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[PATCH v3 1/3] arm,smmu: switch to using iommu_fwspec functions



From: Brian Woods <brian.woods@xxxxxxxxxx>

Modify the smmu driver so that it uses the iommu_fwspec helper
functions.  This means both ARM IOMMU drivers will both use the
iommu_fwspec helper functions, making enabling generic device tree
bindings in the SMMU driver much cleaner.

Signed-off-by: Brian Woods <brian.woods@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
---
Changes in v3:
- add a comment in iommu_add_dt_device
- don't allocate fwspec twice in arm_smmu_add_device
- reuse existing fwspec pointer, don't add a second one
- add comment about supporting fwspec at the top of the file
---
 xen/drivers/passthrough/arm/smmu.c    | 98 ++++++++++++++++-----------
 xen/drivers/passthrough/device_tree.c |  7 ++
 2 files changed, 66 insertions(+), 39 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu.c 
b/xen/drivers/passthrough/arm/smmu.c
index 3e8aa37866..3898d1d737 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -32,6 +32,9 @@
  *     - 4k and 64k pages, with contiguous pte hints.
  *     - Up to 48-bit addressing (dependent on VA_BITS)
  *     - Context fault reporting
+ *
+ * Changes compared to Linux driver:
+ *     - support for fwspec
  */
 
 
@@ -49,6 +52,7 @@
 #include <asm/atomic.h>
 #include <asm/device.h>
 #include <asm/io.h>
+#include <asm/iommu_fwspec.h>
 #include <asm/platform.h>
 
 /* Xen: The below defines are redefined within the file. Undef it */
@@ -302,9 +306,6 @@ static struct iommu_group *iommu_group_get(struct device 
*dev)
 
 /***** Start of Linux SMMU code *****/
 
-/* Maximum number of stream IDs assigned to a single device */
-#define MAX_MASTER_STREAMIDS           MAX_PHANDLE_ARGS
-
 /* Maximum number of context banks per SMMU */
 #define ARM_SMMU_MAX_CBS               128
 
@@ -597,8 +598,6 @@ struct arm_smmu_smr {
 };
 
 struct arm_smmu_master_cfg {
-       int                             num_streamids;
-       u16                             streamids[MAX_MASTER_STREAMIDS];
        struct arm_smmu_smr             *smrs;
 };
 
@@ -686,6 +685,14 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {
        { 0, NULL},
 };
 
+static inline struct iommu_fwspec *
+arm_smmu_get_fwspec(struct arm_smmu_master_cfg *cfg)
+{
+       struct arm_smmu_master *master = container_of(cfg,
+                                                             struct 
arm_smmu_master, cfg);
+       return dev_iommu_fwspec_get(&master->of_node->dev);
+}
+
 static void parse_driver_options(struct arm_smmu_device *smmu)
 {
        int i = 0;
@@ -779,8 +786,9 @@ static int register_smmu_master(struct arm_smmu_device 
*smmu,
                                struct device *dev,
                                struct of_phandle_args *masterspec)
 {
-       int i;
+       int i, ret = 0;
        struct arm_smmu_master *master;
+       struct iommu_fwspec *fwspec;
 
        master = find_smmu_master(smmu, masterspec->np);
        if (master) {
@@ -790,34 +798,37 @@ static int register_smmu_master(struct arm_smmu_device 
*smmu,
                return -EBUSY;
        }
 
-       if (masterspec->args_count > MAX_MASTER_STREAMIDS) {
-               dev_err(dev,
-                       "reached maximum number (%d) of stream IDs for master 
device %s\n",
-                       MAX_MASTER_STREAMIDS, masterspec->np->name);
-               return -ENOSPC;
-       }
-
        master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL);
        if (!master)
                return -ENOMEM;
+       master->of_node = masterspec->np;
 
-       master->of_node                 = masterspec->np;
-       master->cfg.num_streamids       = masterspec->args_count;
+       ret = iommu_fwspec_init(&master->of_node->dev, smmu->dev);
+       if (ret) {
+               kfree(master);
+               return ret;
+       }
+       fwspec = dev_iommu_fwspec_get(dev);
+
+       /* adding the ids here */
+       ret = iommu_fwspec_add_ids(&masterspec->np->dev,
+                                  masterspec->args,
+                                  masterspec->args_count);
+       if (ret)
+               return ret;
 
        /* Xen: Let Xen know that the device is protected by an SMMU */
        dt_device_set_protected(masterspec->np);
 
-       for (i = 0; i < master->cfg.num_streamids; ++i) {
-               u16 streamid = masterspec->args[i];
-
-               if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) &&
-                    (streamid >= smmu->num_mapping_groups)) {
-                       dev_err(dev,
-                               "stream ID for master device %s greater than 
maximum allowed (%d)\n",
-                               masterspec->np->name, smmu->num_mapping_groups);
-                       return -ERANGE;
+       if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH)) {
+               for (i = 0; i < fwspec->num_ids; ++i) {
+                       if (masterspec->args[i] >= smmu->num_mapping_groups) {
+                               dev_err(dev,
+                                       "stream ID for master device %s greater 
than maximum allowed (%d)\n",
+                                       masterspec->np->name, 
smmu->num_mapping_groups);
+                               return -ERANGE;
+                       }
                }
-               master->cfg.streamids[i] = streamid;
        }
        return insert_smmu_master(smmu, master);
 }
@@ -1390,6 +1401,7 @@ static int arm_smmu_master_configure_smrs(struct 
arm_smmu_device *smmu,
        int i;
        struct arm_smmu_smr *smrs;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+       struct iommu_fwspec *fwspec = arm_smmu_get_fwspec(cfg);
 
        if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH))
                return 0;
@@ -1397,15 +1409,14 @@ static int arm_smmu_master_configure_smrs(struct 
arm_smmu_device *smmu,
        if (cfg->smrs)
                return -EEXIST;
 
-       smrs = kmalloc_array(cfg->num_streamids, sizeof(*smrs), GFP_KERNEL);
+       smrs = kmalloc_array(fwspec->num_ids, sizeof(*smrs), GFP_KERNEL);
        if (!smrs) {
-               dev_err(smmu->dev, "failed to allocate %d SMRs\n",
-                       cfg->num_streamids);
+               dev_err(smmu->dev, "failed to allocate %d SMRs\n", 
fwspec->num_ids);
                return -ENOMEM;
        }
 
        /* Allocate the SMRs on the SMMU */
-       for (i = 0; i < cfg->num_streamids; ++i) {
+       for (i = 0; i < fwspec->num_ids; ++i) {
                int idx = __arm_smmu_alloc_bitmap(smmu->smr_map, 0,
                                                  smmu->num_mapping_groups);
                if (IS_ERR_VALUE(idx)) {
@@ -1416,12 +1427,12 @@ static int arm_smmu_master_configure_smrs(struct 
arm_smmu_device *smmu,
                smrs[i] = (struct arm_smmu_smr) {
                        .idx    = idx,
                        .mask   = 0, /* We don't currently share SMRs */
-                       .id     = cfg->streamids[i],
+                       .id     = fwspec->ids[i],
                };
        }
 
        /* It worked! Now, poke the actual hardware */
-       for (i = 0; i < cfg->num_streamids; ++i) {
+       for (i = 0; i < fwspec->num_ids; ++i) {
                u32 reg = SMR_VALID | smrs[i].id << SMR_ID_SHIFT |
                          smrs[i].mask << SMR_MASK_SHIFT;
                writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_SMR(smrs[i].idx));
@@ -1443,12 +1454,13 @@ static void arm_smmu_master_free_smrs(struct 
arm_smmu_device *smmu,
        int i;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
        struct arm_smmu_smr *smrs = cfg->smrs;
+       struct iommu_fwspec *fwspec = arm_smmu_get_fwspec(cfg);
 
        if (!smrs)
                return;
 
        /* Invalidate the SMRs before freeing back to the allocator */
-       for (i = 0; i < cfg->num_streamids; ++i) {
+       for (i = 0; i < fwspec->num_ids; ++i) {
                u8 idx = smrs[i].idx;
 
                writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(idx));
@@ -1465,16 +1477,17 @@ static int arm_smmu_domain_add_master(struct 
arm_smmu_domain *smmu_domain,
        int i, ret;
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+       struct iommu_fwspec *fwspec = arm_smmu_get_fwspec(cfg);
 
        /* Devices in an IOMMU group may already be configured */
        ret = arm_smmu_master_configure_smrs(smmu, cfg);
        if (ret)
                return ret == -EEXIST ? 0 : ret;
 
-       for (i = 0; i < cfg->num_streamids; ++i) {
+       for (i = 0; i < fwspec->num_ids; ++i) {
                u32 idx, s2cr;
 
-               idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i];
+               idx = cfg->smrs ? cfg->smrs[i].idx : fwspec->ids[i];
                s2cr = S2CR_TYPE_TRANS |
                       (smmu_domain->cfg.cbndx << S2CR_CBNDX_SHIFT);
                writel_relaxed(s2cr, gr0_base + ARM_SMMU_GR0_S2CR(idx));
@@ -1489,6 +1502,7 @@ static void arm_smmu_domain_remove_master(struct 
arm_smmu_domain *smmu_domain,
        int i;
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+       struct iommu_fwspec *fwspec = arm_smmu_get_fwspec(cfg);
 
        /* An IOMMU group is torn down by the first device to be removed */
        if ((smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) && !cfg->smrs)
@@ -1499,8 +1513,8 @@ static void arm_smmu_domain_remove_master(struct 
arm_smmu_domain *smmu_domain,
         * that it can be re-allocated immediately.
         * Xen: Unlike Linux, any access to non-configured stream will fault.
         */
-       for (i = 0; i < cfg->num_streamids; ++i) {
-               u32 idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i];
+       for (i = 0; i < fwspec->num_ids; ++i) {
+               u32 idx = cfg->smrs ? cfg->smrs[i].idx : fwspec->ids[i];
 
                writel_relaxed(S2CR_TYPE_FAULT,
                               gr0_base + ARM_SMMU_GR0_S2CR(idx));
@@ -1903,9 +1917,9 @@ static int arm_smmu_add_device(struct device *dev)
        struct arm_smmu_device *smmu;
        struct arm_smmu_master_cfg *cfg;
        struct iommu_group *group;
+       struct iommu_fwspec *fwspec;
        void (*releasefn)(void *) = NULL;
        int ret;
-
        smmu = find_smmu_for_device(dev);
        if (!smmu)
                return -ENODEV;
@@ -1925,13 +1939,19 @@ static int arm_smmu_add_device(struct device *dev)
                        goto out_put_group;
                }
 
-               cfg->num_streamids = 1;
+               ret = iommu_fwspec_init(dev, smmu->dev);
+               if (ret) {
+                       kfree(cfg);
+                       goto out_put_group;
+               }
+               fwspec = dev_iommu_fwspec_get(dev);
+
                /*
                 * Assume Stream ID == Requester ID for now.
                 * We need a way to describe the ID mappings in FDT.
                 */
                pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid,
-                                      &cfg->streamids[0]);
+                                      &fwspec->ids[0]);
                releasefn = __arm_smmu_release_pci_iommudata;
        } else {
                struct arm_smmu_master *master;
diff --git a/xen/drivers/passthrough/device_tree.c 
b/xen/drivers/passthrough/device_tree.c
index 999b831d90..a51ae3c9c3 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -140,6 +140,13 @@ int iommu_add_dt_device(struct dt_device_node *np)
     if ( !ops )
         return -EINVAL;
 
+       /*
+        * This is needed in case a device has both the iommus property and
+        * also apperars in the mmu-masters list.
+        */
+    if ( dt_device_is_protected(np) )
+        return 0;
+
     if ( dev_iommu_fwspec_get(dev) )
         return -EEXIST;
 
-- 
2.17.1




 


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