On Mon, Sep 21, 2015 at 4:53 PM, Julien Grall <julien.gr...@citrix.com> wrote: > Hi Vijay, > > The only things I haven't check on this patch was the ITS command structure. > > On 18/09/15 14:08, vijay.kil...@gmail.com wrote: >> +/* ITS command structure */ >> +typedef union { > > Can you please sort this union by command name in alphabetical order. > It's way easier to find a command in the list. > >> + u64 bits[4]; >> + struct __packed { >> + uint8_t cmd; > > NIT: Please stay consistent with usage of the type. You are using u8 > everywhere within this union except here. > >> + uint8_t pad[7]; > > Why a padding of only 56 bits? Shouldn't it be 248 bits (i.e 31 * 8 > bits) to fit all the command? > >> + } hdr; >> + struct __packed { >> + u8 cmd; >> + u8 res1[3]; >> + u32 devid; >> + u64 size:5; >> + u64 res2:59; >> + /* XXX: Though itt is 40 bit. Keep it 48 to avoid shift */ >> + u64 res3:8; > > It's very confusing for the reviewer to see a mix of usage (u8 res1[n], > u64 res3:8) within the same structure. > > The later (i.e u64 field:n) is the best to use because we can match > quickly the size with the spec. > >> + u64 itt:40; >> + u64 res4:15; >> + u64 valid:1; >> + u64 res5; >> + } mapd; > > [..] > >> + struct __packed { >> + u8 cmd; >> + u8 res1[3]; >> + u32 devid; >> + u32 event; >> + u32 res2; >> + u64 res3; >> + u64 res4; >> + } int_cmd; > > Maybe you want to add the suffix _cmd to everyone to avoid having only > one because of C spec issue.
suffixing _cmd will look ugly ( as below ex) where "cmd" is repeated twice. cmd.mapd_cmd.cmd = GITS_CMD_MAPD; cmd.mapd_cmd.devid = dev->device_id; cmd.mapd_cmd.size = size - 1; _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel