From 45465487897a1c6d508b14b904dc5777f7ec7e04 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:26 -0800 Subject: 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 Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/infiniband/hw/cxgb3/cxio_resource.c | 60 ++++++++++++++--------------- 1 file changed, 29 insertions(+), 31 deletions(-) (limited to 'drivers/infiniband/hw/cxgb3/cxio_resource.c') diff --git a/drivers/infiniband/hw/cxgb3/cxio_resource.c b/drivers/infiniband/hw/cxgb3/cxio_resource.c index bd233c087653..65072bdfc1bf 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); } -- cgit v1.2.3-59-g8ed1b