Blackfin arch: fix bug kernel not to boot up with mtd filesystems

Revert this patch:
move the init sections to the end of memory, so that after they
are free, run time memory is all continugous - this should help decrease
memory fragementation. When doing this, we also pack some of the other
sections a little closer together, to make sure we don't waste memory.
To make this happen, we need to rename the .data.init_task section to
.init_task.data, so it doesn't get picked up by the linker script glob.

Since it causes the kernel not to boot up with mtd filesystems.

Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

3 files changed, 24 insertions, 33 deletions

diff --git a/arch/blackfin/kernel/init_task.c b/arch/blackfin/kernel/init_task.c
index c640154030e2..673c860ffc23 100644
--- a/arch/blackfin/kernel/init_task.c
+++ b/arch/blackfin/kernel/init_task.c
@@ -57,5 +57,5 @@ EXPORT_SYMBOL(init_task);
  * "init_task" linker map entry.
  */
 union thread_union init_thread_union
-    __attribute__ ((__section__(".init_task.data"))) = {
+    __attribute__ ((__section__(".data.init_task"))) = {
 INIT_THREAD_INFO(init_task)};
diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c
index eee5a1fcb64c..d2822010b7ce 100644
--- a/arch/blackfin/kernel/setup.c
+++ b/arch/blackfin/kernel/setup.c
@@ -237,7 +237,7 @@ void __init setup_arch(char **cmdline_p)
         /* by now the stack is part of the init task */
         memory_end = _ramend - DMA_UNCACHED_REGION;
 
-        _ramstart = (unsigned long)_end;
+        _ramstart = (unsigned long)__bss_stop;
         memory_start = PAGE_ALIGN(_ramstart);
 
 #if defined(CONFIG_MTD_UCLINUX)
@@ -286,7 +286,7 @@ void __init setup_arch(char **cmdline_p)
         }
 
         /* Relocate MTD image to the top of memory after the uncached memory area */
-        dma_memcpy((char *)memory_end, _end, mtd_size);
+        dma_memcpy((char *)memory_end, __bss_stop, mtd_size);
 
         memory_mtd_start = memory_end;
         _ebss = memory_mtd_start;       /* define _ebss for compatible */
@@ -358,10 +358,10 @@ void __init setup_arch(char **cmdline_p)
         printk(KERN_INFO "Memory map:\n"
                KERN_INFO "  text      = 0x%p-0x%p\n"
                KERN_INFO "  rodata    = 0x%p-0x%p\n"
-               KERN_INFO "  bss       = 0x%p-0x%p\n"
                KERN_INFO "  data      = 0x%p-0x%p\n"
                KERN_INFO "    stack   = 0x%p-0x%p\n"
                KERN_INFO "  init      = 0x%p-0x%p\n"
+               KERN_INFO "  bss       = 0x%p-0x%p\n"
                KERN_INFO "  available = 0x%p-0x%p\n"
 #ifdef CONFIG_MTD_UCLINUX
                KERN_INFO "  rootfs    = 0x%p-0x%p\n"
@@ -371,10 +371,10 @@ void __init setup_arch(char **cmdline_p)
 #endif
                , _stext, _etext,
                __start_rodata, __end_rodata,
-               __bss_start, __bss_stop,
                _sdata, _edata,
                (void *)&init_thread_union, (void *)((int)(&init_thread_union) + 0x2000),
                __init_begin, __init_end,
+               __bss_start, __bss_stop,
                (void *)_ramstart, (void *)memory_end
 #ifdef CONFIG_MTD_UCLINUX
                , (void *)memory_mtd_start, (void *)(memory_mtd_start + mtd_size)
diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S
index 5bdc0f79bb1a..9b75bc83c71f 100644
--- a/arch/blackfin/kernel/vmlinux.lds.S
+++ b/arch/blackfin/kernel/vmlinux.lds.S
@@ -41,9 +41,6 @@ _jiffies = _jiffies_64;
 SECTIONS
 {
         . = CONFIG_BOOT_LOAD;
-        /* Neither the text, ro_data or bss section need to be aligned
-         * So pack them back to back
-         */
         .text :
         {
                 __text = .;
@@ -61,25 +58,22 @@ SECTIONS
                 *(__ex_table)
                 ___stop___ex_table = .;
 
+                . = ALIGN(4);
                 __etext = .;
         }
 
-        /* Just in case the first read only is a 32-bit access */
-        RO_DATA(4)
-
-        .bss :
-        {
-                . = ALIGN(4);
-                ___bss_start = .;
-                *(.bss .bss.*)
-                *(COMMON)
-                ___bss_stop = .;
-        }
+        RO_DATA(PAGE_SIZE)
 
         .data :
         {
+                /* make sure the init_task is aligned to the
+                 * kernel thread size so we can locate the kernel
+                 * stack properly and quickly.
+                 */
                 __sdata = .;
-                /* This gets done first, so the glob doesn't suck it in */
+                . = ALIGN(THREAD_SIZE);
+                *(.data.init_task)
+
                 . = ALIGN(32);
                 *(.data.cacheline_aligned)
 
@@ -87,22 +81,10 @@ SECTIONS
                 *(.data.*)
                 CONSTRUCTORS
 
-                /* make sure the init_task is aligned to the
-                 * kernel thread size so we can locate the kernel
-                 * stack properly and quickly.
-                 */
                 . = ALIGN(THREAD_SIZE);
-                *(.init_task.data)
-
                 __edata = .;
         }
 
-        /* The init section should be last, so when we free it, it goes into
-         * the general memory pool, and (hopefully) will decrease fragmentation
-         * a tiny bit. The init section has a _requirement_ that it be
-         * PAGE_SIZE aligned
-         */
-        . = ALIGN(PAGE_SIZE);
         ___init_begin = .;
 
         .init.text :
@@ -197,7 +179,16 @@ SECTIONS
         . = ALIGN(PAGE_SIZE);
         ___init_end = .;
 
-        __end =.;
+        .bss :
+        {
+                . = ALIGN(4);
+                ___bss_start = .;
+                *(.bss .bss.*)
+                *(COMMON)
+                . = ALIGN(4);
+                ___bss_stop = .;
+                __end = .;
+        }
 
         STABS_DEBUG