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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 18:46:29 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 18:46:29 +0200
commitfb2af0020a51709ad87ea8055c325d3fbde04158 (patch)
tree88f3bc38d5604c6eed00597873f209726f9aaeb5 /arch/arm/kernel/head-nommu.S
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vir... (diff)
parentMerge branch 'devel-stable' into for-next (diff)
downloadlinux-fb2af0020a51709ad87ea8055c325d3fbde04158.tar.xz
linux-fb2af0020a51709ad87ea8055c325d3fbde04158.zip
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King: "This contains the usual updates from other people (listed below) and the usual random muddle of miscellaneous ARM updates which cover some low priority bug fixes and performance improvements. I've started to put the pull request wording into the merge commits, which are: - NoMMU stuff: This includes the following series sent earlier to the list: - nommu-fixes - R7 Support - MPU support I've left out the ARCH_MULTIPLATFORM/!MMU stuff that Arnd and I were discussing today until we've reached a conclusion/that's had some more review. This is rebased (and re-tested) on your devel-stable branch because otherwise there were going to be conflicts with Uwe's V7M work now that you've merged that. I've included the fix for limiting MPU to CPU_V7. - Huge page support These changes bring both HugeTLB support and Transparent HugePage (THP) support to ARM. Only long descriptors (LPAE) are supported in this series. The code has been tested on an Arndale board (Exynos 5250). - LPAE updates Please pull these miscellaneous LPAE fixes I've been collecting for a while now for 3.11. They've been tested and reviewed by quite a few people, and most of the patches are pretty trivial. -- Will Deacon. - arch_timer cleanups Please pull these arch_timer cleanups I've been holding onto for a while. They're the same as my last posting, but have been rebased to v3.10-rc3. - mpidr linearisation (multiprocessor id register - identifies which CPU number we are in the system) This patch series that implements MPIDR linearization through a simple hashing algorithm and updates current cpu_{suspend}/{resume} code to use the newly created hash structures to retrieve context pointers. It represents a stepping stone for the implementation of power management code on forthcoming multi-cluster ARM systems. It has been tested on TC2 (dual cluster A15xA7 system), iMX6q, OMAP4 and Tegra, with processors hitting low-power states requiring warm-boot resume through the cpu_resume code path" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits) ARM: 7775/1: mm: Remove do_sect_fault from LPAE code ARM: 7777/1: Avoid extra calls to the C compiler ARM: 7774/1: Fix dtb dependency to use order-only prerequisites ARM: 7770/1: remove residual ARMv2 support from decompressor ARM: 7769/1: Cortex-A15: fix erratum 798181 implementation ARM: 7768/1: prevent risks of out-of-bound access in ASID allocator ARM: 7767/1: let the ASID allocator handle suspended animation ARM: 7766/1: versatile: don't mark pen as __INIT ARM: 7765/1: perf: Record the user-mode PC in the call chain. ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and fork ARM: kernel: implement stack pointer save array through MPIDR hashing ARM: kernel: build MPIDR hash function data structure ARM: mpu: Ensure that MPU depends on CPU_V7 ARM: mpu: protect the vectors page with an MPU region ARM: mpu: Allow enabling of the MPU via kconfig ARM: 7758/1: introduce config HAS_BANDGAP ARM: 7757/1: mm: don't flush icache in switch_mm with hardware broadcasting ARM: 7751/1: zImage: don't overwrite ourself with a page table ARM: 7749/1: spinlock: retry trylock operation if strex fails on free lock ARM: 7748/1: oabi: handle faults when loading swi instruction from userspace ...
Diffstat (limited to 'arch/arm/kernel/head-nommu.S')
-rw-r--r--arch/arm/kernel/head-nommu.S160
1 files changed, 156 insertions, 4 deletions
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 8812ce88f7a1..75f14cc3e073 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -17,9 +17,12 @@
#include <asm/assembler.h>
#include <asm/ptrace.h>
#include <asm/asm-offsets.h>
+#include <asm/memory.h>
#include <asm/cp15.h>
#include <asm/thread_info.h>
#include <asm/v7m.h>
+#include <asm/mpu.h>
+#include <asm/page.h>
/*
* Kernel startup entry point.
@@ -63,12 +66,74 @@ ENTRY(stext)
movs r10, r5 @ invalid processor (r5=0)?
beq __error_p @ yes, error 'p'
- adr lr, BSYM(__after_proc_init) @ return (PIC) address
+#ifdef CONFIG_ARM_MPU
+ /* Calculate the size of a region covering just the kernel */
+ ldr r5, =PHYS_OFFSET @ Region start: PHYS_OFFSET
+ ldr r6, =(_end) @ Cover whole kernel
+ sub r6, r6, r5 @ Minimum size of region to map
+ clz r6, r6 @ Region size must be 2^N...
+ rsb r6, r6, #31 @ ...so round up region size
+ lsl r6, r6, #MPU_RSR_SZ @ Put size in right field
+ orr r6, r6, #(1 << MPU_RSR_EN) @ Set region enabled bit
+ bl __setup_mpu
+#endif
+ ldr r13, =__mmap_switched @ address to jump to after
+ @ initialising sctlr
+ adr lr, BSYM(1f) @ return (PIC) address
ARM( add pc, r10, #PROCINFO_INITFUNC )
THUMB( add r12, r10, #PROCINFO_INITFUNC )
THUMB( mov pc, r12 )
+ 1: b __after_proc_init
ENDPROC(stext)
+#ifdef CONFIG_SMP
+ __CPUINIT
+ENTRY(secondary_startup)
+ /*
+ * Common entry point for secondary CPUs.
+ *
+ * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
+ * the processor type - there is no need to check the machine type
+ * as it has already been validated by the primary processor.
+ */
+ setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9
+#ifndef CONFIG_CPU_CP15
+ ldr r9, =CONFIG_PROCESSOR_ID
+#else
+ mrc p15, 0, r9, c0, c0 @ get processor id
+#endif
+ bl __lookup_processor_type @ r5=procinfo r9=cpuid
+ movs r10, r5 @ invalid processor?
+ beq __error_p @ yes, error 'p'
+
+ adr r4, __secondary_data
+ ldmia r4, {r7, r12}
+
+#ifdef CONFIG_ARM_MPU
+ /* Use MPU region info supplied by __cpu_up */
+ ldr r6, [r7] @ get secondary_data.mpu_szr
+ bl __setup_mpu @ Initialize the MPU
+#endif
+
+ adr lr, BSYM(__after_proc_init) @ return address
+ mov r13, r12 @ __secondary_switched address
+ ARM( add pc, r10, #PROCINFO_INITFUNC )
+ THUMB( add r12, r10, #PROCINFO_INITFUNC )
+ THUMB( mov pc, r12 )
+ENDPROC(secondary_startup)
+
+ENTRY(__secondary_switched)
+ ldr sp, [r7, #8] @ set up the stack pointer
+ mov fp, #0
+ b secondary_start_kernel
+ENDPROC(__secondary_switched)
+
+ .type __secondary_data, %object
+__secondary_data:
+ .long secondary_data
+ .long __secondary_switched
+#endif /* CONFIG_SMP */
+
/*
* Set the Control Register and Read the process ID.
*/
@@ -99,10 +164,97 @@ __after_proc_init:
#endif
mcr p15, 0, r0, c1, c0, 0 @ write control reg
#endif /* CONFIG_CPU_CP15 */
-
- b __mmap_switched @ clear the BSS and jump
- @ to start_kernel
+ mov pc, r13
ENDPROC(__after_proc_init)
.ltorg
+#ifdef CONFIG_ARM_MPU
+
+
+/* Set which MPU region should be programmed */
+.macro set_region_nr tmp, rgnr
+ mov \tmp, \rgnr @ Use static region numbers
+ mcr p15, 0, \tmp, c6, c2, 0 @ Write RGNR
+.endm
+
+/* Setup a single MPU region, either D or I side (D-side for unified) */
+.macro setup_region bar, acr, sr, side = MPU_DATA_SIDE
+ mcr p15, 0, \bar, c6, c1, (0 + \side) @ I/DRBAR
+ mcr p15, 0, \acr, c6, c1, (4 + \side) @ I/DRACR
+ mcr p15, 0, \sr, c6, c1, (2 + \side) @ I/DRSR
+.endm
+
+/*
+ * Setup the MPU and initial MPU Regions. We create the following regions:
+ * Region 0: Use this for probing the MPU details, so leave disabled.
+ * Region 1: Background region - covers the whole of RAM as strongly ordered
+ * Region 2: Normal, Shared, cacheable for RAM. From PHYS_OFFSET, size from r6
+ * Region 3: Normal, shared, inaccessible from PL0 to protect the vectors page
+ *
+ * r6: Value to be written to DRSR (and IRSR if required) for MPU_RAM_REGION
+*/
+
+ENTRY(__setup_mpu)
+
+ /* Probe for v7 PMSA compliance */
+ mrc p15, 0, r0, c0, c1, 4 @ Read ID_MMFR0
+ and r0, r0, #(MMFR0_PMSA) @ PMSA field
+ teq r0, #(MMFR0_PMSAv7) @ PMSA v7
+ bne __error_p @ Fail: ARM_MPU on NOT v7 PMSA
+
+ /* Determine whether the D/I-side memory map is unified. We set the
+ * flags here and continue to use them for the rest of this function */
+ mrc p15, 0, r0, c0, c0, 4 @ MPUIR
+ ands r5, r0, #MPUIR_DREGION_SZMASK @ 0 size d region => No MPU
+ beq __error_p @ Fail: ARM_MPU and no MPU
+ tst r0, #MPUIR_nU @ MPUIR_nU = 0 for unified
+
+ /* Setup second region first to free up r6 */
+ set_region_nr r0, #MPU_RAM_REGION
+ isb
+ /* Full access from PL0, PL1, shared for CONFIG_SMP, cacheable */
+ ldr r0, =PHYS_OFFSET @ RAM starts at PHYS_OFFSET
+ ldr r5,=(MPU_AP_PL1RW_PL0RW | MPU_RGN_NORMAL)
+
+ setup_region r0, r5, r6, MPU_DATA_SIDE @ PHYS_OFFSET, shared, enabled
+ beq 1f @ Memory-map not unified
+ setup_region r0, r5, r6, MPU_INSTR_SIDE @ PHYS_OFFSET, shared, enabled
+1: isb
+
+ /* First/background region */
+ set_region_nr r0, #MPU_BG_REGION
+ isb
+ /* Execute Never, strongly ordered, inaccessible to PL0, rw PL1 */
+ mov r0, #0 @ BG region starts at 0x0
+ ldr r5,=(MPU_ACR_XN | MPU_RGN_STRONGLY_ORDERED | MPU_AP_PL1RW_PL0NA)
+ mov r6, #MPU_RSR_ALL_MEM @ 4GB region, enabled
+
+ setup_region r0, r5, r6, MPU_DATA_SIDE @ 0x0, BG region, enabled
+ beq 2f @ Memory-map not unified
+ setup_region r0, r5, r6, MPU_INSTR_SIDE @ 0x0, BG region, enabled
+2: isb
+
+ /* Vectors region */
+ set_region_nr r0, #MPU_VECTORS_REGION
+ isb
+ /* Shared, inaccessible to PL0, rw PL1 */
+ mov r0, #CONFIG_VECTORS_BASE @ Cover from VECTORS_BASE
+ ldr r5,=(MPU_AP_PL1RW_PL0NA | MPU_RGN_NORMAL)
+ /* Writing N to bits 5:1 (RSR_SZ) --> region size 2^N+1 */
+ mov r6, #(((PAGE_SHIFT - 1) << MPU_RSR_SZ) | 1 << MPU_RSR_EN)
+
+ setup_region r0, r5, r6, MPU_DATA_SIDE @ VECTORS_BASE, PL0 NA, enabled
+ beq 3f @ Memory-map not unified
+ setup_region r0, r5, r6, MPU_INSTR_SIDE @ VECTORS_BASE, PL0 NA, enabled
+3: isb
+
+ /* Enable the MPU */
+ mrc p15, 0, r0, c1, c0, 0 @ Read SCTLR
+ bic r0, r0, #CR_BR @ Disable the 'default mem-map'
+ orr r0, r0, #CR_M @ Set SCTRL.M (MPU on)
+ mcr p15, 0, r0, c1, c0, 0 @ Enable MPU
+ isb
+ mov pc,lr
+ENDPROC(__setup_mpu)
+#endif
#include "head-common.S"