From be7b62754e097adc0cb16c25c9ee86ee20de62fb Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Sun, 6 Feb 2011 07:53:23 -0500 Subject: NVMe: Use a symbolic name to represent cancelled commands instead of 0 I have plans for other special values in sync_completion. Plus, this is more self-documenting, and lets us detect bogus usages. Signed-off-by: Matthew Wilcox --- drivers/block/nvme.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index 60c3786..802d763 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -158,15 +159,17 @@ static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx, } /* If you need more than four handlers, you'll need to change how - * alloc_cmdid and nvme_process_cq work. Also, aborted commands take - * the sync_completion path (if they complete), so don't put anything - * else in slot zero. + * alloc_cmdid and nvme_process_cq work. Consider using a special + * CMD_CTX value instead, if that works for your situation. */ enum { sync_completion_id = 0, bio_completion_id, }; +#define CMD_CTX_BASE (POISON_POINTER_DELTA + sync_completion_id) +#define CMD_CTX_CANCELLED (0x2008 + CMD_CTX_BASE) + static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid) { unsigned long data; @@ -177,9 +180,10 @@ static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid) return data; } -static void clear_cmdid_data(struct nvme_queue *nvmeq, int cmdid) +static void cancel_cmdid_data(struct nvme_queue *nvmeq, int cmdid) { - nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)] = 0; + nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)] = + CMD_CTX_CANCELLED; } static struct nvme_queue *get_nvmeq(struct nvme_ns *ns) @@ -396,8 +400,8 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx, struct nvme_completion *cqe) { struct sync_cmd_info *cmdinfo = ctx; - if (!cmdinfo) - return; /* Command aborted */ + if ((unsigned long)cmdinfo == CMD_CTX_CANCELLED) + return; cmdinfo->result = le32_to_cpup(&cqe->result); cmdinfo->status = le16_to_cpup(&cqe->status) >> 1; wake_up_process(cmdinfo->task); @@ -480,7 +484,7 @@ static irqreturn_t nvme_irq_check(int irq, void *data) static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid) { spin_lock_irq(&nvmeq->q_lock); - clear_cmdid_data(nvmeq, cmdid); + cancel_cmdid_data(nvmeq, cmdid); spin_unlock_irq(&nvmeq->q_lock); } -- cgit v1.1