Messages in this thread | | | Subject | Re: [RESEND PATCH v7 17/21] IB/hns: Add QP operations support | From | "Wei Hu (Xavier)" <> | Date | Mon, 23 May 2016 11:30:57 +0800 |
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Hi, Doug Ledford In hns_roce_cmd_wait and hns_roce_cmd_poll, there are down&up seminal operations, So, there are not deadlock and conflict, right?
static int hns_roce_cmd_poll(struct hns_roce_dev *hr_dev, u64 in_param, u64 *out_param, unsigned long in_modifier, u8 op_modifier, u16 op, unsigned long timeout) { struct device *dev = &hr_dev->pdev->dev; u8 __iomem *hcr = hr_dev->cmd.hcr; unsigned long end = 0; u32 status = 0; int ret;
down(&hr_dev->cmd.poll_sem);
..// <snip>
up (&hr_dev->cmd.poll_sem); return ret; }
static int hns_roce_cmd_wait(struct hns_roce_dev *hr_dev, u64 in_param, u64 *out_param, unsigned long in_modifier, u8 op_modifier, u16 op, unsigned long timeout) { struct hns_roce_cmdq *cmd = &hr_dev->cmd; struct device *dev = &hr_dev->pdev->dev; struct hns_roce_cmd_context *context; int ret = 0;
down(&cmd->event_sem);
..// <snip>
up (&cmd->event_sem); return ret; }
int __hns_roce_cmd(struct hns_roce_dev *hr_dev, u64 in_param, u64 *out_param, unsigned long in_modifier, u8 op_modifier, u16 op, unsigned long timeout) { if (hr_dev->cmd.use_events) return hns_roce_cmd_wait(hr_dev, in_param, out_param, in_modifier, op_modifier, op, timeout); else return hns_roce_cmd_poll(hr_dev, in_param, out_param, in_modifier, op_modifier, op, timeout); }
Thanks.
Regards Wei Hu
On 2016/5/14 5:52, Doug Ledford wrote: > On 05/09/2016 11:04 PM, Lijun Ou wrote: >> +int __hns_roce_cmd(struct hns_roce_dev *hr_dev, u64 in_param, u64 *out_param, >> + unsigned long in_modifier, u8 op_modifier, u16 op, >> + unsigned long timeout); >> + >> +/* Invoke a command with no output parameter */ >> +static inline int hns_roce_cmd(struct hns_roce_dev *hr_dev, u64 in_param, >> + unsigned long in_modifier, u8 op_modifier, >> + u16 op, unsigned long timeout) >> +{ >> + return __hns_roce_cmd(hr_dev, in_param, NULL, in_modifier, >> + op_modifier, op, timeout); >> +} >> + >> +/* Invoke a command with an output mailbox */ >> +static inline int hns_roce_cmd_box(struct hns_roce_dev *hr_dev, u64 in_param, >> + u64 out_param, unsigned long in_modifier, >> + u8 op_modifier, u16 op, >> + unsigned long timeout) >> +{ >> + return __hns_roce_cmd(hr_dev, in_param, &out_param, in_modifier, >> + op_modifier, op, timeout); >> +} > This will make people scratch their head in the future. You are using > two commands to map to one command without there being any locking > involved. The typical convention for routine_1() -> __routine_1() is > that the __ version requires that it be called while locked, and the > version without a __ does the locking before calling it. That way a > used can always know if they aren't currently holding the appropriate > lock, then they6 call routine_1() and if they are, they call > __routine_1() to avoid a deadlock. I would suggest changing the name of > __hns_roce_cmd to hns_roce_cmd_box and completely remove the existing > hns_roce_cmd_box inline, and then change the hns_roce_cmd() inline to > directly call hns_roce_cmd_box() which will then select between > event/poll command sends. >
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