====================
[PATCH] sparc64: Use kernel page tables for vmemmap.
For sparse memory configurations, the vmemmap array behaves terribly
and it takes up an inordinate amount of space in the BSS section of
the kernel image unconditionally.
Just build huge PMDs and look them up just like we do for TLB misses
in the vmalloc area.
Align debugging logs with what x86-64 does.
Kernel BSS shrinks by about 2MB.
Signed-off-by: David S. Miller <davem@davemloft.net>
---
arch/sparc/include/asm/tsb.h | 19 ++++++++++++++++
arch/sparc/kernel/ktlb.S | 11 +++++----
arch/sparc/mm/init_64.c | 53 ++++++++++++++++++++++++++++----------------
arch/sparc/mm/init_64.h | 11 ---------
4 files changed, 58 insertions(+), 36 deletions(-)
@@ -155,6 +155,25 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
andn REG2, 0x7, REG2; \
add REG1, REG2, REG1;
+ /* Do a 4MB kernel page table walk. Leaves large PMD value in
+ * REG1. Jumps to FAIL_LABEL on early page table walk termination.
+ * VADDR will not be clobbered, but REG2 will.
+ */
+#define KERN_4M_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL) \
+ sethi %hi(swapper_pg_dir), REG1; \
+ or REG1, %lo(swapper_pg_dir), REG1; \
+ sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
+ srlx REG2, 64 - PAGE_SHIFT, REG2; \
+ andn REG2, 0x7, REG2; \
+ ldx [REG1 + REG2], REG1; \
+ brz,pn REG1, FAIL_LABEL; \
+ sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
+ srlx REG2, 64 - PAGE_SHIFT, REG2; \
+ andn REG2, 0x7, REG2; \
+ ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
+ brz,pn REG1, FAIL_LABEL; \
+ nop;
+
/* PMD has been loaded into REG1, interpret the value, seeing
* if it is a HUGE PMD or a normal one. If it is not valid
* then jump to FAIL_LABEL. If it is a HUGE PMD, and it
@@ -247,13 +247,12 @@ kvmap_dtlb_load:
#ifdef CONFIG_SPARSEMEM_VMEMMAP
kvmap_vmemmap:
- sub %g4, %g5, %g5
- srlx %g5, ILOG2_4MB, %g5
- sethi %hi(vmemmap_table), %g1
- sllx %g5, 3, %g5
- or %g1, %lo(vmemmap_table), %g1
+ KERN_4M_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
+ sethi %hi(4 * 1024 * 1024), %g2
+ andn %g5, %g2, %g5
+ and %g4, %g2, %g2
ba,pt %xcc, kvmap_dtlb_load
- ldx [%g1 + %g5], %g5
+ or %g5, %g2, %g5
#endif
kvmap_dtlb_nonlinear:
@@ -2332,18 +2332,13 @@ unsigned long _PAGE_CACHE __read_mostly;
EXPORT_SYMBOL(_PAGE_CACHE);
#ifdef CONFIG_SPARSEMEM_VMEMMAP
-unsigned long vmemmap_table[VMEMMAP_SIZE];
-
static long __meminitdata addr_start, addr_end;
+static void __meminitdata *p_start, *p_end;
static int __meminitdata node_start;
int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend,
int node)
{
- unsigned long phys_start = (vstart - VMEMMAP_BASE);
- unsigned long phys_end = (vend - VMEMMAP_BASE);
- unsigned long addr = phys_start & VMEMMAP_CHUNK_MASK;
- unsigned long end = VMEMMAP_ALIGN(phys_end);
unsigned long pte_base;
pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4U |
@@ -2354,29 +2349,49 @@ int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend,
_PAGE_CP_4V | _PAGE_CV_4V |
_PAGE_P_4V | _PAGE_W_4V);
- for (; addr < end; addr += VMEMMAP_CHUNK) {
- unsigned long *vmem_pp =
- vmemmap_table + (addr >> VMEMMAP_CHUNK_SHIFT);
- void *block;
+ vstart = vstart & PMD_MASK;
+ vend = ALIGN(vend, PMD_SIZE);
+ for (; vstart < vend; vstart += PMD_SIZE) {
+ pgd_t *pgd = pgd_offset_k(vstart);
+ unsigned long pte;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pud = pud_offset(pgd, vstart);
+ if (pud_none(*pud)) {
+ pmd_t *new = vmemmap_alloc_block(PAGE_SIZE, node);
+
+ if (!new)
+ return -ENOMEM;
+ pud_populate(&init_mm, pud, new);
+ }
+
+ pmd = pmd_offset(pud, vstart);
+
+ pte = pmd_val(*pmd);
+ if (!(pte & _PAGE_VALID)) {
+ void *block = vmemmap_alloc_block(PMD_SIZE, node);
- if (!(*vmem_pp & _PAGE_VALID)) {
- block = vmemmap_alloc_block(1UL << ILOG2_4MB, node);
if (!block)
return -ENOMEM;
- *vmem_pp = pte_base | __pa(block);
+ pmd_val(*pmd) = pte_base | __pa(block);
/* check to see if we have contiguous blocks */
- if (addr_end != addr || node_start != node) {
- if (addr_start)
- printk(KERN_DEBUG " [%lx-%lx] on node %d\n",
- addr_start, addr_end-1, node_start);
- addr_start = addr;
+ if (p_end != block || node_start != node) {
+ if (p_start)
+ printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
+ addr_start, addr_end-1, p_start, p_end-1, node_start);
+ addr_start = vstart;
node_start = node;
+ p_start = block;
}
- addr_end = addr + VMEMMAP_CHUNK;
+
+ addr_end = vstart + PMD_SIZE;
+ p_end = block + PMD_SIZE;
}
}
+
return 0;
}
@@ -35,15 +35,4 @@ extern unsigned long kern_locked_tte_data;
void prom_world(int enter);
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
-#define VMEMMAP_CHUNK_SHIFT 22
-#define VMEMMAP_CHUNK (1UL << VMEMMAP_CHUNK_SHIFT)
-#define VMEMMAP_CHUNK_MASK ~(VMEMMAP_CHUNK - 1UL)
-#define VMEMMAP_ALIGN(x) (((x)+VMEMMAP_CHUNK-1UL)&VMEMMAP_CHUNK_MASK)
-
-#define VMEMMAP_SIZE ((((1UL << MAX_PHYSADDR_BITS) >> PAGE_SHIFT) * \
- sizeof(struct page)) >> VMEMMAP_CHUNK_SHIFT)
-extern unsigned long vmemmap_table[VMEMMAP_SIZE];
-#endif
-
#endif /* _SPARC64_MM_INIT_H */