[S390] boot from NSS support

Add support to boot from a named saved segment (NSS).

Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 170 insertions, 8 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index b1b9a931237d..2569aafcc543 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -38,6 +38,7 @@
 #include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/pfn.h>
+#include <linux/ctype.h>
 #include <linux/reboot.h>
 
 #include <asm/uaccess.h>
@@ -50,6 +51,7 @@
 #include <asm/page.h>
 #include <asm/ptrace.h>
 #include <asm/sections.h>
+#include <asm/ebcdic.h>
 #include <asm/compat.h>
 
 long psw_kernel_bits    = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
@@ -282,6 +284,140 @@ static void __init conmode_default(void)
         }
 }
 
+/*
+ * Create a Kernel NSS if the SAVESYS= parameter is defined
+*/
+#define DEFSYS_CMD_SIZE 96
+#define SAVESYS_CMD_SIZE        32
+
+extern int _eshared;
+char kernel_nss_name[NSS_NAME_SIZE + 1];
+
+#ifdef CONFIG_SHARED_KERNEL
+static __init void create_kernel_nss(void)
+{
+        unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
+#ifdef CONFIG_BLK_DEV_INITRD
+        unsigned int sinitrd_pfn, einitrd_pfn;
+#endif
+        int response;
+        char *savesys_ptr;
+        char upper_command_line[COMMAND_LINE_SIZE];
+        char defsys_cmd[DEFSYS_CMD_SIZE];
+        char savesys_cmd[SAVESYS_CMD_SIZE];
+
+        /* Do nothing if we are not running under VM */
+        if (!MACHINE_IS_VM)
+                return;
+
+        /* Convert COMMAND_LINE to upper case */
+        for (i = 0; i < strlen(COMMAND_LINE); i++)
+                upper_command_line[i] = toupper(COMMAND_LINE[i]);
+
+        savesys_ptr = strstr(upper_command_line, "SAVESYS=");
+
+        if (!savesys_ptr)
+                return;
+
+        savesys_ptr += 8;    /* Point to the beginning of the NSS name */
+        for (i = 0; i < NSS_NAME_SIZE; i++) {
+                if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
+                        break;
+                kernel_nss_name[i] = savesys_ptr[i];
+        }
+
+        stext_pfn = PFN_DOWN(__pa(&_stext));
+        eshared_pfn = PFN_DOWN(__pa(&_eshared));
+        end_pfn = PFN_UP(__pa(&_end));
+        min_size = end_pfn << 2;
+
+        sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
+                kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
+                eshared_pfn, end_pfn);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+        if (INITRD_START && INITRD_SIZE) {
+                sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
+                einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
+                min_size = einitrd_pfn << 2;
+                sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
+                sinitrd_pfn, einitrd_pfn);
+        }
+#endif
+
+        sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size);
+        sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
+                kernel_nss_name, kernel_nss_name);
+
+        __cpcmd(defsys_cmd, NULL, 0, &response);
+
+        if (response != 0)
+                return;
+
+        __cpcmd(savesys_cmd, NULL, 0, &response);
+
+        if (response != strlen(savesys_cmd))
+                return;
+
+        ipl_flags = IPL_NSS_VALID;
+}
+
+#else /* CONFIG_SHARED_KERNEL */
+
+static inline void create_kernel_nss(void) { }
+
+#endif /* CONFIG_SHARED_KERNEL */
+
+/*
+ * Clear bss memory
+ */
+static __init void clear_bss_section(void)
+{
+        memset(__bss_start, 0, _end - __bss_start);
+}
+
+/*
+ * Initialize storage key for kernel pages
+ */
+static __init void init_kernel_storage_key(void)
+{
+        unsigned long end_pfn, init_pfn;
+
+        end_pfn = PFN_UP(__pa(&_end));
+
+        for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
+                page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
+}
+
+static __init void detect_machine_type(void)
+{
+        struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data;
+
+        asm volatile("stidp %0" : "=m" (S390_lowcore.cpu_data.cpu_id));
+
+        /* Running under z/VM ? */
+        if (cpuinfo->cpu_id.version == 0xff)
+                machine_flags |= 1;
+
+        /* Running on a P/390 ? */
+        if (cpuinfo->cpu_id.machine == 0x7490)
+                machine_flags |= 4;
+}
+
+/*
+ * Save ipl parameters, clear bss memory, initialize storage keys
+ * and create a kernel NSS at startup if the SAVESYS= parm is defined
+ */
+void __init startup_init(void)
+{
+        ipl_save_parameters();
+        clear_bss_section();
+        init_kernel_storage_key();
+        lockdep_init();
+        detect_machine_type();
+        create_kernel_nss();
+}
+
 #ifdef CONFIG_SMP
 void (*_machine_restart)(char *command) = machine_restart_smp;
 void (*_machine_halt)(void) = machine_halt_smp;
@@ -523,7 +659,7 @@ setup_lowcore(void)
 static void __init
 setup_resources(void)
 {
-        struct resource *res;
+        struct resource *res, *sub_res;
         int i;
 
         code_resource.start = (unsigned long) &_text;
@@ -548,8 +684,38 @@ setup_resources(void)
                 res->start = memory_chunk[i].addr;
                 res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
                 request_resource(&iomem_resource, res);
-                request_resource(res, &code_resource);
-                request_resource(res, &data_resource);
+
+                if (code_resource.start >= res->start  &&
+                        code_resource.start <= res->end &&
+                        code_resource.end > res->end) {
+                        sub_res = alloc_bootmem_low(sizeof(struct resource));
+                        memcpy(sub_res, &code_resource,
+                                sizeof(struct resource));
+                        sub_res->end = res->end;
+                        code_resource.start = res->end + 1;
+                        request_resource(res, sub_res);
+                }
+
+                if (code_resource.start >= res->start &&
+                        code_resource.start <= res->end &&
+                        code_resource.end <= res->end)
+                        request_resource(res, &code_resource);
+
+                if (data_resource.start >= res->start &&
+                        data_resource.start <= res->end &&
+                        data_resource.end > res->end) {
+                        sub_res = alloc_bootmem_low(sizeof(struct resource));
+                        memcpy(sub_res, &data_resource,
+                                sizeof(struct resource));
+                        sub_res->end = res->end;
+                        data_resource.start = res->end + 1;
+                        request_resource(res, sub_res);
+                }
+
+                if (data_resource.start >= res->start &&
+                        data_resource.start <= res->end &&
+                        data_resource.end <= res->end)
+                        request_resource(res, &data_resource);
         }
 }
 
@@ -585,7 +751,7 @@ static void __init
 setup_memory(void)
 {
         unsigned long bootmap_size;
-        unsigned long start_pfn, end_pfn, init_pfn;
+        unsigned long start_pfn, end_pfn;
         int i;
 
         /*
@@ -595,10 +761,6 @@ setup_memory(void)
         start_pfn = PFN_UP(__pa(&_end));
         end_pfn = max_pfn = PFN_DOWN(memory_end);
 
-        /* Initialize storage key for kernel pages */
-        for (init_pfn = 0 ; init_pfn < start_pfn; init_pfn++)
-                page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
-
 #ifdef CONFIG_BLK_DEV_INITRD
         /*
          * Move the initrd in case the bitmap of the bootmem allocater