[PATCH 2/3] zsmalloc: add generic path and remove x86 dependency
From: Seth Jennings
Date: Mon Jun 25 2012 - 12:28:30 EST
This patch adds generic pages mapping methods that
work on all archs in the absence of support for
local_tlb_flush_kernel_range() advertised by the
arch through __HAVE_LOCAL_TLB_FLUSH_KERNEL_RANGE
Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>
---
drivers/staging/zsmalloc/Kconfig | 4 -
drivers/staging/zsmalloc/zsmalloc-main.c | 136 ++++++++++++++++++++++++------
drivers/staging/zsmalloc/zsmalloc_int.h | 5 +-
3 files changed, 115 insertions(+), 30 deletions(-)
diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig
index a5ab720..9084565 100644
--- a/drivers/staging/zsmalloc/Kconfig
+++ b/drivers/staging/zsmalloc/Kconfig
@@ -1,9 +1,5 @@
config ZSMALLOC
tristate "Memory allocator for compressed pages"
- # X86 dependency is because of the use of __flush_tlb_one and set_pte
- # in zsmalloc-main.c.
- # TODO: convert these to portable functions
- depends on X86
default n
help
zsmalloc is a slab-based memory allocator designed to store
diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 10b0d60..14f04d8 100644
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/drivers/staging/zsmalloc/zsmalloc-main.c
@@ -470,28 +470,116 @@ static struct page *find_get_zspage(struct size_class *class)
return page;
}
+#ifdef __HAVE_LOCAL_FLUSH_TLB_KERNEL_RANGE
+static inline int zs_arch_cpu_up(struct mapping_area *area)
+{
+ if (area->vm)
+ return 0;
+ area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL);
+ if (!area->vm)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void zs_arch_cpu_down(struct mapping_area *area)
+{
+ if (area->vm)
+ free_vm_area(area->vm);
+ area->vm = NULL;
+}
+
+static inline void zs_arch_map_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, &pages));
+ area->vm_addr = area->vm->addr;
+}
+
+static inline void zs_arch_unmap_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ unsigned long addr = (unsigned long)area->vm_addr;
+ unsigned long end = addr + (PAGE_SIZE * 2);
+
+ flush_cache_vunmap(addr, end);
+ unmap_kernel_range_noflush(addr, PAGE_SIZE * 2);
+ local_flush_tlb_kernel_range(addr, end);
+}
+#else
+static inline int zs_arch_cpu_up(struct mapping_area *area)
+{
+ if (area->vm_buf)
+ return 0;
+ area->vm_buf = (char *)__get_free_pages(GFP_KERNEL, 1);
+ if (!area->vm_buf)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void zs_arch_cpu_down(struct mapping_area *area)
+{
+ if (area->vm_buf)
+ free_pages((unsigned long)area->vm_buf, 1);
+ area->vm_buf = NULL;
+}
+
+static void zs_arch_map_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ int sizes[2];
+ char *buf = area->vm_buf + off;
+ void *addr;
+
+ sizes[0] = PAGE_SIZE - off;
+ sizes[1] = size - sizes[0];
+
+ /* copy object to temp buffer */
+ addr = kmap_atomic(pages[0]);
+ memcpy(buf, addr + off, sizes[0]);
+ kunmap_atomic(addr);
+ addr = kmap_atomic(pages[1]);
+ memcpy(buf + sizes[0], addr, sizes[1]);
+ kunmap_atomic(addr);
+ area->vm_addr = area->vm_buf;
+}
+
+static void zs_arch_unmap_object(struct mapping_area *area,
+ struct page *pages[2], int off, int size)
+{
+ int sizes[2];
+ char *buf = area->vm_buf + off;
+ void *addr;
+
+ sizes[0] = PAGE_SIZE - off;
+ sizes[1] = size - sizes[0];
+
+ /* copy temp buffer to obj*/
+ addr = kmap_atomic(pages[0]);
+ memcpy(addr + off, buf, sizes[0]);
+ kunmap_atomic(addr);
+ addr = kmap_atomic(pages[1]);
+ memcpy(addr, buf + sizes[0], sizes[1]);
+ kunmap_atomic(addr);
+}
+#endif
static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action,
void *pcpu)
{
- int cpu = (long)pcpu;
+ int ret, cpu = (long)pcpu;
struct mapping_area *area;
switch (action) {
case CPU_UP_PREPARE:
area = &per_cpu(zs_map_area, cpu);
- if (area->vm)
- break;
- area->vm = alloc_vm_area(2 * PAGE_SIZE, area->vm_ptes);
- if (!area->vm)
- return notifier_from_errno(-ENOMEM);
+ ret = zs_arch_cpu_up(area);
+ if (ret)
+ return notifier_from_errno(ret);
break;
case CPU_DEAD:
case CPU_UP_CANCELED:
area = &per_cpu(zs_map_area, cpu);
- if (area->vm)
- free_vm_area(area->vm);
- area->vm = NULL;
+ zs_arch_cpu_down(area);
break;
}
@@ -716,19 +804,14 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle)
area->vm_addr = kmap_atomic(page);
} else {
/* this object spans two pages */
- struct page *nextp;
-
- nextp = get_next_page(page);
- BUG_ON(!nextp);
+ struct page *pages[2];
+ pages[0] = page;
+ pages[1] = get_next_page(page);
+ BUG_ON(!pages[1]);
- set_pte(area->vm_ptes[0], mk_pte(page, PAGE_KERNEL));
- set_pte(area->vm_ptes[1], mk_pte(nextp, PAGE_KERNEL));
-
- /* We pre-allocated VM area so mapping can never fail */
- area->vm_addr = area->vm->addr;
+ zs_arch_map_object(area, pages, off, class->size);
}
-
return area->vm_addr + off;
}
EXPORT_SYMBOL_GPL(zs_map_object);
@@ -751,13 +834,16 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
off = obj_idx_to_offset(page, obj_idx, class->size);
area = &__get_cpu_var(zs_map_area);
- if (off + class->size <= PAGE_SIZE) {
+ if (off + class->size <= PAGE_SIZE)
kunmap_atomic(area->vm_addr);
- } else {
- set_pte(area->vm_ptes[0], __pte(0));
- set_pte(area->vm_ptes[1], __pte(0));
- __flush_tlb_one((unsigned long)area->vm_addr);
- __flush_tlb_one((unsigned long)area->vm_addr + PAGE_SIZE);
+ else {
+ struct page *pages[2];
+
+ pages[0] = page;
+ pages[1] = get_next_page(page);
+ BUG_ON(!pages[1]);
+
+ zs_arch_unmap_object(area, pages, off, class->size);
}
put_cpu_var(zs_map_area);
}
diff --git a/drivers/staging/zsmalloc/zsmalloc_int.h b/drivers/staging/zsmalloc/zsmalloc_int.h
index 6fd32a9..8a6887e 100644
--- a/drivers/staging/zsmalloc/zsmalloc_int.h
+++ b/drivers/staging/zsmalloc/zsmalloc_int.h
@@ -110,8 +110,11 @@ enum fullness_group {
static const int fullness_threshold_frac = 4;
struct mapping_area {
+#ifdef __HAVE_LOCAL_FLUSH_TLB_KERNEL_RANGE
struct vm_struct *vm;
- pte_t *vm_ptes[2];
+#else
+ char *vm_buf;
+#endif
char *vm_addr;
};
--
1.7.9.5
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