Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / s390 / pci / pci_mmio.c

diff --git a/kernel/arch/s390/pci/pci_mmio.c b/kernel/arch/s390/pci/pci_mmio.c
new file mode 100644 (file)
index 0000000..b1bb2b7
--- /dev/null
+++ b/kernel/arch/s390/pci/pci_mmio.c
@@ -0,0 +1,114 @@
+/*
+ * Access to PCI I/O memory from user space programs.
+ *
+ * Copyright IBM Corp. 2014
+ * Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
+ */
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+
+static long get_pfn(unsigned long user_addr, unsigned long access,
+                   unsigned long *pfn)
+{
+       struct vm_area_struct *vma;
+       long ret;
+
+       down_read(&current->mm->mmap_sem);
+       ret = -EINVAL;
+       vma = find_vma(current->mm, user_addr);
+       if (!vma)
+               goto out;
+       ret = -EACCES;
+       if (!(vma->vm_flags & access))
+               goto out;
+       ret = follow_pfn(vma, user_addr, pfn);
+out:
+       up_read(&current->mm->mmap_sem);
+       return ret;
+}
+
+SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
+               const void __user *, user_buffer, size_t, length)
+{
+       u8 local_buf[64];
+       void __iomem *io_addr;
+       void *buf;
+       unsigned long pfn;
+       long ret;
+
+       if (!zpci_is_enabled())
+               return -ENODEV;
+
+       if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
+               return -EINVAL;
+       if (length > 64) {
+               buf = kmalloc(length, GFP_KERNEL);
+               if (!buf)
+                       return -ENOMEM;
+       } else
+               buf = local_buf;
+
+       ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
+       if (ret)
+               goto out;
+       io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
+
+       ret = -EFAULT;
+       if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
+               goto out;
+
+       if (copy_from_user(buf, user_buffer, length))
+               goto out;
+
+       ret = zpci_memcpy_toio(io_addr, buf, length);
+out:
+       if (buf != local_buf)
+               kfree(buf);
+       return ret;
+}
+
+SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
+               void __user *, user_buffer, size_t, length)
+{
+       u8 local_buf[64];
+       void __iomem *io_addr;
+       void *buf;
+       unsigned long pfn;
+       long ret;
+
+       if (!zpci_is_enabled())
+               return -ENODEV;
+
+       if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
+               return -EINVAL;
+       if (length > 64) {
+               buf = kmalloc(length, GFP_KERNEL);
+               if (!buf)
+                       return -ENOMEM;
+       } else
+               buf = local_buf;
+
+       ret = get_pfn(mmio_addr, VM_READ, &pfn);
+       if (ret)
+               goto out;
+       io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
+
+       if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
+               ret = -EFAULT;
+               goto out;
+       }
+       ret = zpci_memcpy_fromio(buf, io_addr, length);
+       if (ret)
+               goto out;
+       if (copy_to_user(user_buffer, buf, length))
+               ret = -EFAULT;
+
+out:
+       if (buf != local_buf)
+               kfree(buf);
+       return ret;
+}