powerpc/fadump: Return error when fadump registration fails

 - log an error message when registration fails and no error code listed
   in the switch is returned
 - translate the hv error code to posix error code and return it from
   fw_register
 - return the posix error code from fw_register to the process writing
   to sysfs
 - return EEXIST on re-registration
 - return success on deregistration when fadump is not registered
 - return ENODEV when no memory is reserved for fadump

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Tested-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Use pr_err() to shrink the error print]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 466569e26278694c8ceea17509a99ec04c4ea68b..8a5d0e029b93175f8727172415c070177ee0797b 100644 (file)
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -377,9 +377,9 @@ static int __init early_fadump_param(char *p)
 }
 early_param("fadump", early_fadump_param);
 
-static void register_fw_dump(struct fadump_mem_struct *fdm)
+static int register_fw_dump(struct fadump_mem_struct *fdm)
 {
-       int rc;
+       int rc, err;
        unsigned int wait_time;
 
        pr_debug("Registering for firmware-assisted kernel dump...\n");
@@ -396,7 +396,11 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
 
        } while (wait_time);
 
+       err = -EIO;
        switch (rc) {
+       default:
+               pr_err("Failed to register. Unknown Error(%d).\n", rc);
+               break;
        case -1:
                printk(KERN_ERR "Failed to register firmware-assisted kernel"
                        " dump. Hardware Error(%d).\n", rc);
@@ -404,18 +408,22 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
        case -3:
                printk(KERN_ERR "Failed to register firmware-assisted kernel"
                        " dump. Parameter Error(%d).\n", rc);
+               err = -EINVAL;
                break;
        case -9:
                printk(KERN_ERR "firmware-assisted kernel dump is already "
                        " registered.");
                fw_dump.dump_registered = 1;
+               err = -EEXIST;
                break;
        case 0:
                printk(KERN_INFO "firmware-assisted kernel dump registration"
                        " is successful\n");
                fw_dump.dump_registered = 1;
+               err = 0;
                break;
        }
+       return err;
 }
 
 void crash_fadump(struct pt_regs *regs, const char *str)
@@ -956,7 +964,7 @@ static unsigned long init_fadump_header(unsigned long addr)
        return addr;
 }
 
-static void register_fadump(void)
+static int register_fadump(void)
 {
        unsigned long addr;
        void *vaddr;
@@ -966,7 +974,7 @@ static void register_fadump(void)
         * assisted dump.
         */
        if (!fw_dump.reserve_dump_area_size)
-               return;
+               return -ENODEV;
 
        fadump_setup_crash_memory_ranges();
 
@@ -979,7 +987,7 @@ static void register_fadump(void)
        fadump_create_elfcore_headers(vaddr);
 
        /* register the future kernel dump with firmware. */
-       register_fw_dump(&fdm);
+       return register_fw_dump(&fdm);
 }
 
 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
@@ -1161,7 +1169,6 @@ static ssize_t fadump_register_store(struct kobject *kobj,
        switch (buf[0]) {
        case '0':
                if (fw_dump.dump_registered == 0) {
-                       ret = -EINVAL;
                        goto unlock_out;
                }
                /* Un-register Firmware-assisted dump */
@@ -1169,11 +1176,11 @@ static ssize_t fadump_register_store(struct kobject *kobj,
                break;
        case '1':
                if (fw_dump.dump_registered == 1) {
-                       ret = -EINVAL;
+                       ret = -EEXIST;
                        goto unlock_out;
                }
                /* Register Firmware-assisted dump */
-               register_fadump();
+               ret = register_fadump();
                break;
        default:
                ret = -EINVAL;