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 <matthew.r.wilcox@intel.com>
This commit is contained in:
Matthew Wilcox 2011-02-06 07:53:23 -05:00
parent 58ffacb545
commit be7b62754e

View File

@ -31,6 +31,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/poison.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/types.h>
@ -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);
}