On Tue, 2026-10-06 at 11:08 +0300, Alexandru Dadu wrote:
Hi Dadu,
> From: Alessio Belle <[email protected]>
>
> Every time a virtual memory context is created, the driver reads the
> size of the virtual address space, as reported by the firmware binary,
> and compares it against a define for the same, but both values are fixed
> on a given core, and on top of that, all known Imagination GPU cores use
> the same 40-bit virtual address space.
>
> Move the check above to a new function for GPU device info validation
> code, so it's performed only once.
> This also allows other areas of the driver to reference the relevant
> defines without having to perform other checks at runtime, as long as
> all cores keep using the same virtual address space.
>
> Signed-off-by: Alessio Belle <[email protected]>
> Signed-off-by: Alexandru Dadu <[email protected]>
> ---
> drivers/gpu/drm/imagination/pvr_device.c | 43
> +++++++++++++++++++++++++++++---
> drivers/gpu/drm/imagination/pvr_mmu.h | 2 +-
> drivers/gpu/drm/imagination/pvr_vm.c | 22 +---------------
> 3 files changed, 42 insertions(+), 25 deletions(-)
>
Reviewed-by: Brajesh Gupta <[email protected]>
Thanks,
Brajesh
> diff --git a/drivers/gpu/drm/imagination/pvr_device.c
> b/drivers/gpu/drm/imagination/pvr_device.c
> index 35eaa54f75ed..992509d95d28 100644
> --- a/drivers/gpu/drm/imagination/pvr_device.c
> +++ b/drivers/gpu/drm/imagination/pvr_device.c
> @@ -5,6 +5,7 @@
> #include "pvr_device_info.h"
>
> #include "pvr_fw.h"
> +#include "pvr_mmu.h"
> #include "pvr_power.h"
> #include "pvr_queue.h"
> #include "pvr_rogue_cr_defs.h"
> @@ -646,6 +647,36 @@ pvr_set_dma_info(struct pvr_device *pvr_dev)
> return 0;
> }
>
> +/**
> + * pvr_device_info_validate() - Validate PowerVR device information, read
> from
> + * the firmware binary, against what is supported by the driver.
> + * @pvr_dev: Target PowerVR device.
> + *
> + * Returns:
> + * * 0 on success, or
> + * * -%EINVAL if the validation failed.
> + */
> +static int
> +pvr_device_info_validate(struct pvr_device *pvr_dev)
> +{
> + struct drm_device *drm_dev = from_pvr_device(pvr_dev);
> + u16 device_addr_bits;
> + int err;
> +
> + err = PVR_FEATURE_VALUE(pvr_dev, virtual_address_space_bits,
> &device_addr_bits);
> + if (err) {
> + drm_err(drm_dev, "Failed to get device virtual address space
> bits\n");
> + return err;
> + }
> +
> + if (device_addr_bits != PVR_PAGE_TABLE_ADDR_BITS) {
> + drm_err(drm_dev, "Device has unsupported virtual address space
> size\n");
> + return -EINVAL;
> + }
> +
> + return err;
> +}
> +
> /**
> * pvr_device_gpu_init() - GPU-specific initialization for a PowerVR device
> * @pvr_dev: Target PowerVR device.
> @@ -661,9 +692,11 @@ pvr_set_dma_info(struct pvr_device *pvr_dev)
> * Return:
> * * 0 on success,
> * * -%ENODEV if the GPU is not supported,
> - * * Any error returned by pvr_set_dma_info(),
> - * * Any error returned by pvr_memory_context_init(), or
> - * * Any error returned by pvr_request_firmware().
> + * * Any error returned by pvr_request_firmware(),
> + * * Any error returned by pvr_fw_validate_init_device_info(),
> + * * Any error returned by pvr_device_info_validate(),
> + * * Any error returned by pvr_set_dma_info(), or
> + * * Any error returned by pvr_fw_init().
> */
> static int
> pvr_device_gpu_init(struct pvr_device *pvr_dev)
> @@ -691,6 +724,10 @@ pvr_device_gpu_init(struct pvr_device *pvr_dev)
> else
> return -EINVAL;
>
> + err = pvr_device_info_validate(pvr_dev);
> + if (err)
> + return err;
> +
> pvr_stream_create_musthave_masks(pvr_dev);
>
> err = pvr_set_dma_info(pvr_dev);
> diff --git a/drivers/gpu/drm/imagination/pvr_mmu.h
> b/drivers/gpu/drm/imagination/pvr_mmu.h
> index a8ecd460168d..1f9ae00a8b17 100644
> --- a/drivers/gpu/drm/imagination/pvr_mmu.h
> +++ b/drivers/gpu/drm/imagination/pvr_mmu.h
> @@ -62,7 +62,7 @@ struct sg_table;
> *
> * This value is checked at runtime against
> * &pvr_device_features.virtual_address_space_bits by
> - * pvr_vm_create_context(), which will return an error if the feature
> value
> + * pvr_device_info_validate(), which will return an error if the feature
> value
> * does not match this constant.
> *
> * .. admonition:: Future work
> diff --git a/drivers/gpu/drm/imagination/pvr_vm.c
> b/drivers/gpu/drm/imagination/pvr_vm.c
> index ceb78694cd98..304d0743c5aa 100644
> --- a/drivers/gpu/drm/imagination/pvr_vm.c
> +++ b/drivers/gpu/drm/imagination/pvr_vm.c
> @@ -535,8 +535,6 @@ fw_mem_context_init(void *cpu_ptr, void *priv)
> *
> * Return:
> * * A handle to the newly-minted VM context on success,
> - * * -%EINVAL if the feature "virtual address space bits" on @pvr_dev is
> - * missing or has an unsupported value,
> * * -%ENOMEM if allocation of the structure behind the opaque handle fails,
> * or
> * * Any error encountered while setting up internal structures.
> @@ -544,27 +542,9 @@ fw_mem_context_init(void *cpu_ptr, void *priv)
> struct pvr_vm_context *
> pvr_vm_create_context(struct pvr_device *pvr_dev, bool is_userspace_context)
> {
> - struct drm_device *drm_dev = from_pvr_device(pvr_dev);
> -
> struct pvr_vm_context *vm_ctx;
> - u16 device_addr_bits;
> -
> int err;
>
> - err = PVR_FEATURE_VALUE(pvr_dev, virtual_address_space_bits,
> - &device_addr_bits);
> - if (err) {
> - drm_err(drm_dev,
> - "Failed to get device virtual address space bits\n");
> - return ERR_PTR(err);
> - }
> -
> - if (device_addr_bits != PVR_PAGE_TABLE_ADDR_BITS) {
> - drm_err(drm_dev,
> - "Device has unsupported virtual address space size\n");
> - return ERR_PTR(-EINVAL);
> - }
> -
> vm_ctx = kzalloc_obj(*vm_ctx);
> if (!vm_ctx)
> return ERR_PTR(-ENOMEM);
> @@ -589,7 +569,7 @@ pvr_vm_create_context(struct pvr_device *pvr_dev, bool
> is_userspace_context)
> drm_gpuvm_init(&vm_ctx->gpuvm_mgr,
> is_userspace_context ? "PowerVR-user-VM" :
> "PowerVR-FW-VM",
> 0, &pvr_dev->base, &vm_ctx->dummy_gem,
> - 0, 1ULL << device_addr_bits, 0, 0, &pvr_vm_gpuva_ops);
> + 0, PVR_PAGE_TABLE_ADDR_SPACE_SIZE, 0, 0,
> &pvr_vm_gpuva_ops);
>
> mutex_init(&vm_ctx->lock);
> kref_init(&vm_ctx->ref_count);
>
> ---
> base-commit: 6e375de99d0c420169481fcd36064177ab55b09d
> change-id: 20261006-b4-check-virtual-addr-space-size-once-044265ce3fa3
>
> Best regards,
> --
> Alexandru Dadu <[email protected]>
>
