5 files changed, 147 insertions, 12 deletions

diff --git a/arch/sparc64/Kconfig.debug b/arch/sparc64/Kconfig.debug
index af0e9411b83e..fa06ea04837b 100644
--- a/arch/sparc64/Kconfig.debug
+++ b/arch/sparc64/Kconfig.debug
@@ -33,6 +33,14 @@ config DEBUG_BOOTMEM
         depends on DEBUG_KERNEL
         bool "Debug BOOTMEM initialization"
 
+config DEBUG_PAGEALLOC
+        bool "Page alloc debugging"
+        depends on DEBUG_KERNEL && !SOFTWARE_SUSPEND
+        help
+          Unmap pages from the kernel linear mapping after free_pages().
+          This results in a large slowdown, but helps to find certain types
+          of memory corruptions.
+
 config MCOUNT
         bool
         depends on STACK_DEBUG
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 56af714f5f1b..ecc748fb9ad7 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -525,12 +525,6 @@ bootup_user_stack_end:
 
 #include "ttable.S"
 #include "systbls.S"
-
-        .align  1024
-        .globl  swapper_pg_dir
-swapper_pg_dir:
-        .word   0
-
 #include "ktlb.S"
 #include "etrap.S"
 #include "rtrap.S"
diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S
index a591bc0ebc7b..7796b37f478c 100644
--- a/arch/sparc64/kernel/ktlb.S
+++ b/arch/sparc64/kernel/ktlb.S
@@ -132,9 +132,40 @@ kvmap_do_obp:
  */
         .align          32
 kvmap:
-        brlz,pt         %g4, kvmap_load
+        brgez,pn        %g4, kvmap_nonlinear
+         nop
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+        .globl          kvmap_linear_patch
+kvmap_linear_patch:
+#endif
+        ba,pt           %xcc, kvmap_load
          xor            %g2, %g4, %g5
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+        sethi           %hi(swapper_pg_dir), %g5
+        or              %g5, %lo(swapper_pg_dir), %g5
+        sllx            %g4, 64 - (PGDIR_SHIFT + PGDIR_BITS), %g6
+        srlx            %g6, 64 - PAGE_SHIFT, %g6
+        andn            %g6, 0x3, %g6
+        lduw            [%g5 + %g6], %g5
+        brz,pn          %g5, longpath
+         sllx           %g4, 64 - (PMD_SHIFT + PMD_BITS), %g6
+        srlx            %g6, 64 - PAGE_SHIFT, %g6
+        sllx            %g5, 11, %g5
+        andn            %g6, 0x3, %g6
+        lduwa           [%g5 + %g6] ASI_PHYS_USE_EC, %g5
+        brz,pn          %g5, longpath
+         sllx           %g4, 64 - PMD_SHIFT, %g6
+        srlx            %g6, 64 - PAGE_SHIFT, %g6
+        sllx            %g5, 11, %g5
+        andn            %g6, 0x7, %g6
+        ldxa            [%g5 + %g6] ASI_PHYS_USE_EC, %g5
+        brz,pn          %g5, longpath
+         nop
+        ba,a,pt         %xcc, kvmap_load
+#endif
+
 kvmap_nonlinear:
         sethi           %hi(MODULES_VADDR), %g5
         cmp             %g4, %g5
diff --git a/arch/sparc64/kernel/vmlinux.lds.S b/arch/sparc64/kernel/vmlinux.lds.S
index f47d0be39378..2af0cf0a8640 100644
--- a/arch/sparc64/kernel/vmlinux.lds.S
+++ b/arch/sparc64/kernel/vmlinux.lds.S
@@ -9,8 +9,7 @@ ENTRY(_start)
 jiffies = jiffies_64;
 SECTIONS
 {
-  swapper_pmd_dir = 0x0000000000402000;
-  empty_pg_dir = 0x0000000000403000;
+  swapper_low_pmd_dir = 0x0000000000402000;
   . = 0x4000;
   .text 0x0000000000404000 :
   {
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index cf747372f0c9..8d72f8a1268e 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -1332,15 +1332,114 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
         return end_pfn;
 }
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static unsigned long kernel_map_range(unsigned long pstart, unsigned long pend, pgprot_t prot)
+{
+        unsigned long vstart = PAGE_OFFSET + pstart;
+        unsigned long vend = PAGE_OFFSET + pend;
+        unsigned long alloc_bytes = 0UL;
+
+        if ((vstart & ~PAGE_MASK) || (vend & ~PAGE_MASK)) {
+                prom_printf("kernel_map: Unaligned sp_banks[%lx:%lx]\n",
+                            vstart, vend);
+                prom_halt();
+        }
+
+        while (vstart < vend) {
+                unsigned long this_end, paddr = __pa(vstart);
+                pgd_t *pgd = pgd_offset_k(vstart);
+                pud_t *pud;
+                pmd_t *pmd;
+                pte_t *pte;
+
+                pud = pud_offset(pgd, vstart);
+                if (pud_none(*pud)) {
+                        pmd_t *new;
+
+                        new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+                        alloc_bytes += PAGE_SIZE;
+                        pud_populate(&init_mm, pud, new);
+                }
+
+                pmd = pmd_offset(pud, vstart);
+                if (!pmd_present(*pmd)) {
+                        pte_t *new;
+
+                        new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+                        alloc_bytes += PAGE_SIZE;
+                        pmd_populate_kernel(&init_mm, pmd, new);
+                }
+
+                pte = pte_offset_kernel(pmd, vstart);
+                this_end = (vstart + PMD_SIZE) & PMD_MASK;
+                if (this_end > vend)
+                        this_end = vend;
+
+                while (vstart < this_end) {
+                        pte_val(*pte) = (paddr | pgprot_val(prot));
+
+                        vstart += PAGE_SIZE;
+                        paddr += PAGE_SIZE;
+                        pte++;
+                }
+        }
+
+        return alloc_bytes;
+}
+
+extern struct linux_mlist_p1275 *prom_ptot_ptr;
+extern unsigned int kvmap_linear_patch[1];
+
+static void __init kernel_physical_mapping_init(void)
+{
+        struct linux_mlist_p1275 *p = prom_ptot_ptr;
+        unsigned long mem_alloced = 0UL;
+
+        while (p) {
+                unsigned long phys_start, phys_end;
+
+                phys_start = p->start_adr;
+                phys_end = phys_start + p->num_bytes;
+                mem_alloced += kernel_map_range(phys_start, phys_end,
+                                                PAGE_KERNEL);
+
+                p = p->theres_more;
+        }
+
+        printk("Allocated %ld bytes for kernel page tables.\n",
+               mem_alloced);
+
+        kvmap_linear_patch[0] = 0x01000000; /* nop */
+        flushi(&kvmap_linear_patch[0]);
+
+        __flush_tlb_all();
+}
+
+void kernel_map_pages(struct page *page, int numpages, int enable)
+{
+        unsigned long phys_start = page_to_pfn(page) << PAGE_SHIFT;
+        unsigned long phys_end = phys_start + (numpages * PAGE_SIZE);
+
+        kernel_map_range(phys_start, phys_end,
+                         (enable ? PAGE_KERNEL : __pgprot(0)));
+
+        /* we should perform an IPI and flush all tlbs,
+         * but that can deadlock->flush only current cpu.
+         */
+        __flush_tlb_kernel_range(PAGE_OFFSET + phys_start,
+                                 PAGE_OFFSET + phys_end);
+}
+#endif
+
 /* paging_init() sets up the page tables */
 
 extern void cheetah_ecache_flush_init(void);
 
 static unsigned long last_valid_pfn;
+pgd_t swapper_pg_dir[2048];
 
 void __init paging_init(void)
 {
-        extern pmd_t swapper_pmd_dir[1024];
         unsigned long end_pfn, pages_avail, shift;
         unsigned long real_end;
 
@@ -1361,11 +1460,11 @@ void __init paging_init(void)
          */
         init_mm.pgd += ((shift) / (sizeof(pgd_t)));
         
-        memset(swapper_pmd_dir, 0, sizeof(swapper_pmd_dir));
+        memset(swapper_low_pmd_dir, 0, sizeof(swapper_low_pmd_dir));
 
         /* Now can init the kernel/bad page tables. */
         pud_set(pud_offset(&swapper_pg_dir[0], 0),
-                swapper_pmd_dir + (shift / sizeof(pgd_t)));
+                swapper_low_pmd_dir + (shift / sizeof(pgd_t)));
         
         swapper_pgd_zero = pgd_val(swapper_pg_dir[0]);
         
@@ -1390,6 +1489,10 @@ void __init paging_init(void)
         pages_avail = 0;
         last_valid_pfn = end_pfn = bootmem_init(&pages_avail);
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+        kernel_physical_mapping_init();
+#endif
+
         {
                 unsigned long zones_size[MAX_NR_ZONES];
                 unsigned long zholes_size[MAX_NR_ZONES];