* [PATCH 2/3] kshmem implementation, configuration and makefile
@ 2007-05-06 1:53 Wink Saville
0 siblings, 0 replies; only message in thread
From: Wink Saville @ 2007-05-06 1:53 UTC (permalink / raw)
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Signed-off-by: Wink Saville <wink-hKg/bvL8yClBDgjK7y7TUQ@public.gmane.org>
---
include/asm-x86_64/kshmem.h | 17 +++
include/linux/kshmem.h | 47 +++++++
include/linux/mm.h | 1 +
include/linux/vmalloc.h | 3 +
mm/Kconfig | 8 +
mm/Makefile | 1 +
mm/kshmem.c | 296 +++++++++++++++++++++++++++++++++++++++++++
mm/vmalloc.c | 37 +++++-
8 files changed, 406 insertions(+), 4 deletions(-)
create mode 100644 include/asm-x86_64/kshmem.h
create mode 100644 include/linux/kshmem.h
create mode 100644 mm/kshmem.c
Index: linux-2.6/include/asm-x86_64/kshmem.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/include/asm-x86_64/kshmem.h 2007-04-29 21:52:04.000000000 -0700
@@ -0,0 +1,17 @@
+/** * Copyright (C) 2007 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ */
+
+#ifndef _ASM_KSHMEM_H
+#define _ASM_KSHMEM_H
+
+#define KSHMEM_AREA_ADDR 0x6f8000000000
+#define KSHMEM_AREA_SIZE 0x008000000000
+#define KSHMEM_AREA_MASK (~(KSHMEM_AREA_SIZE-1))
+
+#define KSHMEM_USER_DISABLE(x) __pgd(pgd_val(x) & ~_PAGE_USER)
+#define KSHMEM_USER_ENABLE(x) __pgd(pgd_val(x) | _PAGE_USER)
+
+#endif
Index: linux-2.6/include/linux/kshmem.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/include/linux/kshmem.h 2007-04-29 21:52:04.000000000 -0700
@@ -0,0 +1,47 @@
+/** * Copyright (C) 2007 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ */
+
+#ifndef _KSHMEM_H
+#define _KSHMEM_H
+
+#ifdef CONFIG_KSHMEM
+
+#include <asm/kshmem.h>
+
+#ifdef __KERNEL__
+
+extern void kshmem_init(void);
+extern char * kshmem_alloc_at(unsigned long location, unsigned long size, pgprot_t page_flags);
+extern void * kshmem_alloc(unsigned long size, pgprot_t page_flags);
+extern void kshmem_user_disable(void);
+extern void kshmem_user_enable(void);
+extern int kshmem_prepare(struct mm_struct *pNew_mm);
+extern unsigned long kshmem_addr_to_kvaddr(unsigned long kshmem_addr);
+
+#endif
+
+#else
+
+#ifdef __KERNEL__
+
+static inline void kshmem_init(void)
+ {}
+static inline char * kshmem_alloc_at(unsigned long location, unsigned long size, pgprot_t page_flags)
+ { BUG(); return NULL; }
+static inline void * kshmem_alloc(unsigned long size, pgprot_t page_flags)
+ { BUG(); return NULL; }
+static inline void kshmem_free(void *pAddr)
+ { BUG(); }
+static inline int kshmem_prepare(struct mm_struct *pNew_mm)
+ { return 0; }
+static inline unsigned long kshmem_addr_to_kvaddr(unsigned long kshmem_addr)
+ { BUG(); return 0; }
+
+#endif
+
+#endif /* CONFIG_KSHMEM */
+
+#endif /* _KSHMEM_H */
Index: linux-2.6/include/linux/mm.h
===================================================================
--- linux-2.6.orig/include/linux/mm.h 2007-04-29 21:51:39.000000000 -0700
+++ linux-2.6/include/linux/mm.h 2007-04-29 21:52:04.000000000 -0700
@@ -169,6 +169,7 @@
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
#define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */
+#define VM_KSHMEM 0x08000000 /* Kernel shared memory */
#ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
Index: linux-2.6/include/linux/vmalloc.h
===================================================================
--- linux-2.6.orig/include/linux/vmalloc.h 2007-04-29 21:51:39.000000000 -0700
+++ linux-2.6/include/linux/vmalloc.h 2007-04-29 21:52:04.000000000 -0700
@@ -42,6 +42,9 @@
extern void *vmalloc_exec(unsigned long size);
extern void *vmalloc_32(unsigned long size);
extern void *vmalloc_32_user(unsigned long size);
+extern void *__vmalloc_at(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ gfp_t gfp_mask, pgprot_t prot);
extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
extern void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask,
pgprot_t prot);
Index: linux-2.6/mm/Kconfig
===================================================================
--- linux-2.6.orig/mm/Kconfig 2007-04-29 21:51:39.000000000 -0700
+++ linux-2.6/mm/Kconfig 2007-04-29 21:56:30.000000000 -0700
@@ -163,3 +163,11 @@
default "0" if !ZONE_DMA
default "1"
+config KSHMEM
+ bool "Kernel shared memory"
+ def_bool n
+ help
+ Allows an area of memory to be shared between the kernel and
+ user space programs. For instance interrupt service routines
+ and user space programs may share the same memory.
+
Index: linux-2.6/mm/Makefile
===================================================================
--- linux-2.6.orig/mm/Makefile 2007-04-29 21:51:39.000000000 -0700
+++ linux-2.6/mm/Makefile 2007-04-29 21:52:04.000000000 -0700
@@ -29,3 +29,4 @@
obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
obj-$(CONFIG_SMP) += allocpercpu.o
+obj-$(CONFIG_KSHMEM) += kshmem.o
Index: linux-2.6/mm/kshmem.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/mm/kshmem.c 2007-04-29 21:52:04.000000000 -0700
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) 2007 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/kshmem.h>
+
+#include <asm/io.h>
+
+
+#define KSHMEM_DEBUG
+#ifdef KSHMEM_DEBUG
+#define DPK(fmt, args...) printk(KERN_ERR "kshmem " fmt, ## args)
+#else
+#define DPK(fmt, args...)
+#endif
+
+MODULE_AUTHOR("Wink Saville");
+MODULE_LICENSE("Dual BSD/GPL");
+
+#undef KSHMEM_FIX_PTL
+#ifdef KSHMEM_FIX_PTL
+
+/*
+ * get the pte pointer for the address
+ */
+static void _get_pti(struct mm_struct *mm,
+ unsigned long addr,
+ int *pageSize,
+ pgd_t **pgd_ptr,
+ pud_t **pud_ptr,
+ pmd_t **pmd_ptr,
+ pte_t **pte_ptr)
+{
+ int page_size = 0;
+ pgd_t *pgd = NULL;
+ pud_t *pud = NULL;
+ pmd_t *pmd = NULL;
+ pte_t *pte = NULL;
+
+ if (mm == NULL) {
+ goto done;
+ }
+ pgd = pgd_offset(mm, addr);
+ if (pgd_none(*pgd)) goto done;
+ pud = pud_offset(pgd, addr);
+ if (pud_none(*pud)) goto done;
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd)) goto done;
+
+ if (pmd_large(*pmd))
+ {
+ pte = (pte_t *)pmd;
+ page_size = LARGE_PAGE_SIZE;
+ }
+ else
+ {
+ pte = pte_offset_map(pmd, addr);
+ page_size = PAGE_SIZE;
+ }
+done:
+ if (pageSize) *pageSize = page_size;
+ if (pgd_ptr) *pgd_ptr = pgd;
+ if (pud_ptr) *pud_ptr = pud;
+ if (pmd_ptr) *pmd_ptr = pmd;
+ if (pte_ptr) *pte_ptr = pte;
+}
+
+/*
+ * get the page table lock for the addr
+ */
+static spinlock_t *_get_ptl(struct mm_struct *mm, unsigned long addr)
+{
+ pmd_t *pmd = NULL;
+
+ _get_pti(mm, addr, NULL, NULL, NULL, &pmd, NULL);
+ if (pmd) {
+ return pte_lockptr(mm, pmd);
+ } else {
+ return NULL;
+ }
+}
+
+/*
+ * Fix the page table lock
+ */
+static void _fix_ptl(void *addr)
+{
+ spinlock_t *pLock;
+ struct mm_struct *cur_mm = current->active_mm;
+
+ /*
+ * For some reason we need to initialize the page table lock (ptl)
+ */
+ pLock = _get_ptl(cur_mm, (unsigned long)addr);
+ if (pLock) {
+ spin_lock_init(pLock);
+ } else {
+ DPK("_fix_ptl: src_mm=%p addr=%p NO PAGE!!! *********************\n",
+ cur_mm, addr);
+ }
+}
+#endif
+
+/*
+ * For all of the pages:
+ * - make sure they are present
+ * - get so they won't be deallocated
+ * - lock them down so they won't be swapped
+ */
+static void _fixate_range(char *pStart, char *pEnd)
+{
+ char *pAddr;
+
+ make_pages_present((unsigned long)pStart, (unsigned long)pEnd);
+
+ for (pAddr = pStart; pAddr < pEnd; pAddr += PAGE_SIZE) {
+ struct page *pPage = vmalloc_to_page(pAddr);
+
+ get_page(pPage);
+ SetPageLocked(pPage);
+#ifdef KSHMEM_FIX_PTL
+ _fix_ptl(pAddr);
+#endif
+ }
+}
+
+/*
+ * Allocate size number of bytes of kshmem at a specific location,
+ * page_flags should be PAGE_SHARED or PAGE_SHARED_EXEC.
+ *
+ * The resulting pointer will be page aligned and consume at least
+ * on page of memory.
+ */
+char *kshmem_alloc_at(unsigned long location, unsigned long size, pgprot_t page_flags)
+{
+ char *pStart;
+ struct mm_struct *cur_mm;
+
+ DPK("kshmem_alloc_at: current->mm=%p current->active_mm=%p &init_mm=%p\n", current->mm, current->active_mm, &init_mm);
+ /*
+ * Save the current mm and switch to init_mm where we allocate
+ * kshmem memory and then share with all other mm's.
+ */
+ cur_mm = current->mm;
+ current->mm = &init_mm;
+
+ /*
+ * cur_mm is NULL when we start, maybe we should use
+ * active_mm?
+ */
+
+ /* Do we need to hold the semaphore? */
+ down_write(&init_mm.mmap_sem);
+
+ size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
+ pStart = __vmalloc_at(size,
+ VM_ALLOC | VM_USERMAP | VM_KSHMEM | VM_LOCKED | VM_SHARED,
+ location, location + size,
+ GFP_KERNEL | GFP_DMA, page_flags);
+ BUG_ON(pStart != (char *)location);
+ _fixate_range(pStart, pStart + size);
+
+ up_write(&init_mm.mmap_sem);
+
+ /*
+ * Restore mm
+ */
+ current->mm = cur_mm;
+
+ return pStart;
+}
+EXPORT_SYMBOL(kshmem_alloc_at);
+
+/*
+ * Allocate size number of bytes of kshmem, page_flags
+ * should be PAGE_SHARED or PAGE_SHARED_EXEC.
+ *
+ * The resulting pointer will be page aligned and consume at least
+ * on page of memory.
+ */
+void *kshmem_alloc(unsigned long size, pgprot_t page_flags)
+{
+ char *pStart;
+ struct mm_struct *cur_mm;
+
+ /*
+ * Save the current mm and switch to init_mm where we allocate
+ * kshmem memory and then share with all other mm's.
+ */
+ cur_mm = current->mm;
+ current->mm = &init_mm;
+
+ DPK("kshmem_alloc: cur_mm=%p current->mm=%p\n", cur_mm, current->mm);
+
+ /* Do we need to hold the semaphore? */
+ down_write(&init_mm.mmap_sem);
+
+ size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
+ pStart = __vmalloc_at(size,
+ VM_ALLOC | VM_USERMAP | VM_KSHMEM | VM_LOCKED | VM_SHARED,
+ KSHMEM_AREA_ADDR, KSHMEM_AREA_ADDR + KSHMEM_AREA_SIZE,
+ GFP_KERNEL | GFP_DMA, page_flags);
+ BUG_ON(NULL == pStart);
+ _fixate_range(pStart, pStart + size);
+
+ up_write(&init_mm.mmap_sem);
+
+ /*
+ * Restore mm
+ */
+ current->mm = cur_mm;
+
+ return pStart;
+}
+EXPORT_SYMBOL(kshmem_alloc);
+
+/*
+ * Prepare the kernel shared memory of the new_mm
+ */
+int kshmem_prepare(struct mm_struct *new_mm)
+{
+ /**
+ * Set the pgd for the KSHMEM_AREA_ADDR and
+ * point it at the pgd from init_mm.
+ */
+ down_read(&init_mm.mmap_sem);
+ set_pgd(pgd_offset(new_mm, KSHMEM_AREA_ADDR),
+ KSHMEM_USER_DISABLE(*pgd_offset(&init_mm, KSHMEM_AREA_ADDR)));
+ //__pgd(pgd_val(*pgd_offset(&init_mm, KSHMEM_AREA_ADDR)) & ~_PAGE_USER));
+ up_read(&init_mm.mmap_sem);
+
+ return 0;
+}
+EXPORT_SYMBOL(kshmem_prepare);
+
+/*
+ * Disable the kshmem for the current mm
+ */
+void kshmem_user_disable(void)
+{
+ down_read(¤t->active_mm->mmap_sem);
+ set_pgd(pgd_offset(current->active_mm, KSHMEM_AREA_ADDR),
+ KSHMEM_USER_DISABLE(*pgd_offset(&init_mm, KSHMEM_AREA_ADDR)));
+ up_read(¤t->active_mm->mmap_sem);
+}
+
+/*
+ * Enable the kshmem for the current mm
+ */
+void kshmem_user_enable(void)
+{
+ down_read(¤t->active_mm->mmap_sem);
+ set_pgd(pgd_offset(current->active_mm, KSHMEM_AREA_ADDR),
+ KSHMEM_USER_ENABLE(*pgd_offset(&init_mm, KSHMEM_AREA_ADDR)));
+ up_read(¤t->active_mm->mmap_sem);
+}
+
+/*
+ * Convert a vmalloced address to a "kernel" virtual address
+ */
+unsigned long kshmem_addr_to_kvaddr(unsigned long kshmem_addr)
+{
+ struct page *p;
+ unsigned long phys;
+ unsigned long addr;
+
+ p = vmalloc_to_page((unsigned char *)kshmem_addr);
+ phys = page_to_phys(p);
+ addr = (unsigned long)phys_to_virt(phys) + offset_in_page(kshmem_addr);
+
+ return addr;
+}
+EXPORT_SYMBOL(kshmem_addr_to_kvaddr);
+
+/*
+ * Initialize
+ */
+void kshmem_init(void)
+{
+ char *p;
+
+ DPK("kshmem_init E:\n");
+
+ p = kshmem_alloc_at(KSHMEM_AREA_ADDR, PAGE_SIZE, PAGE_SHARED);
+ BUG_ON((unsigned long)p != KSHMEM_AREA_ADDR);
+
+ DPK("kshmem_init X: p=%p\n", p);
+}
+
+
Index: linux-2.6/mm/vmalloc.c
===================================================================
--- linux-2.6.orig/mm/vmalloc.c 2007-04-29 21:51:39.000000000 -0700
+++ linux-2.6/mm/vmalloc.c 2007-04-29 21:52:04.000000000 -0700
@@ -469,8 +469,11 @@
}
/**
- * __vmalloc_node - allocate virtually contiguous memory
+ * __vmalloc_node_at - allocate virtually contiguous memory
* @size: allocation size
+ * @flags: flags for vm area
+ * @start: desired starting location
+ * @end: desired ending location
* @gfp_mask: flags for the page level allocator
* @prot: protection mask for the allocated pages
* @node: node to use for allocation or -1
@@ -479,8 +482,9 @@
* allocator with @gfp_mask flags. Map them into contiguous
* kernel virtual space, using a pagetable protection of @prot.
*/
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
- int node)
+static void *__vmalloc_node_at(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ gfp_t gfp_mask, pgprot_t prot, int node)
{
struct vm_struct *area;
@@ -488,13 +492,38 @@
if (!size || (size >> PAGE_SHIFT) > num_physpages)
return NULL;
- area = get_vm_area_node(size, VM_ALLOC, node, gfp_mask);
+ area = __get_vm_area_node(size, flags, start, end, node, gfp_mask);
if (!area)
return NULL;
return __vmalloc_area_node(area, gfp_mask, prot, node);
}
+void *__vmalloc_at(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ gfp_t gfp_mask, pgprot_t prot)
+{
+ return __vmalloc_node_at(size, flags, start, end, gfp_mask, prot, -1);
+}
+EXPORT_SYMBOL(__vmalloc_at);
+
+/**
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size: allocation size
+ * @gfp_mask: flags for the page level allocator
+ * @prot: protection mask for the allocated pages
+ * @node: node to use for allocation or -1
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags. Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ */
+static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+ int node)
+{
+ return __vmalloc_node_at(size, VM_ALLOC, VMALLOC_START, VMALLOC_END, gfp_mask, prot, node);
+}
+
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
{
return __vmalloc_node(size, gfp_mask, prot, -1);
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2007-05-06 1:53 [PATCH 2/3] kshmem implementation, configuration and makefile Wink Saville
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