drm/tyr: set DMA mask using GPU physical address

Configure the device DMA mask during probe using the GPU's physical
address capability reported in GpuInfo. This ensures DMA allocations
use an appropriate address mask.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Co-developed-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260428-fw-boot-prerequisites-v1-4-c69af9abe1af@collabora.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>

diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
index cdb9b13bdb3291a0356a58cc9b2a18d60becb7a0..e20a5978eed6d0cc434663b65dac18c3bc8c1133 100644 (file)
--- a/drivers/gpu/drm/tyr/driver.rs
+++ b/drivers/gpu/drm/tyr/driver.rs
@@ -11,6 +11,10 @@ use kernel::{
         Device, //
     },
     devres::Devres,
+    dma::{
+        Device as DmaDevice,
+        DmaMask, //
+    },
     drm,
     drm::ioctl,
     io::{
@@ -124,6 +128,14 @@ impl platform::Driver for TyrPlatformDriverData {
         let gpu_info = GpuInfo::new(pdev.as_ref(), &iomem)?;
         gpu_info.log(pdev.as_ref());
 
+        let pa_bits = MMU_FEATURES::from_raw(gpu_info.mmu_features)
+            .pa_bits()
+            .get();
+        // SAFETY: No concurrent DMA allocations or mappings can be made because
+        // the device is still being probed and therefore isn't being used by
+        // other threads of execution.
+        unsafe { pdev.dma_set_mask_and_coherent(DmaMask::try_new(pa_bits)?)? };
+
         let platform: ARef<platform::Device> = pdev.into();
 
         let data = try_pin_init!(TyrDrmDeviceData {