mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and...

[deliverable/linux.git] / drivers / staging / lustre / include / linux / libcfs / libcfs_private.h

/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * libcfs/include/libcfs/libcfs_private.h
 *
 * Various defines for libcfs.
 *
 */

#ifndef __LIBCFS_PRIVATE_H__
#define __LIBCFS_PRIVATE_H__

#ifndef DEBUG_SUBSYSTEM
# define DEBUG_SUBSYSTEM S_UNDEFINED
#endif

/*
 * When this is on, LASSERT macro includes check for assignment used instead
 * of equality check, but doesn't have unlikely(). Turn this on from time to
 * time to make test-builds. This shouldn't be on for production release.
 */
#define LASSERT_CHECKED (0)

#define LASSERTF(cond, fmt, ...)                                        \
do {                                                                    \
        if (unlikely(!(cond))) {                                        \
                LIBCFS_DEBUG_MSG_DATA_DECL(__msg_data, D_EMERG, NULL);  \
                libcfs_debug_msg(&__msg_data,                           \
                                 "ASSERTION( %s ) failed: " fmt, #cond, \
                                 ## __VA_ARGS__);                       \
                lbug_with_loc(&__msg_data);                             \
        }                                                               \
} while (0)

#define LASSERT(cond) LASSERTF(cond, "\n")

#ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
/**
 * This is for more expensive checks that one doesn't want to be enabled all
 * the time. LINVRNT() has to be explicitly enabled by
 * CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK option.
 */
# define LINVRNT(exp) LASSERT(exp)
#else
# define LINVRNT(exp) ((void)sizeof !!(exp))
#endif

#define KLASSERT(e) LASSERT(e)

void __noreturn lbug_with_loc(struct libcfs_debug_msg_data *);

#define LBUG()                                                    \
do {                                                                \
        LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_EMERG, NULL);          \
        lbug_with_loc(&msgdata);                                        \
} while (0)

#ifndef LIBCFS_VMALLOC_SIZE
#define LIBCFS_VMALLOC_SIZE     (2 << PAGE_CACHE_SHIFT) /* 2 pages */
#endif

#define LIBCFS_ALLOC_PRE(size, mask)                                        \
do {                                                                        \
        LASSERT(!in_interrupt() ||                                          \
                ((size) <= LIBCFS_VMALLOC_SIZE &&                           \
                 !gfpflags_allow_blocking(mask)));                          \
} while (0)

#define LIBCFS_ALLOC_POST(ptr, size)                                        \
do {                                                                        \
        if (unlikely((ptr) == NULL)) {                                      \
                CERROR("LNET: out of memory at %s:%d (tried to alloc '"     \
                       #ptr "' = %d)\n", __FILE__, __LINE__, (int)(size));  \
        } else {                                                            \
                memset((ptr), 0, (size));                                   \
        }                                                                   \
} while (0)

/**
 * allocate memory with GFP flags @mask
 */
#define LIBCFS_ALLOC_GFP(ptr, size, mask)                                   \
do {                                                                        \
        LIBCFS_ALLOC_PRE((size), (mask));                                   \
        (ptr) = (size) <= LIBCFS_VMALLOC_SIZE ?                             \
                kmalloc((size), (mask)) : vmalloc(size);            \
        LIBCFS_ALLOC_POST((ptr), (size));                                   \
} while (0)

/**
 * default allocator
 */
#define LIBCFS_ALLOC(ptr, size) \
        LIBCFS_ALLOC_GFP(ptr, size, GFP_NOFS)

/**
 * non-sleeping allocator
 */
#define LIBCFS_ALLOC_ATOMIC(ptr, size) \
        LIBCFS_ALLOC_GFP(ptr, size, GFP_ATOMIC)

/**
 * allocate memory for specified CPU partition
 *   \a cptab != NULL, \a cpt is CPU partition id of \a cptab
 *   \a cptab == NULL, \a cpt is HW NUMA node id
 */
#define LIBCFS_CPT_ALLOC_GFP(ptr, cptab, cpt, size, mask)                   \
do {                                                                        \
        LIBCFS_ALLOC_PRE((size), (mask));                                   \
        (ptr) = (size) <= LIBCFS_VMALLOC_SIZE ?                             \
                kmalloc_node((size), (mask), cfs_cpt_spread_node(cptab, cpt)) :\
                vmalloc_node(size, cfs_cpt_spread_node(cptab, cpt));        \
        LIBCFS_ALLOC_POST((ptr), (size));                                   \
} while (0)

/** default numa allocator */
#define LIBCFS_CPT_ALLOC(ptr, cptab, cpt, size)                             \
        LIBCFS_CPT_ALLOC_GFP(ptr, cptab, cpt, size, GFP_NOFS)

#define LIBCFS_FREE(ptr, size)                                    \
do {                                                                \
        int s = (size);                                          \
        if (unlikely((ptr) == NULL)) {                            \
                CERROR("LIBCFS: free NULL '" #ptr "' (%d bytes) at "    \
                       "%s:%d\n", s, __FILE__, __LINE__);              \
                break;                                            \
        }                                                              \
        if (unlikely(s > LIBCFS_VMALLOC_SIZE))                    \
                vfree(ptr);                                 \
        else                                                        \
                kfree(ptr);                                       \
} while (0)

/******************************************************************************/

/* htonl hack - either this, or compile with -O2. Stupid byteorder/generic.h */
#if defined(__GNUC__) && (__GNUC__ >= 2) && !defined(__OPTIMIZE__)
#define ___htonl(x) __cpu_to_be32(x)
#define ___htons(x) __cpu_to_be16(x)
#define ___ntohl(x) __be32_to_cpu(x)
#define ___ntohs(x) __be16_to_cpu(x)
#define htonl(x) ___htonl(x)
#define ntohl(x) ___ntohl(x)
#define htons(x) ___htons(x)
#define ntohs(x) ___ntohs(x)
#endif

void libcfs_run_upcall(char **argv);
void libcfs_run_lbug_upcall(struct libcfs_debug_msg_data *);
void libcfs_debug_dumplog(void);
int libcfs_debug_init(unsigned long bufsize);
int libcfs_debug_cleanup(void);
int libcfs_debug_clear_buffer(void);
int libcfs_debug_mark_buffer(const char *text);

void libcfs_debug_set_level(unsigned int debug_level);

/*
 * allocate per-cpu-partition data, returned value is an array of pointers,
 * variable can be indexed by CPU ID.
 *      cptable != NULL: size of array is number of CPU partitions
 *      cptable == NULL: size of array is number of HW cores
 */
void *cfs_percpt_alloc(struct cfs_cpt_table *cptab, unsigned int size);
/*
 * destroy per-cpu-partition variable
 */
void  cfs_percpt_free(void *vars);
int   cfs_percpt_number(void *vars);
void *cfs_percpt_current(void *vars);
void *cfs_percpt_index(void *vars, int idx);

#define cfs_percpt_for_each(var, i, vars)               \
        for (i = 0; i < cfs_percpt_number(vars) &&      \
                    ((var) = (vars)[i]) != NULL; i++)

/*
 * allocate a variable array, returned value is an array of pointers.
 * Caller can specify length of array by count.
 */
void *cfs_array_alloc(int count, unsigned int size);
void  cfs_array_free(void *vars);

#define LASSERT_ATOMIC_ENABLED    (1)

#if LASSERT_ATOMIC_ENABLED

/** assert value of @a is equal to @v */
#define LASSERT_ATOMIC_EQ(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) == v,                  \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is unequal to @v */
#define LASSERT_ATOMIC_NE(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) != v,                  \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is little than @v */
#define LASSERT_ATOMIC_LT(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) < v,                    \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is little/equal to @v */
#define LASSERT_ATOMIC_LE(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) <= v,                  \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is great than @v */
#define LASSERT_ATOMIC_GT(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) > v,                    \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is great/equal to @v */
#define LASSERT_ATOMIC_GE(a, v)                          \
do {                                                        \
        LASSERTF(atomic_read(a) >= v,                  \
                 "value: %d\n", atomic_read((a)));        \
} while (0)

/** assert value of @a is great than @v1 and little than @v2 */
#define LASSERT_ATOMIC_GT_LT(a, v1, v2)                  \
do {                                                        \
        int __v = atomic_read(a);                          \
        LASSERTF(__v > v1 && __v < v2, "value: %d\n", __v);     \
} while (0)

/** assert value of @a is great than @v1 and little/equal to @v2 */
#define LASSERT_ATOMIC_GT_LE(a, v1, v2)                  \
do {                                                        \
        int __v = atomic_read(a);                          \
        LASSERTF(__v > v1 && __v <= v2, "value: %d\n", __v);    \
} while (0)

/** assert value of @a is great/equal to @v1 and little than @v2 */
#define LASSERT_ATOMIC_GE_LT(a, v1, v2)                  \
do {                                                        \
        int __v = atomic_read(a);                          \
        LASSERTF(__v >= v1 && __v < v2, "value: %d\n", __v);    \
} while (0)

/** assert value of @a is great/equal to @v1 and little/equal to @v2 */
#define LASSERT_ATOMIC_GE_LE(a, v1, v2)                  \
do {                                                        \
        int __v = atomic_read(a);                          \
        LASSERTF(__v >= v1 && __v <= v2, "value: %d\n", __v);   \
} while (0)

#else /* !LASSERT_ATOMIC_ENABLED */

#define LASSERT_ATOMIC_EQ(a, v)          do {} while (0)
#define LASSERT_ATOMIC_NE(a, v)          do {} while (0)
#define LASSERT_ATOMIC_LT(a, v)          do {} while (0)
#define LASSERT_ATOMIC_LE(a, v)          do {} while (0)
#define LASSERT_ATOMIC_GT(a, v)          do {} while (0)
#define LASSERT_ATOMIC_GE(a, v)          do {} while (0)
#define LASSERT_ATOMIC_GT_LT(a, v1, v2)  do {} while (0)
#define LASSERT_ATOMIC_GT_LE(a, v1, v2)  do {} while (0)
#define LASSERT_ATOMIC_GE_LT(a, v1, v2)  do {} while (0)
#define LASSERT_ATOMIC_GE_LE(a, v1, v2)  do {} while (0)

#endif /* LASSERT_ATOMIC_ENABLED */

#define LASSERT_ATOMIC_ZERO(a)            LASSERT_ATOMIC_EQ(a, 0)
#define LASSERT_ATOMIC_POS(a)              LASSERT_ATOMIC_GT(a, 0)

#define CFS_ALLOC_PTR(ptr)      LIBCFS_ALLOC(ptr, sizeof(*(ptr)))
#define CFS_FREE_PTR(ptr)       LIBCFS_FREE(ptr, sizeof(*(ptr)))

/*
 * percpu partition lock
 *
 * There are some use-cases like this in Lustre:
 * . each CPU partition has it's own private data which is frequently changed,
 *   and mostly by the local CPU partition.
 * . all CPU partitions share some global data, these data are rarely changed.
 *
 * LNet is typical example.
 * CPU partition lock is designed for this kind of use-cases:
 * . each CPU partition has it's own private lock
 * . change on private data just needs to take the private lock
 * . read on shared data just needs to take _any_ of private locks
 * . change on shared data needs to take _all_ private locks,
 *   which is slow and should be really rare.
 */

enum {
        CFS_PERCPT_LOCK_EX      = -1, /* negative */
};

struct cfs_percpt_lock {
        /* cpu-partition-table for this lock */
        struct cfs_cpt_table    *pcl_cptab;
        /* exclusively locked */
        unsigned int            pcl_locked;
        /* private lock table */
        spinlock_t              **pcl_locks;
};

/* return number of private locks */
static inline int
cfs_percpt_lock_num(struct cfs_percpt_lock *pcl)
{
        return cfs_cpt_number(pcl->pcl_cptab);
}

/*
 * create a cpu-partition lock based on CPU partition table \a cptab,
 * each private lock has extra \a psize bytes padding data
 */
struct cfs_percpt_lock *cfs_percpt_lock_alloc(struct cfs_cpt_table *cptab);
/* destroy a cpu-partition lock */
void cfs_percpt_lock_free(struct cfs_percpt_lock *pcl);

/* lock private lock \a index of \a pcl */
void cfs_percpt_lock(struct cfs_percpt_lock *pcl, int index);
/* unlock private lock \a index of \a pcl */
void cfs_percpt_unlock(struct cfs_percpt_lock *pcl, int index);
/* create percpt (atomic) refcount based on @cptab */
atomic_t **cfs_percpt_atomic_alloc(struct cfs_cpt_table *cptab, int val);
/* destroy percpt refcount */
void cfs_percpt_atomic_free(atomic_t **refs);
/* return sum of all percpu refs */
int cfs_percpt_atomic_summary(atomic_t **refs);

/** Compile-time assertion.

 * Check an invariant described by a constant expression at compile time by
 * forcing a compiler error if it does not hold.  \a cond must be a constant
 * expression as defined by the ISO C Standard:
 *
 *       6.8.4.2  The switch statement
 *       ....
 *       [#3] The expression of each case label shall be  an  integer
 *       constant   expression  and  no  two  of  the  case  constant
 *       expressions in the same switch statement shall have the same
 *       value  after  conversion...
 *
 */
#define CLASSERT(cond) do {switch (42) {case (cond): case 0: break; } } while (0)

/* max value for numeric network address */
#define MAX_NUMERIC_VALUE 0xffffffff

/* implication */
#define ergo(a, b) (!(a) || (b))
/* logical equivalence */
#define equi(a, b) (!!(a) == !!(b))

/* --------------------------------------------------------------------
 * Light-weight trace
 * Support for temporary event tracing with minimal Heisenberg effect.
 * -------------------------------------------------------------------- */

struct libcfs_device_userstate {
        int        ldu_memhog_pages;
        struct page   *ldu_memhog_root_page;
};

#define MKSTR(ptr) ((ptr)) ? (ptr) : ""

static inline int cfs_size_round4(int val)
{
        return (val + 3) & (~0x3);
}

#ifndef HAVE_CFS_SIZE_ROUND
static inline int cfs_size_round(int val)
{
        return (val + 7) & (~0x7);
}

#define HAVE_CFS_SIZE_ROUND
#endif

static inline int cfs_size_round16(int val)
{
        return (val + 0xf) & (~0xf);
}

static inline int cfs_size_round32(int val)
{
        return (val + 0x1f) & (~0x1f);
}

static inline int cfs_size_round0(int val)
{
        if (!val)
                return 0;
        return (val + 1 + 7) & (~0x7);
}

static inline size_t cfs_round_strlen(char *fset)
{
        return (size_t)cfs_size_round((int)strlen(fset) + 1);
}

#define LOGL(var, len, ptr)                                    \
do {                                                        \
        if (var)                                                \
                memcpy((char *)ptr, (const char *)var, len);    \
        ptr += cfs_size_round(len);                          \
} while (0)

#define LOGU(var, len, ptr)                                    \
do {                                                        \
        if (var)                                                \
                memcpy((char *)var, (const char *)ptr, len);    \
        ptr += cfs_size_round(len);                          \
} while (0)

#define LOGL0(var, len, ptr)                          \
do {                                                \
        if (!len)                                      \
                break;                            \
        memcpy((char *)ptr, (const char *)var, len);    \
        *((char *)(ptr) + len) = 0;                  \
        ptr += cfs_size_round(len + 1);          \
} while (0)

#endif