Re: [PATCH v3 8/9] PCI: rockchip-ep: Set a 64-bit BAR if requested

From: Niklas Cassel <cassel@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Shawn Lin" <shawn.lin@rock-chips.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Shradha Todi" <shradha.t@samsung.com>,
	"Damien Le Moal" <dlemoal@kernel.org>,
	linux-pci@vger.kernel.org, linux-rockchip@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 8/9] PCI: rockchip-ep: Set a 64-bit BAR if requested
Date: Sat, 13 Apr 2024 00:02:12 +0200	[thread overview]
Message-ID: <ZhmvZJg7A11tyh5Q@ryzen> (raw)
In-Reply-To: <20240412185901.GA10301@bhelgaas>

On Fri, Apr 12, 2024 at 01:59:01PM -0500, Bjorn Helgaas wrote:
> On Wed, Mar 13, 2024 at 11:58:00AM +0100, Niklas Cassel wrote:
> > ...
> 
> > --- a/drivers/pci/controller/pcie-rockchip-ep.c
> > +++ b/drivers/pci/controller/pcie-rockchip-ep.c
> > @@ -153,7 +153,7 @@ static int rockchip_pcie_ep_set_bar(struct pci_epc *epc, u8 fn, u8 vfn,
> >  		ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_IO_32BITS;
> >  	} else {
> >  		bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH);
> > -		bool is_64bits = sz > SZ_2G;
> > +		bool is_64bits = !!(flags & PCI_BASE_ADDRESS_MEM_TYPE_64);
> >  
> >  		if (is_64bits && (bar & 1))
> >  			return -EINVAL;
> 
> Completely unrelated to *these* patches, but the BAR_CFG_CTRL
> definitions in both cadence and rockchip lead to some awkward case
> analysis:
> 
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_32BITS              0x4
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_32BITS     0x5
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_64BITS              0x6
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_64BITS     0x7
> 
>   if (is_64bits && is_prefetch)
>           ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
>   else if (is_prefetch)
>           ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
>   else if (is_64bits)
>           ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_64BITS;
>   else
>           ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM_32BITS;
> 
> that *could* be just something like this:
> 
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM           0x4
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_64BITS        0x2
>   #define ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH      0x1
> 
>   ctrl = ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_MEM;
>   if (is_64bits)
>     ctrl |= ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_64BITS;
>   if (is_prefetch)
>     ctrl |= ROCKCHIP_PCIE_CORE_BAR_CFG_CTRL_PREFETCH;


If you send the cleanup patches, I will send the Reviewed-by tags ;)


Kind regards,
Niklas