lguest: use set_pte/set_pmd uniformly for real page table entries
Rusty Russell [Thu, 24 Sep 2009 04:26:45 +0000 (22:26 -0600)]
If we're building a pte, we can use simple assigment; only use set_pte
etc. when we're actually going to use that destination as a PTE.  I
don't know that we'll ever run under Xen, but it's neater.

And use set_pte/set_pmd rather than assuming native_ versions, even
though that's probably true for most people.

(Includes compile fix by Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>

drivers/lguest/page_tables.c

index a8d0aee..232fba6 100644 (file)
@@ -380,7 +380,7 @@ bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
                 * And we copy the flags to the shadow PMD entry.  The page
                 * number in the shadow PMD is the page we just allocated.
                 */
-               native_set_pmd(spmd, __pmd(__pa(ptepage) | pmd_flags(gpmd)));
+               set_pmd(spmd, __pmd(__pa(ptepage) | pmd_flags(gpmd)));
        }
 
        /*
@@ -447,7 +447,7 @@ bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
                 * we will come back here when a write does actually occur, so
                 * we can update the Guest's _PAGE_DIRTY flag.
                 */
-               native_set_pte(spte, gpte_to_spte(cpu, pte_wrprotect(gpte), 0));
+               set_pte(spte, gpte_to_spte(cpu, pte_wrprotect(gpte), 0));
 
        /*
         * Finally, we write the Guest PTE entry back: we've set the
@@ -528,7 +528,7 @@ static void release_pmd(pmd_t *spmd)
                /* Now we can free the page of PTEs */
                free_page((long)ptepage);
                /* And zero out the PMD entry so we never release it twice. */
-               native_set_pmd(spmd, __pmd(0));
+               set_pmd(spmd, __pmd(0));
        }
 }
 
@@ -833,15 +833,15 @@ static void do_set_pte(struct lg_cpu *cpu, int idx,
                         */
                        if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
                                check_gpte(cpu, gpte);
-                               native_set_pte(spte,
-                                               gpte_to_spte(cpu, gpte,
+                               set_pte(spte,
+                                       gpte_to_spte(cpu, gpte,
                                                pte_flags(gpte) & _PAGE_DIRTY));
                        } else {
                                /*
                                 * Otherwise kill it and we can demand_page()
                                 * it in later.
                                 */
-                               native_set_pte(spte, __pte(0));
+                               set_pte(spte, __pte(0));
                        }
 #ifdef CONFIG_X86_PAE
                }
@@ -983,16 +983,15 @@ static unsigned long setup_pagetables(struct lguest *lg,
         */
        for (i = j = 0; i < mapped_pages && j < PTRS_PER_PMD;
             i += PTRS_PER_PTE, j++) {
-               /* FIXME: native_set_pmd is overkill here. */
-               native_set_pmd(&pmd, __pmd(((unsigned long)(linear + i)
-               - mem_base) | _PAGE_PRESENT | _PAGE_RW | _PAGE_USER));
+               pmd = pfn_pmd(((unsigned long)&linear[i] - mem_base)/PAGE_SIZE,
+                             __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER));
 
                if (copy_to_user(&pmds[j], &pmd, sizeof(pmd)) != 0)
                        return -EFAULT;
        }
 
        /* One PGD entry, pointing to that PMD page. */
-       set_pgd(&pgd, __pgd(((u32)pmds - mem_base) | _PAGE_PRESENT));
+       pgd = __pgd(((unsigned long)pmds - mem_base) | _PAGE_PRESENT);
        /* Copy it in as the first PGD entry (ie. addresses 0-1G). */
        if (copy_to_user(&pgdir[0], &pgd, sizeof(pgd)) != 0)
                return -EFAULT;
@@ -1141,15 +1140,13 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
        pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
        pte_t regs_pte;
-       unsigned long pfn;
 
 #ifdef CONFIG_X86_PAE
        pmd_t switcher_pmd;
        pmd_t *pmd_table;
 
-       /* FIXME: native_set_pmd is overkill here. */
-       native_set_pmd(&switcher_pmd, pfn_pmd(__pa(switcher_pte_page) >>
-                      PAGE_SHIFT, PAGE_KERNEL_EXEC));
+       switcher_pmd = pfn_pmd(__pa(switcher_pte_page) >> PAGE_SHIFT,
+                              PAGE_KERNEL_EXEC);
 
        /* Figure out where the pmd page is, by reading the PGD, and converting
         * it to a virtual address. */
@@ -1157,7 +1154,7 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
                        pgdirs[cpu->cpu_pgd].pgdir[SWITCHER_PGD_INDEX])
                                                                << PAGE_SHIFT);
        /* Now write it into the shadow page table. */
-       native_set_pmd(&pmd_table[SWITCHER_PMD_INDEX], switcher_pmd);
+       set_pmd(&pmd_table[SWITCHER_PMD_INDEX], switcher_pmd);
 #else
        pgd_t switcher_pgd;
 
@@ -1179,10 +1176,8 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
         * page is already mapped there, we don't have to copy them out
         * again.
         */
-       pfn = __pa(cpu->regs_page) >> PAGE_SHIFT;
-       native_set_pte(&regs_pte, pfn_pte(pfn, PAGE_KERNEL));
-       native_set_pte(&switcher_pte_page[pte_index((unsigned long)pages)],
-                       regs_pte);
+       regs_pte = pfn_pte(__pa(cpu->regs_page) >> PAGE_SHIFT, PAGE_KERNEL);
+       set_pte(&switcher_pte_page[pte_index((unsigned long)pages)], regs_pte);
 }
 /*:*/
 
@@ -1209,7 +1204,7 @@ static __init void populate_switcher_pte_page(unsigned int cpu,
 
        /* The first entries are easy: they map the Switcher code. */
        for (i = 0; i < pages; i++) {
-               native_set_pte(&pte[i], mk_pte(switcher_page[i],
+               set_pte(&pte[i], mk_pte(switcher_page[i],
                                __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED)));
        }
 
@@ -1217,14 +1212,14 @@ static __init void populate_switcher_pte_page(unsigned int cpu,
        i = pages + cpu*2;
 
        /* First page (Guest registers) is writable from the Guest */
-       native_set_pte(&pte[i], pfn_pte(page_to_pfn(switcher_page[i]),
+       set_pte(&pte[i], pfn_pte(page_to_pfn(switcher_page[i]),
                         __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW)));
 
        /*
         * The second page contains the "struct lguest_ro_state", and is
         * read-only.
         */
-       native_set_pte(&pte[i+1], pfn_pte(page_to_pfn(switcher_page[i+1]),
+       set_pte(&pte[i+1], pfn_pte(page_to_pfn(switcher_page[i+1]),
                           __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED)));
 }