| Message ID | 20180919084802.183381-14-frankja@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: Huge page splitting and shadowing | expand |
On 19/09/2018 10:48, Janosch Frank wrote: > Not yet sure if I'll keep this. > > The walk should only walk and not check I, but then it looks way > nicer. I agree, while it looks nicer, conceptually it is better to return if "there is something" - in contrast to "pte_none" where there definitely isn't "something". > > Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > --- > arch/s390/mm/gmap.c | 17 +++++++---------- > 1 file changed, 7 insertions(+), 10 deletions(-) > > diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c > index 0220a32aa2b9..8d5ce51637eb 100644 > --- a/arch/s390/mm/gmap.c > +++ b/arch/s390/mm/gmap.c > @@ -952,7 +952,8 @@ static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr, > } > > pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1); > - if (!pmdp || pmd_none(*pmdp)) { > + if (!pmdp || pmd_none(*pmdp) || > + pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) { > if (*ptl) > spin_unlock(*ptl); > pmdp = NULL; > @@ -1161,7 +1162,7 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, > return vmaddr; > vmaddr |= gaddr & ~PMD_MASK; > pmdp = gmap_pmd_op_walk(gmap, gaddr, vmaddr, &ptl_pmd); > - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { > + if (pmdp) { > if (!pmd_large(*pmdp)) { > ptep = gmap_pte_from_pmd(gmap, pmdp, gaddr, > &ptl_pte); > @@ -1266,7 +1267,7 @@ int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val) > if (IS_ERR_VALUE(vmaddr)) > return vmaddr; > pmdp = gmap_pmd_op_walk(gmap, gaddr, vmaddr, &ptl_pmd); > - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { > + if (pmdp) { > if (!pmd_large(*pmdp)) { > ptep = gmap_pte_from_pmd(gmap, pmdp, vmaddr, &ptl_pte); > if (ptep) { > @@ -1380,7 +1381,7 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, > return vmaddr; > vmaddr |= paddr & ~PMD_MASK; > pmdp = gmap_pmd_op_walk(parent, paddr, vmaddr, &ptl_pmd); > - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { > + if (pmdp) { > if (!pmd_large(*pmdp)) { > ptl_pte = NULL; > ptep = gmap_pte_from_pmd(parent, pmdp, paddr, > @@ -2362,8 +2363,7 @@ int gmap_shadow_segment(struct gmap *sg, unsigned long saddr, pmd_t pmd) > break; > } > spmd = *spmdp; > - if (!(pmd_val(spmd) & _SEGMENT_ENTRY_INVALID) && > - !((pmd_val(spmd) & _SEGMENT_ENTRY_PROTECT) && > + if (!((pmd_val(spmd) & _SEGMENT_ENTRY_PROTECT) && > !(pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT))) { > > pmd_val(*spmdp) |= _SEGMENT_ENTRY_GMAP_VSIE; > @@ -2436,7 +2436,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte) > break; > rc = -EAGAIN; > spmdp = gmap_pmd_op_walk(parent, paddr, vmaddr, &ptl_pmd); > - if (spmdp && !(pmd_val(*spmdp) & _SEGMENT_ENTRY_INVALID)) { > + if (spmdp) { > /* Get page table pointer */ > tptep = (pte_t *) gmap_table_walk(sg, saddr, 0); > if (!tptep) { > @@ -2869,9 +2869,6 @@ EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global); > bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp, > unsigned long gaddr, unsigned long vmaddr) > { > - if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) > - return false; > - > /* Already protected memory, which did not change is clean */ > if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT && > !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC)) >
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 0220a32aa2b9..8d5ce51637eb 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -952,7 +952,8 @@ static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr, } pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1); - if (!pmdp || pmd_none(*pmdp)) { + if (!pmdp || pmd_none(*pmdp) || + pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) { if (*ptl) spin_unlock(*ptl); pmdp = NULL; @@ -1161,7 +1162,7 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, return vmaddr; vmaddr |= gaddr & ~PMD_MASK; pmdp = gmap_pmd_op_walk(gmap, gaddr, vmaddr, &ptl_pmd); - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { + if (pmdp) { if (!pmd_large(*pmdp)) { ptep = gmap_pte_from_pmd(gmap, pmdp, gaddr, &ptl_pte); @@ -1266,7 +1267,7 @@ int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val) if (IS_ERR_VALUE(vmaddr)) return vmaddr; pmdp = gmap_pmd_op_walk(gmap, gaddr, vmaddr, &ptl_pmd); - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { + if (pmdp) { if (!pmd_large(*pmdp)) { ptep = gmap_pte_from_pmd(gmap, pmdp, vmaddr, &ptl_pte); if (ptep) { @@ -1380,7 +1381,7 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, return vmaddr; vmaddr |= paddr & ~PMD_MASK; pmdp = gmap_pmd_op_walk(parent, paddr, vmaddr, &ptl_pmd); - if (pmdp && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)) { + if (pmdp) { if (!pmd_large(*pmdp)) { ptl_pte = NULL; ptep = gmap_pte_from_pmd(parent, pmdp, paddr, @@ -2362,8 +2363,7 @@ int gmap_shadow_segment(struct gmap *sg, unsigned long saddr, pmd_t pmd) break; } spmd = *spmdp; - if (!(pmd_val(spmd) & _SEGMENT_ENTRY_INVALID) && - !((pmd_val(spmd) & _SEGMENT_ENTRY_PROTECT) && + if (!((pmd_val(spmd) & _SEGMENT_ENTRY_PROTECT) && !(pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT))) { pmd_val(*spmdp) |= _SEGMENT_ENTRY_GMAP_VSIE; @@ -2436,7 +2436,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte) break; rc = -EAGAIN; spmdp = gmap_pmd_op_walk(parent, paddr, vmaddr, &ptl_pmd); - if (spmdp && !(pmd_val(*spmdp) & _SEGMENT_ENTRY_INVALID)) { + if (spmdp) { /* Get page table pointer */ tptep = (pte_t *) gmap_table_walk(sg, saddr, 0); if (!tptep) { @@ -2869,9 +2869,6 @@ EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global); bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp, unsigned long gaddr, unsigned long vmaddr) { - if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) - return false; - /* Already protected memory, which did not change is clean */ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT && !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
Not yet sure if I'll keep this. The walk should only walk and not check I, but then it looks way nicer. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> --- arch/s390/mm/gmap.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-)