From 008b08d5d58744d8c1532dc9e48d54e1d34ae6a6 Mon Sep 17 00:00:00 2001 From: Tad Date: Sat, 17 Oct 2015 20:49:21 -0400 Subject: [PATCH] Implement KEXEC --- arch/arm/Kconfig | 26 ++++++++++ arch/arm/boot/compressed/head.S | 64 ++++++++++++++++++++++++ arch/arm/configs/cyanogenmod_bacon_defconfig | 6 ++- arch/arm/include/asm/kexec.h | 8 +++ arch/arm/kernel/machine_kexec.c | 58 +++++++++++++++++++-- arch/arm/kernel/relocate_kernel.S | 75 ++++++++++++++++++++++++++++ arch/arm/mach-msm/include/mach/memory.h | 16 ++++++ arch/arm/mach-msm/oppo/board-8974-oppo.c | 27 ++++++++++ arch/arm/mach-msm/restart.c | 28 +++++++++++ include/linux/kexec.h | 19 +++++-- kernel/kexec.c | 4 ++ 11 files changed, 322 insertions(+), 9 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 37d3c6d..f801a19 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2299,6 +2299,32 @@ config ATAGS_PROC Should the atags used to boot the kernel be exported in an "atags" file in procfs. Useful with kexec. +config KEXEC_HARDBOOT + bool "Support hard booting to a kexec kernel" + depends on KEXEC + help + Allows hard booting (i.e., with a full hardware reboot) to a kernel + previously loaded in memory by kexec. This works around the problem of + soft-booted kernel hangs due to improper device shutdown and/or + reinitialization. Support is comprised of two components: + + First, a "hardboot" flag is added to the kexec syscall to force a hard + reboot in relocate_new_kernel() (which requires machine-specific assembly + code). This also requires the kexec userspace tool to load the kexec'd + kernel in memory region left untouched by the bootloader (i.e., not + explicitly cleared and not overwritten by the boot kernel). Just prior + to reboot, the kexec kernel arguments are stashed in a machine-specific + memory page that must also be preserved. Note that this hardboot page + need not be reserved during regular kernel execution. + + Second, the zImage decompresor of the boot (bootloader-loaded) kernel is + modified to check the hardboot page for fresh kexec arguments, and if + present, attempts to jump to the kexec'd kernel preserved in memory. + + Note that hardboot support is only required in the boot kernel and any + kernel capable of performing a hardboot kexec. It is _not_ required by a + kexec'd kernel. + config CRASH_DUMP bool "Build kdump crash kernel (EXPERIMENTAL)" depends on EXPERIMENTAL diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index d3892ef..be05aa1 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -11,6 +11,12 @@ #include .arch armv7-a + +#ifdef CONFIG_KEXEC_HARDBOOT + #include + #include +#endif + /* * Debugging stuff * @@ -136,6 +142,64 @@ start: 1: mov r7, r1 @ save architecture ID mov r8, r2 @ save atags pointer +#ifdef CONFIG_KEXEC_HARDBOOT + /* Check hardboot page for a kexec kernel. */ + ldr r3, =KEXEC_HB_PAGE_ADDR + ldr r0, [r3] + ldr r1, =KEXEC_HB_PAGE_MAGIC + teq r0, r1 + bne not_booting_other + + /* Clear hardboot page magic to avoid boot loop. */ + mov r0, #0 + str r0, [r3] + + /* + * Copy dtb from location up high in memory to default location. + * Kernel freezes if this is not done. + */ + ldr r1, [r3, #12] @ kexec_boot_atags + ldr r2, [r3, #16] @ kexec_boot_atags_len + mov r5, #0 @ iterator +catags_cpy: + ldr r0, [r1, r5] @ from kexec_boot_atags + str r0, [r8, r5] @ to atags_pointer + add r5, r5, #4 + cmp r5, r2 + blo catags_cpy + +#ifdef KEXEC_HB_KERNEL_LOC + /* + * Copy kernel from location up high in memory to location in first 128MB. + * Bootloader on hammerhead erases first 128MB of ram on reboot, so it can't + * be in there before reboot, but decompressing in location above 128MB takes + * a long time. This memcpy is much quicker, for some reason. + */ + ldr r2, [r3, #4] @ kexec_start_address + ldr r4, [r3, #20] @ kexec_kernel_len + ldr r6, =KEXEC_HB_KERNEL_LOC @ target + mov r5, #0 @ iterator +kernel_cpy: + ldr r0, [r2, r5] @ from kexec_start_address + str r0, [r6, r5] @ to KEXEC_HB_KERNEL_LOC + add r5, r5, #4 + cmp r5, r4 + blo kernel_cpy +#else + ldr r6, [r3, #4] @ kexec_start_address +#endif + + /* set registers and boot kexecd' kernel */ + mov r0, #0 + ldr r1, [r3, #8] @ kexec_mach_type + mov r2, r8 @ atags pointer + mov pc, r6 + + .ltorg + +not_booting_other: +#endif + #ifndef __ARM_ARCH_2__ /* * Booting from Angel - need to enter SVC mode and disable diff --git a/arch/arm/configs/cyanogenmod_bacon_defconfig b/arch/arm/configs/cyanogenmod_bacon_defconfig index 6384191..ac68dba 100644 --- a/arch/arm/configs/cyanogenmod_bacon_defconfig +++ b/arch/arm/configs/cyanogenmod_bacon_defconfig @@ -693,7 +693,9 @@ CONFIG_ZBOOT_ROM_BSS=0 # CONFIG_ARM_APPENDED_DTB is not set CONFIG_CMDLINE="" # CONFIG_XIP_KERNEL is not set -# CONFIG_KEXEC is not set +CONFIG_KEXEC=y +CONFIG_KEXEC_HARDBOOT=y +CONFIG_ATAGS_PROC=n # CONFIG_CRASH_DUMP is not set # CONFIG_AUTO_ZRELADDR is not set @@ -1283,7 +1285,7 @@ CONFIG_OF=y # # Device Tree and Open Firmware support # -# CONFIG_PROC_DEVICETREE is not set +CONFIG_PROC_DEVICETREE=y # CONFIG_OF_SELFTEST is not set CONFIG_OF_FLATTREE=y CONFIG_OF_EARLY_FLATTREE=y diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h index c2b9b4b..564c55b 100644 --- a/arch/arm/include/asm/kexec.h +++ b/arch/arm/include/asm/kexec.h @@ -17,6 +17,10 @@ #define KEXEC_ARM_ATAGS_OFFSET 0x1000 #define KEXEC_ARM_ZIMAGE_OFFSET 0x8000 +#ifdef CONFIG_KEXEC_HARDBOOT + #define KEXEC_HB_PAGE_MAGIC 0x4a5db007 +#endif + #ifndef __ASSEMBLY__ /** @@ -53,6 +57,10 @@ static inline void crash_setup_regs(struct pt_regs *newregs, /* Function pointer to optional machine-specific reinitialization */ extern void (*kexec_reinit)(void); +#ifdef CONFIG_KEXEC_HARDBOOT +extern void (*kexec_hardboot_hook)(void); +#endif + #endif /* __ASSEMBLY__ */ #endif /* CONFIG_KEXEC */ diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 357b651..29cdd2f 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -14,6 +14,9 @@ #include #include #include +#include +#include +#include extern const unsigned char relocate_new_kernel[]; extern const unsigned int relocate_new_kernel_size; @@ -22,6 +25,12 @@ extern unsigned long kexec_start_address; extern unsigned long kexec_indirection_page; extern unsigned long kexec_mach_type; extern unsigned long kexec_boot_atags; +#ifdef CONFIG_KEXEC_HARDBOOT +extern unsigned long kexec_hardboot; +extern unsigned long kexec_boot_atags_len; +extern unsigned long kexec_kernel_len; +void (*kexec_hardboot_hook)(void); +#endif static atomic_t waiting_for_crash_ipi; @@ -32,6 +41,37 @@ static atomic_t waiting_for_crash_ipi; int machine_kexec_prepare(struct kimage *image) { + struct kexec_segment *current_segment; + __be32 header; + int i, err; + + /* No segment at default ATAGs address. try to locate + * a dtb using magic */ + for (i = 0; i < image->nr_segments; i++) { + current_segment = &image->segment[i]; + + err = memblock_is_region_memory(current_segment->mem, + current_segment->memsz); + if (!err) + return - EINVAL; + +#ifdef CONFIG_KEXEC_HARDBOOT + if(current_segment->mem == image->start) + mem_text_write_kernel_word(&kexec_kernel_len, current_segment->memsz); +#endif + + err = get_user(header, (__be32*)current_segment->buf); + if (err) + return err; + + if (be32_to_cpu(header) == OF_DT_HEADER) + { + mem_text_write_kernel_word(&kexec_boot_atags, current_segment->mem); +#ifdef CONFIG_KEXEC_HARDBOOT + mem_text_write_kernel_word(&kexec_boot_atags_len, current_segment->memsz); +#endif + } + } return 0; } @@ -123,10 +163,14 @@ void machine_kexec(struct kimage *image) reboot_code_buffer = page_address(image->control_code_page); /* Prepare parameters for reboot_code_buffer*/ - kexec_start_address = image->start; - kexec_indirection_page = page_list; - kexec_mach_type = machine_arch_type; - kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET; + mem_text_write_kernel_word(&kexec_start_address, image->start); + mem_text_write_kernel_word(&kexec_indirection_page, page_list); + mem_text_write_kernel_word(&kexec_mach_type, machine_arch_type); + if (!kexec_boot_atags) + mem_text_write_kernel_word(&kexec_boot_atags, image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET); +#ifdef CONFIG_KEXEC_HARDBOOT + mem_text_write_kernel_word(&kexec_hardboot, image->hardboot); +#endif /* copy our kernel relocation code to the control code page */ memcpy(reboot_code_buffer, @@ -140,6 +184,12 @@ void machine_kexec(struct kimage *image) if (kexec_reinit) kexec_reinit(); +#ifdef CONFIG_KEXEC_HARDBOOT + /* Run any final machine-specific shutdown code. */ + if (image->hardboot && kexec_hardboot_hook) + kexec_hardboot_hook(); +#endif + soft_restart(reboot_code_buffer_phys); } diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S index d0cdedf..0e45ffc 100644 --- a/arch/arm/kernel/relocate_kernel.S +++ b/arch/arm/kernel/relocate_kernel.S @@ -4,6 +4,15 @@ #include +#ifdef CONFIG_KEXEC_HARDBOOT +#include +#if defined(CONFIG_ARCH_TEGRA_2x_SOC) || defined(CONFIG_ARCH_TEGRA_3x_SOC) + #include +#elif defined(CONFIG_ARCH_APQ8064) || defined(CONFIG_ARCH_MSM8974) + #include +#endif +#endif + .globl relocate_new_kernel relocate_new_kernel: @@ -52,6 +61,12 @@ relocate_new_kernel: b 0b 2: +#ifdef CONFIG_KEXEC_HARDBOOT + ldr r0, kexec_hardboot + teq r0, #0 + bne hardboot +#endif + /* Jump to relocated kernel */ mov lr,r1 mov r0,#0 @@ -60,6 +75,52 @@ relocate_new_kernel: ARM( mov pc, lr ) THUMB( bx lr ) +#ifdef CONFIG_KEXEC_HARDBOOT +hardboot: + /* Stash boot arguments in hardboot page: + * 0: KEXEC_HB_PAGE_MAGIC + * 4: kexec_start_address + * 8: kexec_mach_type + * 12: kexec_boot_atags + * 16: kexec_boot_atags_len + * 20: kexec_kernel_len */ + ldr r0, =KEXEC_HB_PAGE_ADDR + str r1, [r0, #4] + ldr r1, kexec_mach_type + str r1, [r0, #8] + ldr r1, kexec_boot_atags + str r1, [r0, #12] + ldr r1, kexec_boot_atags_len + str r1, [r0, #16] + ldr r1, kexec_kernel_len + str r1, [r0, #20] + ldr r1, =KEXEC_HB_PAGE_MAGIC + str r1, [r0] + +#if defined(CONFIG_ARCH_TEGRA_2x_SOC) || defined(CONFIG_ARCH_TEGRA_3x_SOC) + ldr r0, =TEGRA_PMC_BASE + ldr r1, [r0] + orr r1, r1, #0x10 + str r1, [r0] +loop: b loop +#elif defined(CONFIG_ARCH_APQ8064) + /* Restart using the PMIC chip, see mach-msm/restart.c */ + ldr r0, =APQ8064_TLMM_PHYS + mov r1, #0 + str r1, [r0, #0x820] @ PSHOLD_CTL_SU +loop: b loop +#elif defined(CONFIG_ARCH_MSM8974) + /* Restart using the PMIC chip, see mach-msm/restart.c */ + ldr r0, =MSM8974_MPM2_PSHOLD_PHYS + mov r1, #0 + str r1, [r0, #0] +loop: b loop +#else +#error "No reboot method defined for hardboot." +#endif + + .ltorg +#endif .align .globl kexec_start_address @@ -79,6 +140,20 @@ kexec_mach_type: kexec_boot_atags: .long 0x0 +#ifdef CONFIG_KEXEC_HARDBOOT + .globl kexec_boot_atags_len +kexec_boot_atags_len: + .long 0x0 + + .globl kexec_kernel_len +kexec_kernel_len: + .long 0x0 + + .globl kexec_hardboot +kexec_hardboot: + .long 0x0 +#endif + relocate_new_kernel_end: .globl relocate_new_kernel_size diff --git a/arch/arm/mach-msm/include/mach/memory.h b/arch/arm/mach-msm/include/mach/memory.h index 9225230..1c87b96 100644 --- a/arch/arm/mach-msm/include/mach/memory.h +++ b/arch/arm/mach-msm/include/mach/memory.h @@ -20,6 +20,22 @@ /* physical offset of RAM */ #define PLAT_PHYS_OFFSET UL(CONFIG_PHYS_OFFSET) +#if defined(CONFIG_KEXEC_HARDBOOT) +#if defined(CONFIG_MACH_APQ8064_FLO) +#define KEXEC_HB_PAGE_ADDR UL(0x88C00000) +#elif defined(CONFIG_MACH_APQ8064_MAKO) +#define KEXEC_HB_PAGE_ADDR UL(0x88600000) +#elif defined(CONFIG_MACH_MSM8974_HAMMERHEAD) +#define KEXEC_HB_PAGE_ADDR UL(0x10100000) +#define KEXEC_HB_KERNEL_LOC UL(0x3208000) +#elif defined(CONFIG_MACH_OPPO_MSM8974) +#define KEXEC_HB_PAGE_ADDR UL(0x2F600000) +#define KEXEC_HB_KERNEL_LOC UL(0x3208000) +#else +#error "Adress for kexec hardboot page not defined" +#endif +#endif + #ifndef __ASSEMBLY__ void clean_and_invalidate_caches(unsigned long, unsigned long, unsigned long); void clean_caches(unsigned long, unsigned long, unsigned long); diff --git a/arch/arm/mach-msm/oppo/board-8974-oppo.c b/arch/arm/mach-msm/oppo/board-8974-oppo.c index eb24545..10bbbda 100644 --- a/arch/arm/mach-msm/oppo/board-8974-oppo.c +++ b/arch/arm/mach-msm/oppo/board-8974-oppo.c @@ -54,6 +54,13 @@ #include +#ifdef CONFIG_KEXEC_HARDBOOT +#include +#include +#include +#define OPPO_PERSISTENT_RAM_SIZE (SZ_1M) +#endif + static struct platform_device *ram_console_dev; static struct persistent_ram_descriptor msm_prd[] __initdata = { @@ -72,6 +79,26 @@ static struct persistent_ram msm_pr __initdata = { void __init msm_8974_reserve(void) { +#ifdef CONFIG_KEXEC_HARDBOOT + // Reserve space for hardboot page - just after ram_console, + // at the start of second memory bank + int ret; + phys_addr_t start; + struct membank* bank; + + if (meminfo.nr_banks < 2) { + pr_err("%s: not enough membank\n", __func__); + return; + } + + bank = &meminfo.bank[1]; + start = bank->start + SZ_1M + OPPO_PERSISTENT_RAM_SIZE; + ret = memblock_remove(start, SZ_1M); + if(!ret) + pr_info("Hardboot page reserved at 0x%X\n", start); + else + pr_err("Failed to reserve space for hardboot page at 0x%X!\n", start); +#endif persistent_ram_early_init(&msm_pr); of_scan_flat_dt(dt_scan_for_memory_reserve, NULL); } diff --git a/arch/arm/mach-msm/restart.c b/arch/arm/mach-msm/restart.c index a04ab8d..fe89976 100644 --- a/arch/arm/mach-msm/restart.c +++ b/arch/arm/mach-msm/restart.c @@ -38,6 +38,10 @@ #include "timer.h" #include "wdog_debug.h" +#ifdef CONFIG_KEXEC_HARDBOOT +#include +#endif + #define WDT0_RST 0x38 #define WDT0_EN 0x40 #define WDT0_BARK_TIME 0x4C @@ -373,6 +377,26 @@ static int __init msm_pmic_restart_init(void) late_initcall(msm_pmic_restart_init); +#ifdef CONFIG_KEXEC_HARDBOOT +static void msm_kexec_hardboot_hook(void) +{ + set_dload_mode(0); + + // Set PMIC to restart-on-poweroff + pm8xxx_reset_pwr_off(1); + + // These are executed on normal reboot, but with kexec-hardboot, + // they reboot/panic the system immediately. +#if 0 + qpnp_pon_system_pwr_off(PON_POWER_OFF_WARM_RESET); + + /* Needed to bypass debug image on some chips */ + msm_disable_wdog_debug(); + halt_spmi_pmic_arbiter(); +#endif +} +#endif + static int __init msm_restart_init(void) { #ifdef CONFIG_MSM_DLOAD_MODE @@ -392,6 +416,10 @@ static int __init msm_restart_init(void) if (scm_is_call_available(SCM_SVC_PWR, SCM_IO_DISABLE_PMIC_ARBITER) > 0) scm_pmic_arbiter_disable_supported = true; +#ifdef CONFIG_KEXEC_HARDBOOT + kexec_hardboot_hook = msm_kexec_hardboot_hook; +#endif + return 0; } early_initcall(msm_restart_init); diff --git a/include/linux/kexec.h b/include/linux/kexec.h index af84a25..a4509ad 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -111,6 +111,10 @@ struct kimage { #define KEXEC_TYPE_CRASH 1 unsigned int preserve_context : 1; +#ifdef CONFIG_KEXEC_HARDBOOT + unsigned int hardboot : 1; +#endif + #ifdef ARCH_HAS_KIMAGE_ARCH struct kimage_arch arch; #endif @@ -178,6 +182,11 @@ extern struct kimage *kexec_crash_image; #define KEXEC_ON_CRASH 0x00000001 #define KEXEC_PRESERVE_CONTEXT 0x00000002 + +#ifdef CONFIG_KEXEC_HARDBOOT +#define KEXEC_HARDBOOT 0x00000004 +#endif + #define KEXEC_ARCH_MASK 0xffff0000 /* These values match the ELF architecture values. @@ -196,10 +205,14 @@ extern struct kimage *kexec_crash_image; #define KEXEC_ARCH_MIPS ( 8 << 16) /* List of defined/legal kexec flags */ -#ifndef CONFIG_KEXEC_JUMP -#define KEXEC_FLAGS KEXEC_ON_CRASH -#else +#if defined(CONFIG_KEXEC_JUMP) && defined(CONFIG_KEXEC_HARDBOOT) +#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_HARDBOOT) +#elif defined(CONFIG_KEXEC_JUMP) #define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT) +#elif defined(CONFIG_KEXEC_HARDBOOT) +#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_HARDBOOT) +#else +#define KEXEC_FLAGS (KEXEC_ON_CRASH) #endif #define VMCOREINFO_BYTES (4096) diff --git a/kernel/kexec.c b/kernel/kexec.c index 4e2e472..aef7893 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1004,6 +1004,10 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, if (flags & KEXEC_PRESERVE_CONTEXT) image->preserve_context = 1; +#ifdef CONFIG_KEXEC_HARDBOOT + if (flags & KEXEC_HARDBOOT) + image->hardboot = 1; +#endif result = machine_kexec_prepare(image); if (result) goto out;