diff mbox series

[v3,10/18] target/s390: Return exception from mmu_translate

Message ID 20190926162615.31168-11-richard.henderson@linaro.org
State Superseded
Headers show
Series target/s390: Use tcg unwinding for ilen | expand

Commit Message

Richard Henderson Sept. 26, 2019, 4:26 p.m. UTC 
Do not raise the exception directly within mmu_translate,
but pass it back so that caller may do so.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/s390x/internal.h    |  2 +-
 target/s390x/excp_helper.c |  4 ++--
 target/s390x/mem_helper.c  | 13 ++++++++++---
 target/s390x/mmu_helper.c  | 36 ++++++++++++++----------------------
 4 files changed, 27 insertions(+), 28 deletions(-)

-- 
2.17.1

Comments

David Hildenbrand Sept. 27, 2019, 10:55 a.m. UTC | #1 
On 26.09.19 18:26, Richard Henderson wrote:
> Do not raise the exception directly within mmu_translate,

> but pass it back so that caller may do so.

> 

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  target/s390x/internal.h    |  2 +-

>  target/s390x/excp_helper.c |  4 ++--

>  target/s390x/mem_helper.c  | 13 ++++++++++---

>  target/s390x/mmu_helper.c  | 36 ++++++++++++++----------------------

>  4 files changed, 27 insertions(+), 28 deletions(-)

> 

> diff --git a/target/s390x/internal.h b/target/s390x/internal.h

> index c4388aaf23..c993c3ef40 100644

> --- a/target/s390x/internal.h

> +++ b/target/s390x/internal.h

> @@ -360,7 +360,7 @@ void probe_write_access(CPUS390XState *env, uint64_t addr, uint64_t len,

>  

>  /* mmu_helper.c */

>  int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,

> -                  target_ulong *raddr, int *flags, bool exc);

> +                  target_ulong *raddr, int *flags, uint64_t *tec);

>  int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw,

>                         target_ulong *addr, int *flags, uint64_t *tec);

>  

> diff --git a/target/s390x/excp_helper.c b/target/s390x/excp_helper.c

> index 906b87c071..6a0728b65f 100644

> --- a/target/s390x/excp_helper.c

> +++ b/target/s390x/excp_helper.c

> @@ -140,8 +140,8 @@ bool s390_cpu_tlb_fill(CPUState *cs, vaddr address, int size,

>          if (!(env->psw.mask & PSW_MASK_64)) {

>              vaddr &= 0x7fffffff;

>          }

> -        fail = mmu_translate(env, vaddr, access_type, asc, &raddr, &prot, true);

> -        excp = 0; /* exception already raised */

> +        excp = mmu_translate(env, vaddr, access_type, asc, &raddr, &prot, &tec);

> +        fail = excp;


... so what about instruction fetches? I assume this works as designed
as we set  env->int_pgm_ilen = 2 in s390_cpu_tlb_fill() in case of
MMU_INST_FETCH. But the comment indicates that "we may remove this
entirely".

Can you paint me the big picture? :)


>      } else if (mmu_idx == MMU_REAL_IDX) {

>          /* 31-Bit mode */

>          if (!(env->psw.mask & PSW_MASK_64)) {

> diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c

> index 7d2a652823..e15aa296dd 100644

> --- a/target/s390x/mem_helper.c

> +++ b/target/s390x/mem_helper.c

> @@ -2364,8 +2364,8 @@ uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)

>      CPUState *cs = env_cpu(env);

>      uint32_t cc = 0;

>      uint64_t asc = env->psw.mask & PSW_MASK_ASC;

> -    uint64_t ret;

> -    int old_exc, flags;

> +    uint64_t ret, tec;

> +    int old_exc, flags, exc;

>  

>      /* XXX incomplete - has more corner cases */

>      if (!(env->psw.mask & PSW_MASK_64) && (addr >> 32)) {

> @@ -2373,7 +2373,14 @@ uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)

>      }

>  

>      old_exc = cs->exception_index;

> -    if (mmu_translate(env, addr, 0, asc, &ret, &flags, true)) {

> +    exc = mmu_translate(env, addr, 0, asc, &ret, &flags, &tec);

> +    if (exc) {

> +        /*

> +         * We don't care about ILEN or TEC, as we're not going to

> +         * deliver the exception -- thus resetting exception_index below.

> +         * TODO: clean this up.

> +         */

> +        trigger_pgm_exception(env, exc, ILEN_UNWIND);


Yeah, this needs a cleanup.

>          cc = 3;

>      }

>      if (cs->exception_index == EXCP_PGM) {

> diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c

> index ed6570db62..a9219942b1 100644

> --- a/target/s390x/mmu_helper.c

> +++ b/target/s390x/mmu_helper.c

> @@ -349,17 +349,15 @@ static void mmu_handle_skey(target_ulong addr, int rw, int *flags)

>   * @return       0 if the translation was successful, -1 if a fault occurred

>   */

>  int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,

> -                  target_ulong *raddr, int *flags, bool exc)

> +                  target_ulong *raddr, int *flags, uint64_t *tec)

>  {

> -    /* Code accesses have an undefined ilc, let's use 2 bytes. */

> -    const int ilen = (rw == MMU_INST_FETCH) ? 2 : ILEN_AUTO;


Now I realize that this ilen currently gets overwritten in
s390_cpu_tlb_fill().

> -    uint64_t tec = (vaddr & TARGET_PAGE_MASK) | (asc >> 46) |

> -                   (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ);

>      uint64_t asce;

>      int r;

>  

> -

> +    *tec = (vaddr & TARGET_PAGE_MASK) | (asc >> 46) |

> +            (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ);

>      *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC;

> +

>      if (is_low_address(vaddr & TARGET_PAGE_MASK) && lowprot_enabled(env, asc)) {

>          /*

>           * If any part of this page is currently protected, make sure the

> @@ -371,10 +369,7 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,

>           */

>          *flags |= PAGE_WRITE_INV;

>          if (is_low_address(vaddr) && rw == MMU_DATA_STORE) {

> -            if (exc) {

> -                trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0);

> -            }

> -            return -EACCES;

> +            return PGM_PROTECTION;

>          }

>      }

>  

> @@ -404,20 +399,14 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,

>      /* perform the DAT translation */

>      r = mmu_translate_asce(env, vaddr, asc, asce, raddr, flags, rw);

>      if (unlikely(r)) {

> -        if (exc) {

> -            trigger_access_exception(env, r, ilen, tec);

> -        }

> -        return -1;

> +        return r;

>      }

>  

>      /* check for DAT protection */

>      if (unlikely(rw == MMU_DATA_STORE && !(*flags & PAGE_WRITE))) {

> -        if (exc) {

> -            /* DAT sets bit 61 only */

> -            tec |= 0x4;

> -            trigger_access_exception(env, PGM_PROTECTION, ilen, tec);

> -        }

> -        return -1;

> +        /* DAT sets bit 61 only */

> +        *tec |= 0x4;

> +        return PGM_PROTECTION;

>      }

>  

>  nodat:

> @@ -441,9 +430,12 @@ static int translate_pages(S390CPU *cpu, vaddr addr, int nr_pages,

>      int ret, i, pflags;

>  

>      for (i = 0; i < nr_pages; i++) {

> -        ret = mmu_translate(env, addr, is_write, asc, &pages[i], &pflags, true);

> +        uint64_t tec;

> +

> +        ret = mmu_translate(env, addr, is_write, asc, &pages[i], &pflags, &tec);

>          if (ret) {

> -            return ret;

> +            trigger_access_exception(env, ret, ILEN_AUTO, tec);

> +            return -EFAULT;

>          }

>          if (!address_space_access_valid(&address_space_memory, pages[i],

>                                          TARGET_PAGE_SIZE, is_write,

> 



-- 

Thanks,

David / dhildenb
diff mbox series

Patch

diff --git a/target/s390x/internal.h b/target/s390x/internal.h
index c4388aaf23..c993c3ef40 100644
--- a/target/s390x/internal.h
+++ b/target/s390x/internal.h
@@ -360,7 +360,7 @@  void probe_write_access(CPUS390XState *env, uint64_t addr, uint64_t len,
 
 /* mmu_helper.c */
 int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
-                  target_ulong *raddr, int *flags, bool exc);
+                  target_ulong *raddr, int *flags, uint64_t *tec);
 int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw,
                        target_ulong *addr, int *flags, uint64_t *tec);
 
diff --git a/target/s390x/excp_helper.c b/target/s390x/excp_helper.c
index 906b87c071..6a0728b65f 100644
--- a/target/s390x/excp_helper.c
+++ b/target/s390x/excp_helper.c
@@ -140,8 +140,8 @@  bool s390_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
         if (!(env->psw.mask & PSW_MASK_64)) {
             vaddr &= 0x7fffffff;
         }
-        fail = mmu_translate(env, vaddr, access_type, asc, &raddr, &prot, true);
-        excp = 0; /* exception already raised */
+        excp = mmu_translate(env, vaddr, access_type, asc, &raddr, &prot, &tec);
+        fail = excp;
     } else if (mmu_idx == MMU_REAL_IDX) {
         /* 31-Bit mode */
         if (!(env->psw.mask & PSW_MASK_64)) {
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 7d2a652823..e15aa296dd 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -2364,8 +2364,8 @@  uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)
     CPUState *cs = env_cpu(env);
     uint32_t cc = 0;
     uint64_t asc = env->psw.mask & PSW_MASK_ASC;
-    uint64_t ret;
-    int old_exc, flags;
+    uint64_t ret, tec;
+    int old_exc, flags, exc;
 
     /* XXX incomplete - has more corner cases */
     if (!(env->psw.mask & PSW_MASK_64) && (addr >> 32)) {
@@ -2373,7 +2373,14 @@  uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)
     }
 
     old_exc = cs->exception_index;
-    if (mmu_translate(env, addr, 0, asc, &ret, &flags, true)) {
+    exc = mmu_translate(env, addr, 0, asc, &ret, &flags, &tec);
+    if (exc) {
+        /*
+         * We don't care about ILEN or TEC, as we're not going to
+         * deliver the exception -- thus resetting exception_index below.
+         * TODO: clean this up.
+         */
+        trigger_pgm_exception(env, exc, ILEN_UNWIND);
         cc = 3;
     }
     if (cs->exception_index == EXCP_PGM) {
diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c
index ed6570db62..a9219942b1 100644
--- a/target/s390x/mmu_helper.c
+++ b/target/s390x/mmu_helper.c
@@ -349,17 +349,15 @@  static void mmu_handle_skey(target_ulong addr, int rw, int *flags)
  * @return       0 if the translation was successful, -1 if a fault occurred
  */
 int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
-                  target_ulong *raddr, int *flags, bool exc)
+                  target_ulong *raddr, int *flags, uint64_t *tec)
 {
-    /* Code accesses have an undefined ilc, let's use 2 bytes. */
-    const int ilen = (rw == MMU_INST_FETCH) ? 2 : ILEN_AUTO;
-    uint64_t tec = (vaddr & TARGET_PAGE_MASK) | (asc >> 46) |
-                   (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ);
     uint64_t asce;
     int r;
 
-
+    *tec = (vaddr & TARGET_PAGE_MASK) | (asc >> 46) |
+            (rw == MMU_DATA_STORE ? FS_WRITE : FS_READ);
     *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+
     if (is_low_address(vaddr & TARGET_PAGE_MASK) && lowprot_enabled(env, asc)) {
         /*
          * If any part of this page is currently protected, make sure the
@@ -371,10 +369,7 @@  int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
          */
         *flags |= PAGE_WRITE_INV;
         if (is_low_address(vaddr) && rw == MMU_DATA_STORE) {
-            if (exc) {
-                trigger_access_exception(env, PGM_PROTECTION, ILEN_AUTO, 0);
-            }
-            return -EACCES;
+            return PGM_PROTECTION;
         }
     }
 
@@ -404,20 +399,14 @@  int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
     /* perform the DAT translation */
     r = mmu_translate_asce(env, vaddr, asc, asce, raddr, flags, rw);
     if (unlikely(r)) {
-        if (exc) {
-            trigger_access_exception(env, r, ilen, tec);
-        }
-        return -1;
+        return r;
     }
 
     /* check for DAT protection */
     if (unlikely(rw == MMU_DATA_STORE && !(*flags & PAGE_WRITE))) {
-        if (exc) {
-            /* DAT sets bit 61 only */
-            tec |= 0x4;
-            trigger_access_exception(env, PGM_PROTECTION, ilen, tec);
-        }
-        return -1;
+        /* DAT sets bit 61 only */
+        *tec |= 0x4;
+        return PGM_PROTECTION;
     }
 
 nodat:
@@ -441,9 +430,12 @@  static int translate_pages(S390CPU *cpu, vaddr addr, int nr_pages,
     int ret, i, pflags;
 
     for (i = 0; i < nr_pages; i++) {
-        ret = mmu_translate(env, addr, is_write, asc, &pages[i], &pflags, true);
+        uint64_t tec;
+
+        ret = mmu_translate(env, addr, is_write, asc, &pages[i], &pflags, &tec);
         if (ret) {
-            return ret;
+            trigger_access_exception(env, ret, ILEN_AUTO, tec);
+            return -EFAULT;
         }
         if (!address_space_access_valid(&address_space_memory, pages[i],
                                         TARGET_PAGE_SIZE, is_write,