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-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"