RE: [PATCH v2] PCI: dwc: Add upper limit address for outbound iATU

From: Pankaj Dubey
Date: Wed Jan 06 2021 - 06:32:11 EST




> -----Original Message-----
> From: Shradha Todi <shradha.t@xxxxxxxxxxx>
> Sent: Wednesday, January 6, 2021 4:20 PM
> To: linux-kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx
> Cc: jingoohan1@xxxxxxxxx; gustavo.pimentel@xxxxxxxxxxxx;
> robh@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; bhelgaas@xxxxxxxxxx;
> pankaj.dubey@xxxxxxxxxxx; sriram.dash@xxxxxxxxxxx;
> niyas.ahmed@xxxxxxxxxxx; p.rajanbabu@xxxxxxxxxxx;
> l.mehra@xxxxxxxxxxx; hari.tv@xxxxxxxxxxx; Shradha Todi
> <shradha.t@xxxxxxxxxxx>
> Subject: [PATCH v2] PCI: dwc: Add upper limit address for outbound iATU
>
> The size parameter is unsigned long type which can accept size > 4GB. In that
> case, the upper limit address must be programmed. Add support to program
> the upper limit address and set INCREASE_REGION_SIZE in case size > 4GB.
>
> Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
> ---
> v1: https://lkml.org/lkml/2020/12/20/187
> v2:
> Addressed Rob's review comment and added PCI version check condition
> to
> avoid writing to reserved registers.
>

Reviewed-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>

> drivers/pci/controller/dwc/pcie-designware.c | 9 +++++++--
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c
> b/drivers/pci/controller/dwc/pcie-designware.c
> index 74590c7..1d62ca9 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -290,12 +290,17 @@ static void __dw_pcie_prog_outbound_atu(struct
> dw_pcie *pci, u8 func_no,
> upper_32_bits(cpu_addr));
> dw_pcie_writel_dbi(pci, PCIE_ATU_LIMIT,
> lower_32_bits(cpu_addr + size - 1));
> + if (pci->version >= 0x460A)
> + dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_LIMIT,
> + upper_32_bits(cpu_addr + size - 1));
> dw_pcie_writel_dbi(pci, PCIE_ATU_LOWER_TARGET,
> lower_32_bits(pci_addr));
> dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_TARGET,
> upper_32_bits(pci_addr));
> - dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, type |
> - PCIE_ATU_FUNC_NUM(func_no));
> + val = type | PCIE_ATU_FUNC_NUM(func_no);
> + val = ((upper_32_bits(size - 1)) && (pci->version >= 0x460A)) ?
> + val | PCIE_ATU_INCREASE_REGION_SIZE : val;
> + dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val);
> dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, PCIE_ATU_ENABLE);
>
> /*
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h
> b/drivers/pci/controller/dwc/pcie-designware.h
> index 8b905a2..7da79eb 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -102,6 +102,7 @@
> #define PCIE_ATU_DEV(x) FIELD_PREP(GENMASK(23,
> 19), x)
> #define PCIE_ATU_FUNC(x) FIELD_PREP(GENMASK(18, 16), x)
> #define PCIE_ATU_UPPER_TARGET 0x91C
> +#define PCIE_ATU_UPPER_LIMIT 0x924
>
> #define PCIE_MISC_CONTROL_1_OFF 0x8BC
> #define PCIE_DBI_RO_WR_EN BIT(0)
> --
> 2.7.4