[PATCH] drm/radeon: fix VM page table setup on SI

[Jerome Glisse]

On Thu, Jun 28, 2012 at 5:53 PM,  <alexdeucher at gmail.com> wrote:
> From: Alex Deucher <alexander.deucher at amd.com>
>
> Cayman and trinity allow for variable sized VM page
> tables, but SI requires that all page tables be the
> same size.  The current code assumes variablely sized
> VM page tables so SI may end up with part of each page
> table overlapping with other memory which could end
> up being interpreted by the VM hw as garbage.
>
> Change the code to better accomodate SI.  Allocate enough
> space for at least 2 full page tables and always set
> last_pfn to max_pfn on SI so each VM is backed by a full
> page table.  This limits us to only 2 VMs active at any
> given time on SI.  This will be rectified and the code can
> be reunified once we move to two level page tables.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Reviewed-by: Jerome Glisse <jglisse at redhat.com>
> Cc: stable at vger.kernel.org
> ---
>  drivers/gpu/drm/radeon/radeon_gart.c |   13 +++++++++++--
>  drivers/gpu/drm/radeon/si.c          |    4 ++--
>  2 files changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
> index 2b34c1a..8c44d1d 100644
> --- a/drivers/gpu/drm/radeon/radeon_gart.c
> +++ b/drivers/gpu/drm/radeon/radeon_gart.c
> @@ -289,8 +289,9 @@ int radeon_vm_manager_init(struct radeon_device *rdev)
>        rdev->vm_manager.enabled = false;
>
>        /* mark first vm as always in use, it's the system one */
> +       /* allocate enough for 2 full VM pts */
>        r = radeon_sa_bo_manager_init(rdev, &rdev->vm_manager.sa_manager,
> -                                     rdev->vm_manager.max_pfn * 8,
> +                                     rdev->vm_manager.max_pfn * 8 * 2,
>                                      RADEON_GEM_DOMAIN_VRAM);
>        if (r) {
>                dev_err(rdev->dev, "failed to allocate vm bo (%dKB)\n",
> @@ -633,7 +634,15 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
>        mutex_init(&vm->mutex);
>        INIT_LIST_HEAD(&vm->list);
>        INIT_LIST_HEAD(&vm->va);
> -       vm->last_pfn = 0;
> +       /* SI requires equal sized PTs for all VMs, so always set
> +        * last_pfn to max_pfn.  cayman allows variable sized
> +        * pts so we can grow then as needed.  Once we switch
> +        * to two level pts we can unify this again.
> +        */
> +       if (rdev->family >= CHIP_TAHITI)
> +               vm->last_pfn = rdev->vm_manager.max_pfn;
> +       else
> +               vm->last_pfn = 0;
>        /* map the ib pool buffer at 0 in virtual address space, set
>         * read only
>         */
> diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
> index 34603b3c8..127600e 100644
> --- a/drivers/gpu/drm/radeon/si.c
> +++ b/drivers/gpu/drm/radeon/si.c
> @@ -2365,12 +2365,12 @@ int si_pcie_gart_enable(struct radeon_device *rdev)
>        WREG32(0x15DC, 0);
>
>        /* empty context1-15 */
> -       /* FIXME start with 1G, once using 2 level pt switch to full
> +       /* FIXME start with 4G, once using 2 level pt switch to full
>         * vm size space
>         */
>        /* set vm size, must be a multiple of 4 */
>        WREG32(VM_CONTEXT1_PAGE_TABLE_START_ADDR, 0);
> -       WREG32(VM_CONTEXT1_PAGE_TABLE_END_ADDR, (1 << 30) / RADEON_GPU_PAGE_SIZE);
> +       WREG32(VM_CONTEXT1_PAGE_TABLE_END_ADDR, rdev->vm_manager.max_pfn);
>        for (i = 1; i < 16; i++) {
>                if (i < 8)
>                        WREG32(VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2),
> --
> 1.7.7.5
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel