Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936737AbcCQUeC (ORCPT ); Thu, 17 Mar 2016 16:34:02 -0400 Received: from mail-gw1-out.broadcom.com ([216.31.210.62]:30637 "EHLO mail-gw1-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936707AbcCQUd5 (ORCPT ); Thu, 17 Mar 2016 16:33:57 -0400 X-Greylist: delayed 583 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Mar 2016 16:33:57 EDT X-IronPort-AV: E=Sophos;i="5.24,351,1455004800"; d="scan'208";a="90598696" From: Jayachandran C To: Bjorn Helgaas , Tomasz Nowicki , rafael@kernel.org Cc: Jayachandran C , Arnd Bergmann , Will Deacon , Catalin Marinas , Hanjun Guo , Lorenzo Pieralisi , okaya@codeaurora.org, jiang.liu@linux.intel.com, Stefano Stabellini , robert.richter@caviumnetworks.com, Marcin Wojtas , Liviu.Dudau@arm.com, David Daney , wangyijing@huawei.com, Suravee.Suthikulpanit@amd.com, msalter@redhat.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org, Jon Masters Subject: [RFC PATCH 1/4] PCI: Provide generic ECAM mapping functions Date: Fri, 18 Mar 2016 01:48:30 +0530 Message-Id: <1458245913-17211-2-git-send-email-jchandra@broadcom.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1458245913-17211-1-git-send-email-jchandra@broadcom.com> References: <1458245913-17211-1-git-send-email-jchandra@broadcom.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5907 Lines: 204 Add config option PCI_GENERIC_ECAM and file drivers/pci/ecam.c to provide generic functions to access memory mapped PCI config space. The API defines 'struct pci_config_window' to hold the mappings. The function pci_generic_map_config() is provided to allocate the struct, request the memory region, and do the ioremap() calls needed to setup the mapping. pci_generic_unmap_config() is provided to delete a mapping. A helper function pci_generic_map_bus() is also provided to be used to implement pci_ops map_bus method. Signed-off-by: Jayachandran C --- drivers/pci/Kconfig | 3 ++ drivers/pci/Makefile | 2 + drivers/pci/ecam.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 10 ++++ 4 files changed, 142 insertions(+) create mode 100644 drivers/pci/ecam.c diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 209292e..e930d62 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -83,6 +83,9 @@ config HT_IRQ config PCI_ATS bool +config PCI_GENERIC_ECAM + bool + config PCI_IOV bool "PCI IOV support" depends on PCI diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 2154092..810aec8 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -55,6 +55,8 @@ obj-$(CONFIG_PCI_SYSCALL) += syscall.o obj-$(CONFIG_PCI_STUB) += pci-stub.o +obj-$(CONFIG_PCI_GENERIC_ECAM) += ecam.o + obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o obj-$(CONFIG_OF) += of.o diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c new file mode 100644 index 0000000..6a63901 --- /dev/null +++ b/drivers/pci/ecam.c @@ -0,0 +1,127 @@ +/* + * Copyright 2016 Broadcom + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation (the "GPL"). + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 (GPLv2) for more details. + * + * You should have received a copy of the GNU General Public License + * version 2 (GPLv2) along with this source code. + */ + +#include +#include +#include +#include +#include +#include + +/* + * On 64 bit systems, we do a single ioremap for the whole config space + * since we have enough virtual address range available. On 32 bit, do an + * ioremap per bus. + */ +static const bool per_bus_mapping = !config_enabled(CONFIG_64BIT); + +/* + * struct to hold the mappings of a config space window. This + * will be allocated with enough entries in win[] to hold all + * the mappings for the bus range. + */ +struct pci_config_window { + phys_addr_t cfgaddr; + u8 bus_start; + u8 bus_end; + u8 bus_shift; + u8 devfn_shift; + void __iomem *win[0]; +}; + +/* + * helper function provided to implement the pci_ops ->map_bus method + */ +void __iomem *pci_generic_map_bus(struct pci_config_window *cfg, + unsigned int busn, unsigned int devfn, int where) +{ + void __iomem *base; + + if (busn < cfg->bus_start || busn > cfg->bus_end) + return NULL; + + busn -= cfg->bus_start; + if (per_bus_mapping) + base = cfg->win[busn]; + else + base = cfg->win[0] + (busn << cfg->bus_shift); + return base + (devfn << cfg->devfn_shift) + where; +} + +/* + * Create a PCI config space window + * - reserve mem region + * - alloc struct pci_config_window with space for all mappings + * - ioremap the config space + */ +struct pci_config_window *pci_generic_map_config(phys_addr_t addr, + u8 bus_start, u8 bus_end, u8 bus_shift, u8 devfn_shift) +{ + struct pci_config_window *cfg; + unsigned int bus_range, bsz, mapsz; + int i, nidx; + + if (bus_end < bus_start) + return ERR_PTR(-EINVAL); + + bus_range = bus_end - bus_start + 1; + bsz = 1 << bus_shift; + nidx = per_bus_mapping ? bus_range : 1; + mapsz = per_bus_mapping ? bsz : bus_range * bsz; + cfg = kzalloc(sizeof(*cfg) + nidx * sizeof(cfg->win[0]), GFP_KERNEL); + if (!cfg) + return ERR_PTR(-ENOMEM); + + cfg->bus_start = bus_start; + cfg->bus_end = bus_end; + cfg->bus_shift = bus_shift; + cfg->devfn_shift = devfn_shift; + + if (!request_mem_region(addr, bus_range * bsz, "Configuration Space")) + goto err_exit; + + /* cfgaddr has to be set after request_mem_region */ + cfg->cfgaddr = addr; + + for (i = 0; i < nidx; i++) { + cfg->win[i] = ioremap(addr + i * mapsz, mapsz); + if (!cfg->win[i]) + goto err_exit; + } + return cfg; + +err_exit: + pci_generic_unmap_config(cfg); + return ERR_PTR(-ENOMEM); +} + +/* + * Free a config space mapping + */ +void pci_generic_unmap_config(struct pci_config_window *cfg) +{ + unsigned int bus_range; + int i, nidx; + + bus_range = cfg->bus_end - cfg->bus_start + 1; + nidx = per_bus_mapping ? bus_range : 1; + for (i = 0; i < nidx; i++) + if (cfg->win[i]) + iounmap(cfg->win[i]); + if (cfg->cfgaddr) + release_mem_region(cfg->cfgaddr, bus_range << cfg->bus_shift); + kfree(cfg); +} diff --git a/include/linux/pci.h b/include/linux/pci.h index 3df9e37..33c46bc 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -2013,6 +2013,16 @@ static inline bool pci_ari_enabled(struct pci_bus *bus) return bus->self && bus->self->ari_enabled; } +/* Generic ECAM mapping API */ +#ifdef CONFIG_PCI_GENERIC_ECAM +struct pci_config_window; +void __iomem *pci_generic_map_bus(struct pci_config_window *cfg, + unsigned int busn, unsigned int devfn, int where); +struct pci_config_window *pci_generic_map_config(phys_addr_t addr, + u8 bus_start, u8 bus_end, u8 bus_shift, u8 devfn_shift); +void pci_generic_unmap_config(struct pci_config_window *cfg); +#endif + /* provide the legacy pci_dma_* API */ #include -- 1.9.1