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2015-07-27mn10300: Provide atomic_{or,xor,and}Peter Zijlstra1-47/+10
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27mips: Provide atomic_{or,xor,and}Peter Zijlstra1-0/+9
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27metag: Provide atomic_{or,xor,and}Peter Zijlstra2-42/+17
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27m68k: Provide atomic_{or,xor,and}Peter Zijlstra1-4/+10
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27m32r: Provide atomic_{or,xor,and}Peter Zijlstra1-34/+10
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27ia64: Provide atomic_{or,xor,and}Peter Zijlstra1-4/+22
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27hexagon: Provide atomic_{or,xor,and}Peter Zijlstra1-0/+6
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27blackfin: Provide atomic_{or,xor,and}Peter Zijlstra3-25/+40
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. TODO: use inline asm or at least asm macros to collapse the lot. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27avr32: Provide atomic_{or,xor,and}Peter Zijlstra1-0/+14
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27arm64: Provide atomic_{or,xor,and}Peter Zijlstra1-0/+15
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27arm: Provide atomic_{or,xor,and}Peter Zijlstra1-0/+15
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27arc: Provide atomic_{or,xor,and}Peter Zijlstra1-2/+17
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27alpha: Provide atomic_{or,xor,and}Peter Zijlstra1-15/+28
Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27atomic: Prepare generic atomic implementation for logic opsPeter Zijlstra1-2/+10
Clean up the #ifdef guards a bit to prepare for architectures to supply their own logic ops. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27arm64: include linux/types.h in asm/spinlock_types.hWill Deacon1-0/+2
Our ticket-based spinlock structures rely on a definition of u16, so include linux/types.h explicitly to ensure the thing compiles. Found by a module build failure in -next: arch/arm64/include/asm/spinlock_types.h:27:2: error: unknown type name 'u16' arch/arm64/include/asm/spinlock_types.h:28:2: error: unknown type name 'u16' arch/arm64/include/asm/spinlock_types.h:33:13: error: expected declaration specifiers or '...' before numeric constant include/linux/spinlock_types.h:21:2: error: unknown type name 'arch_spinlock_t' arch/arm64/include/asm/spinlock.h:34:35: error: unknown type name 'arch_spinlock_t' arch/arm64/include/asm/spinlock.h:65:37: error: unknown type name 'arch_spinlock_t' Reported-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/BUG: Show explicit backtrace for WARNsDave P Martin1-0/+2
The generic slowpath WARN implementation prints a backtrace, but the report_bug() based implementation does not, opting to print the registers instead which is generally not as useful. Ideally, report_bug() should be fixed to make the behaviour more consistent, but in the meantime this patch generates a backtrace directly from the arm64 backend instead so that this functionality is not lost with the migration to report_bug(). As a side-effect, the backtrace will be outside the oops end marker, but that's hard to avoid without modifying generic code. This patch can go away if report_bug() grows the ability in the future to generate a backtrace directly or call an arch hook at the appropriate time. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/BUG: Use BRK instruction for generic BUG trapsDave P Martin5-3/+142
Currently, the minimal default BUG() implementation from asm- generic is used for arm64. This patch uses the BRK software breakpoint instruction to generate a trap instead, similarly to most other arches, with the generic BUG code generating the dmesg boilerplate. This allows bug metadata to be moved to a separate table and reduces the amount of inline code at BUG and WARN sites. This also avoids clobbering any registers before they can be dumped. To mitigate the size of the bug table further, this patch makes use of the existing infrastructure for encoding addresses within the bug table as 32-bit offsets instead of absolute pointers. (Note that this limits the kernel size to 2GB.) Traps are registered at arch_initcall time for aarch64, but BUG has minimal real dependencies and it is desirable to be able to generate bug splats as early as possible. This patch redirects all debug exceptions caused by BRK directly to bug_handler() until the full debug exception support has been initialised. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Add missing #includesDave P Martin2-0/+5
<asm/debug-monitors.h> relies on <asm/ptrace.h>, but doesn't declare this dependency. This becomes a problem once debug-monitors.h starts getting included all over the place to get the BRK immedates. The missing include of <asm/memory.h> (for UL()) in <asm/esr.h> is also added. The series no longer relies on this, but I spotted it during development and it may as well get fixed. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Simplify BRK insn opcode declarationsDave P Martin2-25/+10
The way the KGDB_DYN_BRK_INS_BYTEx macros are declared is more complex than it needs to be. Also, the macros are only used in one place, which is arch-specific anyway. This patch refactors the macros to simplify them, and exposes an argument so that we can have a single macro instead of 4. As a side effect, this patch also fixes some anomalous spellings of "KGDB". These changes alter the compile types of some integer constants that are harmless but trigger truncation warnings in gcc when assigning to 32-bit variables. This patch adds an explicit cast for the affected cases. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Move BRK ESR template macro into <asm/esr.h>Dave P Martin2-7/+7
It makes sense to keep all the architectural exception syndrome definitions in the same place. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: More consistent naming for the BRK ESR template macroDave P Martin2-4/+5
The naming of DBG_ESR_VAL_BRK is inconsistent with the way other similar macros are named. This patch makes the naming more consistent, and appends "64" as a reminder that this ESR pattern only matches from AArch64 state. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Eliminate magic number from ESR template definitionDave P Martin1-1/+3
<asm/esr.h> has perfectly good constants for defining ESR values already. Let's use them. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Mask off all reserved bits from generated ESR valuesDave P Martin1-1/+1
There are only 16 comment bits in a BRK instruction, which correspond to ESR bits 15:0. Bits 24:16 of the ESR are RES0, and might have weird meanings in the future. This code inserts 16 bits of comment in the ESR value instead of 20 (almost certainly a typo in the original code). Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64/debug: Eliminate magic number for size of BRK instructionDave P Martin1-1/+3
The size of an A64 BRK instruction is the same as the size of all other A64 instructions, because all A64 instructions are the same size. BREAK_INSTR_SIZE is retained for readibility, but it should not be an independent constant from AARCH64_INSN_SIZE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: insn: use set_fixmap_offset to make it more clearyalin wang1-3/+2
A little change to patch_map() function, use set_fixmap_offset() to make code more clear. Signed-off-by: yalin wang <yalin.wang2010@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: efi: prefer AllocatePages() over efi_low_alloc() for vmlinuxArd Biesheuvel1-9/+32
When allocating memory for the kernel image, try the AllocatePages() boot service to obtain memory at the preferred offset of 'dram_base + TEXT_OFFSET', and only revert to efi_low_alloc() if that fails. This is the only way to allocate at the base of DRAM if DRAM starts at 0x0, since efi_low_alloc() refuses to allocate at 0x0. Tested-by: Haojian Zhuang <haojian.zhuang@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: remove non-legit DT warnings when booting using ACPISudeep Holla2-3/+8
Since both CONFIG_ACPI and CONFIG_OF are enabled when booting using ACPI tables on ARM64 platforms, we get few device tree warnings which are not valid for ACPI boot. We can use of_have_populated_dt to check if the device tree is populated or not before throwing out those errors. This patch uses of_have_populated_dt to remove non legitimate device tree warning when booting using ACPI tables. Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: alternatives: add enable parameter to conditional asm macrosWill Deacon1-3/+9
There are cases where we want to compile out both versions of an alternative code block, so add an enable parameter to the new conditional alternative assembly macros in the same way as alternative_insn. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add support for Privileged Access NeverJames Morse14-2/+121
'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: Generalise msr_s/mrs_s operationsSuzuki K. Poulose1-5/+15
The system register encoding generated by sys_reg() works only for MRS/MSR(Register) operations, as we hardcode Bit20 to 1 in mrs_s/msr_s mask. This makes it unusable for generating instructions accessing registers with Op0 < 2(e.g, PSTATE.x with Op0=0). As per ARMv8 ARM, (Ref: ARMv8 ARM, Section: "System instruction class encoding overview", C5.2, version:ARM DDI 0487A.f), the instruction encoding reserves bits [20-19] for Op0. This patch generalises the sys_reg, mrs_s and msr_s macros, so that we could use them to access any of the supported system register. Cc: James Morse <james.morse@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add optional CONFIG_ parameter to ALTERNATIVE()James Morse1-3/+25
Some uses of ALTERNATIVE() may depend on a feature that is disabled at compile time by a Kconfig option. In this case the unused alternative instructions waste space, and if the original instruction is a nop, it wastes time and space. This patch adds an optional 'config' option to ALTERNATIVE() and alternative_insn that allows the compiler to remove both the original and alternative instructions if the config option is not defined. Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add min_field_value and use '>=' for feature detectionJames Morse2-5/+13
When a new cpu feature is available, the cpu feature bits will have some initial value, which is incremented when the feature is updated. This patch changes 'register_value' to be 'min_field_value', and checks the feature bits value (interpreted as a signed int) is greater than this minimum. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add cpufeature 'enable' callbackJames Morse2-0/+7
This patch adds an 'enable()' callback to cpu capability/feature detection, allowing features that require some setup or configuration to get this opportunity once the feature has been detected. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Move config_sctlr_el1James Morse3-13/+13
Later patches need config_sctlr_el1 to set/clear bits in the sctlr_el1 register. This patch moves this function into header a file. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kvm: Adopt new alternative assembler macrosDaniel Thompson1-2/+10
Convert the dynamic patching for ARM64_HAS_SYSREG_GIC_CPUIF over to the newly added alternative assembler macros. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Adopt new alternative assembler macrosDaniel Thompson1-16/+13
Convert the dynamic patching for ARM64_WORKAROUND_845719 over to the newly added alternative assembler macros. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: mm: Adopt new alternative assembler macrosDaniel Thompson1-1/+6
Convert the dynamic patching for ARM64_WORKAROUND_CLEAN_CACHE over to the newly added alternative assembler macros. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: alternative: Provide if/else/endif assembler macrosDaniel Thompson1-0/+41
The existing alternative_insn macro has some limitations that make it hard to work with. In particular the fact it takes instructions from it own macro arguments means it doesn't play very nicely with C pre-processor macros because the macro arguments look like a string to the C pre-processor. Workarounds are (probably) possible but things start to look ugly. Introduce an alternative set of macros that allows instructions to be presented to the assembler as normal and switch everything over to the new macros. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extensionJames Morse1-0/+7
Based on arch/arm/include/asm/cputype.h, this function does the shifting and sign extension necessary when accessing cpu feature fields. Signed-off-by: James Morse <james.morse@arm.com> Suggested-by: Russell King <linux@arm.linux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: perf: condense event number mapsMark Rutland1-102/+22
Most of the cache events an architecture might support do not map well to those provided by the ARM architecture, and as such most entries in the event number maps are *_UNSUPPORTED. Unfortuantely as 0 is a valid physical event identifier, the *_UNSUPPORTED macros expand to a non-zero value and thus each unsupported event must be explicitly initialised as such. This leads to large diffs when adding support for a new CPU, and makes it difficult to spot the important information. This patch follows arch/arm/ in making use of PERF_*_ALL_UNSUPPORTED macros to initialise all entries to *_UNSUPPORTED before overriding this for the specific events we actually support, resulting in a significant source code reduction. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: hugetlb: remove paragraph about writing to FSFJisheng Zhang2-8/+0
Remove paragraph about writing to the Free Software Foundation's mailing address from GPL notice. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: dma-mapping: implement dma_get_sgtable()Robin Murphy1-0/+14
The default dma_common_get_sgtable() implementation relies on the CPU address of the buffer being a regular lowmem address. This is not always the case on arm64, since allocations from the various DMA pools may have remapped vmalloc addresses, rendering the use of virt_to_page() invalid. Fix this by providing our own implementation based on the fact that we can safely derive a physical address from the DMA address in both cases. CC: Jon Medhurst <tixy@linaro.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> [will: made static] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: force CONFIG_SMP=y and remove redundant #ifdefsWill Deacon22-153/+8
Nobody seems to be producing !SMP systems anymore, so this is just becoming a source of kernel bugs, particularly if people want to use coherent DMA with non-shared pages. This patch forces CONFIG_SMP=y for arm64, removing a modest amount of code in the process. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: perf: factor out callchain codeMark Rutland4-180/+198
We currently bundle the callchain handling code with the PMU code, despite the fact the two are distinct, and the former can be useful even in the absence of the latter. Follow the example of arch/arm and factor the callchain handling into its own file dependent on CONFIG_PERF_EVENTS rather than CONFIG_HW_PERF_EVENTS. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: lib: use pair accessors for copy_*_user routinesWill Deacon3-18/+33
The AArch64 instruction set contains load/store pair memory accessors, so use these in our copy_*_user routines to transfer 16 bytes per iteration. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: Better native ptrace support for compat tasksCatalin Marinas1-1/+91
The compat ptrace interface allows access to the TLS register, hardware breakpoints and watchpoints, syscall number. However, a native task using the native ptrace interface to debug compat tasks (e.g. multi-arch gdb) only has access to the general and VFP register sets. The compat ptrace interface cannot be accessed from a native task. This patch adds a new user_aarch32_ptrace_view which contains the TLS, hardware breakpoint/watchpoint and syscall number regsets in addition to the existing GPR and VFP regsets. This view is backwards compatible with the previous kernels. Core dumping of 32-bit tasks and compat ptrace are not affected since the original user_aarch32_view is preserved. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Yao Qi <yao.qi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: enable more compressed Image formatsOlof Johansson2-1/+16
Plumb up Makefile arguments for the already supported formats in the kbuild system: lz4, bzip2, lzma, and lzo. Note that just as with Image.gz, these images are not self-decompressing and the booting firmware still needs to handle decompression before launching the kernel image. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: Add support for hardware updates of the access and dirty pte bitsCatalin Marinas4-2/+178
The ARMv8.1 architecture extensions introduce support for hardware updates of the access and dirty information in page table entries. With TCR_EL1.HA enabled, when the CPU accesses an address with the PTE_AF bit cleared in the page table, instead of raising an access flag fault the CPU sets the actual page table entry bit. To ensure that kernel modifications to the page tables do not inadvertently revert a change introduced by hardware updates, the exclusive monitor (ldxr/stxr) is adopted in the pte accessors. When TCR_EL1.HD is enabled, a write access to a memory location with the DBM (Dirty Bit Management) bit set in the corresponding pte automatically clears the read-only bit (AP[2]). Such DBM bit maps onto the Linux PTE_WRITE bit and to check whether a writable (DBM set) page is dirty, the kernel tests the PTE_RDONLY bit. In order to allow read-only and dirty pages, the kernel needs to preserve the software dirty bit. The hardware dirty status is transferred to the software dirty bit in ptep_set_wrprotect() (using load/store exclusive loop) and pte_modify(). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: remove dead codeMark Salter2-12/+0
Commit 68234df4ea79 ("arm64: kill flush_cache_all()") removed soft_reset() from the kernel. This was the only caller of setup_mm_for_reboot(), so remove that also. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: move update_mmu_cache() into asm/pgtable.hWill Deacon2-14/+15
Mark Brown reported an allnoconfig build failure in -next: Today's linux-next fails to build an arm64 allnoconfig due to "mm: make GUP handle pfn mapping unless FOLL_GET is requested" which causes: > arm64-allnoconfig > ../mm/gup.c:51:4: error: implicit declaration of function 'update_mmu_cache' [-Werror=implicit-function-declaration] Fix the error by moving the function to asm/pgtable.h, as is the case for most other architectures. Reported-by: Mark Brown <broonie@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>