Hi Jayachandran, On Fri, Jan 29, 2016 at 02:35:40PM +0530, Jayachandran C wrote: > Add a simple ACPI based PCI host controller under config option > ACPI_PCI_HOST_GENERIC. This is done by providing an implementation > of pci_acpi_scan_root(). > > The pci_mmcfg_list handling is done by the ACPI code, so we keep a > reference to the pci_mmcfg_region in sysdata. The ECAM region will > be already mapped, so map_bus can be implemented by using the > virt pointer for the pci_mmcfg_region. pci_generic_config_read > and pci_generic_config_write are used for config space read/write. > > Also, we provide implementations of raw_pci_read and raw_pci_write > hat are needed by ACPI based on the pci_mmcfg_list. > > pci_acpi_set_companion() and acpi_pci_get_segment() are defined > using sysdata of generic ACPI host controller so that PCI domain > and ACPI companion are set in PCI code rather than platform code. > > This code is currently enabled only for ARM64. > > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx> > --- > drivers/acpi/Kconfig | 8 ++ > drivers/acpi/Makefile | 1 + > drivers/acpi/pci_host_acpi.c | 186 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci-acpi.h | 17 ++++ > 4 files changed, 212 insertions(+) > create mode 100644 drivers/acpi/pci_host_acpi.c I'm speaking a little bit out of turn here, because this is ACPI code, but I'm confused about pci_host_acpi.c. We already have pci_root.c, which is *supposed* to be arch-independent. I know pci_root.c is crufty and could be improved, but it does work today on x86 and ia64, and it handles some generic things that pci_host_acpi.c does not, e.g., _OSC, NUMA, host bridge hotplug, etc. I'd really like to see pci_root.c improved so it could work on x86, ia64, and arm64. I'm sure that was probably the first thing you tried, so likely there are issues there. Are they insurmountable? Bjorn > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 82b96ee..65fb483 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -294,6 +294,14 @@ config ACPI_NUMA > depends on (X86 || IA64) > default y if IA64_GENERIC || IA64_SGI_SN2 > > +config ACPI_PCI_HOST_GENERIC > + bool "Generic ACPI PCI host controller" > + depends on ARM64 && ACPI > + help > + Say Y here if you want to support a simple generic ACPI PCI host > + controller. > + > + > config ACPI_CUSTOM_DSDT_FILE > string "Custom DSDT Table file to include" > default "" > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 74976f1..346101c 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -41,6 +41,7 @@ acpi-y += ec.o > acpi-$(CONFIG_ACPI_DOCK) += dock.o > acpi-y += pci_root.o pci_link.o pci_irq.o > acpi-$(CONFIG_PCI_MMCONFIG) += pci_mcfg.o > +acpi-$(CONFIG_ACPI_PCI_HOST_GENERIC) += pci_host_acpi.o > acpi-y += acpi_lpss.o acpi_apd.o > acpi-y += acpi_platform.o > acpi-y += acpi_pnp.o > diff --git a/drivers/acpi/pci_host_acpi.c b/drivers/acpi/pci_host_acpi.c > new file mode 100644 > index 0000000..9dbdd81 > --- /dev/null > +++ b/drivers/acpi/pci_host_acpi.c > @@ -0,0 +1,186 @@ > +/* > + * Generic PCI host controller driver for ACPI based systems > + * > + * 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. > + * > + * 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 for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + * > + * Copyright (c) 2015 Broadcom Corporation > + * > + * Based on drivers/pci/host/pci-host-generic.c > + * Copyright (C) 2014 ARM Limited > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/pci.h> > +#include <linux/acpi.h> > +#include <linux/pci-acpi.h> > +#include <linux/sfi_acpi.h> > +#include <linux/slab.h> > + > +#define PREFIX "pci-host-acpi:" > + > +/* sysdata pointer is ->root_info */ > +struct gen_acpi_root_info { > + struct acpi_pci_root_info common; > + struct pci_mmcfg_region *mcfg; > + bool mcfg_added; > +}; > + > +/* find mapping of a MCFG area */ > +static void __iomem *gen_acpi_map_cfg_bus(struct pci_bus *bus, > + unsigned int devfn, int where) > +{ > + struct gen_acpi_root_info *pci = bus->sysdata; > + struct pci_mmcfg_region *mcfg = pci->mcfg; > + > + if (bus->number < mcfg->start_bus || bus->number > mcfg->end_bus) > + return NULL; > + > + return mcfg->virt + > + PCI_MMCFG_OFFSET(bus->number - mcfg->start_bus, devfn) + > + where; > +} > + > +static struct pci_ops gen_acpi_pci_ops = { > + .map_bus = gen_acpi_map_cfg_bus, > + .read = pci_generic_config_read, > + .write = pci_generic_config_write, > +}; > + > +/* Insert the ECFG area for a root bus */ > +static int pci_acpi_root_init_info(struct acpi_pci_root_info *ci) > +{ > + struct gen_acpi_root_info *info; > + struct acpi_pci_root *root = ci->root; > + struct device *dev = &ci->bridge->dev; > + int err; > + > + info = container_of(ci, struct gen_acpi_root_info, common); > + err = pci_mmconfig_insert(dev, root->segment, root->secondary.start, > + root->secondary.end, root->mcfg_addr); > + if (err && err != -EEXIST) > + return err; > + > + info->mcfg = pci_mmconfig_lookup(root->segment, root->secondary.start); > + WARN_ON(info->mcfg == NULL); > + info->mcfg_added = (err == -EEXIST); > + return 0; > +} > + > +static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci) > +{ > + struct gen_acpi_root_info *info; > + struct acpi_pci_root *root = ci->root; > + > + info = container_of(ci, struct gen_acpi_root_info, common); > + if (info->mcfg_added) > + pci_mmconfig_delete(root->segment, root->secondary.start, > + root->secondary.end); > + info->mcfg = NULL; > +} > + > +static struct acpi_pci_root_ops pci_acpi_root_ops = { > + .pci_ops = &gen_acpi_pci_ops, > + .init_info = pci_acpi_root_init_info, > + .release_info = pci_acpi_root_release_info, > +}; > + > +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) > +{ > + struct acpi_device *device = root->device; > + struct gen_acpi_root_info *ri; > + struct pci_bus *bus, *child; > + > + /* allocate acpi_info/sysdata */ > + ri = devm_kzalloc(&device->dev, sizeof(*ri), GFP_KERNEL); > + if (!ri) { > + dev_err(&device->dev, > + "pci_bus %04x:%02x: ignored (out of memory)\n", > + root->segment, (int)root->secondary.start); > + return NULL; > + } > + > + bus = acpi_pci_root_create(root, &pci_acpi_root_ops, > + &ri->common, ri); > + if (!bus) { > + dev_err(&device->dev, "Scanning rootbus failed"); > + return NULL; > + } > + > + pci_bus_size_bridges(bus); > + pci_bus_assign_resources(bus); > + list_for_each_entry(child, &bus->children, node) > + pcie_bus_configure_settings(child); > + > + return bus; > +} > + > +int raw_pci_read(unsigned int seg, unsigned int bus, > + unsigned int devfn, int reg, int len, u32 *val) > +{ > + struct pci_mmcfg_region *mcfg; > + void __iomem *addr; > + int err = -EINVAL; > + > + rcu_read_lock(); > + mcfg = pci_mmconfig_lookup(seg, bus); > + if (!mcfg || !mcfg->virt) > + goto err; > + > + addr = mcfg->virt + PCI_MMCFG_OFFSET(bus, devfn); > + switch (len) { > + case 1: > + *val = readb(addr + reg); > + break; > + case 2: > + *val = readw(addr + reg); > + break; > + case 4: > + *val = readl(addr + reg); > + break; > + } > + err = 0; > +err: > + rcu_read_unlock(); > + return err; > +} > + > +int raw_pci_write(unsigned int seg, unsigned int bus, > + unsigned int devfn, int reg, int len, u32 val) > +{ > + struct pci_mmcfg_region *mcfg; > + void __iomem *addr; > + int err = -EINVAL; > + > + rcu_read_lock(); > + mcfg = pci_mmconfig_lookup(seg, bus); > + if (!mcfg || !mcfg->virt) > + goto err; > + > + addr = mcfg->virt + PCI_MMCFG_OFFSET(bus, devfn); > + switch (len) { > + case 1: > + writeb(val, addr + reg); > + break; > + case 2: > + writew(val, addr + reg); > + break; > + case 4: > + writel(val, addr + reg); > + break; > + } > + err = 0; > +err: > + rcu_read_unlock(); > + return err; > +} > diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h > index d410885..f8d62e3 100644 > --- a/include/linux/pci-acpi.h > +++ b/include/linux/pci-acpi.h > @@ -143,6 +143,22 @@ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } > static inline void acpi_pci_remove_bus(struct pci_bus *bus) { } > #endif /* CONFIG_ACPI */ > > +#if defined(CONFIG_ACPI) && defined(CONFIG_ACPI_PCI_HOST_GENERIC) > +static inline void pci_acpi_set_companion(struct pci_host_bridge *bridge) > +{ > + struct pci_bus *b = bridge->bus; > + struct acpi_pci_root_info *ci = (struct acpi_pci_root_info *)b->sysdata; > + > + ACPI_COMPANION_SET(&bridge->dev, ci->bridge); > +} > + > +static inline u16 acpi_pci_get_segment(void *sysdata) > +{ > + struct acpi_pci_root_info *ci = (struct acpi_pci_root_info *)sysdata; > + > + return ci->root->segment; > +} > +#else > static inline void pci_acpi_set_companion(struct pci_host_bridge *bridge) > { > /* leave it to the platform for now */ > @@ -152,6 +168,7 @@ static inline u16 acpi_pci_get_segment(void *sysdata) > { > return 0; > } > +#endif > > #ifdef CONFIG_ACPI_APEI > extern bool aer_acpi_firmware_first(void); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
