[PATCH v2 3/3] drm/nouveau: Add drm_panic support for nv50+
Jocelyn Falempe
jfalempe at redhat.com
Fri Sep 6 13:10:18 UTC 2024
On 06/09/2024 14:53, Ilia Mirkin wrote:
> On Fri, Sep 6, 2024 at 6:05 AM Jocelyn Falempe <jfalempe at redhat.com
> <mailto:jfalempe at redhat.com>> wrote:
>
> Add drm_panic support, for nv50+ cards.
> It's enough to get the panic screen while running Gnome/Wayland on a
> GTX 1650.
> It doesn't support multi-plane or compressed format.
> Support for other formats and older cards will come later.
> Tiling is only tested on GTX1650, and might be wrong for other cards.
>
>
> I'm moderately sure that nv50 and nvc0 tile differently (the general
> algo is the same, but height is different):
>
> https://envytools.readthedocs.io/en/latest/hw/memory/g80-surface.html?highlight=tiling#blocklinear-surfaces <https://envytools.readthedocs.io/en/latest/hw/memory/g80-surface.html?highlight=tiling#blocklinear-surfaces>
Thanks, it looks like it needs a small adjustment, as in the Doc, GF100
uses a default height of 4, and GF100+ default to 8 (and I've hardcoded
it to NV_TILE_BLK_BASE_HEIGHT 8).
GF100 is still nv50, so it should use this code.
>
> That said, I don't know that nv50 supports scanout of tiled surfaces
> (nor was I aware that nvc0+ did, perhaps it's a recent feature, or
> perhaps I'm just forgetful).
What I know is that when using Gnome/Wayland, the framebuffer is tiled,
and without this tiling code, the panic screen is unreadable.
When using the VT console, the framebuffer is linear, and it's easier.
>
> Cheers,
>
> -ilia
>
>
> Signed-off-by: Jocelyn Falempe <jfalempe at redhat.com
> <mailto:jfalempe at redhat.com>>
> ---
> v2:
> * Rebase and drop already merged patches.
> * Rework the tiling algorithm, using "swizzle" to compute the offset
> inside the block.
>
> drivers/gpu/drm/nouveau/dispnv50/wndw.c | 107 +++++++++++++++++++++++-
> 1 file changed, 105 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> index 7a2cceaee6e9..50ecf6f12b81 100644
> --- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> +++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> @@ -30,11 +30,16 @@
> #include <nvhw/class/cl507e.h>
> #include <nvhw/class/clc37e.h>
>
> +#include <linux/iosys-map.h>
> +
> #include <drm/drm_atomic.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_blend.h>
> -#include <drm/drm_gem_atomic_helper.h>
> #include <drm/drm_fourcc.h>
> +#include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem_atomic_helper.h>
> +#include <drm/drm_panic.h>
> +#include <drm/ttm/ttm_bo.h>
>
> #include "nouveau_bo.h"
> #include "nouveau_gem.h"
> @@ -577,6 +582,93 @@ nv50_wndw_prepare_fb(struct drm_plane *plane,
> struct drm_plane_state *state)
> return 0;
> }
>
> +#define NV_TILE_BLK_BASE_HEIGHT 8 /* In pixel */
> +#define NV_TILE_GOB_SIZE 64 /* In bytes */
> +#define NV_TILE_BLK_WIDTH (NV_TILE_GOB_SIZE / 4) /* For 32 bits
> pixel */
> +
> +/* get the offset in bytes inside the framebuffer, after taking
> tiling into account */
> +static unsigned int nv50_get_tiled_offset(struct drm_scanout_buffer
> *sb, unsigned int blk_h,
> + unsigned int x, unsigned
> int y)
> +{
> + u32 blk_x, blk_y, blk_sz, blk_off, pitch;
> + u32 swizzle;
> +
> + blk_sz = NV_TILE_GOB_SIZE * blk_h;
> + pitch = DIV_ROUND_UP(sb->width, NV_TILE_BLK_WIDTH);
> +
> + /* block coordinate */
> + blk_x = x / NV_TILE_BLK_WIDTH;
> + blk_y = y / blk_h;
> +
> + blk_off = ((blk_y * pitch) + blk_x) * blk_sz;
> +
> + y = y % blk_h;
> +
> + /* Inside the block, use the fast address swizzle to compute
> the offset
> + * For nvidia blocklinear, bit order is yn..y3 x3 y2 x2 y1
> y0 x1 x0
> + */
> + swizzle = (x & 3) | (y & 3) << 2 | (x & 4) << 2 | (y & 4) << 3;
> + swizzle |= (x & 8) << 3 | (y >> 3) << 7;
> +
> + return blk_off + swizzle * 4;
> +}
> +
> +static void nv50_set_pixel(struct drm_scanout_buffer *sb, unsigned
> int x, unsigned int y, u32 color)
> +{
> + struct drm_framebuffer *fb = sb->private;
> + unsigned int off;
> + /* According to DRM_FORMAT_MOD_NVIDIA_BLOCK_LINEAR_2D
> documentation,
> + * the last 4 bits of the modifier is log2(blk_height /
> NV_TILE_BLK_BASE_HEIGHT)
> + */
> + unsigned int blk_h = NV_TILE_BLK_BASE_HEIGHT * (1 <<
> (fb->modifier & 0xf));
> +
> + off = nv50_get_tiled_offset(sb, blk_h, x, y);
> + iosys_map_wr(&sb->map[0], off, u32, color);
> +}
> +
> +static int
> +nv50_wndw_get_scanout_buffer(struct drm_plane *plane, struct
> drm_scanout_buffer *sb)
> +{
> + struct drm_framebuffer *fb;
> + struct nouveau_bo *nvbo;
> +
> + if (!plane->state || !plane->state->fb)
> + return -EINVAL;
> +
> + fb = plane->state->fb;
> + nvbo = nouveau_gem_object(fb->obj[0]);
> +
> + /* Don't support compressed format, or multiplane yet. */
> + if (nvbo->comp || fb->format->num_planes != 1)
> + return -EOPNOTSUPP;
> +
> + if (nouveau_bo_map(nvbo)) {
> + pr_warn("nouveau bo map failed, panic won't be
> displayed\n");
> + return -ENOMEM;
> + }
> +
> + if (nvbo->kmap.bo_kmap_type & TTM_BO_MAP_IOMEM_MASK)
> + iosys_map_set_vaddr_iomem(&sb->map[0],
> nvbo->kmap.virtual);
> + else
> + iosys_map_set_vaddr(&sb->map[0], nvbo->kmap.virtual);
> +
> + sb->height = fb->height;
> + sb->width = fb->width;
> + sb->pitch[0] = fb->pitches[0];
> + sb->format = fb->format;
> +
> + /* If tiling is enabled, use the set_pixel() to display
> correctly.
> + * Only handle 32bits format for now.
> + */
> + if (fb->modifier & 0xf) {
> + if (fb->format->cpp[0] != 4)
> + return -EOPNOTSUPP;
> + sb->private = (void *) fb;
> + sb->set_pixel = nv50_set_pixel;
> + }
> + return 0;
> +}
> +
> static const struct drm_plane_helper_funcs
> nv50_wndw_helper = {
> .prepare_fb = nv50_wndw_prepare_fb,
> @@ -584,6 +676,14 @@ nv50_wndw_helper = {
> .atomic_check = nv50_wndw_atomic_check,
> };
>
> +static const struct drm_plane_helper_funcs
> +nv50_wndw_primary_helper = {
> + .prepare_fb = nv50_wndw_prepare_fb,
> + .cleanup_fb = nv50_wndw_cleanup_fb,
> + .atomic_check = nv50_wndw_atomic_check,
> + .get_scanout_buffer = nv50_wndw_get_scanout_buffer,
> +};
> +
> static void
> nv50_wndw_atomic_destroy_state(struct drm_plane *plane,
> struct drm_plane_state *state)
> @@ -732,7 +832,10 @@ nv50_wndw_new_(const struct nv50_wndw_func
> *func, struct drm_device *dev,
> return ret;
> }
>
> - drm_plane_helper_add(&wndw->plane, &nv50_wndw_helper);
> + if (type == DRM_PLANE_TYPE_PRIMARY)
> + drm_plane_helper_add(&wndw->plane,
> &nv50_wndw_primary_helper);
> + else
> + drm_plane_helper_add(&wndw->plane, &nv50_wndw_helper);
>
> if (wndw->func->ilut) {
> ret = nv50_lut_init(disp, mmu, &wndw->ilut);
> --
> 2.46.0
>
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