kern/slab: move internal data to slab_i.h

As it's done for other modules, this separation makes the public interface
easy to identify.

1 files changed, 220 insertions, 0 deletions

diff --git a/kern/slab_i.h b/kern/slab_i.h
new file mode 100644
index 0000000..a609efb
--- /dev/null
+++ b/kern/slab_i.h
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2010, 2011, 2012, 2013 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _KERN_KMEM_I_H
+#define _KERN_KMEM_I_H
+
+#include <kern/list.h>
+#include <kern/lock.h>
+
+#if SLAB_USE_CPU_POOLS
+/*
+ * L1 cache line size.
+ */
+#define CPU_L1_SIZE (1 << CPU_L1_SHIFT)
+
+/*
+ * Per-processor cache of pre-constructed objects.
+ *
+ * The flags member is a read-only CPU-local copy of the parent cache flags.
+ */
+struct kmem_cpu_pool {
+    simple_lock_data_t lock;
+    int flags;
+    int size;
+    int transfer_size;
+    int nr_objs;
+    void **array;
+} __aligned(CPU_L1_SIZE);
+
+/*
+ * When a cache is created, its CPU pool type is determined from the buffer
+ * size. For small buffer sizes, many objects can be cached in a CPU pool.
+ * Conversely, for large buffer sizes, this would incur much overhead, so only
+ * a few objects are stored in a CPU pool.
+ */
+struct kmem_cpu_pool_type {
+    size_t buf_size;
+    int array_size;
+    size_t array_align;
+    struct kmem_cache *array_cache;
+};
+#endif /* SLAB_USE_CPU_POOLS */
+
+/*
+ * Buffer descriptor.
+ *
+ * For normal caches (i.e. without KMEM_CF_VERIFY), bufctls are located at the
+ * end of (but inside) each buffer. If KMEM_CF_VERIFY is set, bufctls are
+ * located after each buffer.
+ *
+ * When an object is allocated to a client, its bufctl isn't used. This memory
+ * is instead used for redzoning if cache debugging is in effect.
+ */
+union kmem_bufctl {
+    union kmem_bufctl *next;
+    unsigned long redzone;
+};
+
+/*
+ * Redzone guard word.
+ */
+#ifdef __LP64__
+#ifdef _HOST_BIG_ENDIAN
+#define KMEM_REDZONE_WORD 0xfeedfacefeedfaceUL
+#else /* _HOST_BIG_ENDIAN */
+#define KMEM_REDZONE_WORD 0xcefaedfecefaedfeUL
+#endif /* _HOST_BIG_ENDIAN */
+#else /* __LP64__ */
+#ifdef _HOST_BIG_ENDIAN
+#define KMEM_REDZONE_WORD 0xfeedfaceUL
+#else /* _HOST_BIG_ENDIAN */
+#define KMEM_REDZONE_WORD 0xcefaedfeUL
+#endif /* _HOST_BIG_ENDIAN */
+#endif /* __LP64__ */
+
+/*
+ * Redzone byte for padding.
+ */
+#define KMEM_REDZONE_BYTE 0xbb
+
+/*
+ * Buffer tag.
+ *
+ * This structure is only used for KMEM_CF_VERIFY caches. It is located after
+ * the bufctl and includes information about the state of the buffer it
+ * describes (allocated or not). It should be thought of as a debugging
+ * extension of the bufctl.
+ */
+struct kmem_buftag {
+    unsigned long state;
+};
+
+/*
+ * Values the buftag state member can take.
+ */
+#ifdef __LP64__
+#ifdef _HOST_BIG_ENDIAN
+#define KMEM_BUFTAG_ALLOC   0xa110c8eda110c8edUL
+#define KMEM_BUFTAG_FREE    0xf4eeb10cf4eeb10cUL
+#else /* _HOST_BIG_ENDIAN */
+#define KMEM_BUFTAG_ALLOC   0xedc810a1edc810a1UL
+#define KMEM_BUFTAG_FREE    0x0cb1eef40cb1eef4UL
+#endif /* _HOST_BIG_ENDIAN */
+#else /* __LP64__ */
+#ifdef _HOST_BIG_ENDIAN
+#define KMEM_BUFTAG_ALLOC   0xa110c8edUL
+#define KMEM_BUFTAG_FREE    0xf4eeb10cUL
+#else /* _HOST_BIG_ENDIAN */
+#define KMEM_BUFTAG_ALLOC   0xedc810a1UL
+#define KMEM_BUFTAG_FREE    0x0cb1eef4UL
+#endif /* _HOST_BIG_ENDIAN */
+#endif /* __LP64__ */
+
+/*
+ * Free and uninitialized patterns.
+ *
+ * These values are unconditionnally 64-bit wide since buffers are at least
+ * 8-byte aligned.
+ */
+#ifdef _HOST_BIG_ENDIAN
+#define KMEM_FREE_PATTERN   0xdeadbeefdeadbeefULL
+#define KMEM_UNINIT_PATTERN 0xbaddcafebaddcafeULL
+#else /* _HOST_BIG_ENDIAN */
+#define KMEM_FREE_PATTERN   0xefbeaddeefbeaddeULL
+#define KMEM_UNINIT_PATTERN 0xfecaddbafecaddbaULL
+#endif /* _HOST_BIG_ENDIAN */
+
+/*
+ * Page-aligned collection of unconstructed buffers.
+ *
+ * This structure is either allocated from the slab cache, or, when internal
+ * fragmentation allows it, or if forced by the cache creator, from the slab
+ * it describes.
+ */
+struct kmem_slab {
+    struct list node;
+    unsigned long nr_refs;
+    union kmem_bufctl *first_free;
+    void *addr;
+};
+
+/*
+ * Cache name buffer size.  The size is chosen so that struct
+ * kmem_cache fits into two cache lines.  The size of a cache line on
+ * a typical CPU is 64 bytes.
+ */
+#define KMEM_CACHE_NAME_SIZE 24
+
+/*
+ * Cache flags.
+ *
+ * The flags don't change once set and can be tested without locking.
+ */
+#define KMEM_CF_NO_CPU_POOL     0x1 /* CPU pool layer disabled */
+#define KMEM_CF_SLAB_EXTERNAL   0x2 /* Slab data is off slab */
+#define KMEM_CF_VERIFY          0x4 /* Debugging facilities enabled */
+#define KMEM_CF_DIRECT          0x8 /* Quick buf-to-slab lookup */
+
+/*
+ * Cache of objects.
+ *
+ * Locking order : cpu_pool -> cache. CPU pools locking is ordered by CPU ID.
+ *
+ * The partial slabs list is sorted by slab references. Slabs with a high
+ * number of references are placed first on the list to reduce fragmentation.
+ * Sorting occurs at insertion/removal of buffers in a slab. As the list
+ * is maintained sorted, and the number of references only changes by one,
+ * this is a very cheap operation in the average case and the worst (linear)
+ * case is very unlikely.
+ */
+struct kmem_cache {
+#if SLAB_USE_CPU_POOLS
+    /* CPU pool layer */
+    struct kmem_cpu_pool cpu_pools[NCPUS];
+    struct kmem_cpu_pool_type *cpu_pool_type;
+#endif /* SLAB_USE_CPU_POOLS */
+
+    /* Slab layer */
+    simple_lock_data_t lock;
+    struct list node;   /* Cache list linkage */
+    struct list partial_slabs;
+    struct list free_slabs;
+    int flags;
+    size_t bufctl_dist; /* Distance from buffer to bufctl   */
+    size_t slab_size;
+    unsigned long bufs_per_slab;
+    unsigned long nr_objs;  /* Number of allocated objects */
+    unsigned long nr_free_slabs;
+    kmem_cache_ctor_t ctor;
+    /* All fields below are cold  */
+    size_t obj_size;    /* User-provided size */
+    /* Assuming ! SLAB_USE_CPU_POOLS, here is the cacheline boundary */
+    size_t align;
+    size_t buf_size;    /* Aligned object size  */
+    size_t color;
+    size_t color_max;
+    unsigned long nr_bufs;  /* Total number of buffers */
+    unsigned long nr_slabs;
+    kmem_slab_alloc_fn_t slab_alloc_fn;
+    kmem_slab_free_fn_t slab_free_fn;
+    char name[KMEM_CACHE_NAME_SIZE];
+    size_t buftag_dist; /* Distance from buffer to buftag */
+    size_t redzone_pad; /* Bytes from end of object to redzone word */
+} __cacheline_aligned;
+
+#endif /* _KERN_KMEM_I_H */