On Mon, Dec 18, 2023 at 11:48:43PM -0500, Frank Li wrote: > dw_pcie_ep_inbound_atu() > { > ... > if (!ep->bar_to_atu[bar]) > free_win = find_first_zero_bit(ep->ib_window_map, pci->num_ib_windows); > else > free_win = ep->bar_to_atu[bar]; > ... > } > > The atu index 0 is valid case for atu number. The find_first_zero_bit() > will return 6 when second time call into this function if atu is 0. Suppose > it should use branch 'free_win = ep->bar_to_atu[bar]'. > > Change 'bar_to_atu' to s8. Initialize bar_to_atu as -1 to indicate it have > not allocate atu to the bar. > > Reported-by: Niklas Cassel <Niklas.Cassel@xxxxxxx> > Close: https://lore.kernel.org/linux-pci/ZXt2A+Fusfz3luQV@x1-carbon/T/#u > Fixes: 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address") > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > --- > > Notes: > @Niklas: > I have not test your case. I should be equal to previous's fix in > mail list. Hello Frank, Thank you for sending a proper fix for this! Personally, I slightly prefer your fix that saves the iatu index + 1, and keeps 0 to mean unused. That way, you don't need the memset, and you don't need to change the type to signed, but either way is fine by me, so: Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx> > > drivers/pci/controller/dwc/pcie-designware-ep.c | 11 ++++++++--- > drivers/pci/controller/dwc/pcie-designware.h | 2 +- > 2 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c > index f6207989fc6ad..0ff5cd64f49b0 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > @@ -174,7 +174,7 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type, > u32 free_win; > struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > > - if (!ep->bar_to_atu[bar]) > + if (ep->bar_to_atu[bar] < 0) > free_win = find_first_zero_bit(ep->ib_window_map, pci->num_ib_windows); > else > free_win = ep->bar_to_atu[bar]; > @@ -228,14 +228,17 @@ static void dw_pcie_ep_clear_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > struct dw_pcie_ep *ep = epc_get_drvdata(epc); > struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > enum pci_barno bar = epf_bar->barno; > - u32 atu_index = ep->bar_to_atu[bar]; > + s8 atu_index = ep->bar_to_atu[bar]; > + > + if (atu_index < 0) > + return; > > __dw_pcie_ep_reset_bar(pci, func_no, bar, epf_bar->flags); > > dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_IB, atu_index); > clear_bit(atu_index, ep->ib_window_map); > ep->epf_bar[bar] = NULL; > - ep->bar_to_atu[bar] = 0; > + ep->bar_to_atu[bar] = -1; > } > > static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > @@ -767,6 +770,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > return -ENOMEM; > ep->outbound_addr = addr; > > + memset(ep->bar_to_atu, -1, sizeof(ep->bar_to_atu)); > + > epc = devm_pci_epc_create(dev, &epc_ops); > if (IS_ERR(epc)) { > dev_err(dev, "Failed to create epc device\n"); > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 55ff76e3d3846..5879907c5cf25 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -362,7 +362,7 @@ struct dw_pcie_ep { > phys_addr_t phys_base; > size_t addr_size; > size_t page_size; > - u8 bar_to_atu[PCI_STD_NUM_BARS]; > + s8 bar_to_atu[PCI_STD_NUM_BARS]; > phys_addr_t *outbound_addr; > unsigned long *ib_window_map; > unsigned long *ob_window_map; > -- > 2.34.1 >