[PATCH v7 5/5] PCI: ACPI: Add a generic ACPI based host controller
Jayachandran C
jchandra at broadcom.com
Fri Jan 29 01:05:40 PST 2016
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 at broadcom.com>
---
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
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
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