Re: [PATCH v3 2/6] drm/xe/mmio: Map MMIO BAR using managed version of pci_iomap

[Matthew Auld <matthew.auld@intel.com>]

On 22/06/2026 14:23, Michal Wajdeczko wrote:
> This will allow us to simplify our custom release action where we
> will keep only zeroing of the xe->mmio.regs as we still rely on it
> all checks during all xe_mmio operations. While around, add missing
> kernel-doc for the function and update the error message.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Matthew Auld <matthew.auld@intel.com>

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> ---
> v2: keep fini action to zero xe->mmio.regs (Matthew)
> ---
>   drivers/gpu/drm/xe/xe_mmio.c | 24 ++++++++++++++----------
>   1 file changed, 14 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
> index 7e0cefcd16bd..fce890b6410c 100644
> --- a/drivers/gpu/drm/xe/xe_mmio.c
> +++ b/drivers/gpu/drm/xe/xe_mmio.c
> @@ -16,6 +16,7 @@
>   #include "regs/xe_bars.h"
>   #include "xe_device.h"
>   #include "xe_gt_sriov_vf.h"
> +#include "xe_printk.h"
>   #include "xe_sriov.h"
>   #include "xe_tile_printk.h"
>   #include "xe_trace.h"
> @@ -80,27 +81,30 @@ int xe_mmio_probe_tiles(struct xe_device *xe)
>   static void mmio_fini(void *arg)
>   {
>   	struct xe_device *xe = arg;
> -	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
>   
> -	pci_iounmap(to_pci_dev(xe->drm.dev), xe->mmio.regs);
>   	xe->mmio.regs = NULL;
> -	root_tile->mmio.regs = NULL;
>   }
>   
> +/**
> + * xe_mmio_probe_early() - Probe and initialize device's MMIO
> + * @xe: the &xe_device
> + *
> + * Map the entire GTTMMADR_BAR and initialize the first tile's MMIO instance.
> + *
> + * The first 16MB of the GTTMMADR_BAR always belongs to the root tile, and
> + * includes: registers (0-4MB), reserved space (4MB-8MB) and GGTT (8MB-16MB).
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
>   int xe_mmio_probe_early(struct xe_device *xe)
>   {
>   	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
>   	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>   
> -	/*
> -	 * Map the entire BAR.
> -	 * The first 16MB of the BAR, belong to the root tile, and include:
> -	 * registers (0-4MB), reserved space (4MB-8MB) and GGTT (8MB-16MB).
> -	 */
>   	xe->mmio.size = pci_resource_len(pdev, GTTMMADR_BAR);
> -	xe->mmio.regs = pci_iomap(pdev, GTTMMADR_BAR, 0);
> +	xe->mmio.regs = pcim_iomap(pdev, GTTMMADR_BAR, 0);
>   	if (!xe->mmio.regs) {
> -		drm_err(&xe->drm, "failed to map registers\n");
> +		xe_err(xe, "Failed to map GTTMMADR_BAR\n");
>   		return -EIO;
>   	}
>