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* ARM: tegra: reduce DRAM size mapped into MMU on ARM64Stephen Warren2016-10-10-1/+1
| | | | | | | | | | | | | | | | | ARM CPUs can architecturally (speculatively) prefetch completely arbitrary normal memory locations, as defined by the current translation tables. The current MMU configuration for 64-bit Tegras maps an extremely large range of addresses as DRAM, well beyond the actual physical maximum DRAM window, even though U-Boot only needs access to the first 2GB of DRAM; the Tegra port of U-Boot deliberately limits itself to 2GB of RAM since some HW modules on at least some 64-bit Tegra SoCs can only access a 32-bit physical address space. This change reduces the amount of RAM mapped via the MMU to disallow the CPU from ever speculatively accessing RAM that U-Boot will definitely not access. This avoids the possibility of the HW raising SError due to accesses to always-invalid physical addresses. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Tom Warren <twarren@nvidia.com>
* armv8: mmu: Add support of non-identical mappingYork Sun2016-07-15-2/+4
| | | | | | | Introduce virtual and physical addresses in the mapping table. This change have no impact on existing boards because they all use idential mapping. Signed-off-by: York Sun <york.sun@nxp.com>
* tegra: Replace home grown mmu code with generic table approachAlexander Graf2016-03-15-115/+17
| | | | | | | Now that we have nice table driven page table creating code that gives us everything we need, move to that. Signed-off-by: Alexander Graf <agraf@suse.de>
* ARM: tegra: add custom MMU setup on ARMv8Stephen Warren2015-11-10-0/+131
This sets up a fine-grained page table, which is a requirement for noncached_init() to operate correctly. MMU setup code currently exists in a number of places: - A version in the core ARMv8 support code that sets up page tables that use very large block sizes that CONFIG_SYS_NONCACHED_MEMORY doesn't support. - Enhanced versions for fsl-lsch3 and zynmq that set up finer grained page tables. Ideally, rather than duplicating the MMU setup code yet again this patch would instead consolidate all the different routines into the core ARMv8 code so that it supported all use-cases. However, this will require significant effort since there appear to be a number of discrepancies[1] between different versions of the code, and between the defines/values by some copies of the MMU setup code use and the architectural MMU documentation. Some reverse engineering will be required to determine the intent of the current code. [1] For example, in the core ARMv8 MMU setup code, three defines named TCR_EL[123]_IPS_BITS exist, but only one of them sets the IPS field and the others set a different field (T1SZ) in the page tables. As far as I can tell so far, there should be no need to set different values per exception level nor to modify the T1SZ field at all, since TTBR1 shouldn't be enabled anyway. Another example is inconsistent values for *_VA_BITS between the current core ARMv8 MMU setup code and the various SoC- specific MMU setup code. Another example is that asm/armv8/mmu.h's value for SECTION_SHIFT doesn't match asm/system.h's MMU_SECTION_SHIFT; research is needed to determine which code relies on which of those values and why, and whether fixing the incorrect value will cause any regression. Signed-off-by: Stephen Warren <swarren@nvidia.com>