cpm_dpalloc questions

cpm_dpalloc questions

[bhanu jampala]

Hi Guys,

I am working on MCC HDLC controller on MCC8260. I have two important questions:

1. What is the range of DPRAM from which the cpm_dpalloc allocates memory?
    How does the cpm_dpalloc work?
    I need this because, I need to reserve the DPRAM memory for MCC2
from (128 * 60) to (255 * 60)
    for channels ranging from 128 - 255.

2. PROFF_SMC1 pointer placed at 0 , 64 offsets. is this not an area of
MCC1 controller?
    how if I want to use the MCC channel on MCC1.

 In file include/asm-powerpc/cpm2.h.

 /* The SMCs are relocated to any of the first eight DPRAM pages.
  * We will fix these at the first locations of DPRAM, until we
  * get some microcode patches :-).
  * The parameter ram space for the SMCs is fifty-some bytes, and
  * they are required to start on a 64 byte boundary.
  */
 #define PROFF_SMC1      (0)
 #define PROFF_SMC2      (64)

Regards,
Adams

Re: cpm_dpalloc questions

[Scott Wood]

bhanu jampala wrote:
> I am working on MCC HDLC controller on MCC8260. I have two important questions:
> 
> 1. What is the range of DPRAM from which the cpm_dpalloc allocates memory?
>     How does the cpm_dpalloc work?

Assuming you're using arch/powerpc on a recent kernel version, it 
allocates from the memory specified in the muram node of the device tree.

>     I need this because, I need to reserve the DPRAM memory for MCC2
> from (128 * 60) to (255 * 60)
>     for channels ranging from 128 - 255.

Why do you need to reserve a specific address?

> 2. PROFF_SMC1 pointer placed at 0 , 64 offsets. is this not an area of
> MCC1 controller?

No, MCC1 PRAM starts at offset 0x8700.  Any other areas used are under 
software control.

>     how if I want to use the MCC channel on MCC1.
> 
>  In file include/asm-powerpc/cpm2.h.
> 
>  /* The SMCs are relocated to any of the first eight DPRAM pages.
>   * We will fix these at the first locations of DPRAM, until we
>   * get some microcode patches :-).
>   * The parameter ram space for the SMCs is fifty-some bytes, and
>   * they are required to start on a 64 byte boundary.
>   */
>  #define PROFF_SMC1      (0)
>  #define PROFF_SMC2      (64)

This is obsolete arch/ppc stuff and should be removed; the SMC pram is 
now dynamically allocated and relocated (and before that, it came from 
the device tree).

-Scott

Re: cpm_dpalloc questions

[bhanu jampala]

Hi Scott,

> No, MCC1 PRAM starts at offset 0x8700.  Any other areas used are under
> software control.
Yes, you are right. But, I was refereing to MCC channel specific HDLC
parameters.

Reason: I am using the MCC2 which uses memory from offset 0x2000 to
0x4000 for Chan Specific parameters.
you can see that in MCC chapter i.e. 29.3.1 on a MPC8280 manual.
(channel specific HDLC parameters)

I need to make sure that cpm_dpalloc is not using this part of DPRAM
to allocate memory.
I just wanne make sure no other device driver that use cpm_dpalloc to
allocate memory for their BDs i.e. scc, smc, fcc.

and it looks to me like it is allocating me memory starting from 0x128 or 0x400.

> This is obsolete arch/ppc stuff and should be removed; the SMC pram is now
> dynamically allocated and relocated (and before that, it came from the
> device tree).

Yes, I am using 2.6.19.2. I am right now in the middle of finalizing
the BSP port. So, I cannot move on further to device trees. I will
doing that stuff with in a month but now I am with 2.6.19.2.

Regards,
Adams

Re: cpm_dpalloc questions

[bhanu jampala]

Hi Guys,

Figured out that cpm_dpalloc is doing the memory allocation in the
range of  0x0000 - 0x3EFEC.
I tried to dig in and figured out that it is really not affecting me
as the memory address I dont wanted to be touched is 0x2000.
and existing drivers fcc and scc allocate memory at boot time and and
it is something range of ix100 -0x200.
so, no problem.

- mukund

On Thu, Aug 28, 2008 at 1:03 PM, bhanu jampala <adams.ppc@gmail.com> wrote:
> Hi Scott,
>
>> No, MCC1 PRAM starts at offset 0x8700.  Any other areas used are under
>> software control.
> Yes, you are right. But, I was refereing to MCC channel specific HDLC
> parameters.
>
> Reason: I am using the MCC2 which uses memory from offset 0x2000 to
> 0x4000 for Chan Specific parameters.
> you can see that in MCC chapter i.e. 29.3.1 on a MPC8280 manual.
> (channel specific HDLC parameters)
>
> I need to make sure that cpm_dpalloc is not using this part of DPRAM
> to allocate memory.
> I just wanne make sure no other device driver that use cpm_dpalloc to
> allocate memory for their BDs i.e. scc, smc, fcc.
>
> and it looks to me like it is allocating me memory starting from 0x128 or 0x400.
>
>> This is obsolete arch/ppc stuff and should be removed; the SMC pram is now
>> dynamically allocated and relocated (and before that, it came from the
>> device tree).
>
> Yes, I am using 2.6.19.2. I am right now in the middle of finalizing
> the BSP port. So, I cannot move on further to device trees. I will
> doing that stuff with in a month but now I am with 2.6.19.2.
>
> Regards,
> Adams
>