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

On Fri, Sep 9, 2011 at 6:24 PM, Jean Pihet [off-list ref] wrote:

Santosh,

On Fri, Sep 9, 2011 at 11:43 AM, Santosh [off-list ref] wrote:

quoted

On Friday 09 September 2011 12:49 AM, Jean Pihet wrote:

quoted

On Sun, Sep 4, 2011 at 3:54 PM, Santosh Shilimkar
[off-list ref] ?wrote:

quoted

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<redacted>
---
?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.