gpu: host1x: Add IOMMU support

Add support for the Host1x unit to be located behind
an IOMMU. This is required when gather buffers may be
allocated non-contiguously in physical memory, as can
be the case when TegraDRM is also using the IOMMU.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 39 insertions, 2 deletions

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index a62317af76ad..b386a0bf828a 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -27,6 +27,7 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/host1x.h>
+#undef CREATE_TRACE_POINTS
 
 #include "bus.h"
 #include "dev.h"
@@ -168,16 +169,37 @@ static int host1x_probe(struct platform_device *pdev)
                 return err;
         }
 
+        if (iommu_present(&platform_bus_type)) {
+                struct iommu_domain_geometry *geometry;
+                unsigned long order;
+
+                host->domain = iommu_domain_alloc(&platform_bus_type);
+                if (!host->domain)
+                        return -ENOMEM;
+
+                err = iommu_attach_device(host->domain, &pdev->dev);
+                if (err)
+                        goto fail_free_domain;
+
+                geometry = &host->domain->geometry;
+
+                order = __ffs(host->domain->pgsize_bitmap);
+                init_iova_domain(&host->iova, 1UL << order,
+                                 geometry->aperture_start >> order,
+                                 geometry->aperture_end >> order);
+                host->iova_end = geometry->aperture_end;
+        }
+
         err = host1x_channel_list_init(host);
         if (err) {
                 dev_err(&pdev->dev, "failed to initialize channel list\n");
-                return err;
+                goto fail_detach_device;
         }
 
         err = clk_prepare_enable(host->clk);
         if (err < 0) {
                 dev_err(&pdev->dev, "failed to enable clock\n");
-                return err;
+                goto fail_detach_device;
         }
 
         err = host1x_syncpt_init(host);
@@ -206,6 +228,15 @@ fail_deinit_syncpt:
         host1x_syncpt_deinit(host);
 fail_unprepare_disable:
         clk_disable_unprepare(host->clk);
+fail_detach_device:
+        if (host->domain) {
+                put_iova_domain(&host->iova);
+                iommu_detach_device(host->domain, &pdev->dev);
+        }
+fail_free_domain:
+        if (host->domain)
+                iommu_domain_free(host->domain);
+
         return err;
 }
 
@@ -218,6 +249,12 @@ static int host1x_remove(struct platform_device *pdev)
         host1x_syncpt_deinit(host);
         clk_disable_unprepare(host->clk);
 
+        if (host->domain) {
+                put_iova_domain(&host->iova);
+                iommu_detach_device(host->domain, &pdev->dev);
+                iommu_domain_free(host->domain);
+        }
+
         return 0;
 }