Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
new file mode 100644
index 0000000..94862e1
--- /dev/null
+++ b/arch/x86_64/mm/pageattr.c
@@ -0,0 +1,235 @@
+/*
+ * Copyright 2002 Andi Kleen, SuSE Labs.
+ * Thanks to Ben LaHaise for precious feedback.
+ */
+
+#include <linux/config.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/tlbflush.h>
+#include <asm/io.h>
+
+static inline pte_t *lookup_address(unsigned long address)
+{
+ pgd_t *pgd = pgd_offset_k(address);
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ if (pgd_none(*pgd))
+ return NULL;
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ return NULL;
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ return NULL;
+ if (pmd_large(*pmd))
+ return (pte_t *)pmd;
+ pte = pte_offset_kernel(pmd, address);
+ if (pte && !pte_present(*pte))
+ pte = NULL;
+ return pte;
+}
+
+static struct page *split_large_page(unsigned long address, pgprot_t prot,
+ pgprot_t ref_prot)
+{
+ int i;
+ unsigned long addr;
+ struct page *base = alloc_pages(GFP_KERNEL, 0);
+ pte_t *pbase;
+ if (!base)
+ return NULL;
+ address = __pa(address);
+ addr = address & LARGE_PAGE_MASK;
+ pbase = (pte_t *)page_address(base);
+ for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
+ pbase[i] = pfn_pte(addr >> PAGE_SHIFT,
+ addr == address ? prot : ref_prot);
+ }
+ return base;
+}
+
+
+static void flush_kernel_map(void *address)
+{
+ if (0 && address && cpu_has_clflush) {
+ /* is this worth it? */
+ int i;
+ for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
+ asm volatile("clflush (%0)" :: "r" (address + i));
+ } else
+ asm volatile("wbinvd":::"memory");
+ if (address)
+ __flush_tlb_one(address);
+ else
+ __flush_tlb_all();
+}
+
+
+static inline void flush_map(unsigned long address)
+{
+ on_each_cpu(flush_kernel_map, (void *)address, 1, 1);
+}
+
+struct deferred_page {
+ struct deferred_page *next;
+ struct page *fpage;
+ unsigned long address;
+};
+static struct deferred_page *df_list; /* protected by init_mm.mmap_sem */
+
+static inline void save_page(unsigned long address, struct page *fpage)
+{
+ struct deferred_page *df;
+ df = kmalloc(sizeof(struct deferred_page), GFP_KERNEL);
+ if (!df) {
+ flush_map(address);
+ __free_page(fpage);
+ } else {
+ df->next = df_list;
+ df->fpage = fpage;
+ df->address = address;
+ df_list = df;
+ }
+}
+
+/*
+ * No more special protections in this 2/4MB area - revert to a
+ * large page again.
+ */
+static void revert_page(unsigned long address, pgprot_t ref_prot)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t large_pte;
+
+ pgd = pgd_offset_k(address);
+ BUG_ON(pgd_none(*pgd));
+ pud = pud_offset(pgd,address);
+ BUG_ON(pud_none(*pud));
+ pmd = pmd_offset(pud, address);
+ BUG_ON(pmd_val(*pmd) & _PAGE_PSE);
+ pgprot_val(ref_prot) |= _PAGE_PSE;
+ large_pte = mk_pte_phys(__pa(address) & LARGE_PAGE_MASK, ref_prot);
+ set_pte((pte_t *)pmd, large_pte);
+}
+
+static int
+__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
+ pgprot_t ref_prot)
+{
+ pte_t *kpte;
+ struct page *kpte_page;
+ unsigned kpte_flags;
+ kpte = lookup_address(address);
+ if (!kpte) return 0;
+ kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
+ kpte_flags = pte_val(*kpte);
+ if (pgprot_val(prot) != pgprot_val(ref_prot)) {
+ if ((kpte_flags & _PAGE_PSE) == 0) {
+ set_pte(kpte, pfn_pte(pfn, prot));
+ } else {
+ /*
+ * split_large_page will take the reference for this change_page_attr
+ * on the split page.
+ */
+ struct page *split = split_large_page(address, prot, ref_prot);
+ if (!split)
+ return -ENOMEM;
+ set_pte(kpte,mk_pte(split, ref_prot));
+ kpte_page = split;
+ }
+ get_page(kpte_page);
+ } else if ((kpte_flags & _PAGE_PSE) == 0) {
+ set_pte(kpte, pfn_pte(pfn, ref_prot));
+ __put_page(kpte_page);
+ } else
+ BUG();
+
+ /* on x86-64 the direct mapping set at boot is not using 4k pages */
+ BUG_ON(PageReserved(kpte_page));
+
+ switch (page_count(kpte_page)) {
+ case 1:
+ save_page(address, kpte_page);
+ revert_page(address, ref_prot);
+ break;
+ case 0:
+ BUG(); /* memleak and failed 2M page regeneration */
+ }
+ return 0;
+}
+
+/*
+ * Change the page attributes of an page in the linear mapping.
+ *
+ * This should be used when a page is mapped with a different caching policy
+ * than write-back somewhere - some CPUs do not like it when mappings with
+ * different caching policies exist. This changes the page attributes of the
+ * in kernel linear mapping too.
+ *
+ * The caller needs to ensure that there are no conflicting mappings elsewhere.
+ * This function only deals with the kernel linear map.
+ *
+ * Caller must call global_flush_tlb() after this.
+ */
+int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
+{
+ int err = 0;
+ int i;
+
+ down_write(&init_mm.mmap_sem);
+ for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
+ unsigned long pfn = __pa(address) >> PAGE_SHIFT;
+
+ err = __change_page_attr(address, pfn, prot, PAGE_KERNEL);
+ if (err)
+ break;
+ /* Handle kernel mapping too which aliases part of the
+ * lowmem */
+ if (__pa(address) < KERNEL_TEXT_SIZE) {
+ unsigned long addr2;
+ pgprot_t prot2 = prot;
+ addr2 = __START_KERNEL_map + __pa(address);
+ pgprot_val(prot2) &= ~_PAGE_NX;
+ err = __change_page_attr(addr2, pfn, prot2, PAGE_KERNEL_EXEC);
+ }
+ }
+ up_write(&init_mm.mmap_sem);
+ return err;
+}
+
+/* Don't call this for MMIO areas that may not have a mem_map entry */
+int change_page_attr(struct page *page, int numpages, pgprot_t prot)
+{
+ unsigned long addr = (unsigned long)page_address(page);
+ return change_page_attr_addr(addr, numpages, prot);
+}
+
+void global_flush_tlb(void)
+{
+ struct deferred_page *df, *next_df;
+
+ down_read(&init_mm.mmap_sem);
+ df = xchg(&df_list, NULL);
+ up_read(&init_mm.mmap_sem);
+ if (!df)
+ return;
+ flush_map((df && !df->next) ? df->address : 0);
+ for (; df; df = next_df) {
+ next_df = df->next;
+ if (df->fpage)
+ __free_page(df->fpage);
+ kfree(df);
+ }
+}
+
+EXPORT_SYMBOL(change_page_attr);
+EXPORT_SYMBOL(global_flush_tlb);