2fde6d20bb
This fixes a problem where a CPU thread coming out of nap mode can think it has valid values in the nonvolatile GPRs (r14 - r31) as saved away in power7_idle, but in fact the values have been trashed because the thread was used for KVM in the mean time. The result is that the thread crashes because code that called power7_idle (e.g., pnv_smp_cpu_kill_self()) goes to use values in registers that have been trashed. The bit field in SRR1 that tells whether state was lost only reflects the most recent nap, which may not have been the nap instruction in power7_idle. So we need an extra PACA field to indicate that state has been lost even if SRR1 indicates that the most recent nap didn't lose state. We clear this field when saving the state in power7_idle, we set it to a non-zero value when we use the thread for KVM, and we test it in power7_wakeup_noloss. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
184 lines
6.0 KiB
C
184 lines
6.0 KiB
C
/*
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* This control block defines the PACA which defines the processor
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* specific data for each logical processor on the system.
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* There are some pointers defined that are utilized by PLIC.
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*
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* C 2001 PPC 64 Team, IBM Corp
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_POWERPC_PACA_H
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#define _ASM_POWERPC_PACA_H
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#ifdef __KERNEL__
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#ifdef CONFIG_PPC64
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#include <linux/init.h>
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#include <asm/types.h>
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#include <asm/lppaca.h>
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#include <asm/mmu.h>
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#include <asm/page.h>
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#include <asm/exception-64e.h>
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#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
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#include <asm/kvm_book3s_asm.h>
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#endif
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register struct paca_struct *local_paca asm("r13");
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#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
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extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
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/*
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* Add standard checks that preemption cannot occur when using get_paca():
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* otherwise the paca_struct it points to may be the wrong one just after.
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*/
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#define get_paca() ((void) debug_smp_processor_id(), local_paca)
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#else
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#define get_paca() local_paca
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#endif
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#define get_lppaca() (get_paca()->lppaca_ptr)
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#define get_slb_shadow() (get_paca()->slb_shadow_ptr)
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struct task_struct;
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struct opal_machine_check_event;
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/*
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* Defines the layout of the paca.
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*
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* This structure is not directly accessed by firmware or the service
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* processor.
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*/
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struct paca_struct {
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#ifdef CONFIG_PPC_BOOK3S
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/*
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* Because hw_cpu_id, unlike other paca fields, is accessed
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* routinely from other CPUs (from the IRQ code), we stick to
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* read-only (after boot) fields in the first cacheline to
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* avoid cacheline bouncing.
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*/
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struct lppaca *lppaca_ptr; /* Pointer to LpPaca for PLIC */
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#endif /* CONFIG_PPC_BOOK3S */
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/*
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* MAGIC: the spinlock functions in arch/powerpc/lib/locks.c
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* load lock_token and paca_index with a single lwz
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* instruction. They must travel together and be properly
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* aligned.
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*/
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u16 lock_token; /* Constant 0x8000, used in locks */
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u16 paca_index; /* Logical processor number */
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u64 kernel_toc; /* Kernel TOC address */
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u64 kernelbase; /* Base address of kernel */
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u64 kernel_msr; /* MSR while running in kernel */
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#ifdef CONFIG_PPC_STD_MMU_64
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u64 stab_real; /* Absolute address of segment table */
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u64 stab_addr; /* Virtual address of segment table */
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#endif /* CONFIG_PPC_STD_MMU_64 */
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void *emergency_sp; /* pointer to emergency stack */
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u64 data_offset; /* per cpu data offset */
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s16 hw_cpu_id; /* Physical processor number */
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u8 cpu_start; /* At startup, processor spins until */
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/* this becomes non-zero. */
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u8 kexec_state; /* set when kexec down has irqs off */
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#ifdef CONFIG_PPC_STD_MMU_64
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struct slb_shadow *slb_shadow_ptr;
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struct dtl_entry *dispatch_log;
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struct dtl_entry *dispatch_log_end;
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/*
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* Now, starting in cacheline 2, the exception save areas
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*/
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/* used for most interrupts/exceptions */
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u64 exgen[11] __attribute__((aligned(0x80)));
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u64 exmc[11]; /* used for machine checks */
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u64 exslb[11]; /* used for SLB/segment table misses
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* on the linear mapping */
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/* SLB related definitions */
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u16 vmalloc_sllp;
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u16 slb_cache_ptr;
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u16 slb_cache[SLB_CACHE_ENTRIES];
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#endif /* CONFIG_PPC_STD_MMU_64 */
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#ifdef CONFIG_PPC_BOOK3E
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u64 exgen[8] __attribute__((aligned(0x80)));
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/* Keep pgd in the same cacheline as the start of extlb */
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pgd_t *pgd __attribute__((aligned(0x80))); /* Current PGD */
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pgd_t *kernel_pgd; /* Kernel PGD */
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/* We can have up to 3 levels of reentrancy in the TLB miss handler */
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u64 extlb[3][EX_TLB_SIZE / sizeof(u64)];
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u64 exmc[8]; /* used for machine checks */
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u64 excrit[8]; /* used for crit interrupts */
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u64 exdbg[8]; /* used for debug interrupts */
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/* Kernel stack pointers for use by special exceptions */
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void *mc_kstack;
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void *crit_kstack;
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void *dbg_kstack;
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#endif /* CONFIG_PPC_BOOK3E */
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mm_context_t context;
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/*
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* then miscellaneous read-write fields
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*/
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struct task_struct *__current; /* Pointer to current */
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u64 kstack; /* Saved Kernel stack addr */
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u64 stab_rr; /* stab/slb round-robin counter */
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u64 saved_r1; /* r1 save for RTAS calls or PM */
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u64 saved_msr; /* MSR saved here by enter_rtas */
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u16 trap_save; /* Used when bad stack is encountered */
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u8 soft_enabled; /* irq soft-enable flag */
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u8 hard_enabled; /* set if irqs are enabled in MSR */
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u8 io_sync; /* writel() needs spin_unlock sync */
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u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */
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u8 nap_state_lost; /* NV GPR values lost in power7_idle */
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#ifdef CONFIG_PPC_POWERNV
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/* Pointer to OPAL machine check event structure set by the
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* early exception handler for use by high level C handler
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*/
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struct opal_machine_check_event *opal_mc_evt;
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#endif
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/* Stuff for accurate time accounting */
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u64 user_time; /* accumulated usermode TB ticks */
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u64 system_time; /* accumulated system TB ticks */
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u64 user_time_scaled; /* accumulated usermode SPURR ticks */
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u64 starttime; /* TB value snapshot */
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u64 starttime_user; /* TB value on exit to usermode */
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u64 startspurr; /* SPURR value snapshot */
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u64 utime_sspurr; /* ->user_time when ->startspurr set */
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u64 stolen_time; /* TB ticks taken by hypervisor */
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u64 dtl_ridx; /* read index in dispatch log */
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struct dtl_entry *dtl_curr; /* pointer corresponding to dtl_ridx */
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#ifdef CONFIG_KVM_BOOK3S_HANDLER
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#ifdef CONFIG_KVM_BOOK3S_PR
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/* We use this to store guest state in */
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struct kvmppc_book3s_shadow_vcpu shadow_vcpu;
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#endif
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struct kvmppc_host_state kvm_hstate;
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#endif
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};
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extern struct paca_struct *paca;
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extern __initdata struct paca_struct boot_paca;
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extern void initialise_paca(struct paca_struct *new_paca, int cpu);
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extern void setup_paca(struct paca_struct *new_paca);
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extern void allocate_pacas(void);
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extern void free_unused_pacas(void);
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#else /* CONFIG_PPC64 */
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static inline void allocate_pacas(void) { };
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static inline void free_unused_pacas(void) { };
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#endif /* CONFIG_PPC64 */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_PACA_H */
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