From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Wed, 15 Apr 2015 17:34:11 +0200 Subject: [PATCH v4 00/13] arm64: update/clarify/relax Image and FDT placement rules Message-ID: <1429112064-19952-1-git-send-email-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This series came about after Mark Rutland brought up the fact that the current FDT placement logic used by the EFI stub is flawed. But actually, it turned out that the documentation for both the Image and FDT placement was incorrect as well, or confusing at the very least. Changes since v3: As it turns out, it is quite feasible to add a bias to PHYS_OFFSET during early boot so all __pa()/__va() translations are redirected into the kernel mapping even after it has been moved out of the linear region (as suggested by Catalin). So the primary change with respect to v2 is the replacement of all open-coded page table manipulations with invocations of create_mapping() et al. Other changes: - map FDT blocks only as needed: after mapping the first block (2 MB or 64 KB depending on page size) the FDT size is retrieved and remaining blocks are only mapped if necessary; - add header to have the min/max kernel/fdt alignment/size in a single place; - handle the case where the linear region is too small for all of memory to be mapped; - change the memory reservation logic so that statically allocated translation table pages are not reserved unless actually used; - map the linear region as non-executable after we have moved the kernel text out of it; - deal with mem= limits correctly when the kernel image is high in memory; - incorporated various other minor review comments from Mark Rutland. Changes since v2: This is a complete overhaul of the previous version. The FDT changes are mostly equivalent, but have been reimplemented in a way that does not rely on the linear mapping to have been initialized yet. This includes changes to the fixmap code itself to not rely on that either. Combined with the ID map reduction in patch #1, this paves the way for relaxing the Image placement requirements as well, i.e., the kernel Image can now be placed anywhere in memory without affecting the accessibility of memory below it, or causing the resulting mapping to be less efficient due to physical and virtual memory to not be relatively aligned. Changes since v1: - patch #1: split off reservation of the FDT binary itself from the memreserve processing, since the former assumes the FDT is accessed via the linear mapping, which we are about to change - patch #2: mention the older, stricter FDT placement rules in booting.txt, get rid of early_print, use correct format specifier for phys_addr_t, use R/O mapping for FDT, - patches #3 .. #5: add R-b, minor style and grammar tweaks Ard Biesheuvel (13): arm64: reduce ID map to a single page arm64: drop sleep_idmap_phys and clean up cpu_resume() of/fdt: split off FDT self reservation from memreserve processing arm64: use fixmap region for permanent FDT mapping arm64/efi: adapt to relaxed FDT placement requirements arm64: implement our own early_init_dt_add_memory_arch() arm64: use more granular reservations for static page table allocations arm64: split off early mapping code from early_fixmap_init() arm64: mm: explicitly bootstrap the linear mapping arm64: move kernel mapping out of linear region arm64: map linear region as non-executable arm64: allow kernel Image to be loaded anywhere in physical memory arm64/efi: adapt to relaxed kernel Image placement requirements Documentation/arm64/booting.txt | 31 ++-- arch/arm/mm/init.c | 1 + arch/arm64/include/asm/boot.h | 21 +++ arch/arm64/include/asm/compiler.h | 2 + arch/arm64/include/asm/efi.h | 10 +- arch/arm64/include/asm/fixmap.h | 15 ++ arch/arm64/include/asm/memory.h | 28 +++- arch/arm64/include/asm/mmu.h | 1 + arch/arm64/kernel/efi-stub.c | 5 +- arch/arm64/kernel/head.S | 60 ++----- arch/arm64/kernel/setup.c | 32 ++-- arch/arm64/kernel/sleep.S | 9 +- arch/arm64/kernel/suspend.c | 3 - arch/arm64/kernel/vmlinux.lds.S | 50 +++++- arch/arm64/mm/Makefile | 3 + arch/arm64/mm/init.c | 64 +++++++- arch/arm64/mm/mmu.c | 266 ++++++++++++++++++++++---------- arch/arm64/mm/proc.S | 3 +- arch/powerpc/kernel/prom.c | 1 + drivers/firmware/efi/libstub/arm-stub.c | 5 +- drivers/firmware/efi/libstub/efistub.h | 1 - drivers/firmware/efi/libstub/fdt.c | 23 +-- drivers/of/fdt.c | 19 ++- include/linux/of_fdt.h | 2 + 24 files changed, 442 insertions(+), 213 deletions(-) create mode 100644 arch/arm64/include/asm/boot.h -- 1.8.3.2