[POWERPC] Fix handling of memreserve if the range lands in highmem

There were several issues if a memreserve range existed and happened
to be in highmem:

* The bootmem allocator is only aware of lowmem so calling
  reserve_bootmem with a highmem address would cause a BUG_ON
* All highmem pages were provided to the buddy allocator

Added a lmb_is_reserved() api that we now use to determine if a highem
page should continue to be PageReserved or provided to the buddy
allocator.

Also, we incorrectly reported the amount of pages reserved since all
highmem pages are initally marked reserved and we clear the
PageReserved flag as we "free" up the highmem pages.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/mm/lmb.c b/arch/powerpc/mm/lmb.c
index 8f4d2dc4cafb0e832039799c364d8bccfc67d51b..4ce23bcf8a57e8a641579b5fab466c7eaf3172e3 100644 (file)
--- a/arch/powerpc/mm/lmb.c
+++ b/arch/powerpc/mm/lmb.c
@@ -342,3 +342,16 @@ void __init lmb_enforce_memory_limit(unsigned long memory_limit)
                }
        }
 }
+
+int __init lmb_is_reserved(unsigned long addr)
+{
+       int i;
+
+       for (i = 0; i < lmb.reserved.cnt; i++) {
+               unsigned long upper = lmb.reserved.region[i].base +
+                                     lmb.reserved.region[i].size - 1;
+               if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
+                       return 1;
+       }
+       return 0;
+}

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 5402fb6b3aae2b49377d56016996e02e7ded55b8..e8122447f019ef81b5346ab911f82bd3c4439cd6 100644 (file)
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -213,15 +213,30 @@ void __init do_init_bootmem(void)
         */
 #ifdef CONFIG_HIGHMEM
        free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
+
+       /* reserve the sections we're already using */
+       for (i = 0; i < lmb.reserved.cnt; i++) {
+               unsigned long addr = lmb.reserved.region[i].base +
+                                    lmb_size_bytes(&lmb.reserved, i) - 1;
+               if (addr < total_lowmem)
+                       reserve_bootmem(lmb.reserved.region[i].base,
+                                       lmb_size_bytes(&lmb.reserved, i));
+               else if (lmb.reserved.region[i].base < total_lowmem) {
+                       unsigned long adjusted_size = total_lowmem -
+                                     lmb.reserved.region[i].base;
+                       reserve_bootmem(lmb.reserved.region[i].base,
+                                       adjusted_size);
+               }
+       }
 #else
        free_bootmem_with_active_regions(0, max_pfn);
-#endif
 
        /* reserve the sections we're already using */
        for (i = 0; i < lmb.reserved.cnt; i++)
                reserve_bootmem(lmb.reserved.region[i].base,
                                lmb_size_bytes(&lmb.reserved, i));
 
+#endif
        /* XXX need to clip this if using highmem? */
        sparse_memory_present_with_active_regions(0);
 
@@ -334,11 +349,13 @@ void __init mem_init(void)
                highmem_mapnr = total_lowmem >> PAGE_SHIFT;
                for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
                        struct page *page = pfn_to_page(pfn);
-
+                       if (lmb_is_reserved(pfn << PAGE_SHIFT))
+                               continue;
                        ClearPageReserved(page);
                        init_page_count(page);
                        __free_page(page);
                        totalhigh_pages++;
+                       reservedpages--;
                }
                totalram_pages += totalhigh_pages;
                printk(KERN_DEBUG "High memory: %luk\n",

diff --git a/include/asm-powerpc/lmb.h b/include/asm-powerpc/lmb.h
index b5f9f4c9c2940e0f2b1ac4b4a9e200e6f9810c5a..5d1dc48a0bb830229f0dd90ae561ab71d6b769f1 100644 (file)
--- a/include/asm-powerpc/lmb.h
+++ b/include/asm-powerpc/lmb.h
@@ -51,6 +51,7 @@ extern unsigned long __init __lmb_alloc_base(unsigned long size,
 extern unsigned long __init lmb_phys_mem_size(void);
 extern unsigned long __init lmb_end_of_DRAM(void);
 extern void __init lmb_enforce_memory_limit(unsigned long memory_limit);
+extern int __init lmb_is_reserved(unsigned long addr);
 
 extern void lmb_dump_all(void);