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path: root/arch/s390/pci/pci_mmio.c
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Diffstat (limited to 'arch/s390/pci/pci_mmio.c')
-rw-r--r--arch/s390/pci/pci_mmio.c275
1 files changed, 157 insertions, 118 deletions
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index 38efa3e852c4..51e7a28af899 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -11,8 +11,10 @@
#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>
+#include <asm/asm.h>
static inline void zpci_err_mmio(u8 cc, u8 status, u64 offset)
{
@@ -29,29 +31,33 @@ 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"
+ int cc, exception;
+ bool sacf_flag;
+
+ exception = 1;
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile (
+ " sacf 256\n"
+ "0: .insn rsy,0xeb00000000d4,%[len],%[ioaddr],%[src]\n"
+ "1: lhi %[exc],0\n"
+ "2: sacf 768\n"
+ CC_IPM(cc)
EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
- : [cc] "+d" (cc), [len] "+d" (len)
+ : CC_OUT(cc, cc), [len] "+d" (len), [exc] "+d" (exception)
: [ioaddr] "a" (ioaddr), [src] "Q" (*((u8 __force *)src))
- : "cc", "memory");
+ : CC_CLOBBER_LIST("memory"));
+ disable_sacf_uaccess(sacf_flag);
*status = len >> 24 & 0xff;
- return cc;
+ return exception ? -ENXIO : CC_TRANSFORM(cc);
}
static inline int __pcistg_mio_inuser(
void __iomem *ioaddr, const void __user *src,
u64 ulen, u8 *status)
{
- register u64 addr asm("2") = (u64 __force) ioaddr;
- register u64 len asm("3") = ulen;
- int cc = -ENXIO;
+ union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
+ int cc, exception;
+ bool sacf_flag;
u64 val = 0;
u64 cnt = ulen;
u8 tmp;
@@ -61,26 +67,29 @@ static inline int __pcistg_mio_inuser(
* 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"
- " sllg %[val],%[val],8\n"
- " aghi %[src],1\n"
- " ogr %[val],%[tmp]\n"
- " brctg %[cnt],0b\n"
- "1: .insn rre,0xb9d40000,%[val],%[ioaddr]\n"
- "2: ipm %[cc]\n"
- " srl %[cc],28\n"
- "3: sacf 768\n"
- EX_TABLE(0b, 3b) EX_TABLE(1b, 3b) EX_TABLE(2b, 3b)
+ exception = 1;
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline 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: lhi %[exc],0\n"
+ "3: sacf 768\n"
+ CC_IPM(cc)
+ 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), [exc] "+d" (exception),
+ CC_OUT(cc, cc), [ioaddr_len] "+&d" (ioaddr_len.pair)
:
- [src] "+a" (src), [cnt] "+d" (cnt),
- [val] "+d" (val), [tmp] "=d" (tmp),
- [len] "+d" (len), [cc] "+d" (cc),
- [ioaddr] "+a" (addr)
- :: "cc", "memory");
- *status = len >> 24 & 0xff;
+ : CC_CLOBBER_LIST("memory"));
+ disable_sacf_uaccess(sacf_flag);
+ *status = ioaddr_len.odd >> 24 & 0xff;
+ cc = exception ? -ENXIO : CC_TRANSFORM(cc);
/* did we read everything from user memory? */
if (!cc && cnt != 0)
cc = -EFAULT;
@@ -93,16 +102,14 @@ static inline int __memcpy_toio_inuser(void __iomem *dst,
{
int size, rc = 0;
u8 status = 0;
- mm_segment_t old_fs;
if (!src)
return -EINVAL;
- old_fs = enable_sacf_uaccess();
while (n > 0) {
- size = zpci_get_max_write_size((u64 __force) dst,
- (u64 __force) src, n,
- ZPCI_MAX_WRITE_SIZE);
+ size = zpci_get_max_io_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
@@ -113,39 +120,19 @@ static inline int __memcpy_toio_inuser(void __iomem *dst,
dst += size;
n -= size;
}
- disable_sacf_uaccess(old_fs);
if (rc)
zpci_err_mmio(rc, status, (__force u64) dst);
return rc;
}
-static long get_pfn(unsigned long user_addr, unsigned long access,
- unsigned long *pfn)
-{
- struct vm_area_struct *vma;
- long ret;
-
- mmap_read_lock(current->mm);
- 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:
- mmap_read_unlock(current->mm);
- return ret;
-}
-
SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
const void __user *, user_buffer, size_t, length)
{
+ struct follow_pfnmap_args args = { };
u8 local_buf[64];
void __iomem *io_addr;
void *buf;
- unsigned long pfn;
+ struct vm_area_struct *vma;
long ret;
if (!zpci_is_enabled())
@@ -155,10 +142,12 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
return -EINVAL;
/*
- * Only support read access to MIO capable devices on a MIO enabled
- * system. Otherwise we would have to check for every address if it is
- * a special ZPCI_ADDR and we would have to do a get_pfn() which we
- * don't need for MIO capable devices.
+ * 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,
@@ -174,21 +163,43 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
} else
buf = local_buf;
- ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
- if (ret)
- goto out;
- io_addr = (void __iomem *)((pfn << PAGE_SHIFT) |
+ 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;
+
+ args.address = mmio_addr;
+ args.vma = vma;
+ ret = follow_pfnmap_start(&args);
+ if (ret) {
+ fixup_user_fault(current->mm, mmio_addr, FAULT_FLAG_WRITE, NULL);
+ ret = follow_pfnmap_start(&args);
+ if (ret)
+ goto out_unlock_mmap;
+ }
+
+ io_addr = (void __iomem *)((args.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;
+ goto out_unlock_pt;
ret = zpci_memcpy_toio(io_addr, buf, length);
-out:
+out_unlock_pt:
+ follow_pfnmap_end(&args);
+out_unlock_mmap:
+ mmap_read_unlock(current->mm);
+out_free:
if (buf != local_buf)
kfree(buf);
return ret;
@@ -198,11 +209,11 @@ static inline int __pcilg_mio_inuser(
void __user *dst, const void __iomem *ioaddr,
u64 ulen, u8 *status)
{
- register u64 addr asm("2") = (u64 __force) ioaddr;
- register u64 len asm("3") = ulen;
+ union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
+ bool sacf_flag;
u64 cnt = ulen;
int shift = ulen * 8;
- int cc = -ENXIO;
+ int cc, exception;
u64 val, tmp;
/*
@@ -210,33 +221,39 @@ static inline int __pcilg_mio_inuser(
* 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]\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"
- " aghi %[dst],1\n"
- " brctg %[cnt],2b\n"
- "4: sacf 768\n"
- EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b)
- :
- [cc] "+d" (cc), [val] "=d" (val), [len] "+d" (len),
- [dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
- [shift] "+d" (shift)
+ exception = 1;
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile (
+ " sacf 256\n"
+ "0: .insn rre,0xb9d60000,%[val],%[ioaddr_len]\n"
+ "1: lhi %[exc],0\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"
+ /*
+ * Use xr to clear exc and set condition code to zero
+ * to ensure flag output is correct for this branch.
+ */
+ " xr %[exc],%[exc]\n"
+ "4: sacf 768\n"
+ CC_IPM(cc)
+ EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b) EX_TABLE(5b, 4b)
+ : [ioaddr_len] "+&d" (ioaddr_len.pair), [exc] "+d" (exception),
+ CC_OUT(cc, cc), [val] "=d" (val),
+ [dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
+ [shift] "+a" (shift)
:
- [ioaddr] "a" (addr)
- : "cc", "memory");
-
+ : CC_CLOBBER_LIST("memory"));
+ disable_sacf_uaccess(sacf_flag);
+ cc = exception ? -ENXIO : CC_TRANSFORM(cc);
/* did we write everything to the user space buffer? */
if (!cc && cnt != 0)
cc = -EFAULT;
- *status = len >> 24 & 0xff;
+ *status = ioaddr_len.odd >> 24 & 0xff;
return cc;
}
@@ -246,13 +263,11 @@ static inline int __memcpy_fromio_inuser(void __user *dst,
{
int size, rc = 0;
u8 status;
- mm_segment_t old_fs;
- old_fs = enable_sacf_uaccess();
while (n > 0) {
- size = zpci_get_max_write_size((u64 __force) src,
- (u64 __force) dst, n,
- ZPCI_MAX_READ_SIZE);
+ size = zpci_get_max_io_size((u64 __force) src,
+ (u64 __force) dst, n,
+ ZPCI_MAX_READ_SIZE);
rc = __pcilg_mio_inuser(dst, src, size, &status);
if (rc)
break;
@@ -260,7 +275,6 @@ static inline int __memcpy_fromio_inuser(void __user *dst,
dst += size;
n -= size;
}
- disable_sacf_uaccess(old_fs);
if (rc)
zpci_err_mmio(rc, status, (__force u64) dst);
return rc;
@@ -269,10 +283,11 @@ static inline int __memcpy_fromio_inuser(void __user *dst,
SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
void __user *, user_buffer, size_t, length)
{
+ struct follow_pfnmap_args args = { };
u8 local_buf[64];
void __iomem *io_addr;
void *buf;
- unsigned long pfn;
+ struct vm_area_struct *vma;
long ret;
if (!zpci_is_enabled())
@@ -282,10 +297,12 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
return -EINVAL;
/*
- * Only support write access to MIO capable devices on a MIO enabled
- * system. Otherwise we would have to check for every address if it is
- * a special ZPCI_ADDR and we would have to do a get_pfn() which we
- * don't need for MIO capable devices.
+ * 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(
@@ -302,22 +319,44 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
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));
+ 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_READ))
+ goto out_unlock_mmap;
+
+ args.vma = vma;
+ args.address = mmio_addr;
+ ret = follow_pfnmap_start(&args);
+ if (ret) {
+ fixup_user_fault(current->mm, mmio_addr, 0, NULL);
+ ret = follow_pfnmap_start(&args);
+ if (ret)
+ goto out_unlock_mmap;
+ }
+
+ io_addr = (void __iomem *)((args.pfn << PAGE_SHIFT) |
+ (mmio_addr & ~PAGE_MASK));
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
ret = -EFAULT;
- goto out;
+ goto out_unlock_pt;
}
ret = zpci_memcpy_fromio(buf, io_addr, length);
- if (ret)
- goto out;
- if (copy_to_user(user_buffer, buf, length))
+
+out_unlock_pt:
+ follow_pfnmap_end(&args);
+out_unlock_mmap:
+ mmap_read_unlock(current->mm);
+
+ if (!ret && copy_to_user(user_buffer, buf, length))
ret = -EFAULT;
-out:
if (buf != local_buf)
kfree(buf);
return ret;
generated by cgit (git 2.34.1) at 2025-12-26 07:35:50 +0000