linux-kernel - Re: [PATCH v10 1/6] drivers/platform/x86/p2sb: New Primary to Sideband bridge support driver for Intel SOC's

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Date:   Thu, 10 Nov 2016 18:07:16 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Tan Jui Nee <jui.nee.tan@...el.com>,
        mika.westerberg@...ux.intel.com, heikki.krogerus@...ux.intel.com,
        tglx@...utronix.de, dvhart@...radead.org, mingo@...hat.com,
        hpa@...or.com, x86@...nel.org, ptyser@...-inc.com,
        lee.jones@...aro.org, linus.walleij@...aro.org
Cc:     linux-gpio@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org, jonathan.yong@...el.com,
        ong.hock.yu@...el.com, tony.luck@...el.com,
        wan.ahmad.zainie.wan.mohamad@...el.com, yunying.sun@...el.com
Subject: Re: [PATCH v10 1/6] drivers/platform/x86/p2sb: New Primary to
 Sideband bridge support driver for Intel SOC's

On Thu, 2016-11-10 at 17:00 +0800, Tan Jui Nee wrote:
> From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> 
> There is already one and at least one more user coming which
> require an access to Primary to Sideband bridge (P2SB) in order
> to get IO or MMIO bar hidden by BIOS.
> Create a driver to access P2SB for x86 devices.
> 
> Signed-off-by: Yong, Jonathan <jonathan.yong@...el.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>


> +int p2sb_bar(struct pci_dev *pdev, unsigned int devfn,
> +	struct resource *res)
> +{
> +	u32 base_addr;
> +	u64 base64_addr;
> +	unsigned long flags;
> +
> 

> +	if (!res)
> +		return -EINVAL;

I don't remember the details, one version was quite changed, so, I think
these lines are not needed anymore.

> +	/* Get IO or MMIO BAR */
> +	pci_bus_read_config_dword(pdev->bus, devfn, SBREG_BAR,
> &base_addr);
> +	if ((base_addr & PCI_BASE_ADDRESS_SPACE) ==
> PCI_BASE_ADDRESS_SPACE_IO) {
> +		flags = IORESOURCE_IO;
> +		base64_addr = base_addr & PCI_BASE_ADDRESS_IO_MASK;
> +	} else {
> +		flags = IORESOURCE_MEM;
> +		base64_addr = base_addr & PCI_BASE_ADDRESS_MEM_MASK;
> +		if (base_addr & PCI_BASE_ADDRESS_MEM_TYPE_64) {
> +			flags |= IORESOURCE_MEM_64;
> 

> +			pci_bus_read_config_dword(pdev->bus, devfn,
> +				SBREG_BAR + 4, &base_addr);

Fix indentation.

> +			base64_addr |= (u64)base_addr << 32;
> +		}
> +	}
> +
> +	/* Hide the P2SB device */
> +	pci_bus_write_config_byte(pdev->bus, devfn, SBREG_HIDE,
> 0x01);
> +
> +	spin_unlock(&p2sb_spinlock);
> +

> +	/* User provides prefilled resources */

Not anymore as far I as I can see. You just return here the result.

> +	res->start = (resource_size_t)base64_addr;
> +	res->flags = flags;

-- 
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Intel Finland Oy