336 lines
8.1 KiB
C
336 lines
8.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* 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>
|
||
|
|
#include <asm/asm-extable.h>
|
||
|
|
#include <asm/pci_io.h>
|
||
|
|
#include <asm/pci_debug.h>
|
||
|
|
|
||
|
|
static inline void zpci_err_mmio(u8 cc, u8 status, u64 offset)
|
||
|
|
{
|
||
|
|
struct {
|
||
|
|
u64 offset;
|
||
|
|
u8 cc;
|
||
|
|
u8 status;
|
||
|
|
} data = {offset, cc, status};
|
||
|
|
|
||
|
|
zpci_err_hex(&data, sizeof(data));
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int __pcistb_mio_inuser(
|
||
|
|
void __iomem *ioaddr, const void __user *src,
|
||
|
|
u64 len, u8 *status)
|
||
|
|
{
|
||
|
|
int cc = -ENXIO;
|
||
|
|
|
||
|
|
asm volatile (
|
||
|
|
" sacf 256\n"
|
||
|
|
"0: .insn rsy,0xeb00000000d4,%[len],%[ioaddr],%[src]\n"
|
||
|
|
"1: ipm %[cc]\n"
|
||
|
|
" srl %[cc],28\n"
|
||
|
|
"2: sacf 768\n"
|
||
|
|
EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
|
||
|
|
: [cc] "+d" (cc), [len] "+d" (len)
|
||
|
|
: [ioaddr] "a" (ioaddr), [src] "Q" (*((u8 __force *)src))
|
||
|
|
: "cc", "memory");
|
||
|
|
*status = len >> 24 & 0xff;
|
||
|
|
return cc;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int __pcistg_mio_inuser(
|
||
|
|
void __iomem *ioaddr, const void __user *src,
|
||
|
|
u64 ulen, u8 *status)
|
||
|
|
{
|
||
|
|
union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
|
||
|
|
int cc = -ENXIO;
|
||
|
|
u64 val = 0;
|
||
|
|
u64 cnt = ulen;
|
||
|
|
u8 tmp;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* copy 0 < @len <= 8 bytes from @src into the right most bytes of
|
||
|
|
* a register, then store it to PCI at @ioaddr while in secondary
|
||
|
|
* address space. pcistg then uses the user mappings.
|
||
|
|
*/
|
||
|
|
asm volatile (
|
||
|
|
" sacf 256\n"
|
||
|
|
"0: llgc %[tmp],0(%[src])\n"
|
||
|
|
"4: sllg %[val],%[val],8\n"
|
||
|
|
" aghi %[src],1\n"
|
||
|
|
" ogr %[val],%[tmp]\n"
|
||
|
|
" brctg %[cnt],0b\n"
|
||
|
|
"1: .insn rre,0xb9d40000,%[val],%[ioaddr_len]\n"
|
||
|
|
"2: ipm %[cc]\n"
|
||
|
|
" srl %[cc],28\n"
|
||
|
|
"3: sacf 768\n"
|
||
|
|
EX_TABLE(0b, 3b) EX_TABLE(4b, 3b) EX_TABLE(1b, 3b) EX_TABLE(2b, 3b)
|
||
|
|
:
|
||
|
|
[src] "+a" (src), [cnt] "+d" (cnt),
|
||
|
|
[val] "+d" (val), [tmp] "=d" (tmp),
|
||
|
|
[cc] "+d" (cc), [ioaddr_len] "+&d" (ioaddr_len.pair)
|
||
|
|
:: "cc", "memory");
|
||
|
|
*status = ioaddr_len.odd >> 24 & 0xff;
|
||
|
|
|
||
|
|
/* did we read everything from user memory? */
|
||
|
|
if (!cc && cnt != 0)
|
||
|
|
cc = -EFAULT;
|
||
|
|
|
||
|
|
return cc;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int __memcpy_toio_inuser(void __iomem *dst,
|
||
|
|
const void __user *src, size_t n)
|
||
|
|
{
|
||
|
|
int size, rc = 0;
|
||
|
|
u8 status = 0;
|
||
|
|
|
||
|
|
if (!src)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
while (n > 0) {
|
||
|
|
size = zpci_get_max_write_size((u64 __force) dst,
|
||
|
|
(u64 __force) src, n,
|
||
|
|
ZPCI_MAX_WRITE_SIZE);
|
||
|
|
if (size > 8) /* main path */
|
||
|
|
rc = __pcistb_mio_inuser(dst, src, size, &status);
|
||
|
|
else
|
||
|
|
rc = __pcistg_mio_inuser(dst, src, size, &status);
|
||
|
|
if (rc)
|
||
|
|
break;
|
||
|
|
src += size;
|
||
|
|
dst += size;
|
||
|
|
n -= size;
|
||
|
|
}
|
||
|
|
if (rc)
|
||
|
|
zpci_err_mmio(rc, status, (__force u64) dst);
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
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;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
pte_t *ptep;
|
||
|
|
spinlock_t *ptl;
|
||
|
|
long ret;
|
||
|
|
|
||
|
|
if (!zpci_is_enabled())
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We only support write access to MIO capable devices if we are on
|
||
|
|
* a MIO enabled system. Otherwise we would have to check for every
|
||
|
|
* address if it is a special ZPCI_ADDR and would have to do
|
||
|
|
* a pfn lookup which we don't need for MIO capable devices. Currently
|
||
|
|
* ISM devices are the only devices without MIO support and there is no
|
||
|
|
* known need for accessing these from userspace.
|
||
|
|
*/
|
||
|
|
if (static_branch_likely(&have_mio)) {
|
||
|
|
ret = __memcpy_toio_inuser((void __iomem *) mmio_addr,
|
||
|
|
user_buffer,
|
||
|
|
length);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (length > 64) {
|
||
|
|
buf = kmalloc(length, GFP_KERNEL);
|
||
|
|
if (!buf)
|
||
|
|
return -ENOMEM;
|
||
|
|
} else
|
||
|
|
buf = local_buf;
|
||
|
|
|
||
|
|
ret = -EFAULT;
|
||
|
|
if (copy_from_user(buf, user_buffer, length))
|
||
|
|
goto out_free;
|
||
|
|
|
||
|
|
mmap_read_lock(current->mm);
|
||
|
|
ret = -EINVAL;
|
||
|
|
vma = vma_lookup(current->mm, mmio_addr);
|
||
|
|
if (!vma)
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
ret = -EACCES;
|
||
|
|
if (!(vma->vm_flags & VM_WRITE))
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
|
||
|
|
ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl);
|
||
|
|
if (ret)
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
|
||
|
|
io_addr = (void __iomem *)((pte_pfn(*ptep) << PAGE_SHIFT) |
|
||
|
|
(mmio_addr & ~PAGE_MASK));
|
||
|
|
|
||
|
|
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
|
||
|
|
goto out_unlock_pt;
|
||
|
|
|
||
|
|
ret = zpci_memcpy_toio(io_addr, buf, length);
|
||
|
|
out_unlock_pt:
|
||
|
|
pte_unmap_unlock(ptep, ptl);
|
||
|
|
out_unlock_mmap:
|
||
|
|
mmap_read_unlock(current->mm);
|
||
|
|
out_free:
|
||
|
|
if (buf != local_buf)
|
||
|
|
kfree(buf);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int __pcilg_mio_inuser(
|
||
|
|
void __user *dst, const void __iomem *ioaddr,
|
||
|
|
u64 ulen, u8 *status)
|
||
|
|
{
|
||
|
|
union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
|
||
|
|
u64 cnt = ulen;
|
||
|
|
int shift = ulen * 8;
|
||
|
|
int cc = -ENXIO;
|
||
|
|
u64 val, tmp;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* read 0 < @len <= 8 bytes from the PCI memory mapped at @ioaddr (in
|
||
|
|
* user space) into a register using pcilg then store these bytes at
|
||
|
|
* user address @dst
|
||
|
|
*/
|
||
|
|
asm volatile (
|
||
|
|
" sacf 256\n"
|
||
|
|
"0: .insn rre,0xb9d60000,%[val],%[ioaddr_len]\n"
|
||
|
|
"1: ipm %[cc]\n"
|
||
|
|
" srl %[cc],28\n"
|
||
|
|
" ltr %[cc],%[cc]\n"
|
||
|
|
" jne 4f\n"
|
||
|
|
"2: ahi %[shift],-8\n"
|
||
|
|
" srlg %[tmp],%[val],0(%[shift])\n"
|
||
|
|
"3: stc %[tmp],0(%[dst])\n"
|
||
|
|
"5: aghi %[dst],1\n"
|
||
|
|
" brctg %[cnt],2b\n"
|
||
|
|
"4: sacf 768\n"
|
||
|
|
EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b) EX_TABLE(5b, 4b)
|
||
|
|
:
|
||
|
|
[ioaddr_len] "+&d" (ioaddr_len.pair),
|
||
|
|
[cc] "+d" (cc), [val] "=d" (val),
|
||
|
|
[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
|
||
|
|
[shift] "+d" (shift)
|
||
|
|
:: "cc", "memory");
|
||
|
|
|
||
|
|
/* did we write everything to the user space buffer? */
|
||
|
|
if (!cc && cnt != 0)
|
||
|
|
cc = -EFAULT;
|
||
|
|
|
||
|
|
*status = ioaddr_len.odd >> 24 & 0xff;
|
||
|
|
return cc;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int __memcpy_fromio_inuser(void __user *dst,
|
||
|
|
const void __iomem *src,
|
||
|
|
unsigned long n)
|
||
|
|
{
|
||
|
|
int size, rc = 0;
|
||
|
|
u8 status;
|
||
|
|
|
||
|
|
while (n > 0) {
|
||
|
|
size = zpci_get_max_write_size((u64 __force) src,
|
||
|
|
(u64 __force) dst, n,
|
||
|
|
ZPCI_MAX_READ_SIZE);
|
||
|
|
rc = __pcilg_mio_inuser(dst, src, size, &status);
|
||
|
|
if (rc)
|
||
|
|
break;
|
||
|
|
src += size;
|
||
|
|
dst += size;
|
||
|
|
n -= size;
|
||
|
|
}
|
||
|
|
if (rc)
|
||
|
|
zpci_err_mmio(rc, status, (__force u64) dst);
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
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;
|
||
|
|
struct vm_area_struct *vma;
|
||
|
|
pte_t *ptep;
|
||
|
|
spinlock_t *ptl;
|
||
|
|
long ret;
|
||
|
|
|
||
|
|
if (!zpci_is_enabled())
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We only support read access to MIO capable devices if we are on
|
||
|
|
* a MIO enabled system. Otherwise we would have to check for every
|
||
|
|
* address if it is a special ZPCI_ADDR and would have to do
|
||
|
|
* a pfn lookup which we don't need for MIO capable devices. Currently
|
||
|
|
* ISM devices are the only devices without MIO support and there is no
|
||
|
|
* known need for accessing these from userspace.
|
||
|
|
*/
|
||
|
|
if (static_branch_likely(&have_mio)) {
|
||
|
|
ret = __memcpy_fromio_inuser(
|
||
|
|
user_buffer, (const void __iomem *)mmio_addr,
|
||
|
|
length);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (length > 64) {
|
||
|
|
buf = kmalloc(length, GFP_KERNEL);
|
||
|
|
if (!buf)
|
||
|
|
return -ENOMEM;
|
||
|
|
} else {
|
||
|
|
buf = local_buf;
|
||
|
|
}
|
||
|
|
|
||
|
|
mmap_read_lock(current->mm);
|
||
|
|
ret = -EINVAL;
|
||
|
|
vma = vma_lookup(current->mm, mmio_addr);
|
||
|
|
if (!vma)
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
ret = -EACCES;
|
||
|
|
if (!(vma->vm_flags & VM_WRITE))
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
|
||
|
|
ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl);
|
||
|
|
if (ret)
|
||
|
|
goto out_unlock_mmap;
|
||
|
|
|
||
|
|
io_addr = (void __iomem *)((pte_pfn(*ptep) << PAGE_SHIFT) |
|
||
|
|
(mmio_addr & ~PAGE_MASK));
|
||
|
|
|
||
|
|
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
|
||
|
|
ret = -EFAULT;
|
||
|
|
goto out_unlock_pt;
|
||
|
|
}
|
||
|
|
ret = zpci_memcpy_fromio(buf, io_addr, length);
|
||
|
|
|
||
|
|
out_unlock_pt:
|
||
|
|
pte_unmap_unlock(ptep, ptl);
|
||
|
|
out_unlock_mmap:
|
||
|
|
mmap_read_unlock(current->mm);
|
||
|
|
|
||
|
|
if (!ret && copy_to_user(user_buffer, buf, length))
|
||
|
|
ret = -EFAULT;
|
||
|
|
|
||
|
|
if (buf != local_buf)
|
||
|
|
kfree(buf);
|
||
|
|
return ret;
|
||
|
|
}
|