Re: [PATCH v3 2/9] PCI: endpoint: Allocate a 64-bit BAR if that is the only option

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Wed, Mar 13, 2024 at 11:57:54AM +0100, Niklas Cassel wrote:
> pci_epf_alloc_space() already sets the 64-bit flag if the BAR size is
> larger than 4GB, even if the caller did not explicitly request a 64-bit
> BAR.
> 
> Thus, let pci_epf_alloc_space() also set the 64-bit flag if the hardware
> description says that the specific BAR can only be 64-bit.
> 

Could you please update the kdoc of pci_epf_alloc_space() to reflec the same?

> Signed-off-by: Niklas Cassel <cassel@kernel.org>

With that,

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

- Mani

> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 3 ++-
>  drivers/pci/endpoint/pci-epf-core.c           | 7 ++++---
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 01ba088849cc..8c9802b9b835 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -868,7 +868,8 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
>  
>  		/*
>  		 * pci_epf_alloc_space() might have given us a 64-bit BAR,
> -		 * if we requested a size larger than 4 GB.
> +		 * either because the BAR can only be a 64-bit BAR, or if
> +		 * we requested a size larger than 4 GB.
>  		 */
>  		add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1;
>  	}
> diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
> index 0a28a0b0911b..e7dbbeb1f0de 100644
> --- a/drivers/pci/endpoint/pci-epf-core.c
> +++ b/drivers/pci/endpoint/pci-epf-core.c
> @@ -304,9 +304,10 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
>  	epf_bar[bar].addr = space;
>  	epf_bar[bar].size = size;
>  	epf_bar[bar].barno = bar;
> -	epf_bar[bar].flags |= upper_32_bits(size) ?
> -				PCI_BASE_ADDRESS_MEM_TYPE_64 :
> -				PCI_BASE_ADDRESS_MEM_TYPE_32;
> +	if (upper_32_bits(size) || epc_features->bar[bar].only_64bit)
> +		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
> +	else
> +		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_32;
>  
>  	return space;
>  }
> -- 
> 2.44.0
> 

-- 
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