diff options
Diffstat (limited to 'drivers/s390/char/vmcp.c')
| -rw-r--r-- | drivers/s390/char/vmcp.c | 112 |
1 files changed, 89 insertions, 23 deletions
diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c index 98749fa817da..7898bbcc28fc 100644 --- a/drivers/s390/char/vmcp.c +++ b/drivers/s390/char/vmcp.c @@ -17,15 +17,85 @@ #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/slab.h> +#include <linux/uaccess.h> #include <linux/export.h> +#include <linux/mutex.h> +#include <linux/cma.h> +#include <linux/mm.h> #include <asm/compat.h> #include <asm/cpcmd.h> #include <asm/debug.h> -#include <linux/uaccess.h> -#include "vmcp.h" +#include <asm/vmcp.h> + +struct vmcp_session { + char *response; + unsigned int bufsize; + unsigned int cma_alloc : 1; + int resp_size; + int resp_code; + struct mutex mutex; +}; static debug_info_t *vmcp_debug; +static unsigned long vmcp_cma_size __initdata = CONFIG_VMCP_CMA_SIZE * 1024 * 1024; +static struct cma *vmcp_cma; + +static int __init early_parse_vmcp_cma(char *p) +{ + vmcp_cma_size = ALIGN(memparse(p, NULL), PAGE_SIZE); + return 0; +} +early_param("vmcp_cma", early_parse_vmcp_cma); + +void __init vmcp_cma_reserve(void) +{ + if (!MACHINE_IS_VM) + return; + cma_declare_contiguous(0, vmcp_cma_size, 0, 0, 0, false, "vmcp", &vmcp_cma); +} + +static void vmcp_response_alloc(struct vmcp_session *session) +{ + struct page *page = NULL; + int nr_pages, order; + + order = get_order(session->bufsize); + nr_pages = ALIGN(session->bufsize, PAGE_SIZE) >> PAGE_SHIFT; + /* + * For anything below order 3 allocations rely on the buddy + * allocator. If such low-order allocations can't be handled + * anymore the system won't work anyway. + */ + if (order > 2) + page = cma_alloc(vmcp_cma, nr_pages, 0, GFP_KERNEL); + if (page) { + session->response = (char *)page_to_phys(page); + session->cma_alloc = 1; + return; + } + session->response = (char *)__get_free_pages(GFP_KERNEL | __GFP_RETRY_MAYFAIL, order); +} + +static void vmcp_response_free(struct vmcp_session *session) +{ + int nr_pages, order; + struct page *page; + + if (!session->response) + return; + order = get_order(session->bufsize); + nr_pages = ALIGN(session->bufsize, PAGE_SIZE) >> PAGE_SHIFT; + if (session->cma_alloc) { + page = phys_to_page((unsigned long)session->response); + cma_release(vmcp_cma, page, nr_pages); + session->cma_alloc = 0; + } else { + free_pages((unsigned long)session->response, order); + } + session->response = NULL; +} + static int vmcp_open(struct inode *inode, struct file *file) { struct vmcp_session *session; @@ -51,7 +121,7 @@ static int vmcp_release(struct inode *inode, struct file *file) session = file->private_data; file->private_data = NULL; - free_pages((unsigned long)session->response, get_order(session->bufsize)); + vmcp_response_free(session); kfree(session); return 0; } @@ -97,9 +167,7 @@ vmcp_write(struct file *file, const char __user *buff, size_t count, return -ERESTARTSYS; } if (!session->response) - session->response = (char *)__get_free_pages(GFP_KERNEL - | __GFP_RETRY_MAYFAIL | GFP_DMA, - get_order(session->bufsize)); + vmcp_response_alloc(session); if (!session->response) { mutex_unlock(&session->mutex); kfree(cmd); @@ -130,8 +198,8 @@ vmcp_write(struct file *file, const char __user *buff, size_t count, static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct vmcp_session *session; + int ret = -ENOTTY; int __user *argp; - int temp; session = file->private_data; if (is_compat_task()) @@ -142,28 +210,26 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return -ERESTARTSYS; switch (cmd) { case VMCP_GETCODE: - temp = session->resp_code; - mutex_unlock(&session->mutex); - return put_user(temp, argp); + ret = put_user(session->resp_code, argp); + break; case VMCP_SETBUF: - free_pages((unsigned long)session->response, - get_order(session->bufsize)); - session->response=NULL; - temp = get_user(session->bufsize, argp); - if (get_order(session->bufsize) > 8) { + vmcp_response_free(session); + ret = get_user(session->bufsize, argp); + if (ret) session->bufsize = PAGE_SIZE; - temp = -EINVAL; + if (!session->bufsize || get_order(session->bufsize) > 8) { + session->bufsize = PAGE_SIZE; + ret = -EINVAL; } - mutex_unlock(&session->mutex); - return temp; + break; case VMCP_GETSIZE: - temp = session->resp_size; - mutex_unlock(&session->mutex); - return put_user(temp, argp); + ret = put_user(session->resp_size, argp); + break; default: - mutex_unlock(&session->mutex); - return -ENOIOCTLCMD; + break; } + mutex_unlock(&session->mutex); + return ret; } static const struct file_operations vmcp_fops = { |