linux-dev - Linux kernel development work

Age	Commit message (Collapse)	Author	Files	Lines
2012-11-16	arm64: Distinguish between user and kernel XN bits	Catalin Marinas	1	-2/+4
	On AArch64, the meaning of the XN bit has changed to UXN (user). The PXN (privileged) bit must be set to prevent kernel execution. Without the PXN bit set, the CPU may speculatively access device memory. This patch ensures that all the mappings that the kernel must not execute from (including user mappings) have the PXN bit set. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-09-17	arm64: MMU definitions	Catalin Marinas	1	-0/+94
	The virtual memory layout is described in Documentation/arm64/memory.txt. This patch adds the MMU definitions for the 4KB and 64KB translation table configurations. The SECTION_SIZE is 2MB with 4KB page and 512MB with 64KB page configuration. PHYS_OFFSET is calculated at run-time and stored in a variable (no run-time code patching at this stage). On the current implementation, both user and kernel address spaces are 512G (39-bit) each with a maximum of 256G for the RAM linear mapping. Linux uses 3 levels of translation tables with the 4K page configuration and 2 levels with the 64K configuration. Extending the memory space beyond 39-bit with the 4K pages or 42-bit with 64K pages requires an additional level of translation tables. The SPARSEMEM configuration is global to all AArch64 platforms and allows for 1GB sections with SPARSEMEM_VMEMMAP enabled by default. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>