Commit 7aa1c8f4 authored by Ralf Baechle's avatar Ralf Baechle

MIPS: kdump: Add support

[ralf@linux-mips.org: Original patch by Maxim Uvarov <muvarov@gmail.com>
with plenty of further shining, polishing, debugging and testing by me.]
Signed-off-by: default avatarMaxim Uvarov <muvarov@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kexec@lists.infradead.org
Cc: horms@verge.net.au
Patchwork: https://patchwork.linux-mips.org/patch/1025/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 98cdee0e
......@@ -2379,6 +2379,29 @@ config KEXEC
support. As of this writing the exact hardware interface is
strongly in flux, so no good recommendation can be made.
config CRASH_DUMP
bool "Kernel crash dumps"
help
Generate crash dump after being started by kexec.
This should be normally only set in special crash dump kernels
which are loaded in the main kernel with kexec-tools into
a specially reserved region and then later executed after
a crash by kdump/kexec. The crash dump kernel must be compiled
to a memory address not used by the main kernel or firmware using
PHYSICAL_START.
config PHYSICAL_START
hex "Physical address where the kernel is loaded"
default "0xffffffff84000000" if 64BIT
default "0x84000000" if 32BIT
depends on CRASH_DUMP
help
This gives the CKSEG0 or KSEG0 address where the kernel is loaded.
If you plan to use kernel for capturing the crash dump change
this value to start of the reserved region (the "X" value as
specified in the "crashkernel=YM@XM" command line boot parameter
passed to the panic-ed kernel).
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
depends on PROC_FS
......
......@@ -9,22 +9,43 @@
#ifndef _MIPS_KEXEC
# define _MIPS_KEXEC
#include <asm/stacktrace.h>
/* Maximum physical address we can use pages from */
#define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
/* Maximum address we can reach in physical address mode */
#define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000)
/* Maximum address we can use for the control code buffer */
#define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000)
#define KEXEC_CONTROL_PAGE_SIZE 4096
/* Reserve 3*4096 bytes for board-specific info */
#define KEXEC_CONTROL_PAGE_SIZE (4096 + 3*4096)
/* The native architecture */
#define KEXEC_ARCH KEXEC_ARCH_MIPS
#define MAX_NOTE_BYTES 1024
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
/* Dummy implementation for now */
if (oldregs)
memcpy(newregs, oldregs, sizeof(*newregs));
else
prepare_frametrace(newregs);
}
#ifdef CONFIG_KEXEC
struct kimage;
extern unsigned long kexec_args[4];
extern int (*_machine_kexec_prepare)(struct kimage *);
extern void (*_machine_kexec_shutdown)(void);
extern void (*_machine_crash_shutdown)(struct pt_regs *regs);
extern void default_machine_crash_shutdown(struct pt_regs *regs);
#ifdef CONFIG_SMP
extern const unsigned char kexec_smp_wait[];
extern unsigned long secondary_kexec_args[4];
extern void (*relocated_kexec_smp_wait) (void *);
extern atomic_t kexec_ready_to_reboot;
#endif
#endif
#endif /* !_MIPS_KEXEC */
......@@ -40,6 +40,8 @@ extern int __cpu_logical_map[NR_CPUS];
#define SMP_CALL_FUNCTION 0x2
/* Octeon - Tell another core to flush its icache */
#define SMP_ICACHE_FLUSH 0x4
/* Used by kexec crashdump to save all cpu's state */
#define SMP_DUMP 0x8
extern volatile cpumask_t cpu_callin_map;
......@@ -91,4 +93,8 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask)
mp_ops->send_ipi_mask(mask, SMP_CALL_FUNCTION);
}
#if defined(CONFIG_KEXEC)
extern void (*dump_ipi_function_ptr)(void *);
void dump_send_ipi(void (*dump_ipi_callback)(void *));
#endif
#endif /* __ASM_SMP_H */
......@@ -80,7 +80,8 @@ obj-$(CONFIG_I8253) += i8253.o
obj-$(CONFIG_GPIO_TXX9) += gpio_txx9.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_SPINLOCK_TEST) += spinlock_test.o
obj-$(CONFIG_MIPS_MACHINE) += mips_machine.o
......
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/bootmem.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/sched.h>
/* This keeps a track of which one is crashing cpu. */
static int crashing_cpu = -1;
static cpumask_t cpus_in_crash = CPU_MASK_NONE;
#ifdef CONFIG_SMP
static void crash_shutdown_secondary(void *ignore)
{
struct pt_regs *regs;
int cpu = smp_processor_id();
regs = task_pt_regs(current);
if (!cpu_online(cpu))
return;
local_irq_disable();
if (!cpu_isset(cpu, cpus_in_crash))
crash_save_cpu(regs, cpu);
cpu_set(cpu, cpus_in_crash);
while (!atomic_read(&kexec_ready_to_reboot))
cpu_relax();
relocated_kexec_smp_wait(NULL);
/* NOTREACHED */
}
static void crash_kexec_prepare_cpus(void)
{
unsigned int msecs;
unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
dump_send_ipi(crash_shutdown_secondary);
smp_wmb();
/*
* The crash CPU sends an IPI and wait for other CPUs to
* respond. Delay of at least 10 seconds.
*/
pr_emerg("Sending IPI to other cpus...\n");
msecs = 10000;
while ((cpus_weight(cpus_in_crash) < ncpus) && (--msecs > 0)) {
cpu_relax();
mdelay(1);
}
}
#else /* !defined(CONFIG_SMP) */
static void crash_kexec_prepare_cpus(void) {}
#endif /* !defined(CONFIG_SMP) */
void default_machine_crash_shutdown(struct pt_regs *regs)
{
local_irq_disable();
crashing_cpu = smp_processor_id();
crash_save_cpu(regs, crashing_cpu);
crash_kexec_prepare_cpus();
cpu_set(crashing_cpu, cpus_in_crash);
}
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/crash_dump.h>
#include <asm/uaccess.h>
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
static int __init parse_savemaxmem(char *p)
{
if (p)
saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1;
return 1;
}
__setup("savemaxmem=", parse_savemaxmem);
static void *kdump_buf_page;
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
* @buf: target memory address for the copy; this can be in kernel address
* space or user address space (see @userbuf)
* @csize: number of bytes to copy
* @offset: offset in bytes into the page (based on pfn) to begin the copy
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
* otherwise @buf is in kernel address space, use memcpy().
*
* Copy a page from "oldmem". For this page, there is no pte mapped
* in the current kernel.
*
* Calling copy_to_user() in atomic context is not desirable. Hence first
* copying the data to a pre-allocated kernel page and then copying to user
* space in non-atomic context.
*/
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
size_t csize, unsigned long offset, int userbuf)
{
void *vaddr;
if (!csize)
return 0;
vaddr = kmap_atomic_pfn(pfn);
if (!userbuf) {
memcpy(buf, (vaddr + offset), csize);
kunmap_atomic(vaddr);
} else {
if (!kdump_buf_page) {
pr_warning("Kdump: Kdump buffer page not allocated\n");
return -EFAULT;
}
copy_page(kdump_buf_page, vaddr);
kunmap_atomic(vaddr);
if (copy_to_user(buf, (kdump_buf_page + offset), csize))
return -EFAULT;
}
return csize;
}
static int __init kdump_buf_page_init(void)
{
int ret = 0;
kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!kdump_buf_page) {
pr_warning("Kdump: Failed to allocate kdump buffer page\n");
ret = -ENOMEM;
}
return ret;
}
arch_initcall(kdump_buf_page_init);
......@@ -5,7 +5,7 @@
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/compiler.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
......@@ -19,9 +19,19 @@ extern const size_t relocate_new_kernel_size;
extern unsigned long kexec_start_address;
extern unsigned long kexec_indirection_page;
int (*_machine_kexec_prepare)(struct kimage *) = NULL;
void (*_machine_kexec_shutdown)(void) = NULL;
void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
#ifdef CONFIG_SMP
void (*relocated_kexec_smp_wait) (void *);
atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
#endif
int
machine_kexec_prepare(struct kimage *kimage)
{
if (_machine_kexec_prepare)
return _machine_kexec_prepare(kimage);
return 0;
}
......@@ -33,14 +43,20 @@ machine_kexec_cleanup(struct kimage *kimage)
void
machine_shutdown(void)
{
if (_machine_kexec_shutdown)
_machine_kexec_shutdown();
}
void
machine_crash_shutdown(struct pt_regs *regs)
{
if (_machine_crash_shutdown)
_machine_crash_shutdown(regs);
else
default_machine_crash_shutdown(regs);
}
typedef void (*noretfun_t)(void) __attribute__((noreturn));
typedef void (*noretfun_t)(void) __noreturn;
void
machine_kexec(struct kimage *image)
......@@ -52,7 +68,9 @@ machine_kexec(struct kimage *image)
reboot_code_buffer =
(unsigned long)page_address(image->control_code_page);
kexec_start_address = image->start;
kexec_start_address =
(unsigned long) phys_to_virt(image->start);
kexec_indirection_page =
(unsigned long) phys_to_virt(image->head & PAGE_MASK);
......@@ -63,7 +81,7 @@ machine_kexec(struct kimage *image)
* The generic kexec code builds a page list with physical
* addresses. they are directly accessible through KSEG0 (or
* CKSEG0 or XPHYS if on 64bit system), hence the
* pys_to_virt() call.
* phys_to_virt() call.
*/
for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
ptr = (entry & IND_INDIRECTION) ?
......@@ -81,5 +99,12 @@ machine_kexec(struct kimage *image)
printk("Will call new kernel at %08lx\n", image->start);
printk("Bye ...\n");
__flush_cache_all();
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer +
(void *)(kexec_smp_wait - relocate_new_kernel);
smp_wmb();
atomic_set(&kexec_ready_to_reboot, 1);
#endif
((noretfun_t) reboot_code_buffer)();
}
......@@ -15,6 +15,11 @@
#include <asm/addrspace.h>
LEAF(relocate_new_kernel)
PTR_L a0, arg0
PTR_L a1, arg1
PTR_L a2, arg2
PTR_L a3, arg3
PTR_L s0, kexec_indirection_page
PTR_L s1, kexec_start_address
......@@ -26,7 +31,6 @@ process_entry:
and s3, s2, 0x1
beq s3, zero, 1f
and s4, s2, ~0x1 /* store destination addr in s4 */
move a0, s4
b process_entry
1:
......@@ -60,10 +64,92 @@ copy_word:
b process_entry
done:
#ifdef CONFIG_SMP
/* kexec_flag reset is signal to other CPUs what kernel
was moved to it's location. Note - we need relocated address
of kexec_flag. */
bal 1f
1: move t1,ra;
PTR_LA t2,1b
PTR_LA t0,kexec_flag
PTR_SUB t0,t0,t2;
PTR_ADD t0,t1,t0;
LONG_S zero,(t0)
#endif
sync
/* jump to kexec_start_address */
j s1
END(relocate_new_kernel)
#ifdef CONFIG_SMP
/*
* Other CPUs should wait until code is relocated and
* then start at entry (?) point.
*/
LEAF(kexec_smp_wait)
PTR_L a0, s_arg0
PTR_L a1, s_arg1
PTR_L a2, s_arg2
PTR_L a3, s_arg3
PTR_L s1, kexec_start_address
/* Non-relocated address works for args and kexec_start_address ( old
* kernel is not overwritten). But we need relocated address of
* kexec_flag.
*/
bal 1f
1: move t1,ra;
PTR_LA t2,1b
PTR_LA t0,kexec_flag
PTR_SUB t0,t0,t2;
PTR_ADD t0,t1,t0;
1: LONG_L s0, (t0)
bne s0, zero,1b
sync
j s1
END(kexec_smp_wait)
#endif
#ifdef __mips64
/* all PTR's must be aligned to 8 byte in 64-bit mode */
.align 3
#endif
/* All parameters to new kernel are passed in registers a0-a3.
* kexec_args[0..3] are uses to prepare register values.
*/
kexec_args:
EXPORT(kexec_args)
arg0: PTR 0x0
arg1: PTR 0x0
arg2: PTR 0x0
arg3: PTR 0x0
.size kexec_args,PTRSIZE*4
#ifdef CONFIG_SMP
/*
* Secondary CPUs may have different kernel parameters in
* their registers a0-a3. secondary_kexec_args[0..3] are used
* to prepare register values.
*/
secondary_kexec_args:
EXPORT(secondary_kexec_args)
s_arg0: PTR 0x0
s_arg1: PTR 0x0
s_arg2: PTR 0x0
s_arg3: PTR 0x0
.size secondary_kexec_args,PTRSIZE*4
kexec_flag:
LONG 0x1
#endif
kexec_start_address:
EXPORT(kexec_start_address)
PTR 0x0
......
......@@ -22,6 +22,7 @@
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/kexec.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
......@@ -536,12 +537,64 @@ static void __init arch_mem_init(char **cmdline_p)
}
bootmem_init();
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end)
reserve_bootmem(crashk_res.start,
crashk_res.end - crashk_res.start + 1,
BOOTMEM_DEFAULT);
#endif
device_tree_init();
sparse_init();
plat_swiotlb_setup();
paging_init();
}
#ifdef CONFIG_KEXEC
static inline unsigned long long get_total_mem(void)
{
unsigned long long total;
total = max_pfn - min_low_pfn;
return total << PAGE_SHIFT;
}
static void __init mips_parse_crashkernel(void)
{
unsigned long long total_mem;
unsigned long long crash_size, crash_base;
int ret;
total_mem = get_total_mem();
ret = parse_crashkernel(boot_command_line, total_mem,
&crash_size, &crash_base);
if (ret != 0 || crash_size <= 0)
return;
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
static void __init request_crashkernel(struct resource *res)
{
int ret;
ret = request_resource(res, &crashk_res);
if (!ret)
pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
(unsigned long)((crashk_res.end -
crashk_res.start + 1) >> 20),
(unsigned long)(crashk_res.start >> 20));
}
#else /* !defined(CONFIG_KEXEC) */
static void __init mips_parse_crashkernel(void)
{
}
static void __init request_crashkernel(struct resource *res)
{
}
#endif /* !defined(CONFIG_KEXEC) */
static void __init resource_init(void)
{
int i;
......@@ -557,6 +610,8 @@ static void __init resource_init(void)
/*
* Request address space for all standard RAM.
*/
mips_parse_crashkernel();
for (i = 0; i < boot_mem_map.nr_map; i++) {
struct resource *res;
unsigned long start, end;
......@@ -593,6 +648,7 @@ static void __init resource_init(void)
*/
request_resource(res, &code_resource);
request_resource(res, &data_resource);
request_crashkernel(res);
}
}
......
......@@ -386,3 +386,20 @@ void flush_tlb_one(unsigned long vaddr)
EXPORT_SYMBOL(flush_tlb_page);
EXPORT_SYMBOL(flush_tlb_one);
#if defined(CONFIG_KEXEC)
void (*dump_ipi_function_ptr)(void *) = NULL;
void dump_send_ipi(void (*dump_ipi_callback)(void *))
{
int i;
int cpu = smp_processor_id();
dump_ipi_function_ptr = dump_ipi_callback;
smp_mb();
for_each_online_cpu(i)
if (i != cpu)
mp_ops->send_ipi_single(i, SMP_DUMP);
}
EXPORT_SYMBOL(dump_send_ipi);
#endif
......@@ -13,6 +13,7 @@
*/
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/kexec.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
......@@ -409,6 +410,9 @@ void __noreturn die(const char *str, struct pt_regs *regs)
panic("Fatal exception");
}
if (regs && kexec_should_crash(current))
crash_kexec(regs);
do_exit(sig);
}
......
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