diff mbox series

[RFC,1/5] hw/cxl: Use define for build bug detection

Message ID 20230517-rfc-type2-dev-v1-1-6eb2e470981b@intel.com (mailing list archive)
State New, archived
Headers show
Series hw/cxl: Type 2 Device RFC | expand

Commit Message

Ira Weiny May 18, 2023, 2:45 a.m. UTC
Magic numbers can be confusing.

Use the range size define for CXL.cachemem rather than a magic number.
Update/add spec references.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 include/hw/cxl/cxl_component.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Jonathan Cameron May 18, 2023, 9:54 a.m. UTC | #1
On Wed, 17 May 2023 19:45:54 -0700
Ira Weiny <ira.weiny@intel.com> wrote:

> Magic numbers can be confusing.
> 
> Use the range size define for CXL.cachemem rather than a magic number.
> Update/add spec references.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

I guess we should do a scrub to move all refs to 3.0 soon
given it's horrible having a mixture of spec versions for the references.

For future specs, we should only do this when sufficient X.Y references
have started to appear - I think that's true for r3.0 now.

Jonathan

> ---
>  include/hw/cxl/cxl_component.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/include/hw/cxl/cxl_component.h b/include/hw/cxl/cxl_component.h
> index 52b6a2d67f40..bca2b756c202 100644
> --- a/include/hw/cxl/cxl_component.h
> +++ b/include/hw/cxl/cxl_component.h
> @@ -10,7 +10,7 @@
>  #ifndef CXL_COMPONENT_H
>  #define CXL_COMPONENT_H
>  
> -/* CXL 2.0 - 8.2.4 */
> +/* CXL 3.0 - 8.2.3 */
>  #define CXL2_COMPONENT_IO_REGION_SIZE 0x1000
>  #define CXL2_COMPONENT_CM_REGION_SIZE 0x1000
>  #define CXL2_COMPONENT_BLOCK_SIZE 0x10000
> @@ -173,7 +173,9 @@ HDM_DECODER_INIT(3);
>      (CXL_IDE_REGISTERS_OFFSET + CXL_IDE_REGISTERS_SIZE)
>  #define CXL_SNOOP_REGISTERS_SIZE   0x8
>  
> -QEMU_BUILD_BUG_MSG((CXL_SNOOP_REGISTERS_OFFSET + CXL_SNOOP_REGISTERS_SIZE) >= 0x1000,
> +/* CXL 3.0 8.2.3 Table 8-21 */
> +QEMU_BUILD_BUG_MSG((CXL_SNOOP_REGISTERS_OFFSET +
> +                    CXL_SNOOP_REGISTERS_SIZE) >= CXL2_COMPONENT_CM_REGION_SIZE,
>                     "No space for registers");
>  
>  typedef struct component_registers {
>
Ira Weiny May 18, 2023, 8:19 p.m. UTC | #2
Jonathan Cameron wrote:
> On Wed, 17 May 2023 19:45:54 -0700
> Ira Weiny <ira.weiny@intel.com> wrote:
> 
> > Magic numbers can be confusing.
> > 
> > Use the range size define for CXL.cachemem rather than a magic number.
> > Update/add spec references.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
> I guess we should do a scrub to move all refs to 3.0 soon
> given it's horrible having a mixture of spec versions for the references.
> 
> For future specs, we should only do this when sufficient X.Y references
> have started to appear - I think that's true for r3.0 now.

For the kernel side I think Dan is taking the 'if you are updating it then
update the spec' but otherwise leave it be.  So since I'm touching the
code I updated it.

I agree, it is a pain to have to look at the 2.0 spec but you can do it.

Ira
Jonathan Cameron May 19, 2023, 3:14 p.m. UTC | #3
On Thu, 18 May 2023 13:19:12 -0700
Ira Weiny <ira.weiny@intel.com> wrote:

> Jonathan Cameron wrote:
> > On Wed, 17 May 2023 19:45:54 -0700
> > Ira Weiny <ira.weiny@intel.com> wrote:
> >   
> > > Magic numbers can be confusing.
> > > 
> > > Use the range size define for CXL.cachemem rather than a magic number.
> > > Update/add spec references.
> > > 
> > > Signed-off-by: Ira Weiny <ira.weiny@intel.com>  
> > 
> > I guess we should do a scrub to move all refs to 3.0 soon
> > given it's horrible having a mixture of spec versions for the references.
> > 
> > For future specs, we should only do this when sufficient X.Y references
> > have started to appear - I think that's true for r3.0 now.  
> 
> For the kernel side I think Dan is taking the 'if you are updating it then
> update the spec' but otherwise leave it be.  So since I'm touching the
> code I updated it.
> 
> I agree, it is a pain to have to look at the 2.0 spec but you can do it.

Only if you are either a member of the consortium, or happened to have
grabbed a copy in the past I think.  I've had people mentioning they can't
get it today.

Jonathan

> 
> Ira
Ira Weiny May 23, 2023, 2:18 p.m. UTC | #4
Jonathan Cameron wrote:
> On Thu, 18 May 2023 13:19:12 -0700
> Ira Weiny <ira.weiny@intel.com> wrote:
> 
> > Jonathan Cameron wrote:
> > > On Wed, 17 May 2023 19:45:54 -0700
> > > Ira Weiny <ira.weiny@intel.com> wrote:
> > >   
> > > > Magic numbers can be confusing.
> > > > 
> > > > Use the range size define for CXL.cachemem rather than a magic number.
> > > > Update/add spec references.
> > > > 
> > > > Signed-off-by: Ira Weiny <ira.weiny@intel.com>  
> > > 
> > > I guess we should do a scrub to move all refs to 3.0 soon
> > > given it's horrible having a mixture of spec versions for the references.
> > > 
> > > For future specs, we should only do this when sufficient X.Y references
> > > have started to appear - I think that's true for r3.0 now.  
> > 
> > For the kernel side I think Dan is taking the 'if you are updating it then
> > update the spec' but otherwise leave it be.  So since I'm touching the
> > code I updated it.
> > 
> > I agree, it is a pain to have to look at the 2.0 spec but you can do it.
> 
> Only if you are either a member of the consortium, or happened to have
> grabbed a copy in the past I think.  I've had people mentioning they can't
> get it today.
> 

Oh.  :-(  That seems unfortunate.  I've emailed the CXL admins.  Perhaps
they can post an archive page or something?

Ira
diff mbox series

Patch

diff --git a/include/hw/cxl/cxl_component.h b/include/hw/cxl/cxl_component.h
index 52b6a2d67f40..bca2b756c202 100644
--- a/include/hw/cxl/cxl_component.h
+++ b/include/hw/cxl/cxl_component.h
@@ -10,7 +10,7 @@ 
 #ifndef CXL_COMPONENT_H
 #define CXL_COMPONENT_H
 
-/* CXL 2.0 - 8.2.4 */
+/* CXL 3.0 - 8.2.3 */
 #define CXL2_COMPONENT_IO_REGION_SIZE 0x1000
 #define CXL2_COMPONENT_CM_REGION_SIZE 0x1000
 #define CXL2_COMPONENT_BLOCK_SIZE 0x10000
@@ -173,7 +173,9 @@  HDM_DECODER_INIT(3);
     (CXL_IDE_REGISTERS_OFFSET + CXL_IDE_REGISTERS_SIZE)
 #define CXL_SNOOP_REGISTERS_SIZE   0x8
 
-QEMU_BUILD_BUG_MSG((CXL_SNOOP_REGISTERS_OFFSET + CXL_SNOOP_REGISTERS_SIZE) >= 0x1000,
+/* CXL 3.0 8.2.3 Table 8-21 */
+QEMU_BUILD_BUG_MSG((CXL_SNOOP_REGISTERS_OFFSET +
+                    CXL_SNOOP_REGISTERS_SIZE) >= CXL2_COMPONENT_CM_REGION_SIZE,
                    "No space for registers");
 
 typedef struct component_registers {