On Fri, Apr 15, 2016 at 10:36 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote: > This patch is going to implement generic PCI host controller for > ACPI world, similar to what pci-host-generic.c driver does for DT world. > > All such drivers, which we have seen so far, were implemented within > arch/ directory since they had some arch assumptions (x86 and ia64). > However, they all are doing similar thing, so it makes sense to find > some common code and abstract it into the generic driver. > > In order to handle PCI config space regions properly, we define new > MCFG interface which parses MCFG table and keep its entries > in a list. New pci_mcfg_init call is defined so that we do not depend > on PCI_MMCONFIG. Regions are not mapped until host bridge ask for it. > > The implementation of pci_acpi_scan_root() looks up the saved MCFG entries > and sets up a new mapping. Generic PCI functions are used for > accessing config space. Driver selects PCI_GENERIC_ECAM and uses functions > from drivers/pci/ecam.h to create and access ECAM mappings. > > As mentioned in Kconfig help section, ACPI_PCI_HOST_GENERIC choice > should be made on a per-architecture basis. > > This patch is heavily based on the updated version from Jayachandran C: > https://lkml.org/lkml/2016/4/11/908 > git: https://github.com/jchandra-brcm/linux/ (arm64-acpi-pci-v3) This is a little bit unusual because I had not posted the v3 patch to the mailing list yet, but you posted a variant of it The git repository should not be in the commit comment because it is a temporary location. There are some changes here I don't agree with. I think it will be better if you can post a version without the quirk handling and with some of the suggestions below. > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx> > --- > drivers/acpi/Kconfig | 8 ++ > drivers/acpi/Makefile | 1 + > drivers/acpi/bus.c | 1 + > drivers/acpi/pci_gen_host.c | 231 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 6 ++ > 5 files changed, 247 insertions(+) > create mode 100644 drivers/acpi/pci_gen_host.c > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 183ffa3..70272c5 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -346,6 +346,14 @@ config ACPI_PCI_SLOT > i.e., segment/bus/device/function tuples, with physical slots in > the system. If you are unsure, say N. > > +config ACPI_PCI_HOST_GENERIC > + bool > + select PCI_GENERIC_ECAM > + help > + Select this config option from the architecture Kconfig, > + if it is preferred to enable ACPI PCI host controller driver which > + has no arch-specific assumptions. > + > config X86_PM_TIMER > bool "Power Management Timer Support" if EXPERT > depends on X86 > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 81e5cbc..b12fa64 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -40,6 +40,7 @@ acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o > acpi-y += ec.o > acpi-$(CONFIG_ACPI_DOCK) += dock.o > acpi-y += pci_root.o pci_link.o pci_irq.o > +obj-$(CONFIG_ACPI_PCI_HOST_GENERIC) += pci_gen_host.o > acpi-y += acpi_lpss.o acpi_apd.o > acpi-y += acpi_platform.o > acpi-y += acpi_pnp.o > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index c068c82..803a1d7 100644 > --- a/drivers/acpi/bus.c > +++ b/drivers/acpi/bus.c > @@ -1107,6 +1107,7 @@ static int __init acpi_init(void) > } > > pci_mmcfg_late_init(); > + pci_mcfg_init(); Please see below. > acpi_scan_init(); > acpi_ec_init(); > acpi_debugfs_init(); > diff --git a/drivers/acpi/pci_gen_host.c b/drivers/acpi/pci_gen_host.c > new file mode 100644 > index 0000000..fd360b5 > --- /dev/null > +++ b/drivers/acpi/pci_gen_host.c > @@ -0,0 +1,231 @@ > +/* You seem to have removed the copyright line, this is not proper, you should probably add your copyright line if you think your changes are significant. > + * 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 <linux/kernel.h> > +#include <linux/pci.h> > +#include <linux/pci-acpi.h> > +#include <linux/sfi_acpi.h> > +#include <linux/slab.h> > + > +#include "../pci/ecam.h" > + > +#define PREFIX "ACPI: " > + > +/* Structure to hold entries from the MCFG table */ > +struct mcfg_entry { > + struct list_head list; > + phys_addr_t addr; > + u16 segment; > + u8 bus_start; > + u8 bus_end; > +}; > + > +/* List to save mcfg entries */ > +static LIST_HEAD(pci_mcfg_list); > +static DEFINE_MUTEX(pci_mcfg_lock); There is no need to use a list or lock here, I had used an array and that is sufficient since it is not modified after it is filled initially. > +/* ACPI info for generic ACPI PCI controller */ > +struct acpi_pci_generic_root_info { > + struct acpi_pci_root_info common; > + struct pci_config_window *cfg; /* config space mapping */ > +}; > + > +/* Find the entry in mcfg list which contains range bus_start */ > +static struct mcfg_entry *pci_mcfg_lookup(u16 seg, u8 bus_start) > +{ > + struct mcfg_entry *e; > + > + list_for_each_entry(e, &pci_mcfg_list, list) { > + if (e->segment == seg && > + e->bus_start <= bus_start && bus_start <= e->bus_end) > + return e; > + } > + > + return NULL; > +} > + > + > +/* > + * Lookup the bus range for the domain in MCFG, and set up config space > + * mapping. > + */ > +static int pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root, > + struct acpi_pci_generic_root_info *ri) > +{ > + u16 seg = root->segment; > + u8 bus_start = root->secondary.start; > + u8 bus_end = root->secondary.end; > + struct pci_config_window *cfg; > + struct mcfg_entry *e; > + phys_addr_t addr; > + int err = 0; > + > + mutex_lock(&pci_mcfg_lock); > + e = pci_mcfg_lookup(seg, bus_start); > + if (!e) { > + addr = acpi_pci_root_get_mcfg_addr(root->device->handle); The acpi_pci_root_get_mcfg_addr() is already called in pci_root.c, doing it again here is unnecessary. I think you can have a function to pick up addr, bus_start, bus_end given a domain from either MCFG or using _CBA method, but I think that should be done in pci_root.c in a separate patch. > + if (addr == 0) { > + pr_err(PREFIX"%04x:%02x-%02x bus range error\n", > + seg, bus_start, bus_end); > + err = -ENOENT; > + goto err_out; > + } > + } else { > + if (bus_start != e->bus_start) { > + pr_err("%04x:%02x-%02x bus range mismatch %02x\n", > + seg, bus_start, bus_end, e->bus_start); > + err = -EINVAL; > + goto err_out; > + } else if (bus_end != e->bus_end) { > + pr_warn("%04x:%02x-%02x bus end mismatch %02x\n", > + seg, bus_start, bus_end, e->bus_end); > + bus_end = min(bus_end, e->bus_end); > + } > + addr = e->addr; > + } > + > + cfg = pci_generic_ecam_create(&root->device->dev, addr, bus_start, > + bus_end, &pci_generic_ecam_default_ops); > + if (IS_ERR(cfg)) { > + err = PTR_ERR(cfg); > + pr_err("%04x:%02x-%02x error %d mapping CAM\n", seg, > + bus_start, bus_end, err); > + goto err_out; > + } You seem to have moved all the config space mapping to this point. Intel seems to do the mapping when they read MCFG for the entries, and I had followed that model, and that avoids having another array/list to save the values. > + cfg->domain = seg; > + ri->cfg = cfg; > +err_out: > + mutex_unlock(&pci_mcfg_lock); > + return err; > +} > + > +/* release_info: free resrouces allocated by init_info */ > +static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci) > +{ > + struct acpi_pci_generic_root_info *ri; > + > + ri = container_of(ci, struct acpi_pci_generic_root_info, common); > + pci_generic_ecam_free(ri->cfg); > + kfree(ri); > +} > + > +static struct acpi_pci_root_ops acpi_pci_root_ops = { > + .release_info = pci_acpi_generic_release_info, > +}; > + > +/* Interface called from ACPI code to setup PCI host controller */ > +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) > +{ > + int node = acpi_get_node(root->device->handle); > + struct acpi_pci_generic_root_info *ri; > + struct pci_bus *bus, *child; > + int err; > + > + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node); > + if (!ri) > + return NULL; > + > + err = pci_acpi_setup_ecam_mapping(root, ri); > + if (err) > + return NULL; > + > + acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops; > + bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common, > + ri->cfg); > + if (!bus) > + 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; > +} > + > +/* handle MCFG table entries */ > +static __init int pci_mcfg_parse(struct acpi_table_header *header) > +{ > + struct acpi_table_mcfg *mcfg; > + struct acpi_mcfg_allocation *mptr; > + struct mcfg_entry *e, *arr; > + int i, n; > + > + if (!header) > + return -EINVAL; > + > + mcfg = (struct acpi_table_mcfg *)header; > + mptr = (struct acpi_mcfg_allocation *) &mcfg[1]; > + n = (header->length - sizeof(*mcfg)) / sizeof(*mptr); > + if (n <= 0 || n > 255) { > + pr_err(PREFIX " MCFG has incorrect entries (%d).\n", n); > + return -EINVAL; > + } > + > + arr = kcalloc(n, sizeof(*arr), GFP_KERNEL); > + if (!arr) > + return -ENOMEM; Here you already have an array which is also connected as a linked list which is unnecessary. > + for (i = 0, e = arr; i < n; i++, mptr++, e++) { > + e->segment = mptr->pci_segment; > + e->addr = mptr->address; > + e->bus_start = mptr->start_bus_number; > + e->bus_end = mptr->end_bus_number; > + list_add(&e->list, &pci_mcfg_list); > + pr_info(PREFIX > + "MCFG entry for domain %04x [bus %02x-%02x] (base %pa)\n", > + e->segment, e->bus_start, e->bus_end, &e->addr); > + } > + > + return 0; > +} > + > +/* Interface called by ACPI - parse and save MCFG table */ > +void __init pci_mcfg_init(void) > +{ > + int err = acpi_table_parse(ACPI_SIG_MCFG, pci_mcfg_parse); > + if (err) > + pr_err(PREFIX "Failed to parse MCFG (%d)\n", err); > + else if (list_empty(&pci_mcfg_list)) > + pr_info(PREFIX "No valid entries in MCFG table.\n"); > + else { > + struct mcfg_entry *e; > + int i = 0; > + list_for_each_entry(e, &pci_mcfg_list, list) > + i++; > + pr_info(PREFIX "MCFG table loaded, %d entries\n", i); > + } > +} > + > +/* Raw operations, works only for MCFG entries with an associated bus */ > +int raw_pci_read(unsigned int domain, unsigned int busn, unsigned int devfn, > + int reg, int len, u32 *val) > +{ > + struct pci_bus *bus = pci_find_bus(domain, busn); > + > + if (!bus) > + return PCIBIOS_DEVICE_NOT_FOUND; > + return bus->ops->read(bus, devfn, reg, len, val); > +} > + > +int raw_pci_write(unsigned int domain, unsigned int busn, unsigned int devfn, > + int reg, int len, u32 val) > +{ > + struct pci_bus *bus = pci_find_bus(domain, busn); > + > + if (!bus) > + return PCIBIOS_DEVICE_NOT_FOUND; > + return bus->ops->write(bus, devfn, reg, len, val); > +} > diff --git a/include/linux/pci.h b/include/linux/pci.h > index df1f33d..c0422ea 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1729,6 +1729,12 @@ static inline void pci_mmcfg_early_init(void) { } > static inline void pci_mmcfg_late_init(void) { } > #endif > > +#ifdef CONFIG_ACPI_PCI_HOST_GENERIC > +void __init pci_mcfg_init(void); > +#else > +static inline void pci_mcfg_init(void) { return; } > +#endif You can still use the function pci_mmcfg_late_init() if PCI_MMCONFIG or ACPI_PCI_HOST_GENERIC is defined > + > int pci_ext_cfg_avail(void); > > void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar); JC. -- 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
