Subject: Re: [PATCH v5 09/21] IB/hns: Add hca support

From: Leon Romanovsky <[email-masked]>
Date: Tue, 26 Apr 2016 17:18:21 +0300

On Tue, Apr 26, 2016 at 02:34:44PM +0800, oulijun wrote:
> On 2016/4/24 15:54, Leon Romanovsky wrote:
> > On Sat, Apr 23, 2016 at 06:26:47PM +0800, Lijun Ou wrote:
> >> This patch mainly setup hca for RoCE. it will do a series of
> >> initial works as follows:
> >>       1. init uar table, allocate uar resource
> >>       2. init pd table
> >>       3. init cq table
> >>       4. init mr table
> >>       5. init qp table
> >>
> >> Signed-off-by: Lijun Ou <[email-masked]>
> >> Signed-off-by: Wei Hu(Xavier) <[email-masked]>
> >> ---
> >>  drivers/infiniband/hw/hns/hns_roce_alloc.c  | 104 ++++++++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_cq.c     |  25 ++++
> >>  drivers/infiniband/hw/hns/hns_roce_device.h |  69 ++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_eq.c     |   1 -
> >>  drivers/infiniband/hw/hns/hns_roce_icm.c    |  88 +++++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_icm.h    |   9 ++
> >>  drivers/infiniband/hw/hns/hns_roce_main.c   |  79 ++++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_mr.c     | 187 ++++++++++++++++++++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_pd.c     |  65 ++++++++++
> >>  drivers/infiniband/hw/hns/hns_roce_qp.c     |  30 +++++
> >>  10 files changed, 656 insertions(+), 1 deletion(-)
> >>  create mode 100644 drivers/infiniband/hw/hns/hns_roce_alloc.c
> >>  create mode 100644 drivers/infiniband/hw/hns/hns_roce_mr.c
> >>  create mode 100644 drivers/infiniband/hw/hns/hns_roce_pd.c
> >>
> >> diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c
> >> new file mode 100644
> >> index 0000000..0c76f1b
> >> --- /dev/null
> >> +++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c
> >> @@ -0,0 +1,104 @@
> >> +/*
> >> + * Copyright (c) 2016 Hisilicon Limited.
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License as published by
> >> + * the Free Software Foundation; either version 2 of the License, or
> >> + * (at your option) any later version.
> >> + */
> >> +
> >> +#include <linux/bitmap.h>
> >> +#include <linux/dma-mapping.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/mm.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/vmalloc.h>
> >> +#include "hns_roce_device.h"
> >> +
> >> +int hns_roce_bitmap_alloc(struct hns_roce_bitmap *bitmap, u32 *obj)
> >> +{
> >> +	int ret = 0;
> >> +
> >> +	spin_lock(&bitmap->lock);
> >> +	*obj = find_next_zero_bit(bitmap->table, bitmap->max, bitmap->last);
> >> +	if (*obj >= bitmap->max) {
> >> +		bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
> >> +			       & bitmap->mask;
> >> +		*obj = find_first_zero_bit(bitmap->table, bitmap->max);
> > 
> > find_first_zero_bit function returns "unsigned long" which may or may
> > not be equal to u32 on some architectures.
> > 
> Hi Leon,
>     I appreciate your keen eye. this code is meant for ARM64bit therefore should run corretly for 64-bit AARCH64.
> I will consider changing it as part of good partice and better portability "
> I will give a primary plan to modified it.
> for example:
>     *obj = (u32)find_next_zero_bit(bitmap->table, bitmap->max, bitmap->last);
> Beause the max size of bitmap->table is u32 in current version.
> 
> int hns_roce_bitmap_init(struct hns_roce_bitmap *bitmap, u32 num, u32 mask,
> 			 u32 reserved_bot, u32 reserved_top)
> {
> 	u32 i;
> 
> 	if (num != roundup_pow_of_two(num))
> 		return -EINVAL;
> 
> 	bitmap->last = 0;
> 	bitmap->top = 0;
> 	bitmap->max = num - reserved_top;
> 	bitmap->mask = mask;
> 	bitmap->reserved_top = reserved_top;
> 	spin_lock_init(&bitmap->lock);
> 	bitmap->table = kcalloc(BITS_TO_LONGS(bitmap->max), sizeof(long),
> 				GFP_KERNEL);
> 
> Is this plan ok?

No,
You are submitting new driver, please do it properly (without casting)
from the beginning.

> 
> Thanks
> Lijun Ou
> 
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