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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 21:03:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 21:03:26 -0700
commitbb0fd7ab0986105765d11baa82e619c618a235aa (patch)
tree6a0585ece827e1025aa48819959d02155a871be9 /arch/arm/boot
parentbdfa54dfd9eea001274dbcd622657a904fe43b81 (diff)
parent4b2f8838479eb2abe042e094f7d2cced6d5ea772 (diff)
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King: "Included in this update are both some long term fixes and some new features. Fixes: - An integer overflow in the calculation of ELF_ET_DYN_BASE. - Avoiding OOMs for high-order IOMMU allocations - SMP requires the data cache to be enabled for synchronisation primitives to work, so prevent the CPU_DCACHE_DISABLE option being visible on SMP builds. - A bug going back 10+ years in the noMMU ARM94* CPU support code, where it corrupts registers. Found by folk getting Linux running on their cameras. - Versatile Express needs an errata workaround enabled for CPU hot-unplug to work. Features: - Clean up module linker by handling out of range relocations separately from relocation cases we don't handle. - Fix a long term bug in the pci_mmap_page_range() code, which we hope won't impact userspace (we hope there's no users of the existing broken interface.) - Don't map DMA coherent allocations when we don't have a MMU. - Drop experimental status for SMP_ON_UP. - Warn when DT doesn't specify ePAPR mandatory cache properties. - Add documentation concerning how we find the start of physical memory for AUTO_ZRELADDR kernels, detailing why we have chosen the mask and the implications of changing it. - Updates from Ard Biesheuvel to address some issues with large kernels (such as allyesconfig) failing to link. - Allow hibernation to work on modern (ARMv7) CPUs - this appears to have never worked in the past on these CPUs. - Enable IRQ_SHOW_LEVEL, which changes the /proc/interrupts output format (hopefully without userspace breaking... let's hope that if it causes someone a problem, they tell us.) - Fix tegra-ahb DT offsets. - Rework ARM errata 643719 code (and ARMv7 flush_cache_louis()/ flush_dcache_all()) code to be more efficient, and enable this errata workaround by default for ARMv7+SMP CPUs. This complements the Versatile Express fix above. - Rework ARMv7 context code for errata 430973, so that only Cortex A8 CPUs are impacted by the branch target buffer flush when this errata is enabled. Also update the help text to indicate that all r1p* A8 CPUs are impacted. - Switch ARM to the generic show_mem() implementation, it conveys all the information which we were already reporting. - Prevent slow timer sources being used for udelay() - timers running at less than 1MHz are not useful for this, and can cause udelay() to return immediately, without any wait. Using such a slow timer is silly. - VDSO support for 32-bit ARM, mainly for gettimeofday() using the ARM architected timer. - Perf support for Scorpion performance monitoring units" vdso semantic conflict fixed up as per linux-next. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (52 commits) ARM: update errata 430973 documentation to cover Cortex A8 r1p* ARM: ensure delay timer has sufficient accuracy for delays ARM: switch to use the generic show_mem() implementation ARM: proc-v7: avoid errata 430973 workaround for non-Cortex A8 CPUs ARM: enable ARM errata 643719 workaround by default ARM: cache-v7: optimise test for Cortex A9 r0pX devices ARM: cache-v7: optimise branches in v7_flush_cache_louis ARM: cache-v7: consolidate initialisation of cache level index ARM: cache-v7: shift CLIDR to extract appropriate field before masking ARM: cache-v7: use movw/movt instructions ARM: allow 16-bit instructions in ALT_UP() ARM: proc-arm94*.S: fix setup function ARM: vexpress: fix CPU hotplug with CT9x4 tile. ARM: 8276/1: Make CPU_DCACHE_DISABLE depend on !SMP ARM: 8335/1: Documentation: DT bindings: Tegra AHB: document the legacy base address ARM: 8334/1: amba: tegra-ahb: detect and correct bogus base address ARM: 8333/1: amba: tegra-ahb: fix register offsets in the macros ARM: 8339/1: Enable CONFIG_GENERIC_IRQ_SHOW_LEVEL ARM: 8338/1: kexec: Relax SMP validation to improve DT compatibility ARM: 8337/1: mm: Do not invoke OOM for higher order IOMMU DMA allocations ...
Diffstat (limited to 'arch/arm/boot')
-rw-r--r--arch/arm/boot/compressed/head.S52
1 files changed, 45 insertions, 7 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index c41a793b519c..2c45b5709fa4 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -10,8 +10,11 @@
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/v7m.h>
+
+ AR_CLASS( .arch armv7-a )
+ M_CLASS( .arch armv7-m )
- .arch armv7-a
/*
* Debugging stuff
*
@@ -114,7 +117,12 @@
* sort out different calling conventions
*/
.align
- .arm @ Always enter in ARM state
+ /*
+ * Always enter in ARM state for CPUs that support the ARM ISA.
+ * As of today (2014) that's exactly the members of the A and R
+ * classes.
+ */
+ AR_CLASS( .arm )
start:
.type start,#function
.rept 7
@@ -132,14 +140,15 @@ start:
THUMB( .thumb )
1:
- ARM_BE8( setend be ) @ go BE8 if compiled for BE8
- mrs r9, cpsr
+ ARM_BE8( setend be ) @ go BE8 if compiled for BE8
+ AR_CLASS( mrs r9, cpsr )
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install @ get into SVC mode, reversibly
#endif
mov r7, r1 @ save architecture ID
mov r8, r2 @ save atags pointer
+#ifndef CONFIG_CPU_V7M
/*
* Booting from Angel - need to enter SVC mode and disable
* FIQs/IRQs (numeric definitions from angel arm.h source).
@@ -155,6 +164,7 @@ not_angel:
safe_svcmode_maskall r0
msr spsr_cxsf, r9 @ Save the CPU boot mode in
@ SPSR
+#endif
/*
* Note that some cache flushing and other stuff may
* be needed here - is there an Angel SWI call for this?
@@ -168,9 +178,26 @@ not_angel:
.text
#ifdef CONFIG_AUTO_ZRELADDR
- @ determine final kernel image address
+ /*
+ * Find the start of physical memory. As we are executing
+ * without the MMU on, we are in the physical address space.
+ * We just need to get rid of any offset by aligning the
+ * address.
+ *
+ * This alignment is a balance between the requirements of
+ * different platforms - we have chosen 128MB to allow
+ * platforms which align the start of their physical memory
+ * to 128MB to use this feature, while allowing the zImage
+ * to be placed within the first 128MB of memory on other
+ * platforms. Increasing the alignment means we place
+ * stricter alignment requirements on the start of physical
+ * memory, but relaxing it means that we break people who
+ * are already placing their zImage in (eg) the top 64MB
+ * of this range.
+ */
mov r4, pc
and r4, r4, #0xf8000000
+ /* Determine final kernel image address. */
add r4, r4, #TEXT_OFFSET
#else
ldr r4, =zreladdr
@@ -810,6 +837,16 @@ __common_mmu_cache_on:
call_cache_fn: adr r12, proc_types
#ifdef CONFIG_CPU_CP15
mrc p15, 0, r9, c0, c0 @ get processor ID
+#elif defined(CONFIG_CPU_V7M)
+ /*
+ * On v7-M the processor id is located in the V7M_SCB_CPUID
+ * register, but as cache handling is IMPLEMENTATION DEFINED on
+ * v7-M (if existant at all) we just return early here.
+ * If V7M_SCB_CPUID were used the cpu ID functions (i.e.
+ * __armv7_mmu_cache_{on,off,flush}) would be selected which
+ * use cp15 registers that are not implemented on v7-M.
+ */
+ bx lr
#else
ldr r9, =CONFIG_PROCESSOR_ID
#endif
@@ -1310,8 +1347,9 @@ __hyp_reentry_vectors:
__enter_kernel:
mov r0, #0 @ must be 0
- ARM( mov pc, r4 ) @ call kernel
- THUMB( bx r4 ) @ entry point is always ARM
+ ARM( mov pc, r4 ) @ call kernel
+ M_CLASS( add r4, r4, #1 ) @ enter in Thumb mode for M class
+ THUMB( bx r4 ) @ entry point is always ARM for A/R classes
reloc_code_end: