Re: [patch 01/28] cpu alloc: The allocator

Christoph Lameter
2007-11-13T22:20:17Z

On Tue, 13 Nov 2007, David Miller wrote:

> Yes, I could add virtualized area support to sparc64, but we cannot
> impose this on every platform.

Other platforms do not have the 8MB restriction nor do they have so many
processors.

Here is the draft of a virtual cpu area implementation for sparc64. Uses
the VMEMMAP chunks:

---
arch/sparc64/Kconfig | 12 ++++++++++++
arch/sparc64/mm/init.c | 34 ++++++++++++++++++++++++++++++++++
include/asm-sparc64/pgtable.h | 1 +
3 files changed, 47 insertions(+)

Index: linux-2.6/arch/sparc64/mm/init.c
===================================================================
--- linux-2.6.orig/arch/sparc64/mm/init.c 2007-11-13 14:09:44.619500290 -0800
+++ linux-2.6/arch/sparc64/mm/init.c 2007-11-13 14:17:49.794860210 -0800
@@ -1697,6 +1697,40 @@ int __meminit vmemmap_populate(struct pa
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */

+int cpu_area_populate(void *start, unsigned long size, gfp_t flags, int node)
+{
+ unsigned long vstart = (unsigned long) start;
+ unsigned long vend = (unsigned long) (start + size);
+ unsigned long phys_start = (vstart - CPU_AREA_BASE);
+ unsigned long phys_end = (vend - CPU_AREA_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 |
+ _PAGE_CP_4U | _PAGE_CV_4U |
+ _PAGE_P_4U | _PAGE_W_4U);
+ if (tlb_type == hypervisor)
+ pte_base = (_PAGE_VALID | _PAGE_SZ4MB_4V |
+ _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;
+
+ if (!(*vmem_pp & _PAGE_VALID)) {
+ block = vmemmap_alloc_block(1UL << 22, flags, node);
+ if (!block)
+ return -ENOMEM;
+
+ *vmem_pp = pte_base | __pa(block);
+ }
+ }
+ return 0;
+}
+
static void prot_init_common(unsigned long page_none,
unsigned long page_shared,
unsigned long page_copy,
Index: linux-2.6/arch/sparc64/Kconfig
===================================================================
--- linux-2.6.orig/arch/sparc64/Kconfig 2007-11-13 14:12:28.895750307 -0800
+++ linux-2.6/arch/sparc64/Kconfig 2007-11-13 14:18:32.110750142 -0800
@@ -76,6 +76,18 @@ config GENERIC_HARDIRQS_NO__DO_IRQ
bool
def_bool y

+config CPU_AREA_VIRTUAL
+ bool
+ def_bool y
+
+config CPU_AREA_ORDER
+ int
+ default "10"
+
+config CPU_AREA_ALLOC_ORDER
+ int
+ default "0"
+
choice
prompt "Kernel page size"
default SPARC64_PAGE_SIZE_8KB
Index: linux-2.6/include/asm-sparc64/pgtable.h
===================================================================
--- linux-2.6.orig/include/asm-sparc64/pgtable.h 2007-11-13 14:11:51.871000018 -0800
+++ linux-2.6/include/asm-sparc64/pgtable.h 2007-11-13 14:12:21.011750241 -0800
@@ -43,6 +43,7 @@
#define VMALLOC_START _AC(0x0000000100000000,UL)
#define VMALLOC_END _AC(0x0000000200000000,UL)
#define VMEMMAP_BASE _AC(0x0000000200000000,UL)
+#define CPU_AREA_BASE _AC(0x0000000300000000,UL)

#define vmemmap ((struct page *)VMEMMAP_BASE)