Re: n900 in next-20170901

[Joonsoo Kim]

On Mon, Nov 13, 2017 at 01:15:30PM -0800, Tony Lindgren wrote:
> * Tony Lindgren <tony@xxxxxxxxxxx> [171110 07:36]:
> > * Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> [171110 06:34]:
> > > On Thu, Nov 09, 2017 at 07:26:10PM -0800, Tony Lindgren wrote:
> > > > +#define OMAP34XX_SRAM_PHYS	0x40200000
> > > > +#define OMAP34XX_SRAM_VIRT	0xd0010000
> > > > +#define OMAP34XX_SRAM_SIZE	0x10000
> > > 
> > > For my testing environment, vmalloc address space is started at
> > > roughly 0xe0000000 so 0xd0010000 would not be valid.
> > 
> > Well we can map it anywhere we want, got any preferences?
> 
> Hmm and I'm also wondering what you do to make vmalloc space to
> start at 0xe0000000 instead of 0xd0000000?

Please see the another reply.

> 
> The reason I'm asking is because I think we can just move all of
> save_secure_ram_context to run from DDR instead of SRAM. But I'd
> rather do a minimal patch first that fixes your series and then we
> can test the further changes with more time.

Okay. I agree to make a minimal patch first and then go next step.

> After moving save_secure_ram_context to DDR, we can call
> save_secure_ram_context directly with something like:
> 
> 	args_pa = __pa(omap3_secure_ram_storage);
> 	offset = (unsigned long)omap3_secure_ram_storage - args_pa;
> 	ret = save_secure_ram_context(args_pa, offset);
> 
> > Just that the current save_secure_ram_context uses "high_mask"
> > of 0xffff to translate the address. To make this more flexible,
> > we need the save_secure_ram_context changes too. So we might
> > want to do the static mapping and save_secure_ram_context changes
> > as a single patch.
> > 
> > > And, PHYS can be different according to the system type. Maybe either
> > > OMAP3_SRAM_PUB_PA or OMAP3_SRAM_PA. It seems that SIZE and TYPE should
> > > be considered, too. My understanding is correct?
> > 
> > We can have a static map for the whole SRAM area, see function
> > __arm_ioremap_pfn_caller() for the comment "Try to reuse one of the
> > static mapping whenever possible". So the different public SRAM start
> > addresses and sizes don't matter there.
> 
> And then if save_secure_ram_contet runs in DDR, no static map is
> needed.

Okay.

Thanks.