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authorPeter Zijlstra <peterz@infradead.org>2020-01-31 15:45:39 +0300
committerGeert Uytterhoeven <geert@linux-m68k.org>2020-02-10 12:57:48 +0300
commit0e071ee6815692a3b241bbe9a9a29f7cdec023ed (patch)
treefa516f2a287d2f5315a98ebeeb472d46dc6f9ddc /arch/m68k/mm
parent61c64a25ae8df45c2cd2f76343e20c3d266382ea (diff)
downloadlinux-0e071ee6815692a3b241bbe9a9a29f7cdec023ed.tar.xz
m68k: mm: Extend table allocator for multiple sizes
In addition to the PGD/PMD table size (128*4) add a PTE table size (64*4) to the table allocator. This completely removes the pte-table overhead compared to the old code, even for dense tables. Notes: - the allocator gained a list_empty() check to deal with there not being any pages at all. - the free mask is extended to cover more than the 8 bits required for the (512 byte) PGD/PMD tables. - NR_PAGETABLE accounting is restored. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Greg Ungerer <gerg@linux-m68k.org> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Greg Ungerer <gerg@linux-m68k.org> Link: https://lore.kernel.org/r/20200131125403.882175409@infradead.org Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/mm')
-rw-r--r--arch/m68k/mm/init.c16
-rw-r--r--arch/m68k/mm/motorola.c65
2 files changed, 51 insertions, 30 deletions
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index a9b6d26cff8a..3e3a74a5b215 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -40,10 +40,6 @@
void *empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);
-#if !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
-extern void init_pointer_table(unsigned long ptable);
-#endif
-
#ifdef CONFIG_MMU
pg_data_t pg_data_map[MAX_NUMNODES];
@@ -127,12 +123,16 @@ static inline void init_pointer_tables(void)
int i;
/* insert pointer tables allocated so far into the tablelist */
- init_pointer_table((unsigned long)kernel_pg_dir);
+ init_pointer_table(kernel_pg_dir, TABLE_PGD);
for (i = 0; i < PTRS_PER_PGD; i++) {
- pud_t *pud = (pud_t *)(&kernel_pg_dir[i]);
+ pud_t *pud = (pud_t *)&kernel_pg_dir[i];
+ pmd_t *pmd_dir;
+
+ if (!pud_present(*pud))
+ continue;
- if (pud_present(*pud))
- init_pointer_table(pgd_page_vaddr(kernel_pg_dir[i]));
+ pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]);
+ init_pointer_table(pmd_dir, TABLE_PMD);
}
#endif
}
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 600f9c1d96f8..fc16190ec2d6 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -72,24 +72,35 @@ void mmu_page_dtor(void *page)
arch/sparc/mm/srmmu.c ... */
typedef struct list_head ptable_desc;
-static LIST_HEAD(ptable_list);
+
+static struct list_head ptable_list[2] = {
+ LIST_HEAD_INIT(ptable_list[0]),
+ LIST_HEAD_INIT(ptable_list[1]),
+};
#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru))
#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru))
-#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index)
+#define PD_MARKBITS(dp) (*(unsigned int *)&PD_PAGE(dp)->index)
+
+static const int ptable_shift[2] = {
+ 7+2, /* PGD, PMD */
+ 6+2, /* PTE */
+};
-#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t))
+#define ptable_size(type) (1U << ptable_shift[type])
+#define ptable_mask(type) ((1U << (PAGE_SIZE / ptable_size(type))) - 1)
-void __init init_pointer_table(unsigned long ptable)
+void __init init_pointer_table(void *table, int type)
{
ptable_desc *dp;
+ unsigned long ptable = (unsigned long)table;
unsigned long page = ptable & PAGE_MASK;
- unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE);
+ unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
dp = PD_PTABLE(page);
if (!(PD_MARKBITS(dp) & mask)) {
- PD_MARKBITS(dp) = 0xff;
- list_add(dp, &ptable_list);
+ PD_MARKBITS(dp) = ptable_mask(type);
+ list_add(dp, &ptable_list[type]);
}
PD_MARKBITS(dp) &= ~mask;
@@ -102,12 +113,11 @@ void __init init_pointer_table(unsigned long ptable)
return;
}
-pmd_t *get_pointer_table (void)
+void *get_pointer_table(int type)
{
- ptable_desc *dp = ptable_list.next;
- unsigned char mask = PD_MARKBITS (dp);
- unsigned char tmp;
- unsigned int off;
+ ptable_desc *dp = ptable_list[type].next;
+ unsigned int mask = list_empty(&ptable_list[type]) ? 0 : PD_MARKBITS(dp);
+ unsigned int tmp, off;
/*
* For a pointer table for a user process address space, a
@@ -122,30 +132,39 @@ pmd_t *get_pointer_table (void)
if (!(page = (void *)get_zeroed_page(GFP_KERNEL)))
return NULL;
+ if (type == TABLE_PTE) {
+ /*
+ * m68k doesn't have SPLIT_PTE_PTLOCKS for not having
+ * SMP.
+ */
+ pgtable_pte_page_ctor(virt_to_page(page));
+ }
+
mmu_page_ctor(page);
new = PD_PTABLE(page);
- PD_MARKBITS(new) = 0xfe;
+ PD_MARKBITS(new) = ptable_mask(type) - 1;
list_add_tail(new, dp);
return (pmd_t *)page;
}
- for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE)
+ for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += ptable_size(type))
;
PD_MARKBITS(dp) = mask & ~tmp;
if (!PD_MARKBITS(dp)) {
/* move to end of list */
- list_move_tail(dp, &ptable_list);
+ list_move_tail(dp, &ptable_list[type]);
}
- return (pmd_t *) (page_address(PD_PAGE(dp)) + off);
+ return page_address(PD_PAGE(dp)) + off;
}
-int free_pointer_table (pmd_t *ptable)
+int free_pointer_table(void *table, int type)
{
ptable_desc *dp;
- unsigned long page = (unsigned long)ptable & PAGE_MASK;
- unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE);
+ unsigned long ptable = (unsigned long)table;
+ unsigned long page = ptable & PAGE_MASK;
+ unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
dp = PD_PTABLE(page);
if (PD_MARKBITS (dp) & mask)
@@ -153,18 +172,20 @@ int free_pointer_table (pmd_t *ptable)
PD_MARKBITS (dp) |= mask;
- if (PD_MARKBITS(dp) == 0xff) {
+ if (PD_MARKBITS(dp) == ptable_mask(type)) {
/* all tables in page are free, free page */
list_del(dp);
mmu_page_dtor((void *)page);
+ if (type == TABLE_PTE)
+ pgtable_pte_page_dtor(virt_to_page(page));
free_page (page);
return 1;
- } else if (ptable_list.next != dp) {
+ } else if (ptable_list[type].next != dp) {
/*
* move this descriptor to the front of the list, since
* it has one or more free tables.
*/
- list_move(dp, &ptable_list);
+ list_move(dp, &ptable_list[type]);
}
return 0;
}