Re: [PATCH v3 03/12] PCI: rockchip-ep: Improve rockchip_pcie_ep_unmap_addr()

Manivannan Sadhasivam
2024-10-10T07:09:18Z

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

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