The check and definitions related to ramdisk are similar in the
early_reserve_initrd() and reserve_initrd() functions.

This patch introduces struct ramdisk which contains information
about initrd. This structure will be filled in the setup_arch()
and passed to the reserve_initrd() and relocate_initrd() functions.

This allows us to not get/check ramdisk parameters from the bootparams
every time in the early_reserve_initrd(), reserve_initrd() and
relocate_initrd() function.

Additionally we save 85 bytes:

     text     data      bss       dec      hex filename
  9292602  5011696 15675392  29979690  1c9742a vmlinux.orig

     text     data      bss       dec     hex filename
  9292517  5011696 15675392  29979605 1c973d5 vmlinux


Signed-off-by: Alexander Kuleshov <kuleshovm...@gmail.com>
---
Tested as with virtual machine as with real hardware.

Changelog:

v4:

  * bool reserve_ramdisk moved to the struct ramdisk;
  * fields of struct ramdisk are renamed to more understandable
  names
  * early_reserve_initrd() removed as it contains only one call
  of memblock_resere. It was moved to the setup_arch
  * stubs added for get_ramdisk_image() and get_ramdisk_size()
  to prevent compilation error if CONFIG_BLK_DEV_INITRD=n
  * initialization of ramdisk->end_addr is moved from in-place
  initialization to prevent ‘ramdisk_image.size’ is used uninitialized
  in this function warning.

v3: introduced ramdisk setup which is filled in th
setup_arch() and passed to the early_reserve_initrd()
and reserve_initrd().

v2: parameter of reserve_initrd() - int -> bool.
    commit message updated.

 arch/x86/kernel/setup.c | 105 +++++++++++++++++++++++++-----------------------
 1 file changed, 54 insertions(+), 51 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d3d80e6..0f0ba51 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -169,6 +169,15 @@ static struct resource bss_resource = {
        .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
 };
 
+/*
+ * ramdisk setup
+ */
+struct ramdisk {
+       u64 start_addr;         /* ramdisk load address */
+       u64 end_addr;           /* ramdisk end address */
+       u64 size;               /* ramdisk size */
+       bool reserve_ramdisk;   /* do initrd provided by bootloader */
+};
 
 #ifdef CONFIG_X86_32
 /* cpu data as detected by the assembly code in head.S */
@@ -318,90 +327,70 @@ static u64 __init get_ramdisk_size(void)
        return ramdisk_size;
 }
 
-static void __init relocate_initrd(void)
+static void __init relocate_initrd(struct ramdisk *ramdisk)
 {
-       /* Assume only end is not page aligned */
-       u64 ramdisk_image = get_ramdisk_image();
-       u64 ramdisk_size  = get_ramdisk_size();
-       u64 area_size     = PAGE_ALIGN(ramdisk_size);
-
        /* We need to move the initrd down into directly mapped mem */
        relocated_ramdisk = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
-                                                  area_size, PAGE_SIZE);
+                                                  ramdisk->size, PAGE_SIZE);
 
        if (!relocated_ramdisk)
                panic("Cannot find place for new RAMDISK of size %lld\n",
-                     ramdisk_size);
+                     ramdisk->size);
 
        /* Note: this includes all the mem currently occupied by
           the initrd, we rely on that fact to keep the data intact. */
-       memblock_reserve(relocated_ramdisk, area_size);
+       memblock_reserve(relocated_ramdisk, ramdisk->size);
        initrd_start = relocated_ramdisk + PAGE_OFFSET;
-       initrd_end   = initrd_start + ramdisk_size;
+       initrd_end   = initrd_start + ramdisk->size;
        printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
-              relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
+              relocated_ramdisk, relocated_ramdisk + ramdisk->size - 1);
 
-       copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
+       copy_from_early_mem((void *)initrd_start, ramdisk->start_addr, 
ramdisk->size);
 
        printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
                " [mem %#010llx-%#010llx]\n",
-               ramdisk_image, ramdisk_image + ramdisk_size - 1,
-               relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
+               ramdisk->start_addr, ramdisk->start_addr + ramdisk->size - 1,
+               relocated_ramdisk, relocated_ramdisk + ramdisk->size - 1);
 }
 
-static void __init early_reserve_initrd(void)
-{
-       /* Assume only end is not page aligned */
-       u64 ramdisk_image = get_ramdisk_image();
-       u64 ramdisk_size  = get_ramdisk_size();
-       u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
-
-       if (!boot_params.hdr.type_of_loader ||
-           !ramdisk_image || !ramdisk_size)
-               return;         /* No initrd provided by bootloader */
-
-       memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
-}
-static void __init reserve_initrd(void)
+static void __init reserve_initrd(struct ramdisk *ramdisk)
 {
-       /* Assume only end is not page aligned */
-       u64 ramdisk_image = get_ramdisk_image();
-       u64 ramdisk_size  = get_ramdisk_size();
-       u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
        u64 mapped_size;
 
-       if (!boot_params.hdr.type_of_loader ||
-           !ramdisk_image || !ramdisk_size)
-               return;         /* No initrd provided by bootloader */
-
        initrd_start = 0;
 
        mapped_size = memblock_mem_size(max_pfn_mapped);
-       if (ramdisk_size >= (mapped_size>>1))
+       if (ramdisk->size >= (mapped_size>>1))
                panic("initrd too large to handle, "
                       "disabling initrd (%lld needed, %lld available)\n",
-                      ramdisk_size, mapped_size>>1);
+                      ramdisk->size, mapped_size>>1);
 
-       printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
-                       ramdisk_end - 1);
+       printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n",
+               ramdisk->start_addr, ramdisk->end_addr - 1);
 
-       if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
-                               PFN_DOWN(ramdisk_end))) {
+       if (pfn_range_is_mapped(PFN_DOWN(ramdisk->start_addr),
+                               PFN_DOWN(ramdisk->end_addr))) {
                /* All are mapped, easy case */
-               initrd_start = ramdisk_image + PAGE_OFFSET;
-               initrd_end = initrd_start + ramdisk_size;
+               initrd_start = ramdisk->start_addr + PAGE_OFFSET;
+               initrd_end = initrd_start + ramdisk->size;
                return;
        }
 
-       relocate_initrd();
+       relocate_initrd(ramdisk);
 
-       memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
+       memblock_free(ramdisk->start_addr,
+               ramdisk->end_addr - ramdisk->start_addr);
 }
 #else
-static void __init early_reserve_initrd(void)
+static u64 __init get_ramdisk_image(void)
+{
+       return 0;
+}
+static u64 __init get_ramdisk_size(void)
 {
+       return 0;
 }
-static void __init reserve_initrd(void)
+static void __init reserve_initrd(struct ramdisk *ramdisk)
 {
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
@@ -844,13 +833,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned 
long v, void *p)
  *
  * Note: On x86_64, fixmaps are ready for use even before this is called.
  */
-
 void __init setup_arch(char **cmdline_p)
 {
+       struct ramdisk ramdisk_image = {
+               .start_addr = get_ramdisk_image(),
+               .size  = get_ramdisk_size(),
+               .reserve_ramdisk = true
+       };
+
+       /* Assume only end is not page aligned */
+       ramdisk_image.end_addr = PAGE_ALIGN(ramdisk_image.start_addr + 
ramdisk_image.size),
+
        memblock_reserve(__pa_symbol(_text),
                         (unsigned long)__bss_stop - (unsigned long)_text);
 
-       early_reserve_initrd();
+       if (!boot_params.hdr.type_of_loader || !ramdisk_image.start_addr
+               || !ramdisk_image.size)
+               ramdisk_image.reserve_ramdisk = false;  /* No initrd provided 
by bootloader */
+       else
+               memblock_reserve(ramdisk_image.start_addr,
+                               ramdisk_image.end_addr - 
ramdisk_image.start_addr);
 
        /*
         * At this point everything still needed from the boot loader
@@ -1135,7 +1137,8 @@ void __init setup_arch(char **cmdline_p)
        /* Allocate bigger log buffer */
        setup_log_buf(1);
 
-       reserve_initrd();
+       if (ramdisk_image.reserve_ramdisk)
+               reserve_initrd(&ramdisk_image);
 
 #if defined(CONFIG_ACPI) && defined(CONFIG_BLK_DEV_INITRD)
        acpi_initrd_override((void *)initrd_start, initrd_end - initrd_start);
-- 
2.7.0.25.gfc10eb5

Reply via email to