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Date: Wed, 22 Jul 2020 11:45:52 +0200
From: David Hildenbrand <david@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-s390@...r.kernel.org, linux-mm@...ck.org,
David Hildenbrand <david@...hat.com>,
Heiko Carstens <heiko.carstens@...ibm.com>,
Vasily Gorbik <gor@...ux.ibm.com>,
Christian Borntraeger <borntraeger@...ibm.com>,
Gerald Schaefer <gerald.schaefer@...ibm.com>
Subject: [PATCH v2 3/9] s390/vmemmap: extend modify_pagetable() to handle vmemmap
Extend our shiny new modify_pagetable() to handle !direct (vmemmap)
mappings. Convert vmemmap_populate() and implement vmemmap_free().
Cc: Heiko Carstens <heiko.carstens@...ibm.com>
Cc: Vasily Gorbik <gor@...ux.ibm.com>
Cc: Christian Borntraeger <borntraeger@...ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@...ibm.com>
Signed-off-by: David Hildenbrand <david@...hat.com>
---
arch/s390/mm/vmem.c | 181 +++++++++++++++++++-------------------------
1 file changed, 76 insertions(+), 105 deletions(-)
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 177daf389d391..43fe1e2eb90ea 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -29,6 +29,15 @@ static void __ref *vmem_alloc_pages(unsigned int order)
return (void *) memblock_phys_alloc(size, size);
}
+static void vmem_free_pages(unsigned long addr, int order)
+{
+ /* We don't expect boot memory to be removed ever. */
+ if (!slab_is_available() ||
+ WARN_ON_ONCE(PageReserved(phys_to_page(addr))))
+ return;
+ free_pages(addr, order);
+}
+
void *vmem_crst_alloc(unsigned long val)
{
unsigned long *table;
@@ -54,10 +63,12 @@ pte_t __ref *vmem_pte_alloc(void)
return pte;
}
-static void modify_pte_table(pmd_t *pmd, unsigned long addr, unsigned long end,
- bool add)
+/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
+static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr,
+ unsigned long end, bool add, bool direct)
{
unsigned long prot, pages = 0;
+ int ret = -ENOMEM;
pte_t *pte;
prot = pgprot_val(PAGE_KERNEL);
@@ -69,20 +80,34 @@ static void modify_pte_table(pmd_t *pmd, unsigned long addr, unsigned long end,
if (!add) {
if (pte_none(*pte))
continue;
+ if (!direct)
+ vmem_free_pages(pfn_to_phys(pte_pfn(*pte)), 0);
pte_clear(&init_mm, addr, pte);
} else if (pte_none(*pte)) {
- pte_val(*pte) = addr | prot;
+ if (!direct) {
+ void *new_page = vmemmap_alloc_block(PAGE_SIZE,
+ NUMA_NO_NODE);
+
+ if (!new_page)
+ goto out;
+ pte_val(*pte) = __pa(new_page) | prot;
+ } else
+ pte_val(*pte) = addr | prot;
} else
continue;
pages++;
}
-
- update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
+ ret = 0;
+out:
+ if (direct)
+ update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages);
+ return ret;
}
-static int modify_pmd_table(pud_t *pud, unsigned long addr, unsigned long end,
- bool add)
+/* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */
+static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
+ unsigned long end, bool add, bool direct)
{
unsigned long next, prot, pages = 0;
int ret = -ENOMEM;
@@ -103,6 +128,9 @@ static int modify_pmd_table(pud_t *pud, unsigned long addr, unsigned long end,
if (pmd_large(*pmd) && !add) {
if (IS_ALIGNED(addr, PMD_SIZE) &&
IS_ALIGNED(next, PMD_SIZE)) {
+ if (!direct)
+ vmem_free_pages(pmd_deref(*pmd),
+ get_order(PMD_SIZE));
pmd_clear(pmd);
pages++;
}
@@ -111,11 +139,27 @@ static int modify_pmd_table(pud_t *pud, unsigned long addr, unsigned long end,
} else if (pmd_none(*pmd)) {
if (IS_ALIGNED(addr, PMD_SIZE) &&
IS_ALIGNED(next, PMD_SIZE) &&
- MACHINE_HAS_EDAT1 && addr &&
+ MACHINE_HAS_EDAT1 && addr && direct &&
!debug_pagealloc_enabled()) {
pmd_val(*pmd) = addr | prot;
pages++;
continue;
+ } else if (!direct && MACHINE_HAS_EDAT1) {
+ void *new_page;
+
+ /*
+ * Use 1MB frames for vmemmap if available. We
+ * always use large frames even if they are only
+ * partially used. Otherwise we would have also
+ * page tables since vmemmap_populate gets
+ * called for each section separately.
+ */
+ new_page = vmemmap_alloc_block(PMD_SIZE,
+ NUMA_NO_NODE);
+ if (!new_page)
+ goto out;
+ pmd_val(*pmd) = __pa(new_page) | prot;
+ continue;
}
pte = vmem_pte_alloc();
if (!pte)
@@ -124,16 +168,19 @@ static int modify_pmd_table(pud_t *pud, unsigned long addr, unsigned long end,
} else if (pmd_large(*pmd))
continue;
- modify_pte_table(pmd, addr, next, add);
+ ret = modify_pte_table(pmd, addr, next, add, direct);
+ if (ret)
+ goto out;
}
ret = 0;
out:
- update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
+ if (direct)
+ update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages);
return ret;
}
static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
- bool add)
+ bool add, bool direct)
{
unsigned long next, prot, pages = 0;
int ret = -ENOMEM;
@@ -162,7 +209,7 @@ static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
} else if (pud_none(*pud)) {
if (IS_ALIGNED(addr, PUD_SIZE) &&
IS_ALIGNED(next, PUD_SIZE) &&
- MACHINE_HAS_EDAT2 && addr &&
+ MACHINE_HAS_EDAT2 && addr && direct &&
!debug_pagealloc_enabled()) {
pud_val(*pud) = addr | prot;
pages++;
@@ -175,18 +222,19 @@ static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
} else if (pud_large(*pud))
continue;
- ret = modify_pmd_table(pud, addr, next, add);
+ ret = modify_pmd_table(pud, addr, next, add, direct);
if (ret)
goto out;
}
ret = 0;
out:
- update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
+ if (direct)
+ update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages);
return ret;
}
static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
- bool add)
+ bool add, bool direct)
{
unsigned long next;
int ret = -ENOMEM;
@@ -206,7 +254,7 @@ static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
goto out;
}
- ret = modify_pud_table(p4d, addr, next, add);
+ ret = modify_pud_table(p4d, addr, next, add, direct);
if (ret)
goto out;
}
@@ -215,7 +263,8 @@ static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end,
return ret;
}
-static int modify_pagetable(unsigned long start, unsigned long end, bool add)
+static int modify_pagetable(unsigned long start, unsigned long end, bool add,
+ bool direct)
{
unsigned long addr, next;
int ret = -ENOMEM;
@@ -239,7 +288,7 @@ static int modify_pagetable(unsigned long start, unsigned long end, bool add)
pgd_populate(&init_mm, pgd, p4d);
}
- ret = modify_p4d_table(pgd, addr, next, add);
+ ret = modify_p4d_table(pgd, addr, next, add, direct);
if (ret)
goto out;
}
@@ -250,14 +299,14 @@ static int modify_pagetable(unsigned long start, unsigned long end, bool add)
return ret;
}
-static int add_pagetable(unsigned long start, unsigned long end)
+static int add_pagetable(unsigned long start, unsigned long end, bool direct)
{
- return modify_pagetable(start, end, true);
+ return modify_pagetable(start, end, true, direct);
}
-static int remove_pagetable(unsigned long start, unsigned long end)
+static int remove_pagetable(unsigned long start, unsigned long end, bool direct)
{
- return modify_pagetable(start, end, false);
+ return modify_pagetable(start, end, false, direct);
}
/*
@@ -265,7 +314,7 @@ static int remove_pagetable(unsigned long start, unsigned long end)
*/
static int vmem_add_range(unsigned long start, unsigned long size)
{
- return add_pagetable(start, start + size);
+ return add_pagetable(start, start + size, true);
}
/*
@@ -274,7 +323,7 @@ static int vmem_add_range(unsigned long start, unsigned long size)
*/
static void vmem_remove_range(unsigned long start, unsigned long size)
{
- remove_pagetable(start, start + size);
+ remove_pagetable(start, start + size, true);
}
/*
@@ -283,92 +332,14 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
struct vmem_altmap *altmap)
{
- unsigned long pgt_prot, sgt_prot;
- unsigned long address = start;
- pgd_t *pg_dir;
- p4d_t *p4_dir;
- pud_t *pu_dir;
- pmd_t *pm_dir;
- pte_t *pt_dir;
- int ret = -ENOMEM;
-
- pgt_prot = pgprot_val(PAGE_KERNEL);
- sgt_prot = pgprot_val(SEGMENT_KERNEL);
- if (!MACHINE_HAS_NX) {
- pgt_prot &= ~_PAGE_NOEXEC;
- sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
- }
- for (address = start; address < end;) {
- pg_dir = pgd_offset_k(address);
- if (pgd_none(*pg_dir)) {
- p4_dir = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
- if (!p4_dir)
- goto out;
- pgd_populate(&init_mm, pg_dir, p4_dir);
- }
-
- p4_dir = p4d_offset(pg_dir, address);
- if (p4d_none(*p4_dir)) {
- pu_dir = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
- if (!pu_dir)
- goto out;
- p4d_populate(&init_mm, p4_dir, pu_dir);
- }
-
- pu_dir = pud_offset(p4_dir, address);
- if (pud_none(*pu_dir)) {
- pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
- if (!pm_dir)
- goto out;
- pud_populate(&init_mm, pu_dir, pm_dir);
- }
-
- pm_dir = pmd_offset(pu_dir, address);
- if (pmd_none(*pm_dir)) {
- /* Use 1MB frames for vmemmap if available. We always
- * use large frames even if they are only partially
- * used.
- * Otherwise we would have also page tables since
- * vmemmap_populate gets called for each section
- * separately. */
- if (MACHINE_HAS_EDAT1) {
- void *new_page;
-
- new_page = vmemmap_alloc_block(PMD_SIZE, node);
- if (!new_page)
- goto out;
- pmd_val(*pm_dir) = __pa(new_page) | sgt_prot;
- address = (address + PMD_SIZE) & PMD_MASK;
- continue;
- }
- pt_dir = vmem_pte_alloc();
- if (!pt_dir)
- goto out;
- pmd_populate(&init_mm, pm_dir, pt_dir);
- } else if (pmd_large(*pm_dir)) {
- address = (address + PMD_SIZE) & PMD_MASK;
- continue;
- }
-
- pt_dir = pte_offset_kernel(pm_dir, address);
- if (pte_none(*pt_dir)) {
- void *new_page;
-
- new_page = vmemmap_alloc_block(PAGE_SIZE, node);
- if (!new_page)
- goto out;
- pte_val(*pt_dir) = __pa(new_page) | pgt_prot;
- }
- address += PAGE_SIZE;
- }
- ret = 0;
-out:
- return ret;
+ /* We don't care about the node, just use NUMA_NO_NODE on allocations */
+ return add_pagetable(start, end, false);
}
void vmemmap_free(unsigned long start, unsigned long end,
struct vmem_altmap *altmap)
{
+ remove_pagetable(start, end, false);
}
void vmem_remove_mapping(unsigned long start, unsigned long size)
--
2.26.2
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