From 129f6af747b2259a4319a0af536fd80ece16e7cb Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Fri, 13 Dec 2024 15:33:04 +0100 Subject: PCI: dwc: ep: Add 'address' alignment to 'size' check in dw_pcie_prog_ep_inbound_atu() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit dw_pcie_prog_ep_inbound_atu() is used to program an inbound iATU in "BAR Match Mode". A memory address returned by e.g. kmalloc() is guaranteed to have natural alignment (aligned to the size of the allocation). It is however not guaranteed that pci_epc_set_bar() (and thus dw_pcie_prog_ep_inbound_atu()) is supplied an address that has natural alignment. (An EPF driver can send in an arbitrary physical address to pci_epc_set_bar().) The DWC Databook description for the LWR_TARGET_RW and LWR_TARGET_HW fields in the IATU_LWR_TARGET_ADDR_OFF_INBOUND_i registers state that: "Field size depends on log2(BAR_MASK+1) in BAR match mode." I.e. only the upper bits are writable, and the number of writable bits is dependent on the configured BAR_MASK. Add a check to ensure that the physical address programmed in the iATU is aligned to the size of the BAR (BAR_MASK+1), as without this, we can get hard to debug errors, as we could write to bits that are read-only (without getting a write error), which could cause the iATU to end up redirecting to a physical address that is different from the address that we intended. Link: https://lore.kernel.org/r/20241213143301.4158431-11-cassel@kernel.org Signed-off-by: Niklas Cassel Signed-off-by: Krzysztof Wilczyński Reviewed-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pcie-designware.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 6d6cbc8b5b2c..3c683b6119c3 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -597,11 +597,12 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type, } int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index, - int type, u64 cpu_addr, u8 bar) + int type, u64 cpu_addr, u8 bar, size_t size) { u32 retries, val; - if (!IS_ALIGNED(cpu_addr, pci->region_align)) + if (!IS_ALIGNED(cpu_addr, pci->region_align) || + !IS_ALIGNED(cpu_addr, size)) return -EINVAL; dw_pcie_writel_atu_ib(pci, index, PCIE_ATU_LOWER_TARGET, -- cgit v1.2.3