x86: simplify the 32-bit cpa code
simplify the 32-bit cpa code. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar
parent
a2172e2586
commit
78c94abaea
1 changed files with 56 additions and 123 deletions
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@ -15,9 +15,6 @@
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#include <asm/uaccess.h>
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#include <asm/pgalloc.h>
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static DEFINE_SPINLOCK(cpa_lock);
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static struct list_head df_list = LIST_HEAD_INIT(df_list);
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pte_t *lookup_address(unsigned long address, int *level)
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{
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pgd_t *pgd = pgd_offset_k(address);
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@ -48,9 +45,7 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
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pte_t *pbase;
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int i;
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spin_unlock_irq(&cpa_lock);
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base = alloc_pages(GFP_KERNEL, 0);
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spin_lock_irq(&cpa_lock);
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if (!base)
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return NULL;
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@ -58,9 +53,6 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
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* page_private is used to track the number of entries in
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* the page table page that have non standard attributes.
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*/
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SetPagePrivate(base);
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page_private(base) = 0;
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address = __pa(address);
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addr = address & LARGE_PAGE_MASK;
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pbase = (pte_t *)page_address(base);
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@ -73,36 +65,6 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
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return base;
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}
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static void cache_flush_page(struct page *p)
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{
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void *addr = page_address(p);
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int i;
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for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
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clflush(addr + i);
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}
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static void flush_kernel_map(void *arg)
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{
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struct list_head *lh = (struct list_head *)arg;
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struct page *p;
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/*
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* Flush all to work around Errata in early athlons regarding
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* large page flushing.
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*/
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__flush_tlb_all();
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/* High level code is not ready for clflush yet */
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if (0 && cpu_has_clflush) {
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list_for_each_entry(p, lh, lru)
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cache_flush_page(p);
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} else {
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if (boot_cpu_data.x86_model >= 4)
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wbinvd();
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}
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}
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static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
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{
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unsigned long flags;
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@ -127,36 +89,12 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
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spin_unlock_irqrestore(&pgd_lock, flags);
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}
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/*
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* No more special protections in this 2/4MB area - revert to a large
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* page again.
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*/
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static inline void revert_page(struct page *kpte_page, unsigned long address)
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{
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pgprot_t ref_prot;
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pte_t *linear;
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ref_prot =
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((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
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? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
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linear = (pte_t *)
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pmd_offset(pud_offset(pgd_offset_k(address), address), address);
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set_pmd_pte(linear, address,
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pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
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ref_prot));
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}
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static inline void save_page(struct page *kpte_page)
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{
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if (!test_and_set_bit(PG_arch_1, &kpte_page->flags))
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list_add(&kpte_page->lru, &df_list);
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}
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static int __change_page_attr(struct page *page, pgprot_t prot)
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{
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pgprot_t ref_prot = PAGE_KERNEL;
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struct page *kpte_page;
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unsigned long address;
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pgprot_t oldprot;
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pte_t *kpte;
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int level;
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@ -167,58 +105,41 @@ static int __change_page_attr(struct page *page, pgprot_t prot)
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if (!kpte)
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return -EINVAL;
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oldprot = pte_pgprot(*kpte);
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kpte_page = virt_to_page(kpte);
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BUG_ON(PageLRU(kpte_page));
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BUG_ON(PageCompound(kpte_page));
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if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
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if (level == 3) {
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set_pte_atomic(kpte, mk_pte(page, prot));
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} else {
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struct page *split;
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pgprot_t ref_prot;
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ref_prot =
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((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
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? PAGE_KERNEL_EXEC : PAGE_KERNEL;
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split = split_large_page(address, prot, ref_prot);
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if (!split)
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return -ENOMEM;
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set_pmd_pte(kpte, address, mk_pte(split, ref_prot));
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kpte_page = split;
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}
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page_private(kpte_page)++;
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} else {
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if (level == 3) {
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set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
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BUG_ON(page_private(kpte_page) == 0);
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page_private(kpte_page)--;
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} else
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BUG();
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}
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/*
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* If the pte was reserved, it means it was created at boot
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* time (not via split_large_page) and in turn we must not
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* replace it with a largepage.
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* Better fail early if someone sets the kernel text to NX.
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* Does not cover __inittext
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*/
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BUG_ON(address >= (unsigned long)&_text &&
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address < (unsigned long)&_etext &&
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(pgprot_val(prot) & _PAGE_NX));
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save_page(kpte_page);
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if (!PageReserved(kpte_page)) {
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if (cpu_has_pse && (page_private(kpte_page) == 0)) {
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paravirt_release_pt(page_to_pfn(kpte_page));
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revert_page(kpte_page, address);
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}
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if ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
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ref_prot = PAGE_KERNEL_EXEC;
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ref_prot = canon_pgprot(ref_prot);
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prot = canon_pgprot(prot);
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if (level == 3) {
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set_pte_atomic(kpte, mk_pte(page, prot));
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} else {
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struct page *split;
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split = split_large_page(address, prot, ref_prot);
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if (!split)
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return -ENOMEM;
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/*
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* There's a small window here to waste a bit of RAM:
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*/
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set_pmd_pte(kpte, address, mk_pte(split, ref_prot));
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}
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return 0;
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}
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static inline void flush_map(struct list_head *l)
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{
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on_each_cpu(flush_kernel_map, l, 1, 1);
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}
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/*
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* Change the page attributes of an page in the linear mapping.
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*
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@ -234,40 +155,52 @@ static inline void flush_map(struct list_head *l)
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*/
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int change_page_attr(struct page *page, int numpages, pgprot_t prot)
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{
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unsigned long flags;
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int err = 0, i;
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spin_lock_irqsave(&cpa_lock, flags);
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for (i = 0; i < numpages; i++, page++) {
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err = __change_page_attr(page, prot);
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if (err)
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break;
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}
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spin_unlock_irqrestore(&cpa_lock, flags);
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return err;
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}
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EXPORT_SYMBOL(change_page_attr);
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int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot)
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{
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int i;
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unsigned long pfn = (addr >> PAGE_SHIFT);
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for (i = 0; i < numpages; i++) {
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if (!pfn_valid(pfn + i)) {
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break;
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} else {
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int level;
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pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level);
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BUG_ON(pte && !pte_none(*pte));
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}
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}
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return change_page_attr(virt_to_page(addr), i, prot);
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}
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static void flush_kernel_map(void *arg)
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{
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/*
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* Flush all to work around Errata in early athlons regarding
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* large page flushing.
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*/
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__flush_tlb_all();
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if (boot_cpu_data.x86_model >= 4)
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wbinvd();
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}
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void global_flush_tlb(void)
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{
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struct page *pg, *next;
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struct list_head l;
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BUG_ON(irqs_disabled());
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spin_lock_irq(&cpa_lock);
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list_replace_init(&df_list, &l);
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spin_unlock_irq(&cpa_lock);
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flush_map(&l);
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list_for_each_entry_safe(pg, next, &l, lru) {
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list_del(&pg->lru);
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clear_bit(PG_arch_1, &pg->flags);
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if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
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continue;
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ClearPagePrivate(pg);
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__free_page(pg);
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}
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on_each_cpu(flush_kernel_map, NULL, 1, 1);
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}
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EXPORT_SYMBOL(global_flush_tlb);
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