On Wed, Dec 14, 2022 at 12:49:15AM +0000, Frank Li wrote: > > > > On Wed, Nov 02, 2022 at 10:10:14AM -0400, Frank Li wrote: > > > From: Frank Li <frank.li@xxxxxxx> > > > > > > pci-epf-vntb.c:1128:33: sparse: expected void [noderef] __iomem > > *base > > > pci-epf-vntb.c:1128:33: sparse: got struct epf_ntb_ctrl *reg > > > > > > Add __iomem type convert in vntb_epf_peer_spad_read() and > > > vntb_epf_peer_spad_write(). > > > > I don't understand all the bits and pieces here, but I'm a little > > dubious about adding all these "(void __iomem *)"casts. There are > > very few of them in drivers/pci/, and I doubt this driver is so unique > > that it needs them. > > sparse compiler report warning without cast. I write it at commit message. As a matter of fact, I did read your commit message. My point is that I don't think littering the code with casts is the best solution. I wrote more details below; please read the entire email. > > > @@ -1121,7 +1121,7 @@ static u32 vntb_epf_spad_read(struct ntb_dev > > *ndev, int idx) > > > struct epf_ntb *ntb = ntb_ndev(ndev); > > > int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * > > sizeof(u32); > > > u32 val; > > > - void __iomem *base = ntb->reg; > > > + void __iomem *base = (void __iomem *)ntb->reg; > > > > > > val = readl(base + off + ct + idx * sizeof(u32)); > > > return val; > > > @@ -1132,7 +1132,7 @@ static int vntb_epf_spad_write(struct ntb_dev > > *ndev, int idx, u32 val) > > > struct epf_ntb *ntb = ntb_ndev(ndev); > > > struct epf_ntb_ctrl *ctrl = ntb->reg; > > > int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32); > > > - void __iomem *base = ntb->reg; > > > + void __iomem *base = (void __iomem *)ntb->reg; > > > > > > writel(val, base + off + ct + idx * sizeof(u32)); > > > > These things look gratuitously different to begin with: > > > > int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * sizeof(u32); > > int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32); > > > > They're doing the same thing, and they should do it the same way. > > > > Since db_data[] and db_offset[] are never referenced except to be > > initialized to zero, I'm guessing the point of vntb_epf_spad_read() > > and vntb_epf_spad_write() is to read/write things in those arrays? > > > > You access other things in ntb->reg directly by dereferencing a > > pointer, e.g., > > > > ntb->reg->link_status |= LINK_STATUS_UP; > > addr = ntb->reg->addr; > > ctrl->command_status = COMMAND_STATUS_OK; > > > > Why don't you just compute the appropriate *index* and access the > > array directly instead of using readl() and writel()? > > > > Bjorn
