| Message ID | 20241007041218.157516-4-dlemoal@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,01/12] PCI: rockchip-ep: Fix address translation unit programming | expand |
On Mon, Oct 07, 2024 at 01:12:09PM +0900, Damien Le Moal wrote: > From: Damien Le Moal <damien.lemoal@opensource.wdc.com> > > There is no need to loop over all regions to find the memory window used > to map an address. We can use rockchip_ob_region() to determine the > region index, together with a check that the address passed as argument > is the address used to create the mapping. Furthermore, the > ob_region_map bitmap should also be checked to ensure that we are not > attempting to unmap an address that is not mapped. > > Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> > --- > drivers/pci/controller/pcie-rockchip-ep.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c > index 5a07084fb7c4..89ebdf3e4737 100644 > --- a/drivers/pci/controller/pcie-rockchip-ep.c > +++ b/drivers/pci/controller/pcie-rockchip-ep.c > @@ -256,13 +256,9 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn, > { > struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); > struct rockchip_pcie *rockchip = &ep->rockchip; > - u32 r; > - > - for (r = 0; r < ep->max_regions; r++) > - if (ep->ob_addr[r] == addr) > - break; > + u32 r = rockchip_ob_region(addr); > > - if (r == ep->max_regions) > + if (addr != ep->ob_addr[r] || !test_bit(r, &ep->ob_region_map)) Having these two checks looks redundant to me. Is it possible that an address could pass only one check? - Mani
On 10/10/24 16:09, Manivannan Sadhasivam wrote: > On Mon, Oct 07, 2024 at 01:12:09PM +0900, Damien Le Moal wrote: >> From: Damien Le Moal <damien.lemoal@opensource.wdc.com> >> >> There is no need to loop over all regions to find the memory window used >> to map an address. We can use rockchip_ob_region() to determine the >> region index, together with a check that the address passed as argument >> is the address used to create the mapping. Furthermore, the >> ob_region_map bitmap should also be checked to ensure that we are not >> attempting to unmap an address that is not mapped. >> >> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> >> --- >> drivers/pci/controller/pcie-rockchip-ep.c | 8 ++------ >> 1 file changed, 2 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c >> index 5a07084fb7c4..89ebdf3e4737 100644 >> --- a/drivers/pci/controller/pcie-rockchip-ep.c >> +++ b/drivers/pci/controller/pcie-rockchip-ep.c >> @@ -256,13 +256,9 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn, >> { >> struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); >> struct rockchip_pcie *rockchip = &ep->rockchip; >> - u32 r; >> - >> - for (r = 0; r < ep->max_regions; r++) >> - if (ep->ob_addr[r] == addr) >> - break; >> + u32 r = rockchip_ob_region(addr); >> >> - if (r == ep->max_regions) >> + if (addr != ep->ob_addr[r] || !test_bit(r, &ep->ob_region_map)) > > Having these two checks looks redundant to me. Is it possible that an address > could pass only one check? Yes, if the wrong address is passed to rockchip_pcie_ep_unmap_addr() but that address still correspond to an ob_region that is being used. We could do add a WARN_ON_ONCE() around that if condition as calling that function with an invalid address would mean that either the epc core or the function driver is buggy.
diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c index 5a07084fb7c4..89ebdf3e4737 100644 --- a/drivers/pci/controller/pcie-rockchip-ep.c +++ b/drivers/pci/controller/pcie-rockchip-ep.c @@ -256,13 +256,9 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn, { struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); struct rockchip_pcie *rockchip = &ep->rockchip; - u32 r; - - for (r = 0; r < ep->max_regions; r++) - if (ep->ob_addr[r] == addr) - break; + u32 r = rockchip_ob_region(addr); - if (r == ep->max_regions) + if (addr != ep->ob_addr[r] || !test_bit(r, &ep->ob_region_map)) return; rockchip_pcie_clear_ep_ob_atu(rockchip, r);