From: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
To support the DWC ECAM mechanism, prepare the driver by performing below
configurations:
1. Since the ELBI region will be covered by the ECAM 'config' space,
override the 'elbi_base' with the address derived from 'dbi_base' and
the offset from PARF_SLV_DBI_ELBI register.
2. Block the transactions from the host bridge to devices other than Root
Port on the root bus to return all F's. This is required when the 'CFG
Shift Feature' of iATU is enabled.
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
[mani: code split, reworded subject/description and comments]
Signed-off-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom.c | 69 ++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 5092752de23866ef95036bb3f8fae9bb06e8ea1e..4324555de72adbdd3dcdf59497f9bd067d9c90ab 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -55,6 +55,7 @@
#define PARF_AXI_MSTR_WR_ADDR_HALT_V2 0x1a8
#define PARF_Q2A_FLUSH 0x1ac
#define PARF_LTSSM 0x1b0
+#define PARF_SLV_DBI_ELBI 0x1b4
#define PARF_INT_ALL_STATUS 0x224
#define PARF_INT_ALL_CLEAR 0x228
#define PARF_INT_ALL_MASK 0x22c
@@ -64,6 +65,16 @@
#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_OVERRIDE 0x3d4
#define PARF_ATU_BASE_ADDR 0x634
#define PARF_ATU_BASE_ADDR_HI 0x638
@@ -87,6 +98,7 @@
/* 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)
@@ -134,6 +146,9 @@
/* PARF_LTSSM register fields */
#define LTSSM_EN BIT(8)
+/* PARF_SLV_DBI_ELBI */
+#define SLV_DBI_ELBI_ADDR_BASE GENMASK(11, 0)
+
/* PARF_INT_ALL_{STATUS/CLEAR/MASK} register fields */
#define PARF_INT_ALL_LINK_UP BIT(13)
#define PARF_INT_MSI_DEV_0_7 GENMASK(30, 23)
@@ -317,6 +332,47 @@ static void qcom_ep_reset_deassert(struct qcom_pcie *pcie)
qcom_perst_assert(pcie, false);
}
+static void qcom_pci_config_ecam(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct qcom_pcie *pcie = to_qcom_pcie(pci);
+ u64 addr, addr_end;
+ u32 val;
+
+ writel_relaxed(lower_32_bits(pci->dbi_phys_addr), pcie->parf + PARF_ECAM_BASE);
+ writel_relaxed(upper_32_bits(pci->dbi_phys_addr), pcie->parf + PARF_ECAM_BASE_HI);
+
+ /*
+ * The only device on root bus is a single Root Port. So if PCI core
+ * tries to access any devices other than Device/Function (0.0) in Bus
+ * 0, the TLP will go outside of the controller to the PCI bus. But with
+ * CFG Shift Feature (ECAM) enabled in iATU, there is no guarantee that
+ * the response is going to be all F's. Hence, to make sure that the
+ * requester gets all F's response for accesses other than the Root
+ * Port, configure iATU to block the transactions starting from function
+ * 1 of the root bus to the end of the root bus (i.e from dbi_base + 4kb
+ * to dbi_base + 1MB).
+ */
+ addr = pci->dbi_phys_addr + SZ_4K;
+ writel_relaxed(lower_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_WR_BASE);
+ writel_relaxed(upper_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_WR_BASE_HI);
+
+ writel_relaxed(lower_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_RD_BASE);
+ writel_relaxed(upper_32_bits(addr), pcie->parf + PARF_BLOCK_SLV_AXI_RD_BASE_HI);
+
+ addr_end = pci->dbi_phys_addr + SZ_1M - 1;
+
+ writel_relaxed(lower_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_WR_LIMIT);
+ writel_relaxed(upper_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_WR_LIMIT_HI);
+
+ writel_relaxed(lower_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_RD_LIMIT);
+ writel_relaxed(upper_32_bits(addr_end), pcie->parf + PARF_BLOCK_SLV_AXI_RD_LIMIT_HI);
+
+ val = readl_relaxed(pcie->parf + PARF_SYS_CTRL);
+ val |= PCIE_ECAM_BLOCKER_EN;
+ writel_relaxed(val, pcie->parf + PARF_SYS_CTRL);
+}
+
static int qcom_pcie_start_link(struct dw_pcie *pci)
{
struct qcom_pcie *pcie = to_qcom_pcie(pci);
@@ -326,6 +382,9 @@ static int qcom_pcie_start_link(struct dw_pcie *pci)
qcom_pcie_common_set_16gt_lane_margining(pci);
}
+ if (pci->pp.ecam_enabled)
+ qcom_pci_config_ecam(&pci->pp);
+
/* Enable Link Training state machine */
if (pcie->cfg->ops->ltssm_enable)
pcie->cfg->ops->ltssm_enable(pcie);
@@ -1314,6 +1373,7 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct qcom_pcie *pcie = to_qcom_pcie(pci);
+ u16 offset;
int ret;
qcom_ep_reset_assert(pcie);
@@ -1322,6 +1382,15 @@ static int qcom_pcie_host_init(struct dw_pcie_rp *pp)
if (ret)
return ret;
+ if (pp->ecam_enabled) {
+ /*
+ * Override ELBI when ECAM is enabled, as when ECAM is enabled,
+ * ELBI moves under the 'config' space.
+ */
+ offset = FIELD_GET(SLV_DBI_ELBI_ADDR_BASE, readl(pcie->parf + PARF_SLV_DBI_ELBI));
+ pci->elbi_base = pci->dbi_base + offset;
+ }
+
ret = qcom_pcie_phy_power_on(pcie);
if (ret)
goto err_deinit;
--
2.45.2
