The check and definitions related to ramdisk are similar in the
early_reserve_initrd() and reserve_initrd() functions. We can
get size and address of ramdisk in the setup_arch() and than
pass ramdisk structure with filled ramdisk related parameters
to early_reserve_initrd(), reserve_initrd() and relocate_initrd()
functions.

This allows us to not get ramdisk parameters from the bootparams
every time and save 59 bytes:

     text         data      bss             dec            hex filename
  9281618      5010736 15474688        29767042        1c63582 vmlinux.orig

     text         data      bss             dec            hex filename
  9281559      5010736 15474688        29766983        1c63547 vmlinux

Signed-off-by: Alexander Kuleshov <[email protected]>
---
Tested as with virtual machine as with real hardware.

Changelog:

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 | 92 +++++++++++++++++++++++++------------------------
 1 file changed, 47 insertions(+), 45 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d3d80e6..c9d8a86 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -169,6 +169,14 @@ static struct resource bss_resource = {
        .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
 };
 
+/*
+ * ramdisk setup
+ */
+struct ramdisk {
+       u64 image;
+       u64 size;
+       u64 end;
+};
 
 #ifdef CONFIG_X86_32
 /* cpu data as detected by the assembly code in head.S */
@@ -318,12 +326,10 @@ 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);
+       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),
@@ -331,77 +337,60 @@ static void __init relocate_initrd(void)
 
        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);
        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.image, 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.image, ramdisk.image + ramdisk.size - 1,
+               relocated_ramdisk, relocated_ramdisk + ramdisk.size - 1);
 }
 
-static void __init early_reserve_initrd(void)
+static void __init early_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);
-
-       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);
+       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.image,
+                       ramdisk.end - 1);
 
-       if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
-                               PFN_DOWN(ramdisk_end))) {
+       if (pfn_range_is_mapped(PFN_DOWN(ramdisk.image),
+                               PFN_DOWN(ramdisk.end))) {
                /* All are mapped, easy case */
-               initrd_start = ramdisk_image + PAGE_OFFSET;
-               initrd_end = initrd_start + ramdisk_size;
+               initrd_start = ramdisk.image + 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.image, ramdisk.end - ramdisk.image);
 }
 #else
-static void __init early_reserve_initrd(void)
+static void __init early_reserve_initrd(struct ramdisk ramdisk)
 {
 }
-static void __init reserve_initrd(void)
+static void __init reserve_initrd(struct ramdisk ramdisk)
 {
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
@@ -844,13 +833,25 @@ 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 = {
+               .image = get_ramdisk_image(),
+               .size  = get_ramdisk_size(),
+               /* Assume only end is not page aligned */
+               .end = PAGE_ALIGN(ramdisk_image.image + ramdisk_image.size)
+       };
+       bool reserve_ramdisk = true;
+
        memblock_reserve(__pa_symbol(_text),
                         (unsigned long)__bss_stop - (unsigned long)_text);
 
-       early_reserve_initrd();
+       if (!boot_params.hdr.type_of_loader || !ramdisk_image.image
+               || !ramdisk_image.size) {
+               reserve_ramdisk = false;
+               return;         /* No initrd provided by bootloader */
+       } else
+               early_reserve_initrd(ramdisk_image);
 
        /*
         * At this point everything still needed from the boot loader
@@ -1135,7 +1136,8 @@ void __init setup_arch(char **cmdline_p)
        /* Allocate bigger log buffer */
        setup_log_buf(1);
 
-       reserve_initrd();
+       if (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

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