diff options
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/pgtable.h | 2 | ||||
| -rw-r--r-- | include/asm-generic/rwsem.h | 140 | ||||
| -rw-r--r-- | include/asm-generic/syscall.h | 21 | ||||
| -rw-r--r-- | include/asm-generic/tlb.h | 297 |
4 files changed, 275 insertions, 185 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index fa782fba51ee..75d9d68a6de7 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1126,6 +1126,8 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, static inline void init_espfix_bsp(void) { } #endif +extern void __init pgd_cache_init(void); + #ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot) { diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h deleted file mode 100644 index 93e67a055a4d..000000000000 --- a/include/asm-generic/rwsem.h +++ /dev/null @@ -1,140 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_GENERIC_RWSEM_H -#define _ASM_GENERIC_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead." -#endif - -#ifdef __KERNEL__ - -/* - * R/W semaphores originally for PPC using the stuff in lib/rwsem.c. - * Adapted largely from include/asm-i386/rwsem.h - * by Paul Mackerras <paulus@samba.org>. - */ - -/* - * the semaphore definition - */ -#ifdef CONFIG_64BIT -# define RWSEM_ACTIVE_MASK 0xffffffffL -#else -# define RWSEM_ACTIVE_MASK 0x0000ffffL -#endif - -#define RWSEM_UNLOCKED_VALUE 0x00000000L -#define RWSEM_ACTIVE_BIAS 0x00000001L -#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) - rwsem_down_read_failed(sem); -} - -static inline int __down_read_killable(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) { - if (IS_ERR(rwsem_down_read_failed_killable(sem))) - return -EINTR; - } - - return 0; -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - long tmp; - - while ((tmp = atomic_long_read(&sem->count)) >= 0) { - if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - rwsem_down_write_failed(sem); -} - -static inline int __down_write_killable(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - if (IS_ERR(rwsem_down_write_failed_killable(sem))) - return -EINTR; - return 0; -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_dec_return_release(&sem->count); - if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_sub_return_release(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count) < 0)) - rwsem_wake(sem); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - long tmp; - - /* - * When downgrading from exclusive to shared ownership, - * anything inside the write-locked region cannot leak - * into the read side. In contrast, anything in the - * read-locked region is ok to be re-ordered into the - * write side. As such, rely on RELEASE semantics. - */ - tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS, &sem->count); - if (tmp < 0) - rwsem_downgrade_wake(sem); -} - -#endif /* __KERNEL__ */ -#endif /* _ASM_GENERIC_RWSEM_H */ diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h index 0c938a4354f6..b88239e9efe4 100644 --- a/include/asm-generic/syscall.h +++ b/include/asm-generic/syscall.h @@ -105,41 +105,30 @@ void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, * syscall_get_arguments - extract system call parameter values * @task: task of interest, must be blocked * @regs: task_pt_regs() of @task - * @i: argument index [0,5] - * @n: number of arguments; n+i must be [1,6]. * @args: array filled with argument values * - * Fetches @n arguments to the system call starting with the @i'th argument - * (from 0 through 5). Argument @i is stored in @args[0], and so on. - * An arch inline version is probably optimal when @i and @n are constants. + * Fetches 6 arguments to the system call. First argument is stored in +* @args[0], and so on. * * It's only valid to call this when @task is stopped for tracing on * entry to a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. - * It's invalid to call this with @i + @n > 6; we only support system calls - * taking up to 6 arguments. */ void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, - unsigned int i, unsigned int n, unsigned long *args); + unsigned long *args); /** * syscall_set_arguments - change system call parameter value * @task: task of interest, must be in system call entry tracing * @regs: task_pt_regs() of @task - * @i: argument index [0,5] - * @n: number of arguments; n+i must be [1,6]. * @args: array of argument values to store * - * Changes @n arguments to the system call starting with the @i'th argument. - * Argument @i gets value @args[0], and so on. - * An arch inline version is probably optimal when @i and @n are constants. + * Changes 6 arguments to the system call. + * The first argument gets value @args[0], and so on. * * It's only valid to call this when @task is stopped for tracing on * entry to a system call, due to %TIF_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. - * It's invalid to call this with @i + @n > 6; we only support system calls - * taking up to 6 arguments. */ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs, - unsigned int i, unsigned int n, const unsigned long *args); /** diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 6be86c1c5c58..480e5b2a5748 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -19,9 +19,140 @@ #include <linux/swap.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> +#include <asm/cacheflush.h> + +/* + * Blindly accessing user memory from NMI context can be dangerous + * if we're in the middle of switching the current user task or switching + * the loaded mm. + */ +#ifndef nmi_uaccess_okay +# define nmi_uaccess_okay() true +#endif #ifdef CONFIG_MMU +/* + * Generic MMU-gather implementation. + * + * The mmu_gather data structure is used by the mm code to implement the + * correct and efficient ordering of freeing pages and TLB invalidations. + * + * This correct ordering is: + * + * 1) unhook page + * 2) TLB invalidate page + * 3) free page + * + * That is, we must never free a page before we have ensured there are no live + * translations left to it. Otherwise it might be possible to observe (or + * worse, change) the page content after it has been reused. + * + * The mmu_gather API consists of: + * + * - tlb_gather_mmu() / tlb_finish_mmu(); start and finish a mmu_gather + * + * Finish in particular will issue a (final) TLB invalidate and free + * all (remaining) queued pages. + * + * - tlb_start_vma() / tlb_end_vma(); marks the start / end of a VMA + * + * Defaults to flushing at tlb_end_vma() to reset the range; helps when + * there's large holes between the VMAs. + * + * - tlb_remove_page() / __tlb_remove_page() + * - tlb_remove_page_size() / __tlb_remove_page_size() + * + * __tlb_remove_page_size() is the basic primitive that queues a page for + * freeing. __tlb_remove_page() assumes PAGE_SIZE. Both will return a + * boolean indicating if the queue is (now) full and a call to + * tlb_flush_mmu() is required. + * + * tlb_remove_page() and tlb_remove_page_size() imply the call to + * tlb_flush_mmu() when required and has no return value. + * + * - tlb_change_page_size() + * + * call before __tlb_remove_page*() to set the current page-size; implies a + * possible tlb_flush_mmu() call. + * + * - tlb_flush_mmu() / tlb_flush_mmu_tlbonly() + * + * tlb_flush_mmu_tlbonly() - does the TLB invalidate (and resets + * related state, like the range) + * + * tlb_flush_mmu() - in addition to the above TLB invalidate, also frees + * whatever pages are still batched. + * + * - mmu_gather::fullmm + * + * A flag set by tlb_gather_mmu() to indicate we're going to free + * the entire mm; this allows a number of optimizations. + * + * - We can ignore tlb_{start,end}_vma(); because we don't + * care about ranges. Everything will be shot down. + * + * - (RISC) architectures that use ASIDs can cycle to a new ASID + * and delay the invalidation until ASID space runs out. + * + * - mmu_gather::need_flush_all + * + * A flag that can be set by the arch code if it wants to force + * flush the entire TLB irrespective of the range. For instance + * x86-PAE needs this when changing top-level entries. + * + * And allows the architecture to provide and implement tlb_flush(): + * + * tlb_flush() may, in addition to the above mentioned mmu_gather fields, make + * use of: + * + * - mmu_gather::start / mmu_gather::end + * + * which provides the range that needs to be flushed to cover the pages to + * be freed. + * + * - mmu_gather::freed_tables + * + * set when we freed page table pages + * + * - tlb_get_unmap_shift() / tlb_get_unmap_size() + * + * returns the smallest TLB entry size unmapped in this range. + * + * If an architecture does not provide tlb_flush() a default implementation + * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is + * specified, in which case we'll default to flush_tlb_mm(). + * + * Additionally there are a few opt-in features: + * + * HAVE_MMU_GATHER_PAGE_SIZE + * + * This ensures we call tlb_flush() every time tlb_change_page_size() actually + * changes the size and provides mmu_gather::page_size to tlb_flush(). + * + * HAVE_RCU_TABLE_FREE + * + * This provides tlb_remove_table(), to be used instead of tlb_remove_page() + * for page directores (__p*_free_tlb()). This provides separate freeing of + * the page-table pages themselves in a semi-RCU fashion (see comment below). + * Useful if your architecture doesn't use IPIs for remote TLB invalidates + * and therefore doesn't naturally serialize with software page-table walkers. + * + * When used, an architecture is expected to provide __tlb_remove_table() + * which does the actual freeing of these pages. + * + * HAVE_RCU_TABLE_NO_INVALIDATE + * + * This makes HAVE_RCU_TABLE_FREE avoid calling tlb_flush_mmu_tlbonly() before + * freeing the page-table pages. This can be avoided if you use + * HAVE_RCU_TABLE_FREE and your architecture does _NOT_ use the Linux + * page-tables natively. + * + * MMU_GATHER_NO_RANGE + * + * Use this if your architecture lacks an efficient flush_tlb_range(). + */ + #ifdef CONFIG_HAVE_RCU_TABLE_FREE /* * Semi RCU freeing of the page directories. @@ -60,11 +191,11 @@ struct mmu_table_batch { #define MAX_TABLE_BATCH \ ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) -extern void tlb_table_flush(struct mmu_gather *tlb); extern void tlb_remove_table(struct mmu_gather *tlb, void *table); #endif +#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER /* * If we can't allocate a page to make a big batch of page pointers * to work on, then just handle a few from the on-stack structure. @@ -89,14 +220,21 @@ struct mmu_gather_batch { */ #define MAX_GATHER_BATCH_COUNT (10000UL/MAX_GATHER_BATCH) -/* struct mmu_gather is an opaque type used by the mm code for passing around +extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, + int page_size); +#endif + +/* + * struct mmu_gather is an opaque type used by the mm code for passing around * any data needed by arch specific code for tlb_remove_page. */ struct mmu_gather { struct mm_struct *mm; + #ifdef CONFIG_HAVE_RCU_TABLE_FREE struct mmu_table_batch *batch; #endif + unsigned long start; unsigned long end; /* @@ -124,23 +262,30 @@ struct mmu_gather { unsigned int cleared_puds : 1; unsigned int cleared_p4ds : 1; + /* + * tracks VM_EXEC | VM_HUGETLB in tlb_start_vma + */ + unsigned int vma_exec : 1; + unsigned int vma_huge : 1; + + unsigned int batch_count; + +#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER struct mmu_gather_batch *active; struct mmu_gather_batch local; struct page *__pages[MMU_GATHER_BUNDLE]; - unsigned int batch_count; - int page_size; -}; -#define HAVE_GENERIC_MMU_GATHER +#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE + unsigned int page_size; +#endif +#endif +}; void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start, unsigned long end); void tlb_flush_mmu(struct mmu_gather *tlb); void arch_tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end, bool force); -void tlb_flush_mmu_free(struct mmu_gather *tlb); -extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, - int page_size); static inline void __tlb_adjust_range(struct mmu_gather *tlb, unsigned long address, @@ -163,8 +308,94 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->cleared_pmds = 0; tlb->cleared_puds = 0; tlb->cleared_p4ds = 0; + /* + * Do not reset mmu_gather::vma_* fields here, we do not + * call into tlb_start_vma() again to set them if there is an + * intermediate flush. + */ +} + +#ifdef CONFIG_MMU_GATHER_NO_RANGE + +#if defined(tlb_flush) || defined(tlb_start_vma) || defined(tlb_end_vma) +#error MMU_GATHER_NO_RANGE relies on default tlb_flush(), tlb_start_vma() and tlb_end_vma() +#endif + +/* + * When an architecture does not have efficient means of range flushing TLBs + * there is no point in doing intermediate flushes on tlb_end_vma() to keep the + * range small. We equally don't have to worry about page granularity or other + * things. + * + * All we need to do is issue a full flush for any !0 range. + */ +static inline void tlb_flush(struct mmu_gather *tlb) +{ + if (tlb->end) + flush_tlb_mm(tlb->mm); +} + +static inline void +tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } + +#define tlb_end_vma tlb_end_vma +static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) { } + +#else /* CONFIG_MMU_GATHER_NO_RANGE */ + +#ifndef tlb_flush + +#if defined(tlb_start_vma) || defined(tlb_end_vma) +#error Default tlb_flush() relies on default tlb_start_vma() and tlb_end_vma() +#endif + +/* + * When an architecture does not provide its own tlb_flush() implementation + * but does have a reasonably efficient flush_vma_range() implementation + * use that. + */ +static inline void tlb_flush(struct mmu_gather *tlb) +{ + if (tlb->fullmm || tlb->need_flush_all) { + flush_tlb_mm(tlb->mm); + } else if (tlb->end) { + struct vm_area_struct vma = { + .vm_mm = tlb->mm, + .vm_flags = (tlb->vma_exec ? VM_EXEC : 0) | + (tlb->vma_huge ? VM_HUGETLB : 0), + }; + + flush_tlb_range(&vma, tlb->start, tlb->end); + } +} + +static inline void +tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + /* + * flush_tlb_range() implementations that look at VM_HUGETLB (tile, + * mips-4k) flush only large pages. + * + * flush_tlb_range() implementations that flush I-TLB also flush D-TLB + * (tile, xtensa, arm), so it's ok to just add VM_EXEC to an existing + * range. + * + * We rely on tlb_end_vma() to issue a flush, such that when we reset + * these values the batch is empty. + */ + tlb->vma_huge = !!(vma->vm_flags & VM_HUGETLB); + tlb->vma_exec = !!(vma->vm_flags & VM_EXEC); } +#else + +static inline void +tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } + +#endif + +#endif /* CONFIG_MMU_GATHER_NO_RANGE */ + static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) { if (!tlb->end) @@ -196,21 +427,18 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) return tlb_remove_page_size(tlb, page, PAGE_SIZE); } -#ifndef tlb_remove_check_page_size_change -#define tlb_remove_check_page_size_change tlb_remove_check_page_size_change -static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, +static inline void tlb_change_page_size(struct mmu_gather *tlb, unsigned int page_size) { - /* - * We don't care about page size change, just update - * mmu_gather page size here so that debug checks - * doesn't throw false warning. - */ -#ifdef CONFIG_DEBUG_VM +#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE + if (tlb->page_size && tlb->page_size != page_size) { + if (!tlb->fullmm) + tlb_flush_mmu(tlb); + } + tlb->page_size = page_size; #endif } -#endif static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb) { @@ -237,17 +465,30 @@ static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb) * the vmas are adjusted to only cover the region to be torn down. */ #ifndef tlb_start_vma -#define tlb_start_vma(tlb, vma) do { } while (0) -#endif +static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (tlb->fullmm) + return; -#define __tlb_end_vma(tlb, vma) \ - do { \ - if (!tlb->fullmm) \ - tlb_flush_mmu_tlbonly(tlb); \ - } while (0) + tlb_update_vma_flags(tlb, vma); + flush_cache_range(vma, vma->vm_start, vma->vm_end); +} +#endif #ifndef tlb_end_vma -#define tlb_end_vma __tlb_end_vma +static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (tlb->fullmm) + return; + + /* + * Do a TLB flush and reset the range at VMA boundaries; this avoids + * the ranges growing with the unused space between consecutive VMAs, + * but also the mmu_gather::vma_* flags from tlb_start_vma() rely on + * this. + */ + tlb_flush_mmu_tlbonly(tlb); +} #endif #ifndef __tlb_remove_tlb_entry @@ -372,6 +613,4 @@ static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb) #endif /* CONFIG_MMU */ -#define tlb_migrate_finish(mm) do {} while (0) - #endif /* _ASM_GENERIC__TLB_H */ |