Re: [PATCH v8 10/18] iommu/arm-smmu: Implement reserved region get/put callbacks

[Tomasz Nowicki]

On 11.01.2017 10:41, Eric Auger wrote:

The get() populates the list with the MSI IOVA reserved window.

At the moment an arbitray MSI IOVA window is set at 0x8000000
of size 1MB. This will allow to report those info in iommu-group
sysfs.

Signed-off-by: Eric Auger <eric.au...@redhat.com>

Reviewed-by: Tomasz Nowicki <tomasz.nowi...@caviumnetworks.com>

Thanks,
Tomasz

---

v3 -> v4:
- do not handle PCI host bridge windows anymore
- encode prot

RFC v2 -> v3:
- use existing get/put_resv_regions

RFC v1 -> v2:
- use defines for MSI IOVA base and length
---
 drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a60cded..a354572 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -281,6 +281,9 @@ enum arm_smmu_s2cr_privcfg {

 #define FSYNR0_WNR                     (1 << 4)

+#define MSI_IOVA_BASE                  0x8000000
+#define MSI_IOVA_LENGTH                        0x100000
+
 static int force_stage;
 module_param(force_stage, int, S_IRUGO);
 MODULE_PARM_DESC(force_stage,
@@ -1549,6 +1552,29 @@ static int arm_smmu_of_xlate(struct device *dev, struct 
of_phandle_args *args)
        return iommu_fwspec_add_ids(dev, &fwid, 1);
 }

+static void arm_smmu_get_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *region;
+       int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+
+       region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+                                        prot, IOMMU_RESV_MSI);
+       if (!region)
+               return;
+
+       list_add_tail(&region->list, head);
+}
+
+static void arm_smmu_put_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *entry, *next;
+
+       list_for_each_entry_safe(entry, next, head, list)
+               kfree(entry);
+}
+
 static struct iommu_ops arm_smmu_ops = {
        .capable                = arm_smmu_capable,
        .domain_alloc           = arm_smmu_domain_alloc,
@@ -1564,6 +1590,8 @@ static int arm_smmu_of_xlate(struct device *dev, struct 
of_phandle_args *args)
        .domain_get_attr        = arm_smmu_domain_get_attr,
        .domain_set_attr        = arm_smmu_domain_set_attr,
        .of_xlate               = arm_smmu_of_xlate,
+       .get_resv_regions       = arm_smmu_get_resv_regions,
+       .put_resv_regions       = arm_smmu_put_resv_regions,
        .pgsize_bitmap          = -1UL, /* Restricted during device attach */
 };