diff options
| author | Michał Winiarski <michal.winiarski@intel.com> | 2024-08-23 18:30:48 +0200 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2024-08-26 17:06:22 +0200 |
| commit | 071d583e01c88272f6ff216d4f867f8f35e94d7d (patch) | |
| tree | a45574c0d628f519ab5d9f252f4309962b84d47e | |
| parent | 45c4d994b82b08f0ce5eb50f8da29379c92a391e (diff) | |
drm: Expand max DRM device number to full MINORBITS
Having a limit of 64 DRM devices is not good enough for modern world
where we have multi-GPU servers, SR-IOV virtual functions and virtual
devices used for testing.
Let's utilize full minor range for DRM devices.
To avoid regressing the existing userspace, we're still maintaining the
numbering scheme where 0-63 is used for primary, 64-127 is reserved
(formerly for control) and 128-191 is used for render.
For minors >= 192, we're allocating minors dynamically on a first-come,
first-served basis.
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-4-michal.winiarski@intel.com
Acked-by: James Zhu <James.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
| -rw-r--r-- | drivers/gpu/drm/drm_drv.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 0feaaf74abc3..ac30b0ec9d93 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -121,10 +121,19 @@ static void drm_minor_alloc_release(struct drm_device *dev, void *data) xa_erase(drm_minor_get_xa(minor->type), minor->index); } +/* + * DRM used to support 64 devices, for backwards compatibility we need to maintain the + * minor allocation scheme where minors 0-63 are primary nodes, 64-127 are control nodes, + * and 128-191 are render nodes. + * After reaching the limit, we're allocating minors dynamically - first-come, first-serve. + * Accel nodes are using a distinct major, so the minors are allocated in continuous 0-MAX + * range. + */ #define DRM_MINOR_LIMIT(t) ({ \ typeof(t) _t = (t); \ _t == DRM_MINOR_ACCEL ? XA_LIMIT(0, ACCEL_MAX_MINORS) : XA_LIMIT(64 * _t, 64 * _t + 63); \ }) +#define DRM_EXTENDED_MINOR_LIMIT XA_LIMIT(192, (1 << MINORBITS) - 1) static int drm_minor_alloc(struct drm_device *dev, enum drm_minor_type type) { @@ -140,6 +149,9 @@ static int drm_minor_alloc(struct drm_device *dev, enum drm_minor_type type) r = xa_alloc(drm_minor_get_xa(type), &minor->index, NULL, DRM_MINOR_LIMIT(type), GFP_KERNEL); + if (r == -EBUSY && (type == DRM_MINOR_PRIMARY || type == DRM_MINOR_RENDER)) + r = xa_alloc(&drm_minors_xa, &minor->index, + NULL, DRM_EXTENDED_MINOR_LIMIT, GFP_KERNEL); if (r < 0) return r; |