[PATCH 12/25] OMAP: Add support to allocate the memory for secure RAM

[Shilimkar, Santosh]

On Fri, Sep 9, 2011 at 6:24 PM, Jean Pihet <jean.pihet at newoldbits.com> wrote:
> Santosh,
>
> On Fri, Sep 9, 2011 at 11:43 AM, Santosh <santosh.shilimkar at ti.com> wrote:
>> On Friday 09 September 2011 12:49 AM, Jean Pihet wrote:
>>>
>>> On Sun, Sep 4, 2011 at 3:54 PM, Santosh Shilimkar
>>> <santosh.shilimkar at ti.com>  wrote:
>>>>
>>>> Allocate the memory to save secure ram context which needs
>>>> to be done when MPU is hitting off mode.
>>>>
>>>> The ROM code expects a physical address to this memory
>>>> and hence use memblock APIs to reserve this memory as part
>>>> of .reserve() callback.
>>>>
>>>> Maximum possible size is allocated and can cater to OMAP3XXX / OMAP4XXX
>>>> secure RAM size requirements.
>>>>
>>>> Signed-off-by: Santosh Shilimkar<santosh.shilimkar at ti.com>
>>>> ---
>>>>  arch/arm/mach-omap2/include/mach/omap-secure.h |    4 +++
>>>>  arch/arm/mach-omap2/omap-secure.c              |   29
>>>> ++++++++++++++++++++++++
>>>>  arch/arm/plat-omap/common.c                    |    3 ++
>>>>  3 files changed, 36 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/arch/arm/mach-omap2/include/mach/omap-secure.h
>>>> b/arch/arm/mach-omap2/include/mach/omap-secure.h
>>>> index 26e7bcc..e2f95a0 100644
>>>> --- a/arch/arm/mach-omap2/include/mach/omap-secure.h
>>>> +++ b/arch/arm/mach-omap2/include/mach/omap-secure.h
>>>> @@ -26,6 +26,8 @@
>>>>  #define FLAG_FIQ_ENABLE                        0x1
>>>>  #define NO_FLAG                                0x0
>>>>
>>>> +/* Maximum Secure memory storage size */
>>>> +#define OMAP_SECURE_RAM_STORAGE        (88 * SZ_1K)
>>>
>>> Is this valid for all supported devices? How to differentiate
>>> variations in the size for new chips variants in the future?
>>>
>> You don't have to. ROM code does that job. We should just ensure
>> that maximum needed memory is made available to secure code.
> The question was: what would be the code if tomorrow -for example- we
> have OMAP4460 with 88K of secure RAM, OMAP5432 with 128K and OMAP6667
> with 132K? How to code the differences?
>
The size doesn't depend on silicon but depends on Secure software
stack size. As I
said, we will allocate maximum needed as per security team recommendation.
If on newer security stack, if we need more, we will just increase it
to maximum needed.