linux_dsm_epyc7002/arch/powerpc/include/asm/kexec.h
Balbir Singh 4145f35864 powernv/kdump: Fix cases where the kdump kernel can get HMI's
Certain HMI's such as malfunction error propagate through
all threads/core on the system. If a thread was offline
prior to us crashing the system and jumping to the kdump
kernel, bad things happen when it wakes up due to an HMI
in the kdump kernel.

There are several possible ways to solve this problem

1. Put the offline cores in a state such that they are
not woken up for machine check and HMI errors. This
does not work, since we might need to wake up offline
threads to handle TB errors
2. Ignore HMI errors, setup HMEER to mask HMI errors,
but this still leads the window open for any MCEs
and masking them for the duration of the dump might
be a concern
3. Wake up offline CPUs, as in send them to
crash_ipi_callback (not wake them up as in mark them
online as seen by the hotplug). kexec does a
wake_online_cpus() call, this patch does something
similar, but instead sends an IPI and forces them to
crash_ipi_callback()

This patch takes approach #3.

Care is taken to enable this only for powenv platforms
via crash_wake_offline (a global value set at setup
time). The crash code sends out IPI's to all CPU's
which then move to crash_ipi_callback and kexec_smp_wait().

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:11 +11:00

147 lines
3.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_KEXEC_H
#define _ASM_POWERPC_KEXEC_H
#ifdef __KERNEL__
#if defined(CONFIG_FSL_BOOKE) || defined(CONFIG_44x)
/*
* On FSL-BookE we setup a 1:1 mapping which covers the first 2GiB of memory
* and therefore we can only deal with memory within this range
*/
#define KEXEC_SOURCE_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL - 1)
#define KEXEC_DESTINATION_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL - 1)
#define KEXEC_CONTROL_MEMORY_LIMIT (2 * 1024 * 1024 * 1024UL - 1)
#else
/*
* Maximum page that is mapped directly into kernel memory.
* XXX: Since we copy virt we can use any page we allocate
*/
#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
/*
* Maximum address we can reach in physical address mode.
* XXX: I want to allow initrd in highmem. Otherwise set to rmo on LPAR.
*/
#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
/* Maximum address we can use for the control code buffer */
#ifdef __powerpc64__
#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL)
#else
/* TASK_SIZE, probably left over from use_mm ?? */
#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
#endif
#endif
#define KEXEC_CONTROL_PAGE_SIZE 4096
/* The native architecture */
#ifdef __powerpc64__
#define KEXEC_ARCH KEXEC_ARCH_PPC64
#else
#define KEXEC_ARCH KEXEC_ARCH_PPC
#endif
#define KEXEC_STATE_NONE 0
#define KEXEC_STATE_IRQS_OFF 1
#define KEXEC_STATE_REAL_MODE 2
#ifndef __ASSEMBLY__
#include <asm/reg.h>
typedef void (*crash_shutdown_t)(void);
#ifdef CONFIG_KEXEC_CORE
/*
* This function is responsible for capturing register states if coming
* via panic or invoking dump using sysrq-trigger.
*/
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs)
{
if (oldregs)
memcpy(newregs, oldregs, sizeof(*newregs));
else
ppc_save_regs(newregs);
}
extern void kexec_smp_wait(void); /* get and clear naca physid, wait for
master to copy new code to 0 */
extern int crashing_cpu;
extern void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *));
extern void crash_ipi_callback(struct pt_regs *);
extern int crash_wake_offline;
struct kimage;
struct pt_regs;
extern void default_machine_kexec(struct kimage *image);
extern int default_machine_kexec_prepare(struct kimage *image);
extern void default_machine_crash_shutdown(struct pt_regs *regs);
extern int crash_shutdown_register(crash_shutdown_t handler);
extern int crash_shutdown_unregister(crash_shutdown_t handler);
extern void crash_kexec_secondary(struct pt_regs *regs);
extern int overlaps_crashkernel(unsigned long start, unsigned long size);
extern void reserve_crashkernel(void);
extern void machine_kexec_mask_interrupts(void);
static inline bool kdump_in_progress(void)
{
return crashing_cpu >= 0;
}
#ifdef CONFIG_KEXEC_FILE
extern struct kexec_file_ops kexec_elf64_ops;
#ifdef CONFIG_IMA_KEXEC
#define ARCH_HAS_KIMAGE_ARCH
struct kimage_arch {
phys_addr_t ima_buffer_addr;
size_t ima_buffer_size;
};
#endif
int setup_purgatory(struct kimage *image, const void *slave_code,
const void *fdt, unsigned long kernel_load_addr,
unsigned long fdt_load_addr);
int setup_new_fdt(const struct kimage *image, void *fdt,
unsigned long initrd_load_addr, unsigned long initrd_len,
const char *cmdline);
int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size);
#endif /* CONFIG_KEXEC_FILE */
#else /* !CONFIG_KEXEC_CORE */
static inline void crash_kexec_secondary(struct pt_regs *regs) { }
static inline int overlaps_crashkernel(unsigned long start, unsigned long size)
{
return 0;
}
static inline void reserve_crashkernel(void) { ; }
static inline int crash_shutdown_register(crash_shutdown_t handler)
{
return 0;
}
static inline int crash_shutdown_unregister(crash_shutdown_t handler)
{
return 0;
}
static inline bool kdump_in_progress(void)
{
return false;
}
#endif /* CONFIG_KEXEC_CORE */
#endif /* ! __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_KEXEC_H */