diff options
Diffstat (limited to 'arch/s390/mm')
-rw-r--r-- | arch/s390/mm/Makefile | 1 | ||||
-rw-r--r-- | arch/s390/mm/cmm.c | 2 | ||||
-rw-r--r-- | arch/s390/mm/dump_pagetables.c | 2 | ||||
-rw-r--r-- | arch/s390/mm/extmem.c | 9 | ||||
-rw-r--r-- | arch/s390/mm/fault.c | 228 | ||||
-rw-r--r-- | arch/s390/mm/maccess.c | 7 | ||||
-rw-r--r-- | arch/s390/mm/pfault.c | 248 | ||||
-rw-r--r-- | arch/s390/mm/vmem.c | 6 |
8 files changed, 265 insertions, 238 deletions
diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile index d90db06a8af5..352ff520fd94 100644 --- a/arch/s390/mm/Makefile +++ b/arch/s390/mm/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_PTDUMP_CORE) += dump_pagetables.o obj-$(CONFIG_PGSTE) += gmap.o +obj-$(CONFIG_PFAULT) += pfault.o diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c index 5300c6867d5e..f47515313226 100644 --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -90,7 +90,7 @@ static long cmm_alloc_pages(long nr, long *counter, } else free_page((unsigned long) npa); } - diag10_range(virt_to_pfn(addr), 1); + diag10_range(virt_to_pfn((void *)addr), 1); pa->pages[pa->index++] = addr; (*counter)++; spin_unlock(&cmm_lock); diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index ba5f80268878..afa5db750d92 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -297,7 +297,7 @@ static int pt_dump_init(void) address_markers[ABS_LOWCORE_NR].start_address = __abs_lowcore; address_markers[ABS_LOWCORE_END_NR].start_address = __abs_lowcore + ABS_LOWCORE_MAP_SIZE; address_markers[MEMCPY_REAL_NR].start_address = __memcpy_real_area; - address_markers[MEMCPY_REAL_END_NR].start_address = __memcpy_real_area + PAGE_SIZE; + address_markers[MEMCPY_REAL_END_NR].start_address = __memcpy_real_area + MEMCPY_REAL_SIZE; address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap; address_markers[VMEMMAP_END_NR].start_address = (unsigned long)vmemmap + vmemmap_size; address_markers[VMALLOC_NR].start_address = VMALLOC_START; diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c index 1bc42ce26599..e41869f5cc95 100644 --- a/arch/s390/mm/extmem.c +++ b/arch/s390/mm/extmem.c @@ -640,10 +640,13 @@ void segment_warning(int rc, char *seg_name) pr_err("There is not enough memory to load or query " "DCSS %s\n", seg_name); break; - case -ERANGE: - pr_err("DCSS %s exceeds the kernel mapping range (%lu) " - "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS); + case -ERANGE: { + struct range mhp_range = arch_get_mappable_range(); + + pr_err("DCSS %s exceeds the kernel mapping range (%llu) " + "and cannot be loaded\n", seg_name, mhp_range.end + 1); break; + } default: break; } diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index a063774ba584..099c4824dd8a 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -43,8 +43,6 @@ #include "../kernel/entry.h" #define __FAIL_ADDR_MASK -4096L -#define __SUBCODE_MASK 0x0600 -#define __PF_RES_FIELD 0x8000000000000000ULL /* * Allocate private vm_fault_reason from top. Please make sure it won't @@ -582,232 +580,6 @@ void do_dat_exception(struct pt_regs *regs) } NOKPROBE_SYMBOL(do_dat_exception); -#ifdef CONFIG_PFAULT -/* - * 'pfault' pseudo page faults routines. - */ -static int pfault_disable; - -static int __init nopfault(char *str) -{ - pfault_disable = 1; - return 1; -} - -__setup("nopfault", nopfault); - -struct pfault_refbk { - u16 refdiagc; - u16 reffcode; - u16 refdwlen; - u16 refversn; - u64 refgaddr; - u64 refselmk; - u64 refcmpmk; - u64 reserved; -} __attribute__ ((packed, aligned(8))); - -static struct pfault_refbk pfault_init_refbk = { - .refdiagc = 0x258, - .reffcode = 0, - .refdwlen = 5, - .refversn = 2, - .refgaddr = __LC_LPP, - .refselmk = 1ULL << 48, - .refcmpmk = 1ULL << 48, - .reserved = __PF_RES_FIELD -}; - -int pfault_init(void) -{ - int rc; - - if (pfault_disable) - return -1; - diag_stat_inc(DIAG_STAT_X258); - asm volatile( - " diag %1,%0,0x258\n" - "0: j 2f\n" - "1: la %0,8\n" - "2:\n" - EX_TABLE(0b,1b) - : "=d" (rc) - : "a" (&pfault_init_refbk), "m" (pfault_init_refbk) : "cc"); - return rc; -} - -static struct pfault_refbk pfault_fini_refbk = { - .refdiagc = 0x258, - .reffcode = 1, - .refdwlen = 5, - .refversn = 2, -}; - -void pfault_fini(void) -{ - - if (pfault_disable) - return; - diag_stat_inc(DIAG_STAT_X258); - asm volatile( - " diag %0,0,0x258\n" - "0: nopr %%r7\n" - EX_TABLE(0b,0b) - : : "a" (&pfault_fini_refbk), "m" (pfault_fini_refbk) : "cc"); -} - -static DEFINE_SPINLOCK(pfault_lock); -static LIST_HEAD(pfault_list); - -#define PF_COMPLETE 0x0080 - -/* - * The mechanism of our pfault code: if Linux is running as guest, runs a user - * space process and the user space process accesses a page that the host has - * paged out we get a pfault interrupt. - * - * This allows us, within the guest, to schedule a different process. Without - * this mechanism the host would have to suspend the whole virtual cpu until - * the page has been paged in. - * - * So when we get such an interrupt then we set the state of the current task - * to uninterruptible and also set the need_resched flag. Both happens within - * interrupt context(!). If we later on want to return to user space we - * recognize the need_resched flag and then call schedule(). It's not very - * obvious how this works... - * - * Of course we have a lot of additional fun with the completion interrupt (-> - * host signals that a page of a process has been paged in and the process can - * continue to run). This interrupt can arrive on any cpu and, since we have - * virtual cpus, actually appear before the interrupt that signals that a page - * is missing. - */ -static void pfault_interrupt(struct ext_code ext_code, - unsigned int param32, unsigned long param64) -{ - struct task_struct *tsk; - __u16 subcode; - pid_t pid; - - /* - * Get the external interruption subcode & pfault initial/completion - * signal bit. VM stores this in the 'cpu address' field associated - * with the external interrupt. - */ - subcode = ext_code.subcode; - if ((subcode & 0xff00) != __SUBCODE_MASK) - return; - inc_irq_stat(IRQEXT_PFL); - /* Get the token (= pid of the affected task). */ - pid = param64 & LPP_PID_MASK; - rcu_read_lock(); - tsk = find_task_by_pid_ns(pid, &init_pid_ns); - if (tsk) - get_task_struct(tsk); - rcu_read_unlock(); - if (!tsk) - return; - spin_lock(&pfault_lock); - if (subcode & PF_COMPLETE) { - /* signal bit is set -> a page has been swapped in by VM */ - if (tsk->thread.pfault_wait == 1) { - /* Initial interrupt was faster than the completion - * interrupt. pfault_wait is valid. Set pfault_wait - * back to zero and wake up the process. This can - * safely be done because the task is still sleeping - * and can't produce new pfaults. */ - tsk->thread.pfault_wait = 0; - list_del(&tsk->thread.list); - wake_up_process(tsk); - put_task_struct(tsk); - } else { - /* Completion interrupt was faster than initial - * interrupt. Set pfault_wait to -1 so the initial - * interrupt doesn't put the task to sleep. - * If the task is not running, ignore the completion - * interrupt since it must be a leftover of a PFAULT - * CANCEL operation which didn't remove all pending - * completion interrupts. */ - if (task_is_running(tsk)) - tsk->thread.pfault_wait = -1; - } - } else { - /* signal bit not set -> a real page is missing. */ - if (WARN_ON_ONCE(tsk != current)) - goto out; - if (tsk->thread.pfault_wait == 1) { - /* Already on the list with a reference: put to sleep */ - goto block; - } else if (tsk->thread.pfault_wait == -1) { - /* Completion interrupt was faster than the initial - * interrupt (pfault_wait == -1). Set pfault_wait - * back to zero and exit. */ - tsk->thread.pfault_wait = 0; - } else { - /* Initial interrupt arrived before completion - * interrupt. Let the task sleep. - * An extra task reference is needed since a different - * cpu may set the task state to TASK_RUNNING again - * before the scheduler is reached. */ - get_task_struct(tsk); - tsk->thread.pfault_wait = 1; - list_add(&tsk->thread.list, &pfault_list); -block: - /* Since this must be a userspace fault, there - * is no kernel task state to trample. Rely on the - * return to userspace schedule() to block. */ - __set_current_state(TASK_UNINTERRUPTIBLE); - set_tsk_need_resched(tsk); - set_preempt_need_resched(); - } - } -out: - spin_unlock(&pfault_lock); - put_task_struct(tsk); -} - -static int pfault_cpu_dead(unsigned int cpu) -{ - struct thread_struct *thread, *next; - struct task_struct *tsk; - - spin_lock_irq(&pfault_lock); - list_for_each_entry_safe(thread, next, &pfault_list, list) { - thread->pfault_wait = 0; - list_del(&thread->list); - tsk = container_of(thread, struct task_struct, thread); - wake_up_process(tsk); - put_task_struct(tsk); - } - spin_unlock_irq(&pfault_lock); - return 0; -} - -static int __init pfault_irq_init(void) -{ - int rc; - - rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); - if (rc) - goto out_extint; - rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; - if (rc) - goto out_pfault; - irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); - cpuhp_setup_state_nocalls(CPUHP_S390_PFAULT_DEAD, "s390/pfault:dead", - NULL, pfault_cpu_dead); - return 0; - -out_pfault: - unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); -out_extint: - pfault_disable = 1; - return rc; -} -early_initcall(pfault_irq_init); - -#endif /* CONFIG_PFAULT */ - #if IS_ENABLED(CONFIG_PGSTE) void do_secure_storage_access(struct pt_regs *regs) diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index cbe1df1e9c18..c805b3e2592b 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -86,11 +86,12 @@ size_t memcpy_real_iter(struct iov_iter *iter, unsigned long src, size_t count) void *chunk; pte_t pte; + BUILD_BUG_ON(MEMCPY_REAL_SIZE != PAGE_SIZE); while (count) { - phys = src & PAGE_MASK; - offset = src & ~PAGE_MASK; + phys = src & MEMCPY_REAL_MASK; + offset = src & ~MEMCPY_REAL_MASK; chunk = (void *)(__memcpy_real_area + offset); - len = min(count, PAGE_SIZE - offset); + len = min(count, MEMCPY_REAL_SIZE - offset); pte = mk_pte_phys(phys, PAGE_KERNEL_RO); mutex_lock(&memcpy_real_mutex); diff --git a/arch/s390/mm/pfault.c b/arch/s390/mm/pfault.c new file mode 100644 index 000000000000..1aac13bb8f53 --- /dev/null +++ b/arch/s390/mm/pfault.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 1999, 2023 + */ + +#include <linux/cpuhotplug.h> +#include <linux/sched/task.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/irq.h> +#include <asm/asm-extable.h> +#include <asm/pfault.h> +#include <asm/diag.h> + +#define __SUBCODE_MASK 0x0600 +#define __PF_RES_FIELD 0x8000000000000000UL + +/* + * 'pfault' pseudo page faults routines. + */ +static int pfault_disable; + +static int __init nopfault(char *str) +{ + pfault_disable = 1; + return 1; +} +early_param("nopfault", nopfault); + +struct pfault_refbk { + u16 refdiagc; + u16 reffcode; + u16 refdwlen; + u16 refversn; + u64 refgaddr; + u64 refselmk; + u64 refcmpmk; + u64 reserved; +}; + +static struct pfault_refbk pfault_init_refbk = { + .refdiagc = 0x258, + .reffcode = 0, + .refdwlen = 5, + .refversn = 2, + .refgaddr = __LC_LPP, + .refselmk = 1UL << 48, + .refcmpmk = 1UL << 48, + .reserved = __PF_RES_FIELD +}; + +int __pfault_init(void) +{ + int rc = -EOPNOTSUPP; + + if (pfault_disable) + return rc; + diag_stat_inc(DIAG_STAT_X258); + asm volatile( + " diag %[refbk],%[rc],0x258\n" + "0: nopr %%r7\n" + EX_TABLE(0b, 0b) + : [rc] "+d" (rc) + : [refbk] "a" (&pfault_init_refbk), "m" (pfault_init_refbk) + : "cc"); + return rc; +} + +static struct pfault_refbk pfault_fini_refbk = { + .refdiagc = 0x258, + .reffcode = 1, + .refdwlen = 5, + .refversn = 2, +}; + +void __pfault_fini(void) +{ + if (pfault_disable) + return; + diag_stat_inc(DIAG_STAT_X258); + asm volatile( + " diag %[refbk],0,0x258\n" + "0: nopr %%r7\n" + EX_TABLE(0b, 0b) + : + : [refbk] "a" (&pfault_fini_refbk), "m" (pfault_fini_refbk) + : "cc"); +} + +static DEFINE_SPINLOCK(pfault_lock); +static LIST_HEAD(pfault_list); + +#define PF_COMPLETE 0x0080 + +/* + * The mechanism of our pfault code: if Linux is running as guest, runs a user + * space process and the user space process accesses a page that the host has + * paged out we get a pfault interrupt. + * + * This allows us, within the guest, to schedule a different process. Without + * this mechanism the host would have to suspend the whole virtual cpu until + * the page has been paged in. + * + * So when we get such an interrupt then we set the state of the current task + * to uninterruptible and also set the need_resched flag. Both happens within + * interrupt context(!). If we later on want to return to user space we + * recognize the need_resched flag and then call schedule(). It's not very + * obvious how this works... + * + * Of course we have a lot of additional fun with the completion interrupt (-> + * host signals that a page of a process has been paged in and the process can + * continue to run). This interrupt can arrive on any cpu and, since we have + * virtual cpus, actually appear before the interrupt that signals that a page + * is missing. + */ +static void pfault_interrupt(struct ext_code ext_code, + unsigned int param32, unsigned long param64) +{ + struct task_struct *tsk; + __u16 subcode; + pid_t pid; + + /* + * Get the external interruption subcode & pfault initial/completion + * signal bit. VM stores this in the 'cpu address' field associated + * with the external interrupt. + */ + subcode = ext_code.subcode; + if ((subcode & 0xff00) != __SUBCODE_MASK) + return; + inc_irq_stat(IRQEXT_PFL); + /* Get the token (= pid of the affected task). */ + pid = param64 & LPP_PID_MASK; + rcu_read_lock(); + tsk = find_task_by_pid_ns(pid, &init_pid_ns); + if (tsk) + get_task_struct(tsk); + rcu_read_unlock(); + if (!tsk) + return; + spin_lock(&pfault_lock); + if (subcode & PF_COMPLETE) { + /* signal bit is set -> a page has been swapped in by VM */ + if (tsk->thread.pfault_wait == 1) { + /* + * Initial interrupt was faster than the completion + * interrupt. pfault_wait is valid. Set pfault_wait + * back to zero and wake up the process. This can + * safely be done because the task is still sleeping + * and can't produce new pfaults. + */ + tsk->thread.pfault_wait = 0; + list_del(&tsk->thread.list); + wake_up_process(tsk); + put_task_struct(tsk); + } else { + /* + * Completion interrupt was faster than initial + * interrupt. Set pfault_wait to -1 so the initial + * interrupt doesn't put the task to sleep. + * If the task is not running, ignore the completion + * interrupt since it must be a leftover of a PFAULT + * CANCEL operation which didn't remove all pending + * completion interrupts. + */ + if (task_is_running(tsk)) + tsk->thread.pfault_wait = -1; + } + } else { + /* signal bit not set -> a real page is missing. */ + if (WARN_ON_ONCE(tsk != current)) + goto out; + if (tsk->thread.pfault_wait == 1) { + /* Already on the list with a reference: put to sleep */ + goto block; + } else if (tsk->thread.pfault_wait == -1) { + /* + * Completion interrupt was faster than the initial + * interrupt (pfault_wait == -1). Set pfault_wait + * back to zero and exit. + */ + tsk->thread.pfault_wait = 0; + } else { + /* + * Initial interrupt arrived before completion + * interrupt. Let the task sleep. + * An extra task reference is needed since a different + * cpu may set the task state to TASK_RUNNING again + * before the scheduler is reached. + */ + get_task_struct(tsk); + tsk->thread.pfault_wait = 1; + list_add(&tsk->thread.list, &pfault_list); +block: + /* + * Since this must be a userspace fault, there + * is no kernel task state to trample. Rely on the + * return to userspace schedule() to block. + */ + __set_current_state(TASK_UNINTERRUPTIBLE); + set_tsk_need_resched(tsk); + set_preempt_need_resched(); + } + } +out: + spin_unlock(&pfault_lock); + put_task_struct(tsk); +} + +static int pfault_cpu_dead(unsigned int cpu) +{ + struct thread_struct *thread, *next; + struct task_struct *tsk; + + spin_lock_irq(&pfault_lock); + list_for_each_entry_safe(thread, next, &pfault_list, list) { + thread->pfault_wait = 0; + list_del(&thread->list); + tsk = container_of(thread, struct task_struct, thread); + wake_up_process(tsk); + put_task_struct(tsk); + } + spin_unlock_irq(&pfault_lock); + return 0; +} + +static int __init pfault_irq_init(void) +{ + int rc; + + rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); + if (rc) + goto out_extint; + rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; + if (rc) + goto out_pfault; + irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); + cpuhp_setup_state_nocalls(CPUHP_S390_PFAULT_DEAD, "s390/pfault:dead", + NULL, pfault_cpu_dead); + return 0; + +out_pfault: + unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); +out_extint: + pfault_disable = 1; + return rc; +} +early_initcall(pfault_irq_init); diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index b26649233d12..e44243b9c0a4 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -36,7 +36,7 @@ static void vmem_free_pages(unsigned long addr, int order) { /* We don't expect boot memory to be removed ever. */ if (!slab_is_available() || - WARN_ON_ONCE(PageReserved(virt_to_page(addr)))) + WARN_ON_ONCE(PageReserved(virt_to_page((void *)addr)))) return; free_pages(addr, order); } @@ -531,7 +531,7 @@ struct range arch_get_mappable_range(void) struct range mhp_range; mhp_range.start = 0; - mhp_range.end = VMEM_MAX_PHYS - 1; + mhp_range.end = max_mappable - 1; return mhp_range; } @@ -763,6 +763,8 @@ void __init vmem_map_init(void) if (static_key_enabled(&cpu_has_bear)) set_memory_nx(0, 1); set_memory_nx(PAGE_SIZE, 1); + if (debug_pagealloc_enabled()) + set_memory_4k(0, ident_map_size >> PAGE_SHIFT); pr_info("Write protected kernel read-only data: %luk\n", (unsigned long)(__end_rodata - _stext) >> 10); |