These calls allow to map/unmap PCI config space ranges (which are specified in
MMCFG ACPI table).
Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
---
arch/arm64/Kconfig | 3 ++
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/mmconfig.c | 69 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+)
create mode 100644 arch/arm64/kernel/mmconfig.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index aee6a60..f2bcb58 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -186,6 +186,9 @@ config PCI_DOMAINS_GENERIC
config PCI_SYSCALL
def_bool PCI
+config PCI_MMCONFIG
+ def_bool PCI && ACPI
+
source "drivers/pci/Kconfig"
source "drivers/pci/pcie/Kconfig"
source "drivers/pci/hotplug/Kconfig"
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index f48e3f7..ec576e6 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -32,6 +32,7 @@ arm64-obj-$(CONFIG_KGDB) += kgdb.o
arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o
arm64-obj-$(CONFIG_PCI) += pci.o
arm64-obj-$(CONFIG_ACPI) += acpi.o
+arm64-obj-$(CONFIG_PCI_MMCONFIG) += mmconfig.o
obj-y += $(arm64-obj-y) vdso/
obj-m += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/mmconfig.c b/arch/arm64/kernel/mmconfig.c
new file mode 100644
index 0000000..b0ca0ec
--- /dev/null
+++ b/arch/arm64/kernel/mmconfig.c
@@ -0,0 +1,69 @@
+/*
+ * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
+ *
+ * This is an ARM64 version that allows the mmconfig space to be mapped.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/mmconfig.h>
+
+#define PREFIX "PCI: "
+
+static void __iomem *mcfg_ioremap(struct pci_mmcfg_region *cfg)
+{
+ void __iomem *addr;
+ u64 start, size;
+ int num_buses;
+
+ start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus);
+ num_buses = cfg->end_bus - cfg->start_bus + 1;
+ size = PCI_MMCFG_BUS_OFFSET(num_buses);
+ addr = ioremap_nocache(start, size);
+ if (addr)
+ addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus);
+ return addr;
+}
+
+int __init pci_mmcfg_arch_init(void)
+{
+ struct pci_mmcfg_region *cfg;
+
+ list_for_each_entry(cfg, &pci_mmcfg_list, list)
+ if (pci_mmcfg_arch_map(cfg)) {
+ pci_mmcfg_arch_free();
+ return 0;
+ }
+
+ return 1;
+}
+
+void __init pci_mmcfg_arch_free(void)
+{
+ struct pci_mmcfg_region *cfg;
+
+ list_for_each_entry(cfg, &pci_mmcfg_list, list)
+ pci_mmcfg_arch_unmap(cfg);
+}
+
+int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
+{
+ cfg->virt = mcfg_ioremap(cfg);
+ if (!cfg->virt) {
+ pr_err(PREFIX "can't map MMCONFIG at %pR\n", &cfg->res);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
+{
+ if (cfg && cfg->virt) {
+ iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
+ cfg->virt = NULL;
+ }
+}
--
1.9.1
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