Re: [PATCH 3/3] PCI: qcom: Enable ECAM feature based on config size

Manivannan Sadhasivam
2024-12-02T16:54:02Z

On Sun, Nov 17, 2024 at 03:30:20AM +0530, Krishna chaitanya chundru wrote:
> Enable the ECAM feature if the config space size is equal to size required
> to represent number of buses in the bus range property.
>

Please move this change to DWC core.

> The ELBI registers falls after the DBI space, so use the cfg win returned
> from the ecam init to map these regions instead of doing the ioremap again.
> ELBI starts at offset 0xf20 from dbi.
>
> On bus 0, we have only the root complex. Any access other than that should
> not go out of the link and should return all F's. Since the IATU is
> configured for bus 1 onwards, block the transactions for bus 0:0:1 to
> 0:31:7 (i.e., from dbi_base + 4KB to dbi_base + 1MB) from going outside the
> link through ecam blocker through parf registers.
>
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 104 +++++++++++++++++++++++++++++++--
> 1 file changed, 100 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index ef44a82be058..266de2aa3a71 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -61,6 +61,17 @@
> #define PARF_DBI_BASE_ADDR_V2_HI 0x354
> #define PARF_SLV_ADDR_SPACE_SIZE_V2 0x358
> #define PARF_SLV_ADDR_SPACE_SIZE_V2_HI 0x35c
> +#define PARF_BLOCK_SLV_AXI_WR_BASE 0x360
> +#define PARF_BLOCK_SLV_AXI_WR_BASE_HI 0x364
> +#define PARF_BLOCK_SLV_AXI_WR_LIMIT 0x368
> +#define PARF_BLOCK_SLV_AXI_WR_LIMIT_HI 0x36c
> +#define PARF_BLOCK_SLV_AXI_RD_BASE 0x370
> +#define PARF_BLOCK_SLV_AXI_RD_BASE_HI 0x374
> +#define PARF_BLOCK_SLV_AXI_RD_LIMIT 0x378
> +#define PARF_BLOCK_SLV_AXI_RD_LIMIT_HI 0x37c
> +#define PARF_ECAM_BASE 0x380
> +#define PARF_ECAM_BASE_HI 0x384
> +
> #define PARF_NO_SNOOP_OVERIDE 0x3d4
> #define PARF_ATU_BASE_ADDR 0x634
> #define PARF_ATU_BASE_ADDR_HI 0x638
> @@ -68,6 +79,8 @@
> #define PARF_BDF_TO_SID_TABLE_N 0x2000
> #define PARF_BDF_TO_SID_CFG 0x2c00
>
> +#define ELBI_OFFSET 0xf20
> +
> /* ELBI registers */
> #define ELBI_SYS_CTRL 0x04
>
> @@ -84,6 +97,7 @@
>
> /* PARF_SYS_CTRL register fields */
> #define MAC_PHY_POWERDOWN_IN_P2_D_MUX_EN BIT(29)
> +#define PCIE_ECAM_BLOCKER_EN BIT(26)
> #define MST_WAKEUP_EN BIT(13)
> #define SLV_WAKEUP_EN BIT(12)
> #define MSTR_ACLK_CGC_DIS BIT(10)
> @@ -293,15 +307,68 @@ static void qcom_ep_reset_deassert(struct qcom_pcie *pcie)
> usleep_range(PERST_DELAY_US, PERST_DELAY_US + 500);
> }
>
> +static int qcom_pci_config_ecam_blocker(struct dw_pcie_rp *pp)

'config_ecam_blocker' is one of the use of this function, not the only one. So
use something like, 'qcom_pci_config_ecam()'.

> +{
> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> + struct qcom_pcie *pcie = to_qcom_pcie(pci);
> + u64 addr, addr_end;
> + u32 val;
> +
> + /* Set the ECAM base */
> + writel(lower_32_bits(pci->dbi_phys_addr), pcie->parf + PARF_ECAM_BASE);
> + writel(upper_32_bits(pci->dbi_phys_addr), pcie->parf + PARF_ECAM_BASE_HI);
> +
> + /*
> + * On bus 0, we have only the root complex. Any access other than that
> + * should not go out of the link and should return all F's. Since the
> + * IATU is configured for bus 1 onwards, block the transactions for
> + * bus 0:0:1 to 0:31:7 (i.e from dbi_base + 4kb to dbi_base + 1MB) from

s/"for bus 0:0:1 to 0:31:7"/"starting from 0:0.1 to 0:31:7"

> + * going outside the link.
> + */
> + addr = pci->dbi_phys_addr + SZ_4K;
> + writel(lower_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_WR_BASE);
> + writel(upper_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_WR_BASE_HI);
> +
> + writel(lower_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_RD_BASE);
> + writel(upper_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_RD_BASE_HI);
> +
> + addr_end = pci->dbi_phys_addr + SZ_1M - 1;
> +
> + writel(lower_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_WR_LIMIT);
> + writel(upper_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_WR_LIMIT_HI);
> +
> + writel(lower_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_RD_LIMIT);
> + writel(upper_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_RD_LIMIT_HI);
> +
> + val = readl(pcie->parf + PARF_SYS_CTRL);
> + val |= PCIE_ECAM_BLOCKER_EN;
> + writel(val, pcie->parf + PARF_SYS_CTRL);
> + return 0;
> +}
> +
> +static int qcom_pcie_ecam_init(struct dw_pcie *pci, struct pci_config_window *cfg)
> +{
> + struct qcom_pcie *pcie = to_qcom_pcie(pci);
> +
> + pcie->elbi = pci->dbi_base + ELBI_OFFSET;

Can't you derive this offset from DT?

- Mani

--
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