Re: [PATCH] drm/amdgpu: modify a pair of functions for the pcie port wreg/rreg

["Lazar, Lijo" <lijo.lazar@xxxxxxx>]

On 1/18/2022 4:56 PM, Xiaojian Du wrote:
> This patch will modify a pair of functions for pcie port wreg/rreg.
> AMD GPU have had an independent NBIO block from SOC15 arch.
> If the dirver wants to read/write the address space of the pcie devices,
> it has to go through the NBIO block.
> This patch will move the pcie port wreg/rreg functions to
> "amdgpu_device.c", so that to make the functions can be used on the
> future GPU ASICs.
>
> Signed-off-by: Xiaojian Du <Xiaojian.Du@xxxxxxx>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  4 +++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 33 +++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/nv.c            | 34 ++--------------------
>   3 files changed, 39 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index b2da840f4718..691d7868d64d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1421,6 +1421,10 @@ void amdgpu_device_invalidate_hdp(struct amdgpu_device *adev,
>   		struct amdgpu_ring *ring);
>   
>   void amdgpu_device_halt(struct amdgpu_device *adev);
> +u32 amdgpu_device_pcie_port_rreg(struct amdgpu_device *adev,
> +				u32 reg);
> +void amdgpu_device_pcie_port_wreg(struct amdgpu_device *adev,
> +				u32 reg, u32 v);
>   
>   /* atpx handler */
>   #if defined(CONFIG_VGA_SWITCHEROO)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index ff4cf0e2a01f..10f2b7cbb49d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -6023,3 +6023,36 @@ void amdgpu_device_halt(struct amdgpu_device *adev)
>   	pci_disable_device(pdev);
>   	pci_wait_for_pending_transaction(pdev);
>   }
> +
> +u32 amdgpu_device_pcie_port_rreg(struct amdgpu_device *adev,
> +				u32 reg)
> +{
> +	unsigned long flags, address, data;
> +	u32 r;
> +
> +	address = adev->nbio.funcs->get_pcie_port_index_offset(adev);
> +	data = adev->nbio.funcs->get_pcie_port_data_offset(adev);
> +
> +	spin_lock_irqsave(&adev->pcie_idx_lock, flags);
> +	WREG32(address, reg * 4);
> +	(void)RREG32(address);
> +	r = RREG32(data);
> +	spin_unlock_irqrestore(&adev->pcie_idx_lock, flags);
> +	return r;
> +}
> +
> +void amdgpu_device_pcie_port_wreg(struct amdgpu_device *adev,
> +				u32 reg, u32 v)
> +{
> +	unsigned long flags, address, data;
> +
> +	address = adev->nbio.funcs->get_pcie_port_index_offset(adev);
> +	data = adev->nbio.funcs->get_pcie_port_data_offset(adev);
> +
> +	spin_lock_irqsave(&adev->pcie_idx_lock, flags);
> +	WREG32(address, reg * 4);
> +	(void)RREG32(address);
> +	WREG32(data, v);
> +	(void)RREG32(data);
> +	spin_unlock_irqrestore(&adev->pcie_idx_lock, flags);
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
> index e52d1114501c..17480c1eeae8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/nv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/nv.c
> @@ -256,21 +256,6 @@ static u64 nv_pcie_rreg64(struct amdgpu_device *adev, u32 reg)
>   	return amdgpu_device_indirect_rreg64(adev, address, data, reg);
>   }
>   
> -static u32 nv_pcie_port_rreg(struct amdgpu_device *adev, u32 reg)
> -{
> -	unsigned long flags, address, data;
> -	u32 r;
> -	address = adev->nbio.funcs->get_pcie_port_index_offset(adev);
> -	data = adev->nbio.funcs->get_pcie_port_data_offset(adev);
> -
> -	spin_lock_irqsave(&adev->pcie_idx_lock, flags);
> -	WREG32(address, reg * 4);
> -	(void)RREG32(address);
> -	r = RREG32(data);
> -	spin_unlock_irqrestore(&adev->pcie_idx_lock, flags);
> -	return r;
> -}
> -
>   static void nv_pcie_wreg64(struct amdgpu_device *adev, u32 reg, u64 v)
>   {
>   	unsigned long address, data;
> @@ -281,21 +266,6 @@ static void nv_pcie_wreg64(struct amdgpu_device *adev, u32 reg, u64 v)
>   	amdgpu_device_indirect_wreg64(adev, address, data, reg, v);
>   }
>   
> -static void nv_pcie_port_wreg(struct amdgpu_device *adev, u32 reg, u32 v)
> -{
> -	unsigned long flags, address, data;
> -
> -	address = adev->nbio.funcs->get_pcie_port_index_offset(adev);
> -	data = adev->nbio.funcs->get_pcie_port_data_offset(adev);
> -
> -	spin_lock_irqsave(&adev->pcie_idx_lock, flags);
> -	WREG32(address, reg * 4);
> -	(void)RREG32(address);
> -	WREG32(data, v);
> -	(void)RREG32(data);
> -	spin_unlock_irqrestore(&adev->pcie_idx_lock, flags);
> -}
> -
>   static u32 nv_didt_rreg(struct amdgpu_device *adev, u32 reg)
>   {
>   	unsigned long flags, address, data;
> @@ -709,8 +679,8 @@ static int nv_common_early_init(void *handle)
>   	adev->pcie_wreg = &nv_pcie_wreg;
>   	adev->pcie_rreg64 = &nv_pcie_rreg64;
>   	adev->pcie_wreg64 = &nv_pcie_wreg64;

Looks good, would be better if the above ones also are changed to common 
implementation.

Thanks,
Lijo

> -	adev->pciep_rreg = &nv_pcie_port_rreg;
> -	adev->pciep_wreg = &nv_pcie_port_wreg;
> +	adev->pciep_rreg = amdgpu_device_pcie_port_rreg;
> +	adev->pciep_wreg = amdgpu_device_pcie_port_wreg;
>   
>   	/* TODO: will add them during VCN v2 implementation */
>   	adev->uvd_ctx_rreg = NULL;