[PATCH 02/10] drm/ttm: flip over the range manager to self allocated nodes

[Christian König]

Am 02.06.21 um 13:44 schrieb Thomas Hellström (Intel):
>
> On 6/2/21 12:09 PM, Christian König wrote:
>> Start with the range manager to make the resource object the base
>> class for the allocated nodes.
>>
>> While at it cleanup a lot of the code around that.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Reviewed-by: Matthew Auld <matthew.auld at intel.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c |  1 +
>>   drivers/gpu/drm/drm_gem_vram_helper.c   |  2 +
>>   drivers/gpu/drm/nouveau/nouveau_ttm.c   |  2 +
>>   drivers/gpu/drm/qxl/qxl_ttm.c           |  1 +
>>   drivers/gpu/drm/radeon/radeon_ttm.c     |  1 +
>>   drivers/gpu/drm/ttm/ttm_range_manager.c | 56 ++++++++++++++++++-------
>>   drivers/gpu/drm/ttm/ttm_resource.c      | 26 ++++++++----
>>   include/drm/ttm/ttm_bo_driver.h         | 26 ------------
>>   include/drm/ttm/ttm_range_manager.h     | 43 +++++++++++++++++++
>>   include/drm/ttm/ttm_resource.h          |  3 ++
>>   10 files changed, 111 insertions(+), 50 deletions(-)
>>   create mode 100644 include/drm/ttm/ttm_range_manager.h
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index 69db89261650..df1f185faae9 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -45,6 +45,7 @@
>>   #include <drm/ttm/ttm_bo_api.h>
>>   #include <drm/ttm/ttm_bo_driver.h>
>>   #include <drm/ttm/ttm_placement.h>
>> +#include <drm/ttm/ttm_range_manager.h>
>>     #include <drm/amdgpu_drm.h>
>>   diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c 
>> b/drivers/gpu/drm/drm_gem_vram_helper.c
>> index 83e7258c7f90..17a4c5d47b6a 100644
>> --- a/drivers/gpu/drm/drm_gem_vram_helper.c
>> +++ b/drivers/gpu/drm/drm_gem_vram_helper.c
>> @@ -17,6 +17,8 @@
>>   #include <drm/drm_prime.h>
>>   #include <drm/drm_simple_kms_helper.h>
>>   +#include <drm/ttm/ttm_range_manager.h>
>> +
>>   static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
>>     /**
>> diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c 
>> b/drivers/gpu/drm/nouveau/nouveau_ttm.c
>> index 65430912ff72..b08b8efeefba 100644
>> --- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
>> +++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
>> @@ -26,6 +26,8 @@
>>   #include <linux/limits.h>
>>   #include <linux/swiotlb.h>
>>   +#include <drm/ttm/ttm_range_manager.h>
>> +
>>   #include "nouveau_drv.h"
>>   #include "nouveau_gem.h"
>>   #include "nouveau_mem.h"
>> diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c 
>> b/drivers/gpu/drm/qxl/qxl_ttm.c
>> index 8aa87b8edb9c..19fd39d9a00c 100644
>> --- a/drivers/gpu/drm/qxl/qxl_ttm.c
>> +++ b/drivers/gpu/drm/qxl/qxl_ttm.c
>> @@ -32,6 +32,7 @@
>>   #include <drm/ttm/ttm_bo_api.h>
>>   #include <drm/ttm/ttm_bo_driver.h>
>>   #include <drm/ttm/ttm_placement.h>
>> +#include <drm/ttm/ttm_range_manager.h>
>>     #include "qxl_drv.h"
>>   #include "qxl_object.h"
>> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c 
>> b/drivers/gpu/drm/radeon/radeon_ttm.c
>> index cdffa9b65108..ad2a5a791bba 100644
>> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
>> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
>> @@ -45,6 +45,7 @@
>>   #include <drm/ttm/ttm_bo_api.h>
>>   #include <drm/ttm/ttm_bo_driver.h>
>>   #include <drm/ttm/ttm_placement.h>
>> +#include <drm/ttm/ttm_range_manager.h>
>>     #include "radeon_reg.h"
>>   #include "radeon.h"
>> diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c 
>> b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> index b9d5da6e6a81..ce5d07ca384c 100644
>> --- a/drivers/gpu/drm/ttm/ttm_range_manager.c
>> +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> @@ -29,12 +29,13 @@
>>    * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
>>    */
>>   -#include <drm/ttm/ttm_bo_driver.h>
>> +#include <drm/ttm/ttm_device.h>
>>   #include <drm/ttm/ttm_placement.h>
>> +#include <drm/ttm/ttm_range_manager.h>
>> +#include <drm/ttm/ttm_bo_api.h>
>>   #include <drm/drm_mm.h>
>>   #include <linux/slab.h>
>>   #include <linux/spinlock.h>
>> -#include <linux/module.h>
>>     /*
>>    * Currently we use a spinlock for the lock, but a mutex *may* be
>> @@ -60,8 +61,8 @@ static int ttm_range_man_alloc(struct 
>> ttm_resource_manager *man,
>>                      struct ttm_resource *mem)
>>   {
>>       struct ttm_range_manager *rman = to_range_manager(man);
>> +    struct ttm_range_mgr_node *node;
>>       struct drm_mm *mm = &rman->mm;
>> -    struct drm_mm_node *node;
>>       enum drm_mm_insert_mode mode;
>>       unsigned long lpfn;
>>       int ret;
>> @@ -70,7 +71,7 @@ static int ttm_range_man_alloc(struct 
>> ttm_resource_manager *man,
>>       if (!lpfn)
>>           lpfn = man->size;
>>   -    node = kzalloc(sizeof(*node), GFP_KERNEL);
>> +    node = kzalloc(struct_size(node, mm_nodes, 1), GFP_KERNEL);
>
> I'm still a bit confused  about the situation where a driver wants to 
> attach private data to a struct ttm_resource without having to 
> re-implement its own range manager?
>
> Could be cached sg-tables, list of GPU bindings etc. Wouldn't work 
> with the above unless we have a void *driver_private member on the 
> struct ttm_resource. Is that the plan going forward here? Or that the 
> driver actually does the re-implementation?

I don't really understand your concern here. The basic idea is that 
drivers use ttm_resource as a base class for their own implementation.

See for example how nouveau does that:

struct nouveau_mem {
         struct ttm_resource base;
         struct nouveau_cli *cli;
         u8 kind;
         u8 comp;
         struct nvif_mem mem;
         struct nvif_vma vma[2];
};

The range manager is helping driver specific resource managers which 
want to implement something drm_mm_nodes based. E.g. amdgpu_gtt_mgr and 
amdgpu_vram_mgr, but it can also be used stand alone.

The ttm_range_mgr_node can then be used as base class for this 
functionality. I already want to move some more code from 
amdgpu_vram_mgr.c into the range manager, but that is just minor cleanup 
work.

Regards,
Christian.

>
> Thanks,
>
> Thomas
>
>