[GIT PULL] s390 updates for 5.7-rc7

Vasily Gorbik
2020-05-23T10:18:34Z

Hello Linus,

please pull s390 changes for 5.7-rc7.

Thank you,
Vasily

The following changes since commit 2ef96a5bb12be62ef75b5828c0aab838ebb29cb8:

Linux 5.7-rc5 (2020-05-10 15:16:58 -0700)

are available in the Git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git tags/s390-5.7-4

for you to fetch changes up to 4c1cbcbd6c56c79de2c07159be4f55386bb0bef2:

s390/kaslr: add support for R_390_JMP_SLOT relocation type (2020-05-20 10:13:27 +0200)

----------------------------------------------------------------
s390 updates for 5.7-rc7

- Add missing R_390_JMP_SLOT relocation type in KASLR code.

- Fix set_huge_pte_at for empty ptes issue which has been uncovered with
arch page table helper tests.

- Correct initrd location for kdump kernel.

- Fix s390_mmio_read/write with MIO in PCI code.

----------------------------------------------------------------
Gerald Schaefer (2):
s390/mm: fix set_huge_pte_at() for empty ptes
s390/kaslr: add support for R_390_JMP_SLOT relocation type

Niklas Schnelle (1):
s390/pci: Fix s390_mmio_read/write with MIO

Philipp Rudo (1):
s390/kexec_file: fix initrd location for kdump kernel

arch/s390/include/asm/pci_io.h | 10 +-
arch/s390/kernel/machine_kexec_file.c | 2 +-
arch/s390/kernel/machine_kexec_reloc.c | 1 +
arch/s390/mm/hugetlbpage.c | 9 +-
arch/s390/pci/pci_mmio.c | 213 ++++++++++++++++++++++++++++++++-
5 files changed, 227 insertions(+), 8 deletions(-)

diff --git a/arch/s390/include/asm/pci_io.h b/arch/s390/include/asm/pci_io.h
index cd060b5dd8fd..e4dc64cc9c55 100644
--- a/arch/s390/include/asm/pci_io.h
+++ b/arch/s390/include/asm/pci_io.h
@@ -8,6 +8,10 @@
#include <linux/slab.h>
#include <asm/pci_insn.h>

+/* I/O size constraints */
+#define ZPCI_MAX_READ_SIZE 8
+#define ZPCI_MAX_WRITE_SIZE 128
+
/* I/O Map */
#define ZPCI_IOMAP_SHIFT 48
#define ZPCI_IOMAP_ADDR_BASE 0x8000000000000000UL
@@ -140,7 +144,8 @@ static inline int zpci_memcpy_fromio(void *dst,

while (n > 0) {
size = zpci_get_max_write_size((u64 __force) src,
- (u64) dst, n, 8);
+ (u64) dst, n,
+ ZPCI_MAX_READ_SIZE);
rc = zpci_read_single(dst, src, size);
if (rc)
break;
@@ -161,7 +166,8 @@ static inline int zpci_memcpy_toio(volatile void __iomem *dst,

while (n > 0) {
size = zpci_get_max_write_size((u64 __force) dst,
- (u64) src, n, 128);
+ (u64) src, n,
+ ZPCI_MAX_WRITE_SIZE);
if (size > 8) /* main path */
rc = zpci_write_block(dst, src, size);
else
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index 8415ae7d2a23..f9e4baa64b67 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -151,7 +151,7 @@ static int kexec_file_add_initrd(struct kimage *image,
buf.mem += crashk_res.start;
buf.memsz = buf.bufsz;

- data->parm->initrd_start = buf.mem;
+ data->parm->initrd_start = data->memsz;
data->parm->initrd_size = buf.memsz;
data->memsz += buf.memsz;

diff --git a/arch/s390/kernel/machine_kexec_reloc.c b/arch/s390/kernel/machine_kexec_reloc.c
index d5035de9020e..b7182cec48dc 100644
--- a/arch/s390/kernel/machine_kexec_reloc.c
+++ b/arch/s390/kernel/machine_kexec_reloc.c
@@ -28,6 +28,7 @@ int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val,
break;
case R_390_64: /* Direct 64 bit. */
case R_390_GLOB_DAT:
+ case R_390_JMP_SLOT:
*(u64 *)loc = val;
break;
case R_390_PC16: /* PC relative 16 bit. */
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index f01daddcbc5e..4632d4e26b66 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -159,10 +159,13 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
rste &= ~_SEGMENT_ENTRY_NOEXEC;

/* Set correct table type for 2G hugepages */
- if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
- rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
- else
+ if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
+ if (likely(pte_present(pte)))
+ rste |= _REGION3_ENTRY_LARGE;
+ rste |= _REGION_ENTRY_TYPE_R3;
+ } else if (likely(pte_present(pte)))
rste |= _SEGMENT_ENTRY_LARGE;
+
clear_huge_pte_skeys(mm, rste);
pte_val(*ptep) = rste;
}
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index 7d42a8794f10..020a2c514d96 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -11,6 +11,113 @@
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/pci.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)
+{
+ register u64 addr asm("2") = (u64 __force) ioaddr;
+ register u64 len asm("3") = 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"
+ " 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)
+ :
+ [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;
+
+ /* 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;
+ 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);
+ 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;
+ }
+ 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)
@@ -46,6 +153,20 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,

if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
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.
+ */
+ 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)
@@ -56,7 +177,8 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
if (ret)
goto out;
- io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
+ io_addr = (void __iomem *)((pfn << PAGE_SHIFT) |
+ (mmio_addr & ~PAGE_MASK));

ret = -EFAULT;
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
@@ -72,6 +194,78 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
return ret;
}

+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;
+ 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]\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)
+ :
+ [ioaddr] "a" (addr)
+ : "cc", "memory");
+
+ /* did we write everything to the user space buffer? */
+ if (!cc && cnt != 0)
+ cc = -EFAULT;
+
+ *status = len >> 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;
+ 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);
+ rc = __pcilg_mio_inuser(dst, src, size, &status);
+ if (rc)
+ break;
+ src += size;
+ dst += size;
+ n -= size;
+ }
+ disable_sacf_uaccess(old_fs);
+ 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)
{
@@ -86,12 +280,27 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,

if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
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.
+ */
+ 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
+ } else {
buf = local_buf;
+ }

ret = get_pfn(mmio_addr, VM_READ, &pfn);
if (ret)