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2015-06-12ARM: 8383/1: nommu: avoid deprecated source register on movStefan Agner
In Thumb2 mode, the stack register r13 is deprecated if the destination register is the program counter (r15). Similar to head.S, head-nommu.S uses r13 to store the return address used after configuring the CPU's CP15 register. However, since we do not enable a MMU, there will be no address switch and it is possible to use branch with link instruction to call __after_proc_init. Avoid using r13 completely by using bl to call __after_proc_init and get rid of __secondary_switched. Beside removing unnecessary complexity, this also fixes a compiler warning when compiling a !MMU kernel: Warning: Use of r13 as a source register is deprecated when r15 is the destination register. Tested-?by: Maxime Coquelin <mcoquelin.stm32@gmail.com> Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-12Merge branch 'bsym' into for-nextRussell King
Conflicts: arch/arm/kernel/head.S
2015-06-01ARM: redo TTBR setup code for LPAERussell King
Re-engineer the LPAE TTBR setup code. Rather than passing some shifted address in order to fit in a CPU register, pass either a full physical address (in the case of r4, r5 for TTBR0) or a PFN (for TTBR1). This removes the ARCH_PGD_SHIFT hack, and the last dangerous user of cpu_set_ttbr() in the secondary CPU startup code path (which was there to re-set TTBR1 to the appropriate high physical address space on Keystone2.) Tested-by: Murali Karicheri <m-karicheri2@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-05-08ARM: replace BSYM() with badr assembly macroRussell King
BSYM() was invented to allow us to work around a problem with the assembler, where local symbols resolved by the assembler for the 'adr' instruction did not take account of their ISA. Since we don't want BSYM() used elsewhere, replace BSYM() with a new macro 'badr', which is like the 'adr' pseudo-op, but with the BSYM() mechanics integrated into it. This ensures that the BSYM()-ification is only used in conjunction with 'adr'. Acked-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-21ARM: Fix nommu bootingRussell King
Commit bf35706f3d09 ("ARM: 8314/1: replace PROCINFO embedded branch with relative offset") broke booting on nommu platforms as it didn't update the nommu boot code. This patch fixes that oversight. Fixes: bf35706f3d09 ("ARM: 8314/1: replace PROCINFO embedded branch with relative offset") Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-12-13ARM: fix asm/memory.h build errorRussell King
Jason Gunthorpe reports a build failure when ARM_PATCH_PHYS_VIRT is not defined: In file included from arch/arm/include/asm/page.h:163:0, from include/linux/mm_types.h:16, from include/linux/sched.h:24, from arch/arm/kernel/asm-offsets.c:13: arch/arm/include/asm/memory.h: In function '__virt_to_phys': arch/arm/include/asm/memory.h:244:40: error: 'PHYS_OFFSET' undeclared (first use in this function) arch/arm/include/asm/memory.h:244:40: note: each undeclared identifier is reported only once for each function it appears in arch/arm/include/asm/memory.h: In function '__phys_to_virt': arch/arm/include/asm/memory.h:249:13: error: 'PHYS_OFFSET' undeclared (first use in this function) Fixes: ca5a45c06cd4 ("ARM: mm: use phys_addr_t appropriately in p2v and v2p conversions") Tested-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01ARM: Add .text annotations where required after __CPUINIT removalRussell King
Commit 8bd26e3a7 (arm: delete __cpuinit/__CPUINIT usage from all ARM users) caused some code to leak into sections which are discarded through the removal of __CPUINIT annotations. Add appropriate .text annotations to bring these back into the kernel text. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-14arm: delete __cpuinit/__CPUINIT usage from all ARM usersPaul Gortmaker
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-17ARM: mpu: protect the vectors page with an MPU regionJonathan Austin
Without an MMU it is possible for userspace programs to start executing code in places that they have no business executing. The MPU allows some level of protection against this. This patch protects the vectors page from access by userspace processes. Userspace tasks that dereference a null pointer are already protected by an svc at 0x0 that kills them. However when tasks use an offset from a null pointer (eg a function in a null struct) they miss this carefully placed svc and enter the exception vectors in user mode, ending up in the kernel. This patch causes programs that do this to receive a SEGV instead of happily entering the kernel in user-mode, and hence avoid a 'Bad Mode' panic. As part of this change it is necessary to make sigreturn happen via the stack when there is not an sa_restorer function. This change is invisible to userspace, and irrelevant to code compiled using a uClibc toolchain, which always uses an sa_restorer function. Because we don't get to remap the vectors in !MMU kuser_helpers are not in a defined location, and hence aren't usable. This means we don't need to worry about keeping them accessible from PL0 Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Nicolas Pitre <nico@linaro.org> CC: Catalin Marinas <catalin.marinas@arm.com>
2013-06-07ARM: mpu: add MPU initialisation for secondary coresJonathan Austin
The MPU initialisation on the primary core is performed in two stages, one minimal stage to ensure the CPU can boot and a second one after sanity_check_meminfo. As the memory configuration is known by the time we boot secondary cores only a single step is necessary, provided the values for DRSR are passed to secondaries. This patch implements this arrangement. The configuration generated for the MPU regions is made available to the secondary core, which can then use the asm MPU intialisation code to program a complete region configuration. This is necessary for SMP configurations without an MMU, as the MPU initialisation is the only way to ensure that memory is specified as 'shared'. Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Nicolas Pitre <nico@linaro.org>
2013-06-07ARM: mpu: add early bring-up code for the ARMv7 PMSA-compliant MPUJonathan Austin
This patch adds initial support for using the MPU, which is necessary for SMP operation on PMSAv7 processors because it is the only way to ensure memory is shared. This is an initial patch and full SMP support is added later in this series. The setup of the MPU is performed in a way analagous to that for the MMU: Very early initialisation before the C environment is brought up, followed by a sanity check and more complete initialisation in C. This patch provides the simplest possible memory region configuration: MPU_PROBE_REGION: Reserved for probing MPU details, not enabled MPU_BG_REGION: A 'background' region that specifies all memory strongly ordered MPU_RAM_REGION: A single shared, cacheable, normal region for the valid RAM. In this early initialisation code we simply map the whole of the address space with the BG_REGION and (at least) the kernel with the RAM_REGION. The MPU has region alignment constraints that require us to round past the end of the kernel. As region 2 has a higher priority than region 1, it overrides the strongly- ordered behaviour for RAM only. Subsequent patches will add more complete initialisation from the C-world and support for bringing up secondary CPUs. Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Hyok S. Choi <hyok.choi@samsung.com>
2013-06-07ARM: nommu: add entry point for secondary CPUs to head-nommu.SWill Deacon
This patch adds a secondary_startup entry point to head-nommu.S so that we can boot secondary CPUs on an SMP nommu configuration. Signed-off-by: Will Deacon <will.deacon@arm.com> CC: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> CC: Nicolas Pitre <nico@linaro.org>
2013-04-17ARM: Add base support for ARMv7-MCatalin Marinas
This patch adds the base support for the ARMv7-M architecture. It consists of the corresponding arch/arm/mm/ files and various #ifdef's around the kernel. Exception handling is implemented by a subsequent patch. [ukleinek: squash in some changes originating from commit b5717ba (Cortex-M3: Add support for the Microcontroller Prototyping System) from the v2.6.33-arm1 patch stack, port to post 3.6, drop zImage support, drop reorganisation of pt_regs, assert CONFIG_CPU_V7M doesn't leak into installed headers and a few cosmetic changes] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Jonathan Austin <jonathan.austin@arm.com> Tested-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2013-01-31ARM: let CPUs not being able to run in ARM mode enter in THUMB modeUwe Kleine-König
Some ARM cores are not capable to run in ARM mode (e.g. Cortex-M3). So obviously these cannot enter the kernel in ARM mode. Make an exception for them and let them enter in THUMB mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Message-Id: 1358162123-30113-1-git-send-email-u.kleine-koenig@pengutronix.de Acked-by: Nicolas Pitre <nico@linaro.org>
2012-12-07ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6Armando Visconti
This patch keeps disabled the strict alignment CP15 bit for all armv6 and armv7 processor without the mmu. This behaviour is now same as in the mmu case. Signed-off-by: Armando Visconti <armando.visconti@st.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-28ARM: move CP15 definitions to separate header fileRussell King
Avoid namespace conflicts with drivers over the CP15 definitions by moving CP15 related prototypes and definitions to a private header file. Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> [Tegra] Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> [EP93xx] Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com>
2011-07-19ARM: 6999/1: head, zImage: Always Enter the kernel in ARM stateDave Martin
Currently, the documented kernel entry requirements are not explicit about whether the kernel should be entered in ARM or Thumb, leading to an ambiguitity about how to enter Thumb-2 kernels. As a result, the kernel is reliant on the zImage decompressor to enter the kernel proper in the correct instruction set state. This patch changes the boot entry protocol for head.S and Image to be the same as for zImage: in all cases, the kernel is now entered in ARM. Documentation/arm/Booting is updated to reflect this new policy. A different rule will be needed for Cortex-M class CPUs as and when support for those lands in mainline, since these CPUs don't support the ARM instruction set at all: a note is added to the effect that the kernel must be entered in Thumb on such systems. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-15ARM: Defer lookup of machine_type to setup.cRussell King
Since the debug macros no longer depend on the machine type information, the machine type lookup can be deferred to setup_arch() in setup.c which simplifies the code somewhat. We also move the __error_a functionality into setup.c for displaying a message when a bad machine ID is passed to the kernel via the LL debug code. We also log this into the kernel ring buffer which makes it possible to retrieve the message via a debugger. Original idea from Grant Likely. Acked-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08ARM: no need for nommu to jump through the hoops that mmu doesRussell King
nommu can jump directly to __mmap_switched without the absolute address branching which the mmuful kernel does. Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-11-23ARM: convert to use __HEAD and HEAD_TEXT macros.Tim Abbott
This has the consequence of changing the section name used for head code from ".text.head" to ".head.text". Since this commit changes all users in the architecture, this change should be harmless. The .text.head output section is eliminated and the head text code is included at the start of the .init output section. Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-07-24nommu: Do not override the CP15 control reg value returned from initfuncCatalin Marinas
The patch removes the "mrc" instruction in head-nommu.S overriding the r0 register containing the value to be written in the CP15 system control register. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24Thumb-2: Implementation of the unified start-up and exceptions codeCatalin Marinas
This patch implements the ARM/Thumb-2 unified kernel start-up and exception handling code. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-09-01[ARM] 5227/1: Add the ENDPROC declarations to the .S filesCatalin Marinas
This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-07[ARM] Eliminate useless includes of asm/mach-types.hRussell King
There are 43 includes of asm/mach-types.h by files that don't reference anything from that file. Remove these unnecessary includes. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-05-08[ARM] Ensure head text is always placed at the start of kernelRussell King
Commit 86c0baf123e474b6eb404798926ecf62b426bf3a highlighted that we may end up with the head text placed elsewhere in the kernel image. Introduce a new .text.head section to contain the initial kernel startup code, and always place this section at the beginning of the kernel image. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-11-30[ARM] Include asm/elf.h instead of asm/procinfo.hRussell King
These files want to provide/access ELF hwcap information, so should be including asm/elf.h rather than asm/procinfo.h Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-28[ARM] nommu: confirms the CR_V bit in nommu modeHyok S. Choi
In nommu mode, the exception vector location depends on the platforms. Some of the implementations may have some special exception control forwarding method in their ROM/flash and for some of them has its own re-mapping mechanism by the h/w. This patch introduces a special configuration CONFIG_CPU_HIGH_VECTOR which turns on the CR_V bit in nommu mode. The CR_V bit is turned off by default. This feature depends on CP15 and does not supported by ARM740. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-27[ARM] nommu: manage the CP15 thingsHyok S. Choi
All the current CP15 access codes in ARM arch can be categorized and conditioned by the defines as follows: Related operation Safe condition a. any CP15 access !CPU_CP15 b. alignment trap CPU_CP15_MMU c. D-cache(C-bit) CPU_CP15 d. I-cache CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 || CPU_ARM720 || CPU_ARM740 || CPU_XSCALE || CPU_XSC3 ) e. alternate vector CPU_CP15 && !CPU_ARM740 f. TTB CPU_CP15_MMU g. Domain CPU_CP15_MMU h. FSR/FAR CPU_CP15_MMU For example, alternate vector is supported if and only if "CPU_CP15 && !CPU_ARM740" is satisfied. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-25[ARM] Remove MODE_(SVC|IRQ|FIQ|USR) and DEFAULT_FIQRussell King
DEFAULT_FIQ was entirely unused. MODE_* are just redefinitions of *_MODE. Use *_MODE instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-05[ARM] 3496/1: more constants for asm-offsets.hUwe Zeisberger
Patch from Uwe Zeisberger added the following constants: - MACHINFO_TYPE - MACHINFO_NAME - MACHINFO_PHYSIO - MACHINFO_PGOFFIO - PROCINFO_INITFUNC - PROCINFO_MMUFLAGS and removed their definition from head.S and head-nommu.S Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-24[ARM] nommu: trivial fixups for head-nommu.S and the MakefileHyok S. Choi
This patch fix compilation problem of start-up codes. (head-nommu.S, arch/arm/kernel/Makefile) Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-27[ARM] nommu: start-up codeHyok S. Choi
This patch adds nommu version start-up code head-nommu.S. The common part of the start-up codes is moved to head-common.S. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>