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authorVasily Gorbik <gor@linux.ibm.com>2025-03-11 15:29:44 +0100
committerVasily Gorbik <gor@linux.ibm.com>2025-03-11 15:29:44 +0100
commit5983ab168475e609a92669b6d6ca5e145a9ce5db (patch)
tree463868851e731e6f97f7ceaea3675f3001f81a42 /arch/s390/mm
parent8751b6e9e4abf3603b567e871768eb8cca8ef91a (diff)
parent03544866df1bc78fe740fc9d17816874ba7bde5a (diff)
Merge branch 'strict-mm-typechecks-support' into features
Heiko writes: "The recent large kernel Rust thread where Linus commented about that structures may be returned in registers [1] made me again aware that this is not true for s390 where the ABI defines that structures are returned in a return value buffer allocated by the caller. This was also mentioned by Alexander Gordeev a couple of weeks ago. In theory the -freg-struct-return compiler flag would allow to return small structures in registers, however that has not been implemented for s390. Juergen Christ did an experimental gcc implementation which shows the benefit of such a change (bloat-o-meter): add/remove: 3/2 grow/shrink: 12/441 up/down: 740/-7182 (-6442) This result is not very impressive, and doesn't seem to justify a new ABI for the kernel. However there is still the existing STRICT_MM_TYPECHECKS which can be used to change some mm types from structures to simple scalar types. Changing the mm types results in: add/remove: 2/8 grow/shrink: 25/116 up/down: 3902/-6204 (-2302) Which is already a third of the possible savings which would be the result of the described ABI change. Therefore add support for a configurable STRICT_MM_TYPECHECKS which allows to generate better code, but also allows to have type checking for debug builds." [1] https://lore.kernel.org/all/CAHk-=wgb1g9VVHRaAnJjrfRFWAOVT2ouNOMqt0js8h3D6zvHDw@mail.gmail.com/ * strict-mm-typechecks-support: s390/mm: Add configurable STRICT_MM_TYPECHECKS s390/mm: Convert pgste_val() into function s390/mm: Convert pgprot_val() into function s390/mm: Use pgprot_val() instead of open coding Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/init.c2
-rw-r--r--arch/s390/mm/pgtable.c50
2 files changed, 26 insertions, 26 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6e325f81b89a..615ee245cb93 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -286,7 +286,7 @@ int arch_add_memory(int nid, u64 start, u64 size,
unsigned long size_pages = PFN_DOWN(size);
int rc;
- if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
+ if (WARN_ON_ONCE(pgprot_val(params->pgprot) != pgprot_val(PAGE_KERNEL)))
return -EINVAL;
VM_BUG_ON(!mhp_range_allowed(start, size, true));
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index fa66246c1851..9901934284ec 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -165,10 +165,10 @@ static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
skey = (unsigned long) page_get_storage_key(address);
bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
/* Transfer page changed & referenced bit to guest bits in pgste */
- pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
+ pgste = set_pgste_bit(pgste, bits << 48); /* GR bit & GC bit */
/* Copy page access key and fetch protection bit to pgste */
- pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
- pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
+ pgste = clear_pgste_bit(pgste, PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ pgste = set_pgste_bit(pgste, (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56);
#endif
return pgste;
@@ -212,7 +212,7 @@ static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
}
if (!(pte_val(entry) & _PAGE_PROTECT))
/* This pte allows write access, set user-dirty */
- pgste_val(pgste) |= PGSTE_UC_BIT;
+ pgste = set_pgste_bit(pgste, PGSTE_UC_BIT);
}
#endif
set_pte(ptep, entry);
@@ -228,7 +228,7 @@ static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
if (bits) {
- pgste_val(pgste) ^= bits;
+ pgste = __pgste(pgste_val(pgste) ^ bits);
ptep_notify(mm, addr, ptep, bits);
}
#endif
@@ -601,7 +601,7 @@ void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
/* the mm_has_pgste() check is done in set_pte_at() */
preempt_disable();
pgste = pgste_get_lock(ptep);
- pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
+ pgste = clear_pgste_bit(pgste, _PGSTE_GPS_ZERO);
pgste_set_key(ptep, pgste, entry, mm);
pgste = pgste_set_pte(ptep, pgste, entry);
pgste_set_unlock(ptep, pgste);
@@ -614,7 +614,7 @@ void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
preempt_disable();
pgste = pgste_get_lock(ptep);
- pgste_val(pgste) |= PGSTE_IN_BIT;
+ pgste = set_pgste_bit(pgste, PGSTE_IN_BIT);
pgste_set_unlock(ptep, pgste);
preempt_enable();
}
@@ -659,7 +659,7 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
entry = clear_pte_bit(entry, __pgprot(_PAGE_INVALID));
entry = set_pte_bit(entry, __pgprot(_PAGE_PROTECT));
}
- pgste_val(pgste) |= bit;
+ pgste = set_pgste_bit(pgste, bit);
pgste = pgste_set_pte(ptep, pgste, entry);
pgste_set_unlock(ptep, pgste);
return 0;
@@ -679,7 +679,7 @@ int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
if (!(pte_val(spte) & _PAGE_INVALID) &&
!((pte_val(spte) & _PAGE_PROTECT) &&
!(pte_val(pte) & _PAGE_PROTECT))) {
- pgste_val(spgste) |= PGSTE_VSIE_BIT;
+ spgste = set_pgste_bit(spgste, PGSTE_VSIE_BIT);
tpgste = pgste_get_lock(tptep);
tpte = __pte((pte_val(spte) & PAGE_MASK) |
(pte_val(pte) & _PAGE_PROTECT));
@@ -737,7 +737,7 @@ void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
pte_clear(mm, addr, ptep);
}
if (reset)
- pgste_val(pgste) &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
+ pgste = clear_pgste_bit(pgste, _PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
pgste_set_unlock(ptep, pgste);
preempt_enable();
}
@@ -750,8 +750,8 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
/* Clear storage key ACC and F, but set R/C */
preempt_disable();
pgste = pgste_get_lock(ptep);
- pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
- pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
+ pgste = clear_pgste_bit(pgste, PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ pgste = set_pgste_bit(pgste, PGSTE_GR_BIT | PGSTE_GC_BIT);
ptev = pte_val(*ptep);
if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0);
@@ -772,7 +772,7 @@ bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
pgste = pgste_get_lock(ptep);
dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
- pgste_val(pgste) &= ~PGSTE_UC_BIT;
+ pgste = clear_pgste_bit(pgste, PGSTE_UC_BIT);
pte = *ptep;
if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
pgste = pgste_pte_notify(mm, addr, ptep, pgste);
@@ -834,11 +834,11 @@ again:
if (!ptep)
goto again;
new = old = pgste_get_lock(ptep);
- pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
- PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ new = clear_pgste_bit(new, PGSTE_GR_BIT | PGSTE_GC_BIT |
+ PGSTE_ACC_BITS | PGSTE_FP_BIT);
keyul = (unsigned long) key;
- pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
- pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
+ new = set_pgste_bit(new, (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48);
+ new = set_pgste_bit(new, (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56);
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
unsigned long bits, skey;
@@ -849,12 +849,12 @@ again:
/* Set storage key ACC and FP */
page_set_storage_key(paddr, skey, !nq);
/* Merge host changed & referenced into pgste */
- pgste_val(new) |= bits << 52;
+ new = set_pgste_bit(new, bits << 52);
}
/* changing the guest storage key is considered a change of the page */
if ((pgste_val(new) ^ pgste_val(old)) &
(PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
- pgste_val(new) |= PGSTE_UC_BIT;
+ new = set_pgste_bit(new, PGSTE_UC_BIT);
pgste_set_unlock(ptep, new);
pte_unmap_unlock(ptep, ptl);
@@ -942,19 +942,19 @@ again:
goto again;
new = old = pgste_get_lock(ptep);
/* Reset guest reference bit only */
- pgste_val(new) &= ~PGSTE_GR_BIT;
+ new = clear_pgste_bit(new, PGSTE_GR_BIT);
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
paddr = pte_val(*ptep) & PAGE_MASK;
cc = page_reset_referenced(paddr);
/* Merge real referenced bit into host-set */
- pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
+ new = set_pgste_bit(new, ((unsigned long)cc << 53) & PGSTE_HR_BIT);
}
/* Reflect guest's logical view, not physical */
cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
/* Changing the guest storage key is considered a change of the page */
if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
- pgste_val(new) |= PGSTE_UC_BIT;
+ new = set_pgste_bit(new, PGSTE_UC_BIT);
pgste_set_unlock(ptep, new);
pte_unmap_unlock(ptep, ptl);
@@ -1118,7 +1118,7 @@ int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
if (res)
pgstev |= _PGSTE_GPS_ZERO;
- pgste_val(pgste) = pgstev;
+ pgste = __pgste(pgstev);
pgste_set_unlock(ptep, pgste);
pte_unmap_unlock(ptep, ptl);
return res;
@@ -1151,8 +1151,8 @@ int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
return -EFAULT;
new = pgste_get_lock(ptep);
- pgste_val(new) &= ~bits;
- pgste_val(new) |= value & bits;
+ new = clear_pgste_bit(new, bits);
+ new = set_pgste_bit(new, value & bits);
pgste_set_unlock(ptep, new);
pte_unmap_unlock(ptep, ptl);