| Message ID | 20170619165753.25049-16-julien.grall@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/arm: Clean-up memory subsystems | expand |
On Mon, 19 Jun 2017, Julien Grall wrote: > This is improving the code readability and avoid to dereference the > table every single time we need to access the entry. > > Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > > Changes in v2: > - Patch added > --- > xen/arch/arm/mm.c | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c > index 6241c53821..657fee0b17 100644 > --- a/xen/arch/arm/mm.c > +++ b/xen/arch/arm/mm.c > @@ -986,28 +986,30 @@ static int create_xen_entries(enum xenmap_operation op, > { > int rc; > unsigned long addr = virt, addr_end = addr + nr_mfns * PAGE_SIZE; > - lpae_t pte; > + lpae_t pte, *entry; > lpae_t *third = NULL; > > for(; addr < addr_end; addr += PAGE_SIZE, mfn = mfn_add(mfn, 1)) > { > - if ( !lpae_table(xen_second[second_linear_offset(addr)]) ) > + entry = &xen_second[second_linear_offset(addr)]; > + if ( !lpae_table(*entry) ) > { > - rc = create_xen_table(&xen_second[second_linear_offset(addr)]); > + rc = create_xen_table(entry); > if ( rc < 0 ) { > printk("create_xen_entries: L2 failed\n"); > goto out; > } > } > > - BUG_ON(!lpae_valid(xen_second[second_linear_offset(addr)])); > + BUG_ON(!lpae_valid(*entry)); > > - third = mfn_to_virt(xen_second[second_linear_offset(addr)].pt.base); > + third = mfn_to_virt(entry->pt.base); > + entry = &third[third_table_offset(addr)]; > > switch ( op ) { > case INSERT: > case RESERVE: > - if ( lpae_valid(third[third_table_offset(addr)]) ) > + if ( lpae_valid(*entry) ) > { > printk("create_xen_entries: trying to replace an existing mapping addr=%lx mfn=%"PRI_mfn"\n", > addr, mfn_x(mfn)); > @@ -1017,11 +1019,11 @@ static int create_xen_entries(enum xenmap_operation op, > break; > pte = mfn_to_xen_entry(mfn, ai); > pte.pt.table = 1; > - write_pte(&third[third_table_offset(addr)], pte); > + write_pte(entry, pte); > break; > case MODIFY: > case REMOVE: > - if ( !lpae_valid(third[third_table_offset(addr)]) ) > + if ( !lpae_valid(*entry) ) > { > printk("create_xen_entries: trying to %s a non-existing mapping addr=%lx\n", > op == REMOVE ? "remove" : "modify", addr); > @@ -1031,7 +1033,7 @@ static int create_xen_entries(enum xenmap_operation op, > pte.bits = 0; > else > { > - pte = third[third_table_offset(addr)]; > + pte = *entry; > pte.pt.ro = PTE_RO_MASK(ai); > pte.pt.xn = PTE_NX_MASK(ai); > if ( !pte.pt.ro && !pte.pt.xn ) > @@ -1041,7 +1043,7 @@ static int create_xen_entries(enum xenmap_operation op, > return -EINVAL; > } > } > - write_pte(&third[third_table_offset(addr)], pte); > + write_pte(entry, pte); > break; > default: > BUG(); > -- > 2.11.0 >
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 6241c53821..657fee0b17 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -986,28 +986,30 @@ static int create_xen_entries(enum xenmap_operation op, { int rc; unsigned long addr = virt, addr_end = addr + nr_mfns * PAGE_SIZE; - lpae_t pte; + lpae_t pte, *entry; lpae_t *third = NULL; for(; addr < addr_end; addr += PAGE_SIZE, mfn = mfn_add(mfn, 1)) { - if ( !lpae_table(xen_second[second_linear_offset(addr)]) ) + entry = &xen_second[second_linear_offset(addr)]; + if ( !lpae_table(*entry) ) { - rc = create_xen_table(&xen_second[second_linear_offset(addr)]); + rc = create_xen_table(entry); if ( rc < 0 ) { printk("create_xen_entries: L2 failed\n"); goto out; } } - BUG_ON(!lpae_valid(xen_second[second_linear_offset(addr)])); + BUG_ON(!lpae_valid(*entry)); - third = mfn_to_virt(xen_second[second_linear_offset(addr)].pt.base); + third = mfn_to_virt(entry->pt.base); + entry = &third[third_table_offset(addr)]; switch ( op ) { case INSERT: case RESERVE: - if ( lpae_valid(third[third_table_offset(addr)]) ) + if ( lpae_valid(*entry) ) { printk("create_xen_entries: trying to replace an existing mapping addr=%lx mfn=%"PRI_mfn"\n", addr, mfn_x(mfn)); @@ -1017,11 +1019,11 @@ static int create_xen_entries(enum xenmap_operation op, break; pte = mfn_to_xen_entry(mfn, ai); pte.pt.table = 1; - write_pte(&third[third_table_offset(addr)], pte); + write_pte(entry, pte); break; case MODIFY: case REMOVE: - if ( !lpae_valid(third[third_table_offset(addr)]) ) + if ( !lpae_valid(*entry) ) { printk("create_xen_entries: trying to %s a non-existing mapping addr=%lx\n", op == REMOVE ? "remove" : "modify", addr); @@ -1031,7 +1033,7 @@ static int create_xen_entries(enum xenmap_operation op, pte.bits = 0; else { - pte = third[third_table_offset(addr)]; + pte = *entry; pte.pt.ro = PTE_RO_MASK(ai); pte.pt.xn = PTE_NX_MASK(ai); if ( !pte.pt.ro && !pte.pt.xn ) @@ -1041,7 +1043,7 @@ static int create_xen_entries(enum xenmap_operation op, return -EINVAL; } } - write_pte(&third[third_table_offset(addr)], pte); + write_pte(entry, pte); break; default: BUG();
This is improving the code readability and avoid to dereference the table every single time we need to access the entry. Signed-off-by: Julien Grall <julien.grall@arm.com> --- Changes in v2: - Patch added --- xen/arch/arm/mm.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)