Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / x86 / pci / mmconfig_64.c

diff --git a/kernel/arch/x86/pci/mmconfig_64.c b/kernel/arch/x86/pci/mmconfig_64.c
new file mode 100644 (file)
index 0000000..bea5249
--- /dev/null
+++ b/kernel/arch/x86/pci/mmconfig_64.c
@@ -0,0 +1,153 @@
+/*
+ * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
+ *
+ * This is an 64bit optimized version that always keeps the full mmconfig
+ * space mapped. This allows lockless config space operation.
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/bitmap.h>
+#include <linux/rcupdate.h>
+#include <asm/e820.h>
+#include <asm/pci_x86.h>
+
+#define PREFIX "PCI: "
+
+static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
+{
+       struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
+
+       if (cfg && cfg->virt)
+               return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
+       return NULL;
+}
+
+static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
+                         unsigned int devfn, int reg, int len, u32 *value)
+{
+       char __iomem *addr;
+
+       /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
+       if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
+err:           *value = -1;
+               return -EINVAL;
+       }
+
+       rcu_read_lock();
+       addr = pci_dev_base(seg, bus, devfn);
+       if (!addr) {
+               rcu_read_unlock();
+               goto err;
+       }
+
+       switch (len) {
+       case 1:
+               *value = mmio_config_readb(addr + reg);
+               break;
+       case 2:
+               *value = mmio_config_readw(addr + reg);
+               break;
+       case 4:
+               *value = mmio_config_readl(addr + reg);
+               break;
+       }
+       rcu_read_unlock();
+
+       return 0;
+}
+
+static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
+                          unsigned int devfn, int reg, int len, u32 value)
+{
+       char __iomem *addr;
+
+       /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
+       if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
+               return -EINVAL;
+
+       rcu_read_lock();
+       addr = pci_dev_base(seg, bus, devfn);
+       if (!addr) {
+               rcu_read_unlock();
+               return -EINVAL;
+       }
+
+       switch (len) {
+       case 1:
+               mmio_config_writeb(addr + reg, value);
+               break;
+       case 2:
+               mmio_config_writew(addr + reg, value);
+               break;
+       case 4:
+               mmio_config_writel(addr + reg, value);
+               break;
+       }
+       rcu_read_unlock();
+
+       return 0;
+}
+
+const struct pci_raw_ops pci_mmcfg = {
+       .read =         pci_mmcfg_read,
+       .write =        pci_mmcfg_write,
+};
+
+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;
+               }
+
+       raw_pci_ext_ops = &pci_mmcfg;
+
+       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;
+       }
+}