Messages in this thread | | | From | "Masayuki Ohtake" <> | Subject | Re: [PATCH] Topcliff PHUB: Generate PacketHub driver | Date | Fri, 18 Jun 2010 08:49:35 +0900 |
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Hi Arnd,
I will modify for your comments by today or tomorrow.
Thanks, Ohtake
----- Original Message ----- From: "Arnd Bergmann" <arnd@arndb.de> To: "Masayuki Ohtak" <masa-korg@dsn.okisemi.com> Cc: "Alan Cox" <alan@lxorguk.ukuu.org.uk>; "LKML" <linux-kernel@vger.kernel.org>; "Andrew" <andrew.chih.howe.khor@intel.com>; "Intel OTC" <joel.clark@intel.com>; "Wang, Qi" <qi.wang@intel.com>; "Wang, Yong Y" <yong.y.wang@intel.com> Sent: Thursday, June 17, 2010 8:59 PM Subject: Re: [PATCH] Topcliff PHUB: Generate PacketHub driver
> Looks almost good to me now. Some more details (only the -EFAULT return code > is a real issue, the other ones are cosmetic changes): > > On Thursday 17 June 2010, Masayuki Ohtak wrote: > > + > > +#define PCH_READ_REG(a) ioread32(pch_phub_reg.pch_phub_base_address + (a)) > > + > > +#define PCH_WRITE_REG(a, b) iowrite32((a), pch_phub_reg.pch_phub_base_address +\ > > + (b)) > > I'd recommend just getting rid of these abstractions. You only use > them in one or two functions each, so you can just as well add a local > variable there and do > > void __iomem *p = pch_phub_reg.pch_phub_base_address; > foo = ioread32(p + foo_offset); > bar = ioread32(p + bar_offset); > ... > > Not really important, but this way it would be more conventional > without having to write extra code. > > > +/*-------------------------------------------- > > + global variables > > +--------------------------------------------*/ > > +/** > > + * struct pch_phub_reg_t - PHUB register structure > > + * @phub_id_reg: PHUB_ID register val > > + * @q_pri_val_reg: QUEUE_PRI_VAL register val > > + * @rc_q_maxsize_reg: RC_QUEUE_MAXSIZE register val > > + * @bri_q_maxsize_reg: BRI_QUEUE_MAXSIZE register val > > + * @comp_resp_timeout_reg: COMP_RESP_TIMEOUT register val > > + * @bus_slave_control_reg: BUS_SLAVE_CONTROL_REG register val > > + * @deadlock_avoid_type_reg: DEADLOCK_AVOID_TYPE register val > > + * @intpin_reg_wpermit_reg0: INTPIN_REG_WPERMIT register 0 val > > + * @intpin_reg_wpermit_reg1: INTPIN_REG_WPERMIT register 1 val > > + * @intpin_reg_wpermit_reg2: INTPIN_REG_WPERMIT register 2 val > > + * @intpin_reg_wpermit_reg3: INTPIN_REG_WPERMIT register 3 val > > + * @int_reduce_control_reg: INT_REDUCE_CONTROL registers val > > + * @clkcfg_reg: CLK CFG register val > > + * @pch_phub_base_address: register base address > > + * @pch_phub_extrom_base_address: external rom base address > > + * @pch_phub_suspended: PHUB status val > > + */ > > +struct pch_phub_reg_t { > > It would be better to drop the _t postfix on the type name. > By convention, we use this only for typedefs on simple data > types like off_t but not for structures. > > > + __u32 phub_id_reg; > > + __u32 q_pri_val_reg; > > + __u32 rc_q_maxsize_reg; > > When I told you to change the ioctl arguments to use __u32 instead > of u32, I was only referring to those parts that are in the user-visible > section of the header file. While it does not hurt to use __u32 in > the kernel, you should understand the distinction. > > > +/** pch_phub_write - Implements the write functionality of the Packet Hub > > + * module. > > + * @file: Contains the reference of the file structure > > + * @buf: Usermode buffer pointer > > + * @size: Usermode buffer size > > + * @ppos: Contains the reference of the file structure > > + */ > > +static ssize_t pch_phub_write(struct file *file, const char __user *buf, > > + size_t size, loff_t *ppos) > > +{ > > + static __u32 data; > > No need to make data static. > > > + __s32 ret_value; > > + __u32 addr_offset = 0; > > + loff_t pos = *ppos; > > + > > + if (pos < 0) > > + return -EINVAL; > > + > > + for (addr_offset = 0; addr_offset < size; addr_offset++) { > > + get_user(data, &buf[addr_offset]); > > + > > + ret_value = pch_phub_write_serial_rom(0x80 + addr_offset + pos, > > + data); > > + if (ret_value) > > + return -EFAULT; > > You should return -EFAULT if the get_user() call fails, otherwise you have > a possible security hole. If pch_phub_write_serial_rom fails, the correct > return code would be -EIO. > > > +/** > > + * file_operations structure initialization > > + */ > > +static const struct file_operations pch_phub_fops = { > > + .owner = THIS_MODULE, > > + .read = pch_phub_read, > > + .write = pch_phub_write, > > + .unlocked_ioctl = pch_phub_ioctl, > > +}; > > If would be good to add a line of > .llseek = default_llseek, > here. I have a patch to change the default llseek method to one > that disallows seeking, so if you add this line, there is one > less driver for me to patch. > > Arnd >
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