From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [PATCH] PCI: rockchip: Fix register number offset to program IO outbound ATU Date: Thu, 12 Dec 2019 15:29:36 -0600 Message-ID: <20191212212936.GA13645@google.com> References: <20191211093450.7481-1-enric.balletbo@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20191211093450.7481-1-enric.balletbo@collabora.com> Sender: linux-kernel-owner@vger.kernel.org To: Enric Balletbo i Serra Cc: linux-kernel@vger.kernel.org, Collabora Kernel ML , Andrew Murray , Heiko Stuebner , Lorenzo Pieralisi , linux-rockchip@lists.infradead.org, Shawn Lin , groeck@chromium.org, bleung@chromium.org, dtor@chromium.org, gwendal@chromium.org, Rob Herring , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Vicente Bergas List-Id: linux-rockchip.vger.kernel.org [+cc Vicente] On Wed, Dec 11, 2019 at 10:34:50AM +0100, Enric Balletbo i Serra wrote: > Since commit '62240a88004b ("PCI: rockchip: Drop storing driver private > outbound resource data)' the offset calculation is wrong to access the > register number to program the IO outbound ATU. The offset should be > based on the IORESOURCE_MEM resource size instead of the IORESOURCE_IO > size. > > ... > Fixes: 62240a88004b ("PCI: rockchip: Drop storing driver private outbound resource data) > Reported-by: Enric Balletbo i Serra > Suggested-by: Lorenzo Pieralisi > Signed-off-by: Enric Balletbo i Serra Thanks, I applied this with Vicente's reported-by and tested-by and Andrew's ack to for-linus for v5.5. I'm confused about "msg_bus_addr". It is computed as "entry->res->start - entry->offset + ". A struct resource contains a CPU physical address, and adding entry->offset gets you a PCI bus address. But later rockchip_pcie_probe() calls devm_ioremap(rockchip->msg_bus_addr), which expects a CPU physical address. So it looks like we're passing a PCI bus address when we should be passing a CPU physical address. What am I missing? For the future, I do think we should consider: - Renaming rockchip_pcie_prog_ob_atu() and rockchip_pcie_prog_ib_atu() so they match dw_pcie_prog_outbound_atu() and dw_pcie_prog_inbound_atu(). - Changing the rockchip_pcie_prog_ob_atu() and rockchip_pcie_prog_ib_atu() interfaces so they take a 64-bit pci_addr/cpu_addr instead of 32-bit lower_addr and upper_addr, also to follow the dw examples. - Renaming the rockchip_pcie_cfg_atu() local "offset" to "index" or similar since it's a register number, not a memory or I/O space offset. - Reworking the rockchip_pcie_cfg_atu() loops. Currently there are three different ways to compute the register number. The msg_bus_addr computation is split between the top and bottom of the function and uses "reg_no" left over from the IO loop and "offset" left from the memory loop. Maybe something like this: rockchip_pcie_prog_inbound_atu(rockchip, 2, 32 - 1, 0); atu_idx = 1; mem = resource_list_first_type(&bridge->windows, IORESOURCE_MEM); mem_entries = resource_size(mem->res) >> 20; mem_pci_addr = mem->res->start - mem->offset; for (i = 0; i < mem_entries; i++, atu_idx++) rockchip_pcie_prog_outbound_atu(rockchip, atu_idx, AXI_WRAPPER_MEM_WRITE, 20 - 1, mem_pci_addr + (i << 20)); io = resource_list_first_type(&bridge->windows, IORESOURCE_IO); io_entries = resource_size(entry->res) >> 20; io_pci_addr = io->res->start - io->offset; for (i = 0; i < io_entries; i++, atu_idx++) rockchip_pcie_prog_outbound_atu(rockchip, atu_idx, AXI_WRAPPER_IO_WRITE, 20 - 1, io_pci_addr + (i << 20)); rockchip_pcie_prog_outbound_atu(rockchip, atu_idx, AXI_WRAPPER_NOR_MSG, 20 - 1, 0); rockchip->msg_bus_addr = mem_pci_addr + (mem_entries + io_entries) << 20); > --- > > drivers/pci/controller/pcie-rockchip-host.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c > index d9b63bfa5dd7..94af6f5828a3 100644 > --- a/drivers/pci/controller/pcie-rockchip-host.c > +++ b/drivers/pci/controller/pcie-rockchip-host.c > @@ -834,10 +834,12 @@ static int rockchip_pcie_cfg_atu(struct rockchip_pcie *rockchip) > if (!entry) > return -ENODEV; > > + /* store the register number offset to program RC io outbound ATU */ > + offset = size >> 20; > + > size = resource_size(entry->res); > pci_addr = entry->res->start - entry->offset; > > - offset = size >> 20; > for (reg_no = 0; reg_no < (size >> 20); reg_no++) { > err = rockchip_pcie_prog_ob_atu(rockchip, > reg_no + 1 + offset, > -- > 2.20.1 >