On Wed, Feb 16, 2022 at 5:34 AM Naveen Krishna Chatradhi <nchatrad@xxxxxxx> wrote: > > From: Suma Hegde <suma.hegde@xxxxxxx> > > Recent Fam19h EPYC server line of processors from AMD support system > management functionality via HSMP (Host System Management Port) interface. > > The Host System Management Port (HSMP) is an interface to provide > OS-level software with access to system management functions via a > set of mailbox registers. > > More details on the interface can be found in chapter > "7 Host System Management Port (HSMP)" of the following PPR > https://www.amd.com/system/files/TechDocs/55898_B1_pub_0.50.zip > > This patch adds new amd_hsmp module under the drivers/platforms/x86/ > which creates miscdevice with an IOCTL interface to the user space. > /dev/hsmp is for running the hsmp mailbox commands. > > Signed-off-by: Suma Hegde <suma.hegde@xxxxxxx> > Signed-off-by: Naveen Krishna Chatradhi <nchatrad@xxxxxxx> > Reviewed-by: Carlos Bilbao <carlos.bilbao@xxxxxxx> Acked-by: Song Liu <song@xxxxxxxxxx> With a couple minor comments below. > --- [...] > + > +struct hsmp_message { > + __u32 msg_id; /* Message ID */ > + __u16 num_args; /* Number of input argument words in message */ > + __u16 response_sz; /* Number of expected output/response words */ > + __u32 buf[HSMP_MAX_MSG_LEN]; /* argument/response buffer */ How about we call these args instead of buf? [...] > + > +static long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) > +{ > + int __user *arguser = (int __user *)arg; > + struct hsmp_message msg = { 0 }; > + int ret; > + > + if (copy_struct_from_user(&msg, sizeof(msg), arguser, sizeof(struct hsmp_message))) > + return -EFAULT; > + > + ret = validate_message(&msg); We call validate_message() twice in this path. This is not a big issue, but it will be nice if we can avoid the extra check. [...]
