Re: [PATCH v2 12/12] drm/gma500: Move GTT memory-range setup into helper

[Patrik Jakobsson <patrik.r.jakobsson@gmail.com>]

On Tue, Mar 8, 2022 at 8:52 PM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Move the setup code for GTT/GATT memory ranges into a new helper and
> call the function from psb_gtt_init() and psb_gtt_resume(). Removes
> code duplication.

LGTM
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/gma500/gtt.c | 153 +++++++++++++++--------------------
>  1 file changed, 64 insertions(+), 89 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
> index 83d9a9f7c73c..379bc218aa6b 100644
> --- a/drivers/gpu/drm/gma500/gtt.c
> +++ b/drivers/gpu/drm/gma500/gtt.c
> @@ -182,68 +182,91 @@ static void psb_gtt_clear(struct drm_psb_private *pdev)
>         (void)ioread32(pdev->gtt_map + i - 1);
>  }
>
> -int psb_gtt_init(struct drm_device *dev)
> +static void psb_gtt_init_ranges(struct drm_psb_private *dev_priv)
>  {
> -       struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
> +       struct drm_device *dev = &dev_priv->dev;
>         struct pci_dev *pdev = to_pci_dev(dev->dev);
>         struct psb_gtt *pg = &dev_priv->gtt;
> -       unsigned gtt_pages;
> -       int ret;
> -
> -       mutex_init(&dev_priv->gtt_mutex);
> -
> -       ret = psb_gtt_enable(dev_priv);
> -       if (ret)
> -               goto err_mutex_destroy;
> +       resource_size_t gtt_phys_start, mmu_gatt_start, gtt_start, gtt_pages,
> +                       gatt_start, gatt_pages;
> +       struct resource *gtt_mem;
>
>         /* The root resource we allocate address space from */
> -       pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
> +       gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
>
>         /*
> -        *      The video mmu has a hw bug when accessing 0x0D0000000.
> -        *      Make gatt start at 0x0e000,0000. This doesn't actually
> -        *      matter for us but may do if the video acceleration ever
> -        *      gets opened up.
> +        * The video MMU has a HW bug when accessing 0x0d0000000. Make
> +        * GATT start at 0x0e0000000. This doesn't actually matter for
> +        * us now, but maybe will if the video acceleration ever gets
> +        * opened up.
>          */
> -       pg->mmu_gatt_start = 0xE0000000;
> +       mmu_gatt_start = 0xe0000000;
> +
> +       gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
> +       gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE) >> PAGE_SHIFT;
>
> -       pg->gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
> -       gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE)
> -                                                               >> PAGE_SHIFT;
>         /* CDV doesn't report this. In which case the system has 64 gtt pages */
> -       if (pg->gtt_start == 0 || gtt_pages == 0) {
> +       if (!gtt_start || !gtt_pages) {
>                 dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
>                 gtt_pages = 64;
> -               pg->gtt_start = dev_priv->pge_ctl;
> +               gtt_start = dev_priv->pge_ctl;
>         }
>
> -       pg->gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
> -       pg->gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE)
> -                                                               >> PAGE_SHIFT;
> -       dev_priv->gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];
> +       gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
> +       gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE) >> PAGE_SHIFT;
>
> -       if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
> +       if (!gatt_pages || !gatt_start) {
>                 static struct resource fudge;   /* Preferably peppermint */
> -               /* This can occur on CDV systems. Fudge it in this case.
> -                  We really don't care what imaginary space is being allocated
> -                  at this point */
> +
> +               /*
> +                * This can occur on CDV systems. Fudge it in this case. We
> +                * really don't care what imaginary space is being allocated
> +                * at this point.
> +                */
>                 dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
> -               pg->gatt_start = 0x40000000;
> -               pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
> -               /* This is a little confusing but in fact the GTT is providing
> -                  a view from the GPU into memory and not vice versa. As such
> -                  this is really allocating space that is not the same as the
> -                  CPU address space on CDV */
> +               gatt_start = 0x40000000;
> +               gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
> +
> +               /*
> +                * This is a little confusing but in fact the GTT is providing
> +                * a view from the GPU into memory and not vice versa. As such
> +                * this is really allocating space that is not the same as the
> +                * CPU address space on CDV.
> +                */
>                 fudge.start = 0x40000000;
>                 fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
>                 fudge.name = "fudge";
>                 fudge.flags = IORESOURCE_MEM;
> -               dev_priv->gtt_mem = &fudge;
> +
> +               gtt_mem = &fudge;
> +       } else {
> +               gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];
>         }
>
> +       pg->gtt_phys_start = gtt_phys_start;
> +       pg->mmu_gatt_start = mmu_gatt_start;
> +       pg->gtt_start = gtt_start;
>         pg->gtt_pages = gtt_pages;
> +       pg->gatt_start = gatt_start;
> +       pg->gatt_pages = gatt_pages;
> +       dev_priv->gtt_mem = gtt_mem;
> +}
> +
> +int psb_gtt_init(struct drm_device *dev)
> +{
> +       struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
> +       struct psb_gtt *pg = &dev_priv->gtt;
> +       int ret;
> +
> +       mutex_init(&dev_priv->gtt_mutex);
> +
> +       ret = psb_gtt_enable(dev_priv);
> +       if (ret)
> +               goto err_mutex_destroy;
>
> -       dev_priv->gtt_map = ioremap(pg->gtt_phys_start, gtt_pages << PAGE_SHIFT);
> +       psb_gtt_init_ranges(dev_priv);
> +
> +       dev_priv->gtt_map = ioremap(pg->gtt_phys_start, pg->gtt_pages << PAGE_SHIFT);
>         if (!dev_priv->gtt_map) {
>                 dev_err(dev->dev, "Failure to map gtt.\n");
>                 ret = -ENOMEM;
> @@ -264,9 +287,8 @@ int psb_gtt_init(struct drm_device *dev)
>  int psb_gtt_resume(struct drm_device *dev)
>  {
>         struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
> -       struct pci_dev *pdev = to_pci_dev(dev->dev);
>         struct psb_gtt *pg = &dev_priv->gtt;
> -       unsigned int gtt_pages;
> +       unsigned int old_gtt_pages = pg->gtt_pages;
>         int ret;
>
>         /* Enable the GTT */
> @@ -274,61 +296,14 @@ int psb_gtt_resume(struct drm_device *dev)
>         if (ret)
>                 return ret;
>
> -       /* The root resource we allocate address space from */
> -       pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
> -
> -       /*
> -        *      The video mmu has a hw bug when accessing 0x0D0000000.
> -        *      Make gatt start at 0x0e000,0000. This doesn't actually
> -        *      matter for us but may do if the video acceleration ever
> -        *      gets opened up.
> -        */
> -       pg->mmu_gatt_start = 0xE0000000;
> -
> -       pg->gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
> -       gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE) >> PAGE_SHIFT;
> -       /* CDV doesn't report this. In which case the system has 64 gtt pages */
> -       if (pg->gtt_start == 0 || gtt_pages == 0) {
> -               dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
> -               gtt_pages = 64;
> -               pg->gtt_start = dev_priv->pge_ctl;
> -       }
> -
> -       pg->gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
> -       pg->gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE) >> PAGE_SHIFT;
> -       dev_priv->gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];
> +       psb_gtt_init_ranges(dev_priv);
>
> -       if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
> -               static struct resource fudge;   /* Preferably peppermint */
> -               /*
> -                * This can occur on CDV systems. Fudge it in this case. We
> -                * really don't care what imaginary space is being allocated
> -                * at this point.
> -                */
> -               dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
> -               pg->gatt_start = 0x40000000;
> -               pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
> -               /*
> -                * This is a little confusing but in fact the GTT is providing
> -                * a view from the GPU into memory and not vice versa. As such
> -                *  this is really allocating space that is not the same as the
> -                *  CPU address space on CDV.
> -                */
> -               fudge.start = 0x40000000;
> -               fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
> -               fudge.name = "fudge";
> -               fudge.flags = IORESOURCE_MEM;
> -               dev_priv->gtt_mem = &fudge;
> -       }
> -
> -       if (gtt_pages != pg->gtt_pages) {
> +       if (old_gtt_pages != pg->gtt_pages) {
>                 dev_err(dev->dev, "GTT resume error.\n");
> -               ret = -EINVAL;
> +               ret = -ENODEV;
>                 goto err_psb_gtt_disable;
>         }
>
> -       pg->gtt_pages = gtt_pages;
> -
>         psb_gtt_clear(dev_priv);
>
>  err_psb_gtt_disable:
> --
> 2.35.1
>