diff mbox series

[drm-misc-next,v4,6/8] drm/gpuvm: add drm_gpuvm_flags to drm_gpuvm

Message ID 20230920144343.64830-7-dakr@redhat.com
State New
Headers
Series DRM GPUVA Manager GPU-VM features |

Commit Message

Danilo Krummrich Sept. 20, 2023, 2:42 p.m. UTC 
  Introduce flags for struct drm_gpuvm, this required by subsequent
commits.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
---
 drivers/gpu/drm/drm_gpuvm.c            |  3 ++-
 drivers/gpu/drm/nouveau/nouveau_uvmm.c |  2 +-
 include/drm/drm_gpuvm.h                | 17 ++++++++++++++++-
 3 files changed, 19 insertions(+), 3 deletions(-)

Comments

kernel test robot Sept. 20, 2023, 4:40 p.m. UTC | #1 
Hi Danilo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 1c7a387ffef894b1ab3942f0482dac7a6e0a909c]

url:    https://github.com/intel-lab-lkp/linux/commits/Danilo-Krummrich/drm-gpuvm-rename-struct-drm_gpuva_manager-to-struct-drm_gpuvm/20230920-224605
base:   1c7a387ffef894b1ab3942f0482dac7a6e0a909c
patch link:    https://lore.kernel.org/r/20230920144343.64830-7-dakr%40redhat.com
patch subject: [PATCH drm-misc-next v4 6/8] drm/gpuvm: add drm_gpuvm_flags to drm_gpuvm
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20230921/202309210041.Ypce0gUk-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230921/202309210041.Ypce0gUk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309210041.Ypce0gUk-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/drm_gpuvm.c:712: warning: Function parameter or member 'flags' not described in 'drm_gpuvm_init'


vim +712 drivers/gpu/drm/drm_gpuvm.c

e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  689  
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  690  /**
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  691   * drm_gpuvm_init() - initialize a &drm_gpuvm
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  692   * @gpuvm: pointer to the &drm_gpuvm to initialize
52ef25512ca721 drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  693   * @drm: the drivers &drm_device
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  694   * @name: the name of the GPU VA space
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  695   * @start_offset: the start offset of the GPU VA space
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  696   * @range: the size of the GPU VA space
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  697   * @reserve_offset: the start of the kernel reserved GPU VA area
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  698   * @reserve_range: the size of the kernel reserved GPU VA area
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  699   * @ops: &drm_gpuvm_ops called on &drm_gpuvm_sm_map / &drm_gpuvm_sm_unmap
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  700   *
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  701   * The &drm_gpuvm must be initialized with this function before use.
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  702   *
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  703   * Note that @gpuvm must be cleared to 0 before calling this function. The given
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  704   * &name is expected to be managed by the surrounding driver structures.
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  705   */
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  706  void
52ef25512ca721 drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  707  drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_device *drm,
790facc6dac6ef drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  708  	       const char *name, enum drm_gpuva_flags flags,
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  709  	       u64 start_offset, u64 range,
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  710  	       u64 reserve_offset, u64 reserve_range,
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  711  	       const struct drm_gpuvm_ops *ops)
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20 @712  {
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  713  	gpuvm->rb.tree = RB_ROOT_CACHED;
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  714  	INIT_LIST_HEAD(&gpuvm->rb.list);
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  715  
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  716  	drm_gpuvm_check_overflow(start_offset, range);
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  717  	gpuvm->mm_start = start_offset;
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  718  	gpuvm->mm_range = range;
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  719  
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  720  	gpuvm->name = name ? name : "unknown";
790facc6dac6ef drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  721  	gpuvm->flags = flags;
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  722  	gpuvm->ops = ops;
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  723  
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  724  	memset(&gpuvm->kernel_alloc_node, 0, sizeof(struct drm_gpuva));
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  725  
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  726  	if (reserve_range) {
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  727  		gpuvm->kernel_alloc_node.va.addr = reserve_offset;
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  728  		gpuvm->kernel_alloc_node.va.range = reserve_range;
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  729  
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  730  		if (likely(!drm_gpuvm_check_overflow(reserve_offset,
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  731  						     reserve_range)))
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  732  			__drm_gpuva_insert(gpuvm, &gpuvm->kernel_alloc_node);
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  733  	}
52ef25512ca721 drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  734  
52ef25512ca721 drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  735  	drm_gem_private_object_init(drm, &gpuvm->d_obj, 0);
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  736  }
06f9274d201d5d drivers/gpu/drm/drm_gpuvm.c     Danilo Krummrich 2023-09-20  737  EXPORT_SYMBOL_GPL(drm_gpuvm_init);
e6303f323b1ad9 drivers/gpu/drm/drm_gpuva_mgr.c Danilo Krummrich 2023-07-20  738
Boris Brezillon Sept. 22, 2023, 11:42 a.m. UTC | #2 
On Wed, 20 Sep 2023 16:42:39 +0200
Danilo Krummrich <dakr@redhat.com> wrote:

>  void drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_device *drm,
> -		    const char *name,
> +		    const char *name, enum drm_gpuva_flags flags,

s/drm_gpuva_flags/drm_gpuvm_flags/gc
Boris Brezillon Sept. 22, 2023, 11:58 a.m. UTC | #3 
On Wed, 20 Sep 2023 16:42:39 +0200
Danilo Krummrich <dakr@redhat.com> wrote:

> +/**
> + * enum drm_gpuvm_flags - flags for struct drm_gpuvm
> + */
> +enum drm_gpuvm_flags {
> +	/**
> +	 * @DRM_GPUVM_USERBITS: user defined bits
> +	 */
> +	DRM_GPUVM_USERBITS = (1 << 0),

Nit: I tried declaring driver-specific flags, and I find this
counter-intuitive. You basically end up with something like:

enum my_gpuvm_flags {
	MY_FLAG_X = DRM_GPUVM_USERBITS,
	MY_FLAG_Y = DRM_GPUVM_USERBITS << 1,
};

instead of the usual

enum my_gpuvm_flags {
	MY_FLAG_X = BIT(0),
	MY_FLAG_Y = BIT(1),
};

pattern.

Another issue I see coming is if we end up adding more core flags and
drivers start falling short of bits for their own flags. This makes me
wonder if we shouldn't kill this notion of USER flags and let drivers
store their flags in some dedicated field, given they're likely to
derive drm_gpuvm and drm_gpuva with their own object anyway.

> +};
> +
Danilo Krummrich Sept. 27, 2023, 4:52 p.m. UTC | #4 
On 9/22/23 13:58, Boris Brezillon wrote:
> On Wed, 20 Sep 2023 16:42:39 +0200
> Danilo Krummrich <dakr@redhat.com> wrote:
> 
>> +/**
>> + * enum drm_gpuvm_flags - flags for struct drm_gpuvm
>> + */
>> +enum drm_gpuvm_flags {
>> +	/**
>> +	 * @DRM_GPUVM_USERBITS: user defined bits
>> +	 */
>> +	DRM_GPUVM_USERBITS = (1 << 0),
> 
> Nit: I tried declaring driver-specific flags, and I find this
> counter-intuitive. You basically end up with something like:
> 
> enum my_gpuvm_flags {
> 	MY_FLAG_X = DRM_GPUVM_USERBITS,
> 	MY_FLAG_Y = DRM_GPUVM_USERBITS << 1,
> };
> 
> instead of the usual
> 
> enum my_gpuvm_flags {
> 	MY_FLAG_X = BIT(0),
> 	MY_FLAG_Y = BIT(1),
> };
> 
> pattern.

Right, same as with dma_fence flags.

> 
> Another issue I see coming is if we end up adding more core flags and
> drivers start falling short of bits for their own flags. This makes me
> wonder if we shouldn't kill this notion of USER flags and let drivers
> store their flags in some dedicated field, given they're likely to
> derive drm_gpuvm and drm_gpuva with their own object anyway.

The only reason I have this in the code is that Xe asked for this with
drm_gpuva_flags. Hence, for consistency reasons I added it for drm_gpuvm_flags
too.

Drivers can still have their own flag fields if needed, otherwise I guess it
doesn't really hurt to keep DRM_GPUVM_USERBITS in case someone wants to use it.

> 
>> +};
>> +
>
Boris Brezillon Sept. 28, 2023, 12:19 p.m. UTC | #5 
On Wed, 27 Sep 2023 18:52:55 +0200
Danilo Krummrich <dakr@redhat.com> wrote:

> On 9/22/23 13:58, Boris Brezillon wrote:
> > On Wed, 20 Sep 2023 16:42:39 +0200
> > Danilo Krummrich <dakr@redhat.com> wrote:
> >   
> >> +/**
> >> + * enum drm_gpuvm_flags - flags for struct drm_gpuvm
> >> + */
> >> +enum drm_gpuvm_flags {
> >> +	/**
> >> +	 * @DRM_GPUVM_USERBITS: user defined bits
> >> +	 */
> >> +	DRM_GPUVM_USERBITS = (1 << 0),  
> > 
> > Nit: I tried declaring driver-specific flags, and I find this
> > counter-intuitive. You basically end up with something like:
> > 
> > enum my_gpuvm_flags {
> > 	MY_FLAG_X = DRM_GPUVM_USERBITS,
> > 	MY_FLAG_Y = DRM_GPUVM_USERBITS << 1,
> > };
> > 
> > instead of the usual
> > 
> > enum my_gpuvm_flags {
> > 	MY_FLAG_X = BIT(0),
> > 	MY_FLAG_Y = BIT(1),
> > };
> > 
> > pattern.  
> 
> Right, same as with dma_fence flags.
> 
> > 
> > Another issue I see coming is if we end up adding more core flags and
> > drivers start falling short of bits for their own flags. This makes me
> > wonder if we shouldn't kill this notion of USER flags and let drivers
> > store their flags in some dedicated field, given they're likely to
> > derive drm_gpuvm and drm_gpuva with their own object anyway.  
> 
> The only reason I have this in the code is that Xe asked for this with
> drm_gpuva_flags. Hence, for consistency reasons I added it for drm_gpuvm_flags
> too.

Yeah, my comment stands for both drm_gpuva_flags and drm_gpuvm_flags
actually.

> 
> Drivers can still have their own flag fields if needed, otherwise I guess it
> doesn't really hurt to keep DRM_GPUVM_USERBITS in case someone wants to use it.

Sure, it doesn't hurt, but given drivers are inheriting from this
object anyway, I thought it'd be simpler/more future proof to let them
have their flags in a separate field. It's not like we care about
saving 4 bytes in such a big object. Might be a bit different for
drm_gpuva given the amount of live mappings one VM might have, but even
there, I suspect the current drm_gpuva size is going to hurt if we have
millions of 4k mappings, so, four more bytes won't make a huge
difference...

Anyway, I don't think that's a blocker, I just thought I'd mention it,
that's all.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
index 6ee224e1121e..6e9d2d478bb8 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -705,7 +705,7 @@  drm_gpuva_range_valid(struct drm_gpuvm *gpuvm,
  */
 void
 drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_device *drm,
-	       const char *name,
+	       const char *name, enum drm_gpuva_flags flags,
 	       u64 start_offset, u64 range,
 	       u64 reserve_offset, u64 reserve_range,
 	       const struct drm_gpuvm_ops *ops)
@@ -718,6 +718,7 @@  drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_device *drm,
 	gpuvm->mm_range = range;
 
 	gpuvm->name = name ? name : "unknown";
+	gpuvm->flags = flags;
 	gpuvm->ops = ops;
 
 	memset(&gpuvm->kernel_alloc_node, 0, sizeof(struct drm_gpuva));
diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
index cf709afd2ac7..3de8533841db 100644
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
@@ -1864,7 +1864,7 @@  nouveau_uvmm_init(struct nouveau_uvmm *uvmm, struct nouveau_cli *cli,
 	uvmm->kernel_managed_addr = kernel_managed_addr;
 	uvmm->kernel_managed_size = kernel_managed_size;
 
-	drm_gpuvm_init(&uvmm->base, cli->drm->dev, cli->name,
+	drm_gpuvm_init(&uvmm->base, cli->drm->dev, cli->name, 0,
 		       NOUVEAU_VA_SPACE_START,
 		       NOUVEAU_VA_SPACE_END,
 		       kernel_managed_addr, kernel_managed_size,
diff --git a/include/drm/drm_gpuvm.h b/include/drm/drm_gpuvm.h
index 2c9ad6eb9401..f57ad1f0f0d0 100644
--- a/include/drm/drm_gpuvm.h
+++ b/include/drm/drm_gpuvm.h
@@ -192,6 +192,16 @@  static inline bool drm_gpuva_invalidated(struct drm_gpuva *va)
 	return va->flags & DRM_GPUVA_INVALIDATED;
 }
 
+/**
+ * enum drm_gpuvm_flags - flags for struct drm_gpuvm
+ */
+enum drm_gpuvm_flags {
+	/**
+	 * @DRM_GPUVM_USERBITS: user defined bits
+	 */
+	DRM_GPUVM_USERBITS = (1 << 0),
+};
+
 /**
  * struct drm_gpuvm - DRM GPU VA Manager
  *
@@ -210,6 +220,11 @@  struct drm_gpuvm {
 	 */
 	const char *name;
 
+	/**
+	 * @flags: the &drm_gpuvm_flags of this GPUVM
+	 */
+	enum drm_gpuva_flags flags;
+
 	/**
 	 * @mm_start: start of the VA space
 	 */
@@ -256,7 +271,7 @@  struct drm_gpuvm {
 };
 
 void drm_gpuvm_init(struct drm_gpuvm *gpuvm, struct drm_device *drm,
-		    const char *name,
+		    const char *name, enum drm_gpuva_flags flags,
 		    u64 start_offset, u64 range,
 		    u64 reserve_offset, u64 reserve_range,
 		    const struct drm_gpuvm_ops *ops);