[PATCH v5 5/5] PCI: ACPI: Add a generic ACPI based host controller
Jayachandran C
jchandra at broadcom.com
Sun Jan 3 21:13:23 PST 2016
Add a simple ACPI based PCI host controller. This is done by
providing a simple implementation for pci_acpi_scan_root().
The pci_mmcfg_list handling is done by the ACPI code, we
keep a reference to the pci_mmcfg_region which is already
mapped.
Provide implementations of raw_pci_read and raw_pci_write based
on the pci_mmcfg_list
This is enabled only for ARM64 now.
Signed-off-by: Jayachandran C <jchandra at broadcom.com>
---
drivers/acpi/Kconfig | 8 ++
drivers/acpi/Makefile | 1 +
drivers/acpi/pci_host_acpi.c | 186 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 195 insertions(+)
create mode 100644 drivers/acpi/pci_host_acpi.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 25dbb76..dceb871 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -283,6 +283,14 @@ 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 0780ced..52eb38f 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;
+}
--
1.9.1
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