Re: [PATCH ipmi/kcs_bmc v1] ipmi: kcs_bmc: optimize the data buffers allocation

From: Wang, Haiyue
Date: Tue Apr 03 2018 - 20:34:12 EST

Just a small piece of cake, not so urgent. I just try to understand

the code commitment process, such as time etc. :)



On 2018-04-04 02:45, Corey Minyard wrote:
On 04/03/2018 01:00 AM, Wang, Haiyue wrote:
Hi Corey,

The 4.17 merge window is opened now, this patch is not yet in linux-next tree,

so it will be merged into 4.18 ?

Yeah, this came in kind of late, and I had some other critical
things I was having to focus on, so I've been kind of out of the loop.

If it's urgent, I can work on getting it into 4.17 later, but I'd rather
wait on 4.18.


Thanks & Regards,


On 2018-03-15 20:20, Haiyue Wang wrote:
Allocate a continuous memory block for the three KCS data buffers with
related index assignment.

Signed-off-by: Haiyue Wang <>
 drivers/char/ipmi/kcs_bmc.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index fbfc05e..dc19c0d 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -435,6 +435,7 @@ static const struct file_operations kcs_bmc_fops = {
 struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
ÂÂÂÂÂ struct kcs_bmc *kcs_bmc;
+ÂÂÂ void *buf;
 Â kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
ÂÂÂÂÂ if (!kcs_bmc)
@@ -448,11 +449,12 @@ struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
ÂÂÂÂÂ mutex_init(&kcs_bmc->mutex);
ÂÂÂÂÂ init_waitqueue_head(&kcs_bmc->queue);
 - kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-ÂÂÂ kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-ÂÂÂ kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-ÂÂÂ if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer)
+ÂÂÂ buf = devm_kmalloc_array(dev, 3, KCS_MSG_BUFSIZ, GFP_KERNEL);
+ÂÂÂ if (!buf)
+ kcs_bmc->data_in = buf;
+ÂÂÂ kcs_bmc->data_out = buf + KCS_MSG_BUFSIZ;
+ kcs_bmc->kbuffer = buf + KCS_MSG_BUFSIZ * 2;
 Â kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
ÂÂÂÂÂ kcs_bmc-> = dev_name(dev);