106
> > +--
> 
> Doesn't this break "msi-parent" parsing for !CONFIG_OF_IOMMU?

Yes, this will be a problem with MSI 

> 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/address.c may be proper place to move until someone have better idea.

Thanks
-Bharat

> 
> >   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, _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;
> >

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

[Robin Murphy]

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 
---
  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, _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 = 0x;
+
+   /*
+* Can be overridden by "{iommu,msi}-map-mask" property.
+*/
+   if (map_mask_name)
+   of_property_read_u32(np, map_mask_name, _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);

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

[Nipun Gupta]

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 
---
 drivers/iommu/of_iommu.c | 106 +--
 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, _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 = 0x;
+
+   /*
+* Can be overridden by "{iommu,msi}-map-mask" property.
+*/
+   if (map_mask_name)
+   of_property_read_u32(np, map_mask_name, _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 =