[RFC PATCH 06/09] robust VM per_cpu i386 bootmem

[Steven Rostedt]

This patch was to get my VM percpu working on my laptop.  This patch
still needs work to handle NUMA and other types of X86 architectures.

Signed-off-by: Steven Rostedt <rostedt at goodmis.org>

Index: linux-2.6.16-test/arch/i386/mm/init.c
===================================================================
--- linux-2.6.16-test.orig/arch/i386/mm/init.c	2006-05-17 04:32:28.000000000 -0400
+++ linux-2.6.16-test/arch/i386/mm/init.c	2006-05-17 04:58:37.000000000 -0400
@@ -772,3 +772,39 @@ void free_initrd_mem(unsigned long start
 	}
 }
 #endif
+
+/*
+ * The following three functions are to impement per_cpu variables
+ * into VM.  per_cpu variables are initialized very early on startup
+ * and before memory management. So the per_cpu initialization needs
+ * a way to allocate pages using bootmem.
+ */
+pud_t __init *pud_boot_alloc(struct mm_struct *mm, pgd_t *pgd,
+			     unsigned long addr, int cpu)
+{
+	return (pud_t*)pgd;
+}
+
+pmd_t __init *pmd_boot_alloc(struct mm_struct *mm, pud_t *pud,
+			     unsigned long addr, int cpu)
+{
+	return pmd_offset(pud, addr);
+}
+
+/* FIXME - handle NUMA handling with the CPU parameter */
+pte_t __init *pte_boot_alloc(struct mm_struct *mm, pmd_t *pmd,
+			     unsigned long addr, int cpu)
+{
+	pte_t *pte;
+
+	if (pmd_none(*pmd)) {
+		pte = alloc_bootmem_pages(PAGE_SIZE);
+		if (!pte)
+			return NULL;
+		mm->nr_ptes++;
+		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
+	} else
+		pte = pte_offset_kernel(pmd, addr);
+
+	return pte;
+}