Re: [PATCH 4/6] ehea: header files

[Jan-Bernd Themann <ossthema@de.ibm.com>]

Michael Ellerman wrote:
> > --- linux-2.6.18-rc4-orig/drivers/net/ehea/ehea.h	1969-12-31 16:00:00.000000000 -0800
> > +++ kernel/drivers/net/ehea/ehea.h	2006-08-08 23:59:39.927452928 -0700
> > +
> > +#define EHEA_PAGESHIFT  12
> > +#define EHEA_PAGESIZE   4096UL
> > +#define EHEA_CACHE_LINE 128
>
> This looks like a very bad idea, what happens if you're running on a
> machine with 64K pages?

The EHEA_PAGESIZE define is needed for queue management to hardware side.

> > +
> > +#define EHEA_ENABLE	1
> > +#define EHEA_DISABLE	0
>
> Do you really need hash defines for 0 and 1 ? They're fairly well
> understood in C as meaning true and false.

removed

> > +
> > +/*
> > + *  h_galpa:
> > + *  for pSeries this is a 64bit memory address where
> > + *  I/O memory is mapped into CPU address space
> > + */
> > +
> > +struct h_galpa {
> > +	u64 fw_handle;
> > +};
>
> What is a h_galpa? And why does it need a struct if it's just a u64?

The eHEA chip is not PCI attached but directly connected to a proprietary
bus. Currently, we can access it by a simple 64 bit address, but this is not
true in all cases. Having a struct here allows us to encapsulate the chip
register access and to respond to changes to system hardware.

We'll change the name to h_epa meaning "ehea physical address"

> > +
> > +struct h_galpas {
> > +	struct h_galpa kernel;	/* kernel space accessible resource,
> > +				   set to 0 if unused */
> > +	struct h_galpa user;	/* user space accessible resource
> > +				   set to 0 if unused */
> > +	u32 pid;		/* PID of userspace galpa checking */
> > +};
> > +

> > +struct port_res_cfg {
> > +	int max_entries_rcq;
> > +	int max_entries_scq;
> > +	int max_entries_sq;
> > +	int max_entries_rq1;
> > +	int max_entries_rq2;
> > +	int max_entries_rq3;
> > +};
>
> Enormous structs with no comments.

changed

Regards,
Jan-Bernd
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