On Thu, Apr 2, 2020 at 0:58:13, Alan Mikhak <alan.mikhak@xxxxxxxxxx>
wrote:
> From: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
>
> Function dw_pcie_prog_outbound_atu_unroll() does not program the upper
> 32-bit ATU limit register. Since ATU programming functions limit the
> size of the translated region to 4GB by using a u32 size parameter,
> these issues may combine into undefined behavior for resource sizes
> with non-zero upper 32-bits.
>
> For example, a 128GB address space starting at physical CPU address of
> 0x2000000000 with size of 0x2000000000 needs the following values
> programmed into the lower and upper 32-bit limit registers:
> 0x3fffffff in the upper 32-bit limit register
> 0xffffffff in the lower 32-bit limit register
>
> Currently, only the lower 32-bit limit register is programmed with a
> value of 0xffffffff but the upper 32-bit limit register is not being
> programmed. As a result, the upper 32-bit limit register remains at its
> default value after reset of 0x0.
>
> These issues may combine to produce undefined behavior since the ATU
> limit address may be lower than the ATU base address. Programming the
> upper ATU limit address register prevents such undefined behavior despite
> the region size getting truncated due to the 32-bit size limit.
>
> Signed-off-by: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-designware.c | 7 +++++--
> drivers/pci/controller/dwc/pcie-designware.h | 3 ++-
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 681548c88282..c92496e36fd5 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -244,13 +244,16 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, int index,
> u64 pci_addr, u32 size)
> {
> u32 retries, val;
> + u64 limit_addr = cpu_addr + size - 1;
>
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LOWER_BASE,
> lower_32_bits(cpu_addr));
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_BASE,
> upper_32_bits(cpu_addr));
> - dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LIMIT,
> - lower_32_bits(cpu_addr + size - 1));
> + dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LOWER_LIMIT,
> + lower_32_bits(limit_addr));
> + dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_LIMIT,
> + upper_32_bits(limit_addr));
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LOWER_TARGET,
> lower_32_bits(pci_addr));
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index a22ea5982817..5ce1aef706c5 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -112,9 +112,10 @@
> #define PCIE_ATU_UNR_REGION_CTRL2 0x04
> #define PCIE_ATU_UNR_LOWER_BASE 0x08
> #define PCIE_ATU_UNR_UPPER_BASE 0x0C
> -#define PCIE_ATU_UNR_LIMIT 0x10
> +#define PCIE_ATU_UNR_LOWER_LIMIT 0x10
> #define PCIE_ATU_UNR_LOWER_TARGET 0x14
> #define PCIE_ATU_UNR_UPPER_TARGET 0x18
> +#define PCIE_ATU_UNR_UPPER_LIMIT 0x20
>
> /*
> * The default address offset between dbi_base and atu_base. Root controller
> --
> 2.7.4
Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
