Re: [PATCH 1/2] drm/radeon: implement ACPI VFCT vbios fetch

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Aug 16, 2012 at 01:54:55PM -0400, alexdeucher@gmail.com wrote:
> From: David L <equinox-freedesktopbugs@diac24.net>
> 
> This is required for pure UEFI systems.  The vbios is stored
> in ACPI rather than at the legacy vga location.
> 
> Fixes:
> https://bugs.freedesktop.org/show_bug.cgi?id=26891
> 
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/gpu/drm/radeon/radeon_bios.c |   59 ++++++++++++++++++++++++++++++++++
>  1 files changed, 59 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
> index 501f488..f06494a7 100644
> --- a/drivers/gpu/drm/radeon/radeon_bios.c
> +++ b/drivers/gpu/drm/radeon/radeon_bios.c
> @@ -32,6 +32,9 @@
>  
>  #include <linux/vga_switcheroo.h>
>  #include <linux/slab.h>
> +#ifdef CONFIG_ACPI
> +#include <linux/acpi.h>
> +#endif

This #ifdef should not be needed, right?


> +#ifdef CONFIG_ACPI
> +static bool radeon_acpi_vfct_bios(struct radeon_device *rdev)
> +{
> +	bool ret = false;
> +	struct acpi_table_header *hdr;
> +	/* acpi_get_table_with_size is not exported :( */
> +	acpi_size tbl_size = 0x7fffffff;
> +	UEFI_ACPI_VFCT *vfct;
> +	GOP_VBIOS_CONTENT *vbios;
> +	VFCT_IMAGE_HEADER *vhdr;
> +
> +	if (!ACPI_SUCCESS(acpi_get_table("VFCT", 1, &hdr)))
> +		return false;
> +	if (tbl_size < sizeof(UEFI_ACPI_VFCT)) {
> +		DRM_ERROR("ACPI VFCT table present but broken (too short #1)\n");
> +		goto out_unmap;
> +	}
> +
> +	vfct = (UEFI_ACPI_VFCT *)hdr;
> +	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) > tbl_size) {
> +		DRM_ERROR("ACPI VFCT table present but broken (too short #2)\n");
> +		goto out_unmap;
> +	}
> +
> +	vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + vfct->VBIOSImageOffset);
> +	vhdr = &vbios->VbiosHeader;
> +	DRM_INFO("ACPI VFCT contains a BIOS for %02x:%02x.%d %04x:%04x, size %d\n",
> +			vhdr->PCIBus, vhdr->PCIDevice, vhdr->PCIFunction,
> +			vhdr->VendorID, vhdr->DeviceID, vhdr->ImageLength);
> +
> +	if (vhdr->PCIBus != rdev->pdev->bus->number ||
> +	    vhdr->PCIDevice != PCI_SLOT(rdev->pdev->devfn) ||
> +	    vhdr->PCIFunction != PCI_FUNC(rdev->pdev->devfn) ||
> +	    vhdr->VendorID != rdev->pdev->vendor ||
> +	    vhdr->DeviceID != rdev->pdev->device) {
> +		DRM_INFO("ACPI VFCT table is not for this card\n");
> +		goto out_unmap;
> +	};
> +
> +	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) + vhdr->ImageLength > tbl_size) {
> +		DRM_ERROR("ACPI VFCT image truncated\n");
> +		goto out_unmap;
> +	}
> +
> +	rdev->bios = kmemdup(&vbios->VbiosContent, vhdr->ImageLength, GFP_KERNEL);
> +	ret = !!rdev->bios;
> +
> +out_unmap:
> +	/* uh, no idea what to do here... */
> +	return ret;
> +}
> +#endif

Please provide an "empty" function here if the #ifdef is not true, which
then makes the following #ifdef not needed:

> @@ -487,6 +542,10 @@ bool radeon_get_bios(struct radeon_device *rdev)
>  		r = igp_read_bios_from_vram(rdev);
>  	if (r == false)
>  		r = radeon_read_bios(rdev);
> +#ifdef CONFIG_ACPI
> +	if (r == false)
> +		r = radeon_acpi_vfct_bios(rdev);
> +#endif

See, then that #ifdef isn't needed.

That cleans up the code more, remember, we don't want #ifdefs in .c
files unless we _really_ have to have them.

thanks,

greg k-h