aboutsummaryrefslogtreecommitdiff
path: root/arch/um/drivers/mconsole_kern.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/um/drivers/mconsole_kern.c')
-rw-r--r--arch/um/drivers/mconsole_kern.c143
1 files changed, 141 insertions, 2 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 54388d10bcf..28e3760e8b9 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -20,6 +20,8 @@
#include "linux/namei.h"
#include "linux/proc_fs.h"
#include "linux/syscalls.h"
+#include "linux/list.h"
+#include "linux/mm.h"
#include "linux/console.h"
#include "asm/irq.h"
#include "asm/uaccess.h"
@@ -347,6 +349,142 @@ static struct mc_device *mconsole_find_dev(char *name)
return(NULL);
}
+#define UNPLUGGED_PER_PAGE \
+ ((PAGE_SIZE - sizeof(struct list_head)) / sizeof(unsigned long))
+
+struct unplugged_pages {
+ struct list_head list;
+ void *pages[UNPLUGGED_PER_PAGE];
+};
+
+static unsigned long long unplugged_pages_count = 0;
+static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
+static int unplug_index = UNPLUGGED_PER_PAGE;
+
+static int mem_config(char *str)
+{
+ unsigned long long diff;
+ int err = -EINVAL, i, add;
+ char *ret;
+
+ if(str[0] != '=')
+ goto out;
+
+ str++;
+ if(str[0] == '-')
+ add = 0;
+ else if(str[0] == '+'){
+ add = 1;
+ }
+ else goto out;
+
+ str++;
+ diff = memparse(str, &ret);
+ if(*ret != '\0')
+ goto out;
+
+ diff /= PAGE_SIZE;
+
+ for(i = 0; i < diff; i++){
+ struct unplugged_pages *unplugged;
+ void *addr;
+
+ if(add){
+ if(list_empty(&unplugged_pages))
+ break;
+
+ unplugged = list_entry(unplugged_pages.next,
+ struct unplugged_pages, list);
+ if(unplug_index > 0)
+ addr = unplugged->pages[--unplug_index];
+ else {
+ list_del(&unplugged->list);
+ addr = unplugged;
+ unplug_index = UNPLUGGED_PER_PAGE;
+ }
+
+ free_page((unsigned long) addr);
+ unplugged_pages_count--;
+ }
+ else {
+ struct page *page;
+
+ page = alloc_page(GFP_ATOMIC);
+ if(page == NULL)
+ break;
+
+ unplugged = page_address(page);
+ if(unplug_index == UNPLUGGED_PER_PAGE){
+ INIT_LIST_HEAD(&unplugged->list);
+ list_add(&unplugged->list, &unplugged_pages);
+ unplug_index = 0;
+ }
+ else {
+ struct list_head *entry = unplugged_pages.next;
+ addr = unplugged;
+
+ unplugged = list_entry(entry,
+ struct unplugged_pages,
+ list);
+ unplugged->pages[unplug_index++] = addr;
+ err = os_drop_memory(addr, PAGE_SIZE);
+ if(err)
+ printk("Failed to release memory - "
+ "errno = %d\n", err);
+ }
+
+ unplugged_pages_count++;
+ }
+ }
+
+ err = 0;
+out:
+ return err;
+}
+
+static int mem_get_config(char *name, char *str, int size, char **error_out)
+{
+ char buf[sizeof("18446744073709551615")];
+ int len = 0;
+
+ sprintf(buf, "%ld", uml_physmem);
+ CONFIG_CHUNK(str, size, len, buf, 1);
+
+ return len;
+}
+
+static int mem_id(char **str, int *start_out, int *end_out)
+{
+ *start_out = 0;
+ *end_out = 0;
+
+ return 0;
+}
+
+static int mem_remove(int n)
+{
+ return -EBUSY;
+}
+
+static struct mc_device mem_mc = {
+ .name = "mem",
+ .config = mem_config,
+ .get_config = mem_get_config,
+ .id = mem_id,
+ .remove = mem_remove,
+};
+
+static int mem_mc_init(void)
+{
+ if(can_drop_memory())
+ mconsole_register_dev(&mem_mc);
+ else printk("Can't release memory to the host - memory hotplug won't "
+ "be supported\n");
+ return 0;
+}
+
+__initcall(mem_mc_init);
+
#define CONFIG_BUF_SIZE 64
static void mconsole_get_config(int (*get_config)(char *, char *, int,
@@ -478,7 +616,7 @@ static void console_write(struct console *console, const char *string,
return;
while(1){
- n = min(len, ARRAY_SIZE(console_buf) - console_index);
+ n = min((size_t)len, ARRAY_SIZE(console_buf) - console_index);
strncpy(&console_buf[console_index], string, n);
console_index += n;
string += n;
@@ -762,7 +900,8 @@ static struct notifier_block panic_exit_notifier = {
static int add_notifier(void)
{
- notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &panic_exit_notifier);
return(0);
}