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

Krishna Chaitanya Chundru
2024-12-04T02:18:41Z

On 12/2/2024 10:23 PM, Manivannan Sadhasivam wrote:
> 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
instread of macro & dt In the next patch we will read a parf register
which will give the offset value from dbi, PARF_SLV_DBI_ELBI (0x1C001B4)

- Krishna Chaitanya.
>