From 37bf0f4e39de9b53bc6f8d3702b021e2c6b5bae3 Mon Sep 17 00:00:00 2001 From: Ziyue Zhang Date: Thu, 4 Sep 2025 14:52:23 +0800 Subject: PCI: qcom: Add equalization settings for 8.0 GT/s and 32.0 GT/s Add lane equalization setting for 8.0 GT/s and 32.0 GT/s to enhance link stability and avoid AER Correctable Errors reported on some platforms (eg. SA8775P). 8.0 GT/s, 16.0 GT/s and 32.0 GT/s require the same equalization setting. This setting is programmed into a group of shadow registers, which can be switched to configure equalization for different speeds by writing 00b, 01b and 10b to `RATE_SHADOW_SEL`. Hence, program equalization registers in a loop using link speed as index, so that equalization setting can be programmed for 8.0 GT/s, 16.0 GT/s and 32.0 GT/s. Fixes: 489f14be0e0a ("arm64: dts: qcom: sa8775p: Add pcie0 and pcie1 nodes") Co-developed-by: Qiang Yu Signed-off-by: Qiang Yu Signed-off-by: Ziyue Zhang [mani: wrapped the warning to fit 100 columns, used post-increment for loop] Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250904065225.1762793-2-ziyue.zhang@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-designware.h | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.h') diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 00f52d472dcd..cc71a2d90cd4 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -123,7 +123,6 @@ #define GEN3_RELATED_OFF_GEN3_EQ_DISABLE BIT(16) #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT 24 #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK GENMASK(25, 24) -#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_16_0GT 0x1 #define GEN3_EQ_CONTROL_OFF 0x8A8 #define GEN3_EQ_CONTROL_OFF_FB_MODE GENMASK(3, 0) -- cgit v1.2.3 From ea5fbbc15906abdef174c88cecfec4b2a0c748b9 Mon Sep 17 00:00:00 2001 From: Ziyue Zhang Date: Thu, 4 Sep 2025 14:52:24 +0800 Subject: PCI: qcom: Fix macro typo for CURSOR Correct a typo in the macro names GEN3_EQ_FMDC_MAX_PRE_CURSOR_DELTA and GEN3_EQ_FMDC_MAX_POST_CURSOR_DELTA. Signed-off-by: Ziyue Zhang [mani: reworded description] Signed-off-by: Manivannan Sadhasivam Reviewed-by: Konrad Dybcio Link: https://patch.msgid.link/20250904065225.1762793-3-ziyue.zhang@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-designware.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.h') diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index cc71a2d90cd4..2418214730e4 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -133,8 +133,8 @@ #define GEN3_EQ_FB_MODE_DIR_CHANGE_OFF 0x8AC #define GEN3_EQ_FMDC_T_MIN_PHASE23 GENMASK(4, 0) #define GEN3_EQ_FMDC_N_EVALS GENMASK(9, 5) -#define GEN3_EQ_FMDC_MAX_PRE_CUSROR_DELTA GENMASK(13, 10) -#define GEN3_EQ_FMDC_MAX_POST_CUSROR_DELTA GENMASK(17, 14) +#define GEN3_EQ_FMDC_MAX_PRE_CURSOR_DELTA GENMASK(13, 10) +#define GEN3_EQ_FMDC_MAX_POST_CURSOR_DELTA GENMASK(17, 14) #define PCIE_PORT_MULTI_LANE_CTRL 0x8C0 #define PORT_MLTI_UPCFG_SUPPORT BIT(7) -- cgit v1.2.3 From c96992a24beca0768c1c42ad25d6a466e17ec70f Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Tue, 23 Sep 2025 16:56:51 +0530 Subject: PCI: dwc: Add support for ELBI resource mapping External Local Bus Interface (ELBI) is an optional register space for all DWC IPs containing the vendor specific registers. There is no need for the vendor glue drivers to fetch and map the ELBI region separately. Hence, optionally fetch and map the resource from DT in the DWC core. This also warrants dropping the corresponding code from glue drivers. Hence, drop the ELBI resource fetch and map logic from glue drivers and convert them to use 'dw_pci::elbi_base'. Note that the pcie-qcom-ep driver used devm_pci_remap_cfg_resource() to map the ELBI resource previously. But it was a mistake since devm_pci_remap_cfg_resource() should only be used for mapping the PCIe config space region as it maps the region as Non-Posted. As ELBI is used to hold vendor specific registers, there is no need to map the region as Non-Posted. With this conversion, the region will get mapped as normal MMIO memory. Suggested-by: Manivannan Sadhasivam Signed-off-by: Krishna Chaitanya Chundru [mani: removed elbi override, converted glue drivers and reworded description] Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250923-controller-dwc-ecam-v10-1-e84390ba75fa@kernel.org --- drivers/pci/controller/dwc/pcie-designware.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.h') diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 2418214730e4..9eb3c4c762dd 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -491,6 +491,7 @@ struct dw_pcie { resource_size_t dbi_phys_addr; void __iomem *dbi_base2; void __iomem *atu_base; + void __iomem *elbi_base; resource_size_t atu_phys_addr; size_t atu_size; resource_size_t parent_bus_offset; -- cgit v1.2.3 From f6fd357f7afbeb34a633e5688a23b9d7eb49d558 Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Tue, 23 Sep 2025 16:56:52 +0530 Subject: PCI: dwc: Prepare the driver for enabling ECAM mechanism using iATU 'CFG Shift Feature' In order to enable PCIe ECAM mechanism in DWC driver as per the 'CFG Shift Feature' documented in Designware databook r5.20a, sec 3.10.10.3, prepare the driver to handle the one time iATU setup and creating ECAM window. Signed-off-by: Krishna Chaitanya Chundru [mani: splitted the preparatory code into a separate commit for bisectability] Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250923-controller-dwc-ecam-v10-2-e84390ba75fa@kernel.org --- drivers/pci/controller/dwc/pcie-designware.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.h') diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 9eb3c4c762dd..779868e8fa8f 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -168,6 +169,7 @@ #define PCIE_ATU_REGION_CTRL2 0x004 #define PCIE_ATU_ENABLE BIT(31) #define PCIE_ATU_BAR_MODE_ENABLE BIT(30) +#define PCIE_ATU_CFG_SHIFT_MODE_ENABLE BIT(28) #define PCIE_ATU_INHIBIT_PAYLOAD BIT(22) #define PCIE_ATU_FUNC_NUM_MATCH_EN BIT(19) #define PCIE_ATU_LOWER_BASE 0x008 @@ -386,6 +388,7 @@ struct dw_pcie_ob_atu_cfg { u8 func_no; u8 code; u8 routing; + u32 ctrl2; u64 parent_bus_addr; u64 pci_addr; u64 size; @@ -424,6 +427,8 @@ struct dw_pcie_rp { struct resource *msg_res; bool use_linkup_irq; struct pci_eq_presets presets; + struct pci_config_window *cfg; + bool ecam_enabled; }; struct dw_pcie_ep_ops { -- cgit v1.2.3 From 0da48c5b2fa731b21bc523c82d927399a1e508b0 Mon Sep 17 00:00:00 2001 From: Krishna Chaitanya Chundru Date: Tue, 23 Sep 2025 16:56:54 +0530 Subject: PCI: dwc: Support ECAM mechanism by enabling iATU 'CFG Shift Feature' Designware databook r5.20a, sec 3.10.10.3 documents the 'CFG Shift Feature' of the internal Address Translation Unit (iATU). When this feature is enabled, it shifts/maps the BDF contained in the bits [27:12] of the target address in MEM TLP to become BDF of the CFG TLP. This essentially implements the Enhanced Configuration Address Mapping (ECAM) mechanism as defined in PCIe r6.0, sec 7.2.2. Currently, the driver is not making use of this CFG shift feature, thereby creating the iATU outbound map for each config access to the devices, causing latency and wasting CPU cycles. So to avoid this, configure the controller to enable CFG shift feature by enabling the 'CFG Shift' bit of the 'iATU Control 2 Register'. As a result of enabling CFG shift (ECAM), there is no longer a need to map the DBI register space separately as the DBI region falls under the 'config' space used for ECAM (as DBI is used to access the Root Port). For enabling ECAM using CFG shift, the platform has to satisfy following requirements: 1. Size of the 'config' memory space to be used as ECAM memory should be able to accommodate the number of buses defined in the 'bus-range' property of the host bridge DT node. 2. The 'config' memory space should be 256 MiB aligned. This requirement comes from PCIe r6.0, sec 7.2.2, which says the base address of ECAM memory should be aligned to a 2^(n+20) byte address boundary. For the DWC cores, n is 8, so this results in 2^28 byte alignment requirement. It should be noted that some DWC vendor glue drivers like pcie-al may use their own ECAM mechanism. For those controllers, set 'dw_pcie_rp::native_ecam' flag and skip enabling the CFG Shift feature in the DWC core. Signed-off-by: Krishna Chaitanya Chundru [mani: code split, reworded subject/description, comment, native_ecam flag] Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250923-controller-dwc-ecam-v10-4-e84390ba75fa@kernel.org --- drivers/pci/controller/dwc/pcie-designware.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.h') diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 779868e8fa8f..625320565360 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -429,6 +429,7 @@ struct dw_pcie_rp { struct pci_eq_presets presets; struct pci_config_window *cfg; bool ecam_enabled; + bool native_ecam; }; struct dw_pcie_ep_ops { -- cgit v1.2.3