Re: New DRM driver model - gets rid of DRM() macros!

[Dave Airlie <airlied@linux.ie>]

As with Ian, I'm trying to grab the time to review this over the next day
or two, I have one or two worries but as I haven't read over the code I'll
wait until I'm ready to dedicate some proper time to it ..

Dave.

On Tue, 28 Sep 2004, Jon Smirl wrote:

> I've checked two new directories into DRM CVS for Linux 2.6 -
> linux-core, shared-core. This code implements a new model for DRM
> where DRM is split into a core piece and personality modules that
> share the core. The major reason for doing this is that it allows me
> to remove all of the DRM() macros; something that is causing lot's of
> complaints from the Linux kernel people.
>
> cvs -z3 -d:pserver:anonymous@dri.freedesktop.org:/cvs/dri co drm
>
> The patch for this is quite large, 500K, and it will mess up the Linux
> 2.4/BSD DRM builds since it removes the DRM() macro. Instead of doing
> this as a patch I made the new CVS directories.
>
> I've checked radeon and r128 and they work. Everything else should
> work except ffb, please check the other drivers and let me know. I've
> probably made some typos with a edit this large.
>
> ffb should work in principle but since I don't own one or a Sparc
> machine so I can't compile the driver. I suspect ffb has compiler
> errors but the are easily fixed just by copying similar code from one
> of the working modules. Please send patches.
>
> The API between the core and personalities doesn't look to be all that
> huge. With work I'd guess that 10% of the entry points could be
> eliminated. After another year of development we might be able to
> specify a stable core API.
>
> What are everyone's thoughts on this? There is no technical reason it
> can't be implemented on Linux 2.4/BSD, although I don't see any reason
> to do it for 2.4.
>
> Any ideas on how to generate a unique identifier for the core? It
> probably should be regenerated by the Makefile whenever the core
> changes. Personalities would have to match the core identifier. This
> would stop people from loading binary modules that don't match the
> core.
>
> After sometime testing and fixing obvious problems I'll generate a
> patch for the 2.6 kernel and lkml.
>
> [root@smirl linux-2.6]# lsmod | more
> Module                  Size  Used by
> tdfx                    2816  0
> sis                    10176  0
> mga                    56704  0
> i915                   16896  0
> via                    19428  0
> savage                  3840  0
> r128                   44672  0
> radeon                 70272  0
> drm                    59684  8 tdfx,sis,mga,i915,via,savage,r128,radeon
>
> The core provides these entry points....
>
> [root@smirl linux-2.6]# grep EXPORT_SYMBOL *
> drm_bufs.c:EXPORT_SYMBOL(drm_order);
> drm_bufs.c:EXPORT_SYMBOL(drm_initmap);
> drm_dma.c:EXPORT_SYMBOL(drm_core_reclaim_buffers);
> drm_drv.c:EXPORT_SYMBOL(drm_cleanup_pci);
> drm_drv.c:EXPORT_SYMBOL(drm_init);
> drm_drv.c:EXPORT_SYMBOL(drm_exit);
> drm_drv.c:EXPORT_SYMBOL(drm_open);
> drm_drv.c:EXPORT_SYMBOL(drm_release);
> drm_drv.c:EXPORT_SYMBOL(drm_ioctl);
> drm_fops.c:EXPORT_SYMBOL(drm_flush);
> drm_fops.c:EXPORT_SYMBOL(drm_fasync);
> drm_init.c:EXPORT_SYMBOL(drm_flags);
> drm_irq.c:EXPORT_SYMBOL(drm_irq_uninstall);
> drm_irq.c:EXPORT_SYMBOL(drm_vbl_send_signals);
> drm_memory.c:EXPORT_SYMBOL(drm_calloc);
> drm_pci.c:EXPORT_SYMBOL(drm_pci_alloc);
> drm_pci.c:EXPORT_SYMBOL(drm_pci_free);
> drm_stub.c:EXPORT_SYMBOL(drm_probe);
> drm_vm.c:EXPORT_SYMBOL(drm_core_get_map_ofs);
> drm_vm.c:EXPORT_SYMBOL(drm_core_get_reg_ofs);
>
> Drivers provide these callbacks......
>
> struct drm_driver_fn {
>        u32 driver_features;
>        int dev_priv_size;
>        int permanent_maps;
>        drm_ioctl_desc_t *ioctls;
>        int num_ioctls;
>        int (*preinit)(struct drm_device *, unsigned long flags);
>        void (*prerelease)(struct drm_device *, struct file *filp);
>        void (*pretakedown)(struct drm_device *);
>        int (*postcleanup)(struct drm_device *);
>        int (*presetup)(struct drm_device *);
>        int (*postsetup)(struct drm_device *);
>        int (*dma_ioctl)( DRM_IOCTL_ARGS );
>        /* these are opposites at the moment */
>        int (*open_helper)(struct drm_device *, drm_file_t *);
>        void (*free_filp_priv)(struct drm_device *, drm_file_t *);
>
>        void (*release)(struct drm_device *, struct file *filp);
>        void (*dma_ready)(struct drm_device *);
>        int (*dma_quiescent)(struct drm_device *);
>        int (*context_ctor)(struct drm_device *dev, int context);
>        int (*context_dtor)(struct drm_device *dev, int context);
>        int (*kernel_context_switch)(struct drm_device *dev, int old, int new);
>        int (*kernel_context_switch_unlock)(struct drm_device *dev);
>        int (*vblank_wait)(struct drm_device *dev, unsigned int *sequence);
> /* these have to be filled in */
>        int (*postinit)(struct drm_device *, unsigned long flags);
>        irqreturn_t (*irq_handler)( DRM_IRQ_ARGS );
>        void (*irq_preinstall)(struct drm_device *dev);
>        void (*irq_postinstall)(struct drm_device *dev);
>        void (*irq_uninstall)(struct drm_device *dev);
>        void (*reclaim_buffers)(struct file *filp);
>        unsigned long (*get_map_ofs)(drm_map_t *map);
>        unsigned long (*get_reg_ofs)(struct drm_device *dev);
>        void (*set_version)(struct drm_device *dev, drm_set_version_t *sv);
>        int (*version)(drm_version_t *version);
> };
>
>

-- 
David Airlie, Software Engineer
http://www.skynet.ie/~airlied / airlied at skynet.ie
pam_smb / Linux DECstation / Linux VAX / ILUG person