[U-Boot] mvebu: reserve SRAM memory on Marvell Armada 3700/7K/8K

[Mark Kettenis]

> From: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Date: Thu, 13 Jun 2019 08:09:17 +0200
> 
> On 6/13/19 7:48 AM, Stefan Roese wrote:
> > Added Heinrich to Cc (and use Alex's new address)
> >
> > On 11.06.19 13:00, Patrick Wildt wrote:
> >> The ARM-TF and the optional OP-TEE use the memory region 0x4000000
> >> to 0x5400000 and should be reserved in the memory map, otherwise the
> >> OS might wrongly assume that it can use that memory area for itself.
> >> This has also been done in EDK2 [0].
> >>
> >> [0]
> >> https://github.com/tianocore/edk2-platforms/commit/bf1c4a2cf8024669d1748e78c7e417433f85707e
> >>
> >>
> >> Signed-off-by: Patrick Wildt <patrick at blueri.se>
> >>
> >> diff --git a/arch/arm/mach-mvebu/arm64-common.c
> >> b/arch/arm/mach-mvebu/arm64-common.c
> >> index aaf7b7c447..7572aad8c9 100644
> >> --- a/arch/arm/mach-mvebu/arm64-common.c
> >> +++ b/arch/arm/mach-mvebu/arm64-common.c
> >> @@ -14,6 +14,7 @@
> >>   #include <asm/arch/cpu.h>
> >>   #include <asm/arch/soc.h>
> >>   #include <asm/armv8/mmu.h>
> >> +#include <efi_loader.h>
> >>     DECLARE_GLOBAL_DATA_PTR;
> >>   @@ -142,5 +143,11 @@ int arch_early_init_r(void)
> >>       pci_init();
> >>   #endif
> >>   +#ifdef CONFIG_EFI_LOADER
> >> +    /* Reserve trusted SRAM section */
> >> +    efi_add_memory_map(0x04000000, 0x01400000 >> EFI_PAGE_SHIFT,
> >> +               EFI_RESERVED_MEMORY_TYPE, false);
> >> +#endif
> 
> We already have a reservation via the device tree for a part of this
> area [0x4000000-0x4200000[ in U-Boot and Linux:
> 
> cf63dad014bae080445bccbf9cecbe05f2cbed45
> arm64: dts: marvell: armada-ap806: reserve PSCI area
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.2-rc4&id=132ac39cffbcfed80ada38ef0fc6d34d95da7be6
> 
> As the concerned boards can be booted not only via bootefi but also via
> booti I suggest to update the device trees in Linux and U-Boot.

But surely the EFI memory map should be correct and not include these
reserved regions as "free".  Otherwise EFI boot services might hand
out memory that will crash the system when accessed once we've
switched out of EL3.  And I don't think the current code adjusts the
EFI memory based on reservations in the device tree does it?