From 6104033bd25ef48d2013220f66632d8b0fc8cddb Mon Sep 17 00:00:00 2001 From: Vidya Sagar Date: Wed, 30 Dec 2020 22:27:23 +0530 Subject: PCI: dwc: Work around ECRC configuration issue DesignWare core has a TLP digest (TD) override bit in one of the control registers of ATU. This bit also needs to be programmed for proper ECRC functionality. This is currently identified as an issue with DesignWare IP version 4.90a. [bhelgaas: fix typos/grammar errors] Link: https://lore.kernel.org/r/20201230165723.673-1-vidyas@nvidia.com Signed-off-by: Vidya Sagar Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Bjorn Helgaas --- drivers/pci/controller/dwc/pcie-designware.c | 49 ++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 645fa1892375..c49c8b5b4800 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -225,6 +225,47 @@ static void dw_pcie_writel_ob_unroll(struct dw_pcie *pci, u32 index, u32 reg, dw_pcie_writel_atu(pci, offset + reg, val); } +static inline u32 dw_pcie_enable_ecrc(u32 val) +{ + /* + * DesignWare core version 4.90A has a design issue where the 'TD' + * bit in the Control register-1 of the ATU outbound region acts + * like an override for the ECRC setting, i.e., the presence of TLP + * Digest (ECRC) in the outgoing TLPs is solely determined by this + * bit. This is contrary to the PCIe spec which says that the + * enablement of the ECRC is solely determined by the AER + * registers. + * + * Because of this, even when the ECRC is enabled through AER + * registers, the transactions going through ATU won't have TLP + * Digest as there is no way the PCI core AER code could program + * the TD bit which is specific to the DesignWare core. + * + * The best way to handle this scenario is to program the TD bit + * always. It affects only the traffic from root port to downstream + * devices. + * + * At this point, + * When ECRC is enabled in AER registers, everything works normally + * When ECRC is NOT enabled in AER registers, then, + * on Root Port:- TLP Digest (DWord size) gets appended to each packet + * even through it is not required. Since downstream + * TLPs are mostly for configuration accesses and BAR + * accesses, they are not in critical path and won't + * have much negative effect on the performance. + * on End Point:- TLP Digest is received for some/all the packets coming + * from the root port. TLP Digest is ignored because, + * as per the PCIe Spec r5.0 v1.0 section 2.2.3 + * "TLP Digest Rules", when an endpoint receives TLP + * Digest when its ECRC check functionality is disabled + * in AER registers, received TLP Digest is just ignored. + * Since there is no issue or error reported either side, best way to + * handle the scenario is to program TD bit by default. + */ + + return val | PCIE_ATU_TD; +} + static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no, int index, int type, u64 cpu_addr, u64 pci_addr, @@ -248,6 +289,8 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no, val = type | PCIE_ATU_FUNC_NUM(func_no); val = upper_32_bits(size - 1) ? val | PCIE_ATU_INCREASE_REGION_SIZE : val; + if (pci->version == 0x490A) + val = dw_pcie_enable_ecrc(val); dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1, val); dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2, PCIE_ATU_ENABLE); @@ -294,8 +337,10 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no, 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); + if (pci->version == 0x490A) + val = dw_pcie_enable_ecrc(val); + dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val); dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, PCIE_ATU_ENABLE); /* -- cgit From 3856e1c5b88e5d363c251a2bc0d9fd0efdc6184a Mon Sep 17 00:00:00 2001 From: Shradha Todi Date: Wed, 6 Jan 2021 16:15:00 +0530 Subject: PCI: dwc: Change size to u64 for EP outbound iATU Since outbound iATU permits size to be greater than 4GB for which the support is also available, allow EP function to send u64 size instead of truncating to u32. Link: https://lore.kernel.org/r/1609929900-19082-1-git-send-email-shradha.t@samsung.com Signed-off-by: Shradha Todi Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Pankaj Dubey --- drivers/pci/controller/dwc/pcie-designware.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index c49c8b5b4800..e7b9a7d7c9a2 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -366,7 +366,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type, void dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index, int type, u64 cpu_addr, u64 pci_addr, - u32 size) + u64 size) { __dw_pcie_prog_outbound_atu(pci, func_no, index, type, cpu_addr, pci_addr, size); -- cgit From 5b4cf0f6532434537818e4a3c656b9f11c81729b Mon Sep 17 00:00:00 2001 From: Shradha Todi Date: Tue, 2 Feb 2021 12:58:38 +0530 Subject: 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. Link: https://lore.kernel.org/r/1612250918-19610-1-git-send-email-shradha.t@samsung.com Signed-off-by: Shradha Todi Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Pankaj Dubey Reviewed-by: Rob Herring --- drivers/pci/controller/dwc/pcie-designware.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index e7b9a7d7c9a2..fb637830bc71 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -333,11 +333,16 @@ 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)); val = type | PCIE_ATU_FUNC_NUM(func_no); + val = ((upper_32_bits(size - 1)) && (pci->version >= 0x460A)) ? + val | PCIE_ATU_INCREASE_REGION_SIZE : val; if (pci->version == 0x490A) val = dw_pcie_enable_ecrc(val); dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val); -- cgit From a2f882d84406ac3a31af09ebd2ec2410fda3e80d Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 28 Jan 2021 14:42:58 +0800 Subject: PCI: dwc: Don't assume the ops in dw_pcie always exist Some dwc-based device drivers, especially host-only drivers, may work well with the default read_dbi/write_dbi/link_up implementations in pcie-designware.c, so remove the assumption that every driver implements them to simplify those drivers. Link: https://lore.kernel.org/r/20210128144258.10329aa4@xhacker.debian Signed-off-by: Jisheng Zhang Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/dwc/pcie-designware.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index fb637830bc71..004cb860e266 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -141,7 +141,7 @@ u32 dw_pcie_read_dbi(struct dw_pcie *pci, u32 reg, size_t size) int ret; u32 val; - if (pci->ops->read_dbi) + if (pci->ops && pci->ops->read_dbi) return pci->ops->read_dbi(pci, pci->dbi_base, reg, size); ret = dw_pcie_read(pci->dbi_base + reg, size, &val); @@ -156,7 +156,7 @@ void dw_pcie_write_dbi(struct dw_pcie *pci, u32 reg, size_t size, u32 val) { int ret; - if (pci->ops->write_dbi) { + if (pci->ops && pci->ops->write_dbi) { pci->ops->write_dbi(pci, pci->dbi_base, reg, size, val); return; } @@ -171,7 +171,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val) { int ret; - if (pci->ops->write_dbi2) { + if (pci->ops && pci->ops->write_dbi2) { pci->ops->write_dbi2(pci, pci->dbi_base2, reg, size, val); return; } @@ -186,7 +186,7 @@ static u32 dw_pcie_readl_atu(struct dw_pcie *pci, u32 reg) int ret; u32 val; - if (pci->ops->read_dbi) + if (pci->ops && pci->ops->read_dbi) return pci->ops->read_dbi(pci, pci->atu_base, reg, 4); ret = dw_pcie_read(pci->atu_base + reg, 4, &val); @@ -200,7 +200,7 @@ static void dw_pcie_writel_atu(struct dw_pcie *pci, u32 reg, u32 val) { int ret; - if (pci->ops->write_dbi) { + if (pci->ops && pci->ops->write_dbi) { pci->ops->write_dbi(pci, pci->atu_base, reg, 4, val); return; } @@ -316,7 +316,7 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no, { u32 retries, val; - if (pci->ops->cpu_addr_fixup) + if (pci->ops && pci->ops->cpu_addr_fixup) cpu_addr = pci->ops->cpu_addr_fixup(pci, cpu_addr); if (pci->iatu_unroll_enabled) { @@ -531,7 +531,7 @@ int dw_pcie_link_up(struct dw_pcie *pci) { u32 val; - if (pci->ops->link_up) + if (pci->ops && pci->ops->link_up) return pci->ops->link_up(pci); val = readl(pci->dbi_base + PCIE_PORT_DEBUG1); -- cgit