[RFC PATCH 13/14] sparc64 mm: add shared context support to mmap() and shmat() APIs
From: Mike Kravetz <hidden>
Date: 2016-12-16 18:37:34
Also in:
lkml, sparclinux
Subsystem:
sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
"David S. Miller", Andreas Larsson, Linus Torvalds
Add new mmap(MAP_SHAREDCTX) and shm(SHM_SHAREDCTX) flags to specify desire for shared context mappings. This only works on HUGETLB mappings. In addition, the mappings must be SHARED and at a FIXED address otherwize EINVAL will be returned. Also, populate the sparc specific hooks to mmap and shmat that perform shared context processing. Signed-off-by: Mike Kravetz <redacted> --- arch/sparc/include/asm/hugetlb.h | 4 +++ arch/sparc/include/asm/mman.h | 6 ++++ arch/sparc/include/asm/mmu_context_64.h | 62 ++++++++++++++++++++++++++++++++- arch/sparc/include/uapi/asm/mman.h | 1 + arch/sparc/kernel/sys_sparc_64.c | 17 +++++++++ arch/sparc/mm/init_64.c | 36 +++++++++++++++++++ include/uapi/linux/shm.h | 1 + 7 files changed, 126 insertions(+), 1 deletion(-)
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index dcbf985..13157b3 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h@@ -78,4 +78,8 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end, unsigned long floor, unsigned long ceiling); +#if defined(CONFIG_SHARED_MMU_CTX) +void huge_get_shared_ctx(struct mm_struct *mm, unsigned long addr); +#endif + #endif /* _ASM_SPARC64_HUGETLB_H */
diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
index 59bb593..cbe384e 100644
--- a/arch/sparc/include/asm/mman.h
+++ b/arch/sparc/include/asm/mman.h@@ -6,5 +6,11 @@ #ifndef __ASSEMBLY__ #define arch_mmap_check(addr,len,flags) sparc_mmap_check(addr,len) int sparc_mmap_check(unsigned long addr, unsigned long len); + +#if defined(CONFIG_SHARED_MMU_CTX) +#define arch_shmat_check(file, shmflg, flags) \ + sparc_shmat_check(file, shmflg, flags) +int sparc_shmat_check(struct file *file, int shmflg, unsigned long *flags); +#endif #endif #endif /* __SPARC_MMAN_H__ */
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h
index 46c2c7e..8ab05f2 100644
--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h@@ -7,7 +7,6 @@ #include <linux/spinlock.h> #include <asm/spitfire.h> -#include <asm-generic/mm_hooks.h> static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) {
@@ -24,6 +23,13 @@ void put_shared_context(struct mm_struct *mm); void set_mm_shared_ctx(struct mm_struct *mm, struct shared_mmu_ctx *ctx); void destroy_shared_context(struct mm_struct *mm); void set_vma_shared_ctx(struct vm_area_struct *vma); +void sparc64_exit_mmap(struct mm_struct *mm); +void sparc64_unmap(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long start, unsigned long end); +unsigned long sparc64_pre_mmap_flags(struct file *file, unsigned long flags, + vm_flags_t *vm_flags); +void sparc64_post_mmap(struct mm_struct *mm, unsigned long addr, + vm_flags_t vm_flags); #endif #ifdef CONFIG_SMP void smp_new_mmu_context_version(void);
@@ -208,6 +214,60 @@ static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm spin_unlock_irqrestore(&mm->context.lock, flags); } +#if defined(CONFIG_SHARED_MMU_CTX) +/* + * mm_hooks only needed for CONFIG_SHARED_MMU_CTX + */ +static inline unsigned long arch_pre_mmap_flags(struct file *file, + unsigned long flags, + vm_flags_t *vm_flags) +{ + return sparc64_pre_mmap_flags(file, flags, vm_flags); +} + +static inline void arch_post_mmap(struct mm_struct *mm, unsigned long addr, + vm_flags_t vm_flags) +{ + sparc64_post_mmap(mm, addr, vm_flags); +} + +static inline void arch_dup_mmap(struct mm_struct *oldmm, + struct mm_struct *mm) +{ +} + +static inline void arch_exit_mmap(struct mm_struct *mm) +{ + sparc64_exit_mmap(mm); +} + +static inline void arch_unmap(struct mm_struct *mm, + struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + sparc64_unmap(mm, vma, start, end); +} + +static inline void arch_bprm_mm_init(struct mm_struct *mm, + struct vm_area_struct *vma) +{ +} + +static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, + bool write, bool execute, bool foreign) +{ + /* by default, allow everything */ + return true; +} + +static inline bool arch_pte_access_permitted(pte_t pte, bool write) +{ + /* by default, allow everything */ + return true; +} +#else +#include <asm-generic/mm_hooks.h> +#endif #endif /* !(__ASSEMBLY__) */ #endif /* !(__SPARC64_MMU_CONTEXT_H) */
diff --git a/arch/sparc/include/uapi/asm/mman.h b/arch/sparc/include/uapi/asm/mman.h
index 9765896..a52c6fe 100644
--- a/arch/sparc/include/uapi/asm/mman.h
+++ b/arch/sparc/include/uapi/asm/mman.h@@ -23,6 +23,7 @@ #define MAP_NONBLOCK 0x10000 /* do not block on IO */ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +#define MAP_SHAREDCTX 0x80000 /* request shared cxt mapping */ #endif /* _UAPI__SPARC_MMAN_H__ */
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index fe8b8ee..23fa538 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c@@ -25,6 +25,7 @@ #include <linux/random.h> #include <linux/export.h> #include <linux/context_tracking.h> +#include <linux/hugetlb.h> #include <asm/uaccess.h> #include <asm/utrap.h>
@@ -444,6 +445,22 @@ int sparc_mmap_check(unsigned long addr, unsigned long len) return 0; } +int sparc_shmat_check(struct file *file, int shmflg, unsigned long *flags) +{ + if (shmflg & SHM_SHAREDCTX) { + if ((*flags & (MAP_SHARED | MAP_FIXED)) != + (unsigned long)(MAP_SHARED | MAP_FIXED)) + return -EINVAL; + + if (!is_file_hugepages(file)) + return -EINVAL; + + *flags |= MAP_SHAREDCTX; + } + + return 0; +} + /* Linux version of mmap */ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags, unsigned long, fd,
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 25ad5bd..0637762 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c@@ -27,6 +27,7 @@ #include <linux/memblock.h> #include <linux/mmzone.h> #include <linux/gfp.h> +#include <linux/mman.h> #include <asm/head.h> #include <asm/page.h>
@@ -832,6 +833,41 @@ void set_vma_shared_ctx(struct vm_area_struct *vma) atomic_inc(&mm->context.shared_ctx->refcount); vma->vm_shared_mmu_ctx.ctx = mm->context.shared_ctx; } + +unsigned long sparc64_pre_mmap_flags(struct file *file, unsigned long flags, + vm_flags_t *vm_flags) +{ + if (flags & MAP_SHAREDCTX) { + /* Must be a shared huge page mapping */ + if (!(flags & (MAP_SHARED | MAP_FIXED))) + return -EINVAL; + if (!(flags & MAP_HUGETLB) && + !(file && is_file_hugepages(file))) + return -EINVAL; + + *vm_flags |= VM_SHARED_CTX; + } + + return 0; +} + +void sparc64_post_mmap(struct mm_struct *mm, unsigned long addr, + vm_flags_t vm_flags) +{ + if (vm_flags & VM_SHARED_CTX) + huge_get_shared_ctx(mm, addr); +} + +void sparc64_exit_mmap(struct mm_struct *mm) +{ + put_shared_context(mm); +} + +void sparc64_unmap(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + put_shared_context(mm); +} #endif static int numa_enabled = 1;
diff --git a/include/uapi/linux/shm.h b/include/uapi/linux/shm.h
index 1fbf24e..3373567 100644
--- a/include/uapi/linux/shm.h
+++ b/include/uapi/linux/shm.h@@ -49,6 +49,7 @@ struct shmid_ds { #define SHM_RND 020000 /* round attach address to SHMLBA boundary */ #define SHM_REMAP 040000 /* take-over region on attach */ #define SHM_EXEC 0100000 /* execution access */ +#define SHM_SHAREDCTX 0200000 /* share context (TLB entries) if possible */ /* super user shmctl commands */ #define SHM_LOCK 11
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2.7.4
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