Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752123AbdFTIVJ convert rfc822-to-8bit (ORCPT ); Tue, 20 Jun 2017 04:21:09 -0400 Received: from us-smtp-delivery-107.mimecast.com ([63.128.21.107]:52557 "EHLO us-smtp-delivery-107.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbdFTIUv (ORCPT ); Tue, 20 Jun 2017 04:20:51 -0400 Subject: [PATCH v9 2/3] PCI: Add tango PCIe host bridge support From: Marc Gonzalez To: Bjorn Helgaas , Marc Zyngier , Thomas Gleixner CC: linux-pci , Linux ARM , LKML , Mason , Thibaud Cornic References: <987fac41-80dc-f1d0-ec0b-91ae57b91bfd@sigmadesigns.com> Message-ID: Date: Tue, 20 Jun 2017 10:17:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0 SeaMonkey/2.49.1 MIME-Version: 1.0 In-Reply-To: <987fac41-80dc-f1d0-ec0b-91ae57b91bfd@sigmadesigns.com> X-Originating-IP: [172.27.0.114] X-MC-Unique: nfnOQAhqMryzSLbIhqnvBw-1 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6544 Lines: 228 This driver is required to work around several hardware bugs in the PCIe controller. NB: Revision 1 does not support legacy interrupts, or IO space. Signed-off-by: Marc Gonzalez --- drivers/pci/host/Kconfig | 8 +++ drivers/pci/host/Makefile | 1 + drivers/pci/host/pcie-tango.c | 164 ++++++++++++++++++++++++++++++++++++++++++ include/linux/pci_ids.h | 2 + 4 files changed, 175 insertions(+) create mode 100644 drivers/pci/host/pcie-tango.c diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index d7e7c0a827c3..5183d9095c3a 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -285,6 +285,14 @@ config PCIE_ROCKCHIP There is 1 internal PCIe port available to support GEN2 with 4 slots. +config PCIE_TANGO + bool "Tango PCIe controller" + depends on ARCH_TANGO && PCI_MSI && OF + select PCI_HOST_COMMON + help + Say Y here to enable PCIe controller support for Sigma Designs + Tango systems, such as SMP8759 and later chips. + config VMD depends on PCI_MSI && X86_64 tristate "Intel Volume Management Device Driver" diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index 084cb4983645..fc7ea90196f3 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -32,4 +32,5 @@ obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o +obj-$(CONFIG_PCIE_TANGO) += pcie-tango.o obj-$(CONFIG_VMD) += vmd.o diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c new file mode 100644 index 000000000000..67aaadcc1c5e --- /dev/null +++ b/drivers/pci/host/pcie-tango.c @@ -0,0 +1,164 @@ +#include +#include +#include + +#define MSI_MAX 256 + +#define SMP8759_MUX 0x48 +#define SMP8759_TEST_OUT 0x74 + +struct tango_pcie { + void __iomem *mux; +}; + +/*** HOST BRIDGE SUPPORT ***/ + +static int smp8759_config_read(struct pci_bus *bus, + unsigned int devfn, int where, int size, u32 *val) +{ + int ret; + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + + /* + * QUIRK #1 + * Reads in configuration space outside devfn 0 return garbage. + */ + if (devfn != 0) + return PCIBIOS_FUNC_NOT_SUPPORTED; + + /* + * QUIRK #2 + * Unfortunately, config and mem spaces are muxed. + * Linux does not support such a setting, since drivers are free + * to access mem space directly, at any time. + * Therefore, we can only PRAY that config and mem space accesses + * NEVER occur concurrently. + */ + writel_relaxed(1, pcie->mux); + ret = pci_generic_config_read(bus, devfn, where, size, val); + writel_relaxed(0, pcie->mux); + + return ret; +} + +static int smp8759_config_write(struct pci_bus *bus, + unsigned int devfn, int where, int size, u32 val) +{ + int ret; + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + + writel_relaxed(1, pcie->mux); + ret = pci_generic_config_write(bus, devfn, where, size, val); + writel_relaxed(0, pcie->mux); + + return ret; +} + +static struct pci_ecam_ops smp8759_ecam_ops = { + .bus_shift = 20, + .pci_ops = { + .map_bus = pci_ecam_map_bus, + .read = smp8759_config_read, + .write = smp8759_config_write, + } +}; + +static const struct of_device_id tango_pcie_ids[] = { + { .compatible = "sigma,smp8759-pcie" }, + { /* sentinel */ }, +}; + +static int tango_check_pcie_link(void __iomem *test_out) +{ + int i; + + writel_relaxed(16, test_out); + for (i = 0; i < 10; ++i) { + u32 ltssm_state = readl_relaxed(test_out) >> 8; + if ((ltssm_state & 0x1f) == 0xf) /* L0 */ + return 0; + usleep_range(3000, 4000); + } + + return -ENODEV; +} + +static int smp8759_init(struct tango_pcie *pcie, void __iomem *base) +{ + pcie->mux = base + SMP8759_MUX; + + return tango_check_pcie_link(base + SMP8759_TEST_OUT); +} + +static int tango_pcie_probe(struct platform_device *pdev) +{ + int ret = -EINVAL; + void __iomem *base; + struct resource *res; + struct tango_pcie *pcie; + struct device *dev = &pdev->dev; + + pr_err("MAJOR ISSUE: PCIe config and mem spaces are muxed\n"); + pr_err("Tainting kernel... Use driver at your own risk\n"); + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); + + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); + if (!pcie) + return -ENOMEM; + + platform_set_drvdata(pdev, pcie); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + if (of_device_is_compatible(dev->of_node, "sigma,smp8759-pcie")) + ret = smp8759_init(pcie, base); + + if (ret) + return ret; + + return pci_host_common_probe(pdev, &smp8759_ecam_ops); +} + +static struct platform_driver tango_pcie_driver = { + .probe = tango_pcie_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = tango_pcie_ids, + }, +}; + +builtin_platform_driver(tango_pcie_driver); + +/* + * QUIRK #3 + * The root complex advertizes the wrong device class. + * Header Type 1 is for PCI-to-PCI bridges. + */ +static void tango_fixup_class(struct pci_dev *dev) +{ + dev->class = PCI_CLASS_BRIDGE_PCI << 8; +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x24, tango_fixup_class); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x28, tango_fixup_class); + +/* + * QUIRK #4 + * The root complex exposes a "fake" BAR, which is used to filter + * bus-to-system accesses. Only accesses within the range defined + * by this BAR are forwarded to the host, others are ignored. + * + * By default, the DMA framework expects an identity mapping, + * and DRAM0 is mapped at 0x80000000. + */ +static void tango_fixup_bar(struct pci_dev *dev) +{ + dev->non_compliant_bars = true; + pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, 0x80000000); +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x24, tango_fixup_bar); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x28, tango_fixup_bar); diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index f020ab4079d3..b577dbe46f8f 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -1369,6 +1369,8 @@ #define PCI_DEVICE_ID_TTI_HPT374 0x0008 #define PCI_DEVICE_ID_TTI_HPT372N 0x0009 /* apparently a 372N variant? */ +#define PCI_VENDOR_ID_SIGMA 0x1105 + #define PCI_VENDOR_ID_VIA 0x1106 #define PCI_DEVICE_ID_VIA_8763_0 0x0198 #define PCI_DEVICE_ID_VIA_8380_0 0x0204 -- 2.11.0