Merge branch 'for-linus-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml (9936f44a) · Commits · e / devices / android_kernel_fairphone_FP4

arch/um/drivers/ubd.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -11,5 +11,10 @@ extern int start_io_thread(unsigned long sp, int *fds_out);
		extern int io_thread(void *arg);
		extern int kernel_fd;

		extern int ubd_read_poll(int timeout);
		extern int ubd_write_poll(int timeout);

		#define UBD_REQ_BUFFER_SIZE 64

		#endif

arch/um/drivers/ubd_kern.c

+142 −26

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2015-2016 Anton Ivanov (aivanov@brocade.com)
		* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
		* Licensed under the GPL
		*/
		@@ -58,6 +59,17 @@ struct io_thread_req {
		int error;
		};


		static struct io_thread_req * (*irq_req_buffer)[];
		static struct io_thread_req *irq_remainder;
		static int irq_remainder_size;

		static struct io_thread_req * (*io_req_buffer)[];
		static struct io_thread_req *io_remainder;
		static int io_remainder_size;



		static inline int ubd_test_bit(__u64 bit, unsigned char *data)
		{
		__u64 n;
		@@ -442,29 +454,91 @@ static void do_ubd_request(struct request_queue * q);
		static int thread_fd = -1;
		static LIST_HEAD(restart);

		/* XXX - move this inside ubd_intr. */
		/* Function to read several request pointers at a time
		* handling fractional reads if (and as) needed
		*/

		static int bulk_req_safe_read(
		int fd,
		struct io_thread_req * (*request_buffer)[],
		struct io_thread_req **remainder,
		int *remainder_size,
		int max_recs
		)
		{
		int n = 0;
		int res = 0;

		if (*remainder_size > 0) {
		memmove(
		(char *) request_buffer,
		(char ) remainder, remainder_size
		);
		n = *remainder_size;
		}

		res = os_read_file(
		fd,
		((char ) request_buffer) + remainder_size,
		sizeof(struct io_thread_req )max_recs
		- *remainder_size
		);
		if (res > 0) {
		n += res;
		if ((n % sizeof(struct io_thread_req *)) > 0) {
		/*
		* Read somehow returned not a multiple of dword
		* theoretically possible, but never observed in the
		* wild, so read routine must be able to handle it
		*/
		remainder_size = n % sizeof(struct io_thread_req );
		WARN(*remainder_size > 0, "UBD IPC read returned a partial result");
		memmove(
		remainder,
		((char *) request_buffer) +
		(n/sizeof(struct io_thread_req ))sizeof(struct io_thread_req *),
		*remainder_size
		);
		n = n - *remainder_size;
		}
		} else {
		n = res;
		}
		return n;
		}

		/* Called without dev->lock held, and only in interrupt context. */
		static void ubd_handler(void)
		{
		struct io_thread_req *req;
		struct ubd *ubd;
		struct list_head list, next_ele;
		unsigned long flags;
		int n;
		int count;

		while(1){
		n = os_read_file(thread_fd, &req,
		sizeof(struct io_thread_req *));
		if(n != sizeof(req)){
		n = bulk_req_safe_read(
		thread_fd,
		irq_req_buffer,
		&irq_remainder,
		&irq_remainder_size,
		UBD_REQ_BUFFER_SIZE
		);
		if (n < 0) {
		if(n == -EAGAIN)
		break;
		printk(KERN_ERR "spurious interrupt in ubd_handler, "
		"err = %d\n", -n);
		return;
		}

		blk_end_request(req->req, 0, req->length);
		kfree(req);
		for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
		blk_end_request(
		(*irq_req_buffer)[count]->req,
		0,
		(*irq_req_buffer)[count]->length
		);
		kfree((*irq_req_buffer)[count]);
		}
		}
		reactivate_fd(thread_fd, UBD_IRQ);

		@@ -1064,6 +1138,28 @@ static int __init ubd_init(void)
		if (register_blkdev(fake_major, "ubd"))
		return -1;
		}

		irq_req_buffer = kmalloc(
		sizeof(struct io_thread_req ) UBD_REQ_BUFFER_SIZE,
		GFP_KERNEL
		);
		irq_remainder = 0;

		if (irq_req_buffer == NULL) {
		printk(KERN_ERR "Failed to initialize ubd buffering\n");
		return -1;
		}
		io_req_buffer = kmalloc(
		sizeof(struct io_thread_req ) UBD_REQ_BUFFER_SIZE,
		GFP_KERNEL
		);

		io_remainder = 0;

		if (io_req_buffer == NULL) {
		printk(KERN_ERR "Failed to initialize ubd buffering\n");
		return -1;
		}
		platform_driver_register(&ubd_driver);
		mutex_lock(&ubd_lock);
		for (i = 0; i < MAX_DEV; i++){
		@@ -1458,31 +1554,51 @@ static int io_count = 0;

		int io_thread(void *arg)
		{
		struct io_thread_req *req;
		int n;
		int n, count, written, res;

		os_fix_helper_signals();

		while(1){
		n = os_read_file(kernel_fd, &req,
		sizeof(struct io_thread_req *));
		if(n != sizeof(struct io_thread_req *)){
		if(n < 0)
		n = bulk_req_safe_read(
		kernel_fd,
		io_req_buffer,
		&io_remainder,
		&io_remainder_size,
		UBD_REQ_BUFFER_SIZE
		);
		if (n < 0) {
		if (n == -EAGAIN) {
		ubd_read_poll(-1);
		continue;
		} else {
		printk("io_thread - read failed, fd = %d, "
		"err = %d\n", kernel_fd, -n);
		else {
		printk("io_thread - short read, fd = %d, "
		"length = %d\n", kernel_fd, n);
		"err = %d,"
		"reminder = %d\n",
		kernel_fd, -n, io_remainder_size);
		}
		continue;
		}

		for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
		io_count++;
		do_io(req);
		n = os_write_file(kernel_fd, &req,
		sizeof(struct io_thread_req *));
		if(n != sizeof(struct io_thread_req *))
		printk("io_thread - write failed, fd = %d, err = %d\n",
		kernel_fd, -n);
		do_io((*io_req_buffer)[count]);
		}

		written = 0;

		do {
		res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
		if (res > 0) {
		written += res;
		} else {
		if (res != -EAGAIN) {
		printk("io_thread - read failed, fd = %d, "
		"err = %d\n", kernel_fd, -n);
		}
		}
		if (written < n) {
		ubd_write_poll(-1);
		}
		} while (written < n);
		}

		return 0;

arch/um/drivers/ubd_user.c

+20 −1

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 Anton Ivanov (aivanov@brocade.com)
		* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
		* Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
		* Licensed under the GPL
		@@ -20,6 +21,9 @@

		#include "ubd.h"
		#include <os.h>
		#include <poll.h>

		struct pollfd kernel_pollfd;

		int start_io_thread(unsigned long sp, int *fd_out)
		{
		@@ -32,9 +36,12 @@ int start_io_thread(unsigned long sp, int *fd_out)
		}

		kernel_fd = fds[0];
		kernel_pollfd.fd = kernel_fd;
		kernel_pollfd.events = POLLIN;
		*fd_out = fds[1];

		err = os_set_fd_block(*fd_out, 0);
		err = os_set_fd_block(kernel_fd, 0);
		if (err) {
		printk("start_io_thread - failed to set nonblocking I/O.\n");
		goto out_close;
		@@ -57,3 +64,15 @@ int start_io_thread(unsigned long sp, int *fd_out)
		out:
		return err;
		}

		int ubd_read_poll(int timeout)
		{
		kernel_pollfd.events = POLLIN;
		return poll(&kernel_pollfd, 1, timeout);
		}
		int ubd_write_poll(int timeout)
		{
		kernel_pollfd.events = POLLOUT;
		return poll(&kernel_pollfd, 1, timeout);
		}