x86, boot: add linked list of struct setup_data

This patch adds a field of 64-bit physical pointer to NULL terminated
single linked list of struct setup_data to real-mode kernel
header. This is used as a more extensible boot parameters passing
mechanism.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 42 insertions, 0 deletions

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index d31d6b72d60d..e25c57b8aa84 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -11,6 +11,7 @@
 #include <linux/string.h>
 #include <linux/percpu.h>
 #include <linux/start_kernel.h>
+#include <linux/io.h>
 
 #include <asm/processor.h>
 #include <asm/proto.h>
@@ -100,6 +101,24 @@ static void __init reserve_ebda_region(void)
         reserve_early(lowmem, 0x100000, "BIOS reserved");
 }
 
+static void __init reserve_setup_data(void)
+{
+        struct setup_data *data;
+        unsigned long pa_data;
+        char buf[32];
+
+        if (boot_params.hdr.version < 0x0209)
+                return;
+        pa_data = boot_params.hdr.setup_data;
+        while (pa_data) {
+                data = early_ioremap(pa_data, sizeof(*data));
+                sprintf(buf, "setup data %x", data->type);
+                reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
+                pa_data = data->next;
+                early_iounmap(data, sizeof(*data));
+        }
+}
+
 void __init x86_64_start_kernel(char * real_mode_data)
 {
         int i;
@@ -156,6 +175,7 @@ void __init x86_64_start_kernel(char * real_mode_data)
 #endif
 
         reserve_ebda_region();
+        reserve_setup_data();
 
         /*
          * At this point everything still needed from the boot loader
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 17bdf2343095..e1a21d6b3671 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -264,6 +264,26 @@ void __attribute__((weak)) __init memory_setup(void)
        machine_specific_memory_setup();
 }
 
+static void __init parse_setup_data(void)
+{
+        struct setup_data *data;
+        unsigned long pa_data;
+
+        if (boot_params.hdr.version < 0x0209)
+                return;
+        pa_data = boot_params.hdr.setup_data;
+        while (pa_data) {
+                data = early_ioremap(pa_data, PAGE_SIZE);
+                switch (data->type) {
+                default:
+                        break;
+                }
+                free_early(pa_data, pa_data+sizeof(*data)+data->len);
+                pa_data = data->next;
+                early_iounmap(data, PAGE_SIZE);
+        }
+}
+
 /*
  * setup_arch - architecture-specific boot-time initializations
  *
@@ -316,6 +336,8 @@ void __init setup_arch(char **cmdline_p)
         strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
         *cmdline_p = command_line;
 
+        parse_setup_data();
+
         parse_early_param();
 
 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT