diff options
author | Stefani Seibold <stefani@seibold.net> | 2009-12-21 14:37:26 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-22 14:17:55 -0800 |
commit | 45465487897a1c6d508b14b904dc5777f7ec7e04 (patch) | |
tree | 935c8dae68dc793ff2f795d57cf027531475cd53 /drivers/infiniband/hw | |
parent | 2ec91eec47f713e3d158ba5b28a24a85a2cf3650 (diff) |
kfifo: move struct kfifo in place
This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains. Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
- The API is to simple, important functions are missing
- A fifo can be only allocated dynamically
- There is a requirement of a spinlock whether you need it or not
- There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much. The new API has the following benefits:
- Generic usage: For kernel internal use and/or device driver.
- Provide an API for the most use case.
- Slim API: The whole API provides 25 functions.
- Linux style habit.
- DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
- Direct copy_to_user from the fifo and copy_from_user into the fifo.
- The kfifo itself is an in place member of the using data structure, this save an
indirection access and does not waste the kernel allocator.
- Lockless access: if only one reader and one writer is active on the fifo,
which is the common use case, no additional locking is necessary.
- Remove spinlock - give the user the freedom of choice what kind of locking to use if
one is required.
- Ability to handle records. Three type of records are supported:
- Variable length records between 0-255 bytes, with a record size
field of 1 bytes.
- Variable length records between 0-65535 bytes, with a record size
field of 2 bytes.
- Fixed size records, which no record size field.
- Preserve memory resource.
- Performance!
- Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure. This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them. This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/infiniband/hw')
-rw-r--r-- | drivers/infiniband/hw/cxgb3/cxio_hal.h | 9 | ||||
-rw-r--r-- | drivers/infiniband/hw/cxgb3/cxio_resource.c | 60 |
2 files changed, 34 insertions, 35 deletions
diff --git a/drivers/infiniband/hw/cxgb3/cxio_hal.h b/drivers/infiniband/hw/cxgb3/cxio_hal.h index bfd03bf8be5..f3d440cc68f 100644 --- a/drivers/infiniband/hw/cxgb3/cxio_hal.h +++ b/drivers/infiniband/hw/cxgb3/cxio_hal.h @@ -34,6 +34,7 @@ #include <linux/list.h> #include <linux/mutex.h> +#include <linux/kfifo.h> #include "t3_cpl.h" #include "t3cdev.h" @@ -75,13 +76,13 @@ struct cxio_hal_ctrl_qp { }; struct cxio_hal_resource { - struct kfifo *tpt_fifo; + struct kfifo tpt_fifo; spinlock_t tpt_fifo_lock; - struct kfifo *qpid_fifo; + struct kfifo qpid_fifo; spinlock_t qpid_fifo_lock; - struct kfifo *cqid_fifo; + struct kfifo cqid_fifo; spinlock_t cqid_fifo_lock; - struct kfifo *pdid_fifo; + struct kfifo pdid_fifo; spinlock_t pdid_fifo_lock; }; diff --git a/drivers/infiniband/hw/cxgb3/cxio_resource.c b/drivers/infiniband/hw/cxgb3/cxio_resource.c index bd233c08765..65072bdfc1b 100644 --- a/drivers/infiniband/hw/cxgb3/cxio_resource.c +++ b/drivers/infiniband/hw/cxgb3/cxio_resource.c @@ -39,12 +39,12 @@ #include "cxio_resource.h" #include "cxio_hal.h" -static struct kfifo *rhdl_fifo; +static struct kfifo rhdl_fifo; static spinlock_t rhdl_fifo_lock; #define RANDOM_SIZE 16 -static int __cxio_init_resource_fifo(struct kfifo **fifo, +static int __cxio_init_resource_fifo(struct kfifo *fifo, spinlock_t *fifo_lock, u32 nr, u32 skip_low, u32 skip_high, @@ -55,12 +55,11 @@ static int __cxio_init_resource_fifo(struct kfifo **fifo, u32 rarray[16]; spin_lock_init(fifo_lock); - *fifo = kfifo_alloc(nr * sizeof(u32), GFP_KERNEL, fifo_lock); - if (IS_ERR(*fifo)) + if (kfifo_alloc(fifo, nr * sizeof(u32), GFP_KERNEL, fifo_lock)) return -ENOMEM; for (i = 0; i < skip_low + skip_high; i++) - __kfifo_put(*fifo, (unsigned char *) &entry, sizeof(u32)); + __kfifo_put(fifo, (unsigned char *) &entry, sizeof(u32)); if (random) { j = 0; random_bytes = random32(); @@ -72,33 +71,33 @@ static int __cxio_init_resource_fifo(struct kfifo **fifo, random_bytes = random32(); } idx = (random_bytes >> (j * 2)) & 0xF; - __kfifo_put(*fifo, + __kfifo_put(fifo, (unsigned char *) &rarray[idx], sizeof(u32)); rarray[idx] = i; j++; } for (i = 0; i < RANDOM_SIZE; i++) - __kfifo_put(*fifo, + __kfifo_put(fifo, (unsigned char *) &rarray[i], sizeof(u32)); } else for (i = skip_low; i < nr - skip_high; i++) - __kfifo_put(*fifo, (unsigned char *) &i, sizeof(u32)); + __kfifo_put(fifo, (unsigned char *) &i, sizeof(u32)); for (i = 0; i < skip_low + skip_high; i++) - kfifo_get(*fifo, (unsigned char *) &entry, sizeof(u32)); + kfifo_get(fifo, (unsigned char *) &entry, sizeof(u32)); return 0; } -static int cxio_init_resource_fifo(struct kfifo **fifo, spinlock_t * fifo_lock, +static int cxio_init_resource_fifo(struct kfifo *fifo, spinlock_t * fifo_lock, u32 nr, u32 skip_low, u32 skip_high) { return (__cxio_init_resource_fifo(fifo, fifo_lock, nr, skip_low, skip_high, 0)); } -static int cxio_init_resource_fifo_random(struct kfifo **fifo, +static int cxio_init_resource_fifo_random(struct kfifo *fifo, spinlock_t * fifo_lock, u32 nr, u32 skip_low, u32 skip_high) { @@ -113,15 +112,14 @@ static int cxio_init_qpid_fifo(struct cxio_rdev *rdev_p) spin_lock_init(&rdev_p->rscp->qpid_fifo_lock); - rdev_p->rscp->qpid_fifo = kfifo_alloc(T3_MAX_NUM_QP * sizeof(u32), + if (kfifo_alloc(&rdev_p->rscp->qpid_fifo, T3_MAX_NUM_QP * sizeof(u32), GFP_KERNEL, - &rdev_p->rscp->qpid_fifo_lock); - if (IS_ERR(rdev_p->rscp->qpid_fifo)) + &rdev_p->rscp->qpid_fifo_lock)) return -ENOMEM; for (i = 16; i < T3_MAX_NUM_QP; i++) if (!(i & rdev_p->qpmask)) - __kfifo_put(rdev_p->rscp->qpid_fifo, + __kfifo_put(&rdev_p->rscp->qpid_fifo, (unsigned char *) &i, sizeof(u32)); return 0; } @@ -134,7 +132,7 @@ int cxio_hal_init_rhdl_resource(u32 nr_rhdl) void cxio_hal_destroy_rhdl_resource(void) { - kfifo_free(rhdl_fifo); + kfifo_free(&rhdl_fifo); } /* nr_* must be power of 2 */ @@ -167,11 +165,11 @@ int cxio_hal_init_resource(struct cxio_rdev *rdev_p, goto pdid_err; return 0; pdid_err: - kfifo_free(rscp->cqid_fifo); + kfifo_free(&rscp->cqid_fifo); cqid_err: - kfifo_free(rscp->qpid_fifo); + kfifo_free(&rscp->qpid_fifo); qpid_err: - kfifo_free(rscp->tpt_fifo); + kfifo_free(&rscp->tpt_fifo); tpt_err: return -ENOMEM; } @@ -195,17 +193,17 @@ static void cxio_hal_put_resource(struct kfifo *fifo, u32 entry) u32 cxio_hal_get_stag(struct cxio_hal_resource *rscp) { - return cxio_hal_get_resource(rscp->tpt_fifo); + return cxio_hal_get_resource(&rscp->tpt_fifo); } void cxio_hal_put_stag(struct cxio_hal_resource *rscp, u32 stag) { - cxio_hal_put_resource(rscp->tpt_fifo, stag); + cxio_hal_put_resource(&rscp->tpt_fifo, stag); } u32 cxio_hal_get_qpid(struct cxio_hal_resource *rscp) { - u32 qpid = cxio_hal_get_resource(rscp->qpid_fifo); + u32 qpid = cxio_hal_get_resource(&rscp->qpid_fifo); PDBG("%s qpid 0x%x\n", __func__, qpid); return qpid; } @@ -213,35 +211,35 @@ u32 cxio_hal_get_qpid(struct cxio_hal_resource *rscp) void cxio_hal_put_qpid(struct cxio_hal_resource *rscp, u32 qpid) { PDBG("%s qpid 0x%x\n", __func__, qpid); - cxio_hal_put_resource(rscp->qpid_fifo, qpid); + cxio_hal_put_resource(&rscp->qpid_fifo, qpid); } u32 cxio_hal_get_cqid(struct cxio_hal_resource *rscp) { - return cxio_hal_get_resource(rscp->cqid_fifo); + return cxio_hal_get_resource(&rscp->cqid_fifo); } void cxio_hal_put_cqid(struct cxio_hal_resource *rscp, u32 cqid) { - cxio_hal_put_resource(rscp->cqid_fifo, cqid); + cxio_hal_put_resource(&rscp->cqid_fifo, cqid); } u32 cxio_hal_get_pdid(struct cxio_hal_resource *rscp) { - return cxio_hal_get_resource(rscp->pdid_fifo); + return cxio_hal_get_resource(&rscp->pdid_fifo); } void cxio_hal_put_pdid(struct cxio_hal_resource *rscp, u32 pdid) { - cxio_hal_put_resource(rscp->pdid_fifo, pdid); + cxio_hal_put_resource(&rscp->pdid_fifo, pdid); } void cxio_hal_destroy_resource(struct cxio_hal_resource *rscp) { - kfifo_free(rscp->tpt_fifo); - kfifo_free(rscp->cqid_fifo); - kfifo_free(rscp->qpid_fifo); - kfifo_free(rscp->pdid_fifo); + kfifo_free(&rscp->tpt_fifo); + kfifo_free(&rscp->cqid_fifo); + kfifo_free(&rscp->qpid_fifo); + kfifo_free(&rscp->pdid_fifo); kfree(rscp); } |