diff options
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 14 | ||||
| -rw-r--r-- | arch/arm/kernel/hyp-stub.S | 223 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 20 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 8 | ||||
| -rw-r--r-- | arch/arm/kernel/suspend.c | 17 |
6 files changed, 279 insertions, 5 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5dfef9d97ed..5bbec7b8183 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -81,4 +81,6 @@ head-y := head$(MMUEXT).o obj-$(CONFIG_DEBUG_LL) += debug.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o + extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 9874d074119..4eee351f466 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -83,8 +83,12 @@ ENTRY(stext) THUMB( .thumb ) @ switch to Thumb now. THUMB(1: ) - setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode - @ and irqs disabled +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install +#endif + @ ensure svc mode and all interrupts masked + safe_svcmode_maskall r9 + mrc p15, 0, r9, c0, c0 @ get processor id bl __lookup_processor_type @ r5=procinfo r9=cpuid movs r10, r5 @ invalid processor (r5=0)? @@ -326,7 +330,11 @@ ENTRY(secondary_startup) * 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 +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install +#endif + safe_svcmode_maskall r9 + mrc p15, 0, r9, c0, c0 @ get processor id bl __lookup_processor_type movs r10, r5 @ invalid processor? diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S new file mode 100644 index 00000000000..65b2417aebc --- /dev/null +++ b/arch/arm/kernel/hyp-stub.S @@ -0,0 +1,223 @@ +/* + * Copyright (c) 2012 Linaro Limited. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/virt.h> + +#ifndef ZIMAGE +/* + * For the kernel proper, we need to find out the CPU boot mode long after + * boot, so we need to store it in a writable variable. + * + * This is not in .bss, because we set it sufficiently early that the boot-time + * zeroing of .bss would clobber it. + */ +.data +ENTRY(__boot_cpu_mode) + .long 0 +.text + + /* + * Save the primary CPU boot mode. Requires 3 scratch registers. + */ + .macro store_primary_cpu_mode reg1, reg2, reg3 + mrs \reg1, cpsr + and \reg1, \reg1, #MODE_MASK + adr \reg2, .L__boot_cpu_mode_offset + ldr \reg3, [\reg2] + str \reg1, [\reg2, \reg3] + .endm + + /* + * Compare the current mode with the one saved on the primary CPU. + * If they don't match, record that fact. The Z bit indicates + * if there's a match or not. + * Requires 3 additionnal scratch registers. + */ + .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 + adr \reg2, .L__boot_cpu_mode_offset + ldr \reg3, [\reg2] + ldr \reg1, [\reg2, \reg3] + cmp \mode, \reg1 @ matches primary CPU boot mode? + orrne r7, r7, #BOOT_CPU_MODE_MISMATCH + strne r7, [r5, r6] @ record what happened and give up + .endm + +#else /* ZIMAGE */ + + .macro store_primary_cpu_mode reg1:req, reg2:req, reg3:req + .endm + +/* + * The zImage loader only runs on one CPU, so we don't bother with mult-CPU + * consistency checking: + */ + .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 + cmp \mode, \mode + .endm + +#endif /* ZIMAGE */ + +/* + * Hypervisor stub installation functions. + * + * These must be called with the MMU and D-cache off. + * They are not ABI compliant and are only intended to be called from the kernel + * entry points in head.S. + */ +@ Call this from the primary CPU +ENTRY(__hyp_stub_install) + store_primary_cpu_mode r4, r5, r6 +ENDPROC(__hyp_stub_install) + + @ fall through... + +@ Secondary CPUs should call here +ENTRY(__hyp_stub_install_secondary) + mrs r4, cpsr + and r4, r4, #MODE_MASK + + /* + * If the secondary has booted with a different mode, give up + * immediately. + */ + compare_cpu_mode_with_primary r4, r5, r6, r7 + bxne lr + + /* + * Once we have given up on one CPU, we do not try to install the + * stub hypervisor on the remaining ones: because the saved boot mode + * is modified, it can't compare equal to the CPSR mode field any + * more. + * + * Otherwise... + */ + + cmp r4, #HYP_MODE + bxne lr @ give up if the CPU is not in HYP mode + +/* + * Configure HSCTLR to set correct exception endianness/instruction set + * state etc. + * Turn off all traps + * Eventually, CPU-specific code might be needed -- assume not for now + * + * This code relies on the "eret" instruction to synchronize the + * various coprocessor accesses. + */ + @ Now install the hypervisor stub: + adr r7, __hyp_stub_vectors + mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR) + + @ Disable all traps, so we don't get any nasty surprise + mov r7, #0 + mcr p15, 4, r7, c1, c1, 0 @ HCR + mcr p15, 4, r7, c1, c1, 2 @ HCPTR + mcr p15, 4, r7, c1, c1, 3 @ HSTR + +THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE +#ifdef CONFIG_CPU_BIG_ENDIAN + orr r7, #(1 << 9) @ HSCTLR.EE +#endif + mcr p15, 4, r7, c1, c0, 0 @ HSCTLR + + mrc p15, 4, r7, c1, c1, 1 @ HDCR + and r7, #0x1f @ Preserve HPMN + mcr p15, 4, r7, c1, c1, 1 @ HDCR + +#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) + @ make CNTP_* and CNTPCT accessible from PL1 + mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 + lsr r7, #16 + and r7, #0xf + cmp r7, #1 + bne 1f + mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL + orr r7, r7, #3 @ PL1PCEN | PL1PCTEN + mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL +1: +#endif + + bic r7, r4, #MODE_MASK + orr r7, r7, #SVC_MODE +THUMB( orr r7, r7, #PSR_T_BIT ) + msr spsr_cxsf, r7 @ This is SPSR_hyp. + + __MSR_ELR_HYP(14) @ msr elr_hyp, lr + __ERET @ return, switching to SVC mode + @ The boot CPU mode is left in r4. +ENDPROC(__hyp_stub_install_secondary) + +__hyp_stub_do_trap: + cmp r0, #-1 + mrceq p15, 4, r0, c12, c0, 0 @ get HVBAR + mcrne p15, 4, r0, c12, c0, 0 @ set HVBAR + __ERET +ENDPROC(__hyp_stub_do_trap) + +/* + * __hyp_set_vectors: Call this after boot to set the initial hypervisor + * vectors as part of hypervisor installation. On an SMP system, this should + * be called on each CPU. + * + * r0 must be the physical address of the new vector table (which must lie in + * the bottom 4GB of physical address space. + * + * r0 must be 32-byte aligned. + * + * Before calling this, you must check that the stub hypervisor is installed + * everywhere, by waiting for any secondary CPUs to be brought up and then + * checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true. + * + * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or + * something else went wrong... in such cases, trying to install a new + * hypervisor is unlikely to work as desired. + * + * When you call into your shiny new hypervisor, sp_hyp will contain junk, + * so you will need to set that to something sensible at the new hypervisor's + * initialisation entry point. + */ +ENTRY(__hyp_get_vectors) + mov r0, #-1 +ENDPROC(__hyp_get_vectors) + @ fall through +ENTRY(__hyp_set_vectors) + __HVC(0) + bx lr +ENDPROC(__hyp_set_vectors) + +#ifndef ZIMAGE +.align 2 +.L__boot_cpu_mode_offset: + .long __boot_cpu_mode - . +#endif + +.align 5 +__hyp_stub_vectors: +__hyp_stub_reset: W(b) . +__hyp_stub_und: W(b) . +__hyp_stub_svc: W(b) . +__hyp_stub_pabort: W(b) . +__hyp_stub_dabort: W(b) . +__hyp_stub_trap: W(b) __hyp_stub_do_trap +__hyp_stub_irq: W(b) . +__hyp_stub_fiq: W(b) . +ENDPROC(__hyp_stub_vectors) + diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index febafa0f552..da1d1aa20ad 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -53,6 +53,7 @@ #include <asm/traps.h> #include <asm/unwind.h> #include <asm/memblock.h> +#include <asm/virt.h> #include "atags.h" #include "tcm.h" @@ -703,6 +704,21 @@ static int __init meminfo_cmp(const void *_a, const void *_b) return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; } +void __init hyp_mode_check(void) +{ +#ifdef CONFIG_ARM_VIRT_EXT + if (is_hyp_mode_available()) { + pr_info("CPU: All CPU(s) started in HYP mode.\n"); + pr_info("CPU: Virtualization extensions available.\n"); + } else if (is_hyp_mode_mismatched()) { + pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n", + __boot_cpu_mode & MODE_MASK); + pr_warn("CPU: This may indicate a broken bootloader or firmware.\n"); + } else + pr_info("CPU: All CPU(s) started in SVC mode.\n"); +#endif +} + void __init setup_arch(char **cmdline_p) { struct machine_desc *mdesc; @@ -748,6 +764,10 @@ void __init setup_arch(char **cmdline_p) smp_init_cpus(); } #endif + + if (!is_smp()) + hyp_mode_check(); + reserve_crashkernel(); tcm_init(); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index d100eacdb79..8e20754dd31 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -43,6 +43,7 @@ #include <asm/ptrace.h> #include <asm/localtimer.h> #include <asm/smp_plat.h> +#include <asm/virt.h> #include <asm/mach/arch.h> /* @@ -202,8 +203,11 @@ int __cpuinit __cpu_disable(void) /* * Flush user cache and TLB mappings, and then remove this CPU * from the vm mask set of all processes. + * + * Caches are flushed to the Level of Unification Inner Shareable + * to write-back dirty lines to unified caches shared by all CPUs. */ - flush_cache_all(); + flush_cache_louis(); local_flush_tlb_all(); clear_tasks_mm_cpumask(cpu); @@ -355,6 +359,8 @@ void __init smp_cpus_done(unsigned int max_cpus) num_online_cpus(), bogosum / (500000/HZ), (bogosum / (5000/HZ)) % 100); + + hyp_mode_check(); } void __init smp_prepare_boot_cpu(void) diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c index 1794cc3b0f1..358bca3a995 100644 --- a/arch/arm/kernel/suspend.c +++ b/arch/arm/kernel/suspend.c @@ -17,6 +17,8 @@ extern void cpu_resume_mmu(void); */ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) { + u32 *ctx = ptr; + *save_ptr = virt_to_phys(ptr); /* This must correspond to the LDM in cpu_resume() assembly */ @@ -26,7 +28,20 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) cpu_do_suspend(ptr); - flush_cache_all(); + flush_cache_louis(); + + /* + * flush_cache_louis does not guarantee that + * save_ptr and ptr are cleaned to main memory, + * just up to the Level of Unification Inner Shareable. + * Since the context pointer and context itself + * are to be retrieved with the MMU off that + * data must be cleaned from all cache levels + * to main memory using "area" cache primitives. + */ + __cpuc_flush_dcache_area(ctx, ptrsz); + __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); + outer_clean_range(*save_ptr, *save_ptr + ptrsz); outer_clean_range(virt_to_phys(save_ptr), virt_to_phys(save_ptr) + sizeof(*save_ptr)); |