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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-23 09:03:07 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-23 09:03:07 -0700
commit0d6810091cdbd05efeb31654c6a41a6cbdfdd2c8 (patch)
tree44d79f8133ea6acd791fe4f32188789c2c65da93 /drivers/char
parenta98ce5c6feead6bfedefabd46cb3d7f5be148d9a (diff)
parent43d33b21a03d3abcc8cbdeb4d52bc4568f822c5e (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: (45 commits) Use "struct boot_params" in example launcher Loading bzImage directly. Revert lguest magic and use hook in head.S Update lguest documentation to reflect the new virtual block device name. generalize lgread_u32/lgwrite_u32. Example launcher handle guests not being ready for input Update example launcher for virtio Lguest support for Virtio Remove old lguest I/O infrrasructure. Remove old lguest bus and drivers. Virtio helper routines for a descriptor ringbuffer implementation Module autoprobing support for virtio drivers. Virtio console driver Block driver using virtio. Net driver using virtio Virtio interface Boot with virtual == physical to get closer to native Linux. Allow guest to specify syscall vector to use. Rename "cr3" to "gpgdir" to avoid x86-specific naming. Pagetables to use normal kernel types ...
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/Kconfig4
-rw-r--r--drivers/char/Makefile2
-rw-r--r--drivers/char/hvc_lguest.c177
-rw-r--r--drivers/char/virtio_console.c225
4 files changed, 230 insertions, 178 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 65491103e0fb..bf18d757b876 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -613,6 +613,10 @@ config HVC_XEN
help
Xen virtual console device driver
+config VIRTIO_CONSOLE
+ bool
+ select HVC_DRIVER
+
config HVCS
tristate "IBM Hypervisor Virtual Console Server support"
depends on PPC_PSERIES
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index c78ff26647ee..07304d50e0cb 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_SYNCLINK_GT) += synclink_gt.o
obj-$(CONFIG_N_HDLC) += n_hdlc.o
obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
obj-$(CONFIG_SX) += sx.o generic_serial.o
-obj-$(CONFIG_LGUEST_GUEST) += hvc_lguest.o
obj-$(CONFIG_RIO) += rio/ generic_serial.o
obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi.o
obj-$(CONFIG_HVC_ISERIES) += hvc_iseries.o
@@ -50,6 +49,7 @@ obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o
obj-$(CONFIG_HVC_BEAT) += hvc_beat.o
obj-$(CONFIG_HVC_DRIVER) += hvc_console.o
obj-$(CONFIG_HVC_XEN) += hvc_xen.o
+obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
obj-$(CONFIG_RAW_DRIVER) += raw.o
obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o
obj-$(CONFIG_MSPEC) += mspec.o
diff --git a/drivers/char/hvc_lguest.c b/drivers/char/hvc_lguest.c
deleted file mode 100644
index efccb2155830..000000000000
--- a/drivers/char/hvc_lguest.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/*D:300
- * The Guest console driver
- *
- * This is a trivial console driver: we use lguest's DMA mechanism to send
- * bytes out, and register a DMA buffer to receive bytes in. It is assumed to
- * be present and available from the very beginning of boot.
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically support any
- * virtual console. We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more. Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006 Rusty Russell, IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/lguest_bus.h>
-#include <asm/paravirt.h>
-#include "hvc_console.h"
-
-/*D:340 This is our single console input buffer, with associated "struct
- * lguest_dma" referring to it. Note the 0-terminated length array, and the
- * use of physical address for the buffer itself. */
-static char inbuf[256];
-static struct lguest_dma cons_input = { .used_len = 0,
- .addr[0] = __pa(inbuf),
- .len[0] = sizeof(inbuf),
- .len[1] = 0 };
-
-/*D:310 The put_chars() callback is pretty straightforward.
- *
- * First we put the pointer and length in a "struct lguest_dma": we only have
- * one pointer, so we set the second length to 0. Then we use SEND_DMA to send
- * the data to (Host) buffers attached to the console key. Usually a device's
- * key is a physical address within the device's memory, but because the
- * console device doesn't have any associated physical memory, we use the
- * LGUEST_CONSOLE_DMA_KEY constant (aka 0). */
-static int put_chars(u32 vtermno, const char *buf, int count)
-{
- struct lguest_dma dma;
-
- /* FIXME: DMA buffers in a "struct lguest_dma" are not allowed
- * to go over page boundaries. This never seems to happen,
- * but if it did we'd need to fix this code. */
- dma.len[0] = count;
- dma.len[1] = 0;
- dma.addr[0] = __pa(buf);
-
- lguest_send_dma(LGUEST_CONSOLE_DMA_KEY, &dma);
- /* We're expected to return the amount of data we wrote: all of it. */
- return count;
-}
-
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Firstly we see if our buffer has been filled: if not, we return. The rest
- * of the code deals with the fact that the hvc_console() infrastructure only
- * asks us for 16 bytes at a time. We keep a "cons_offset" variable for
- * partially-read buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
-{
- static int cons_offset;
-
- /* Nothing left to see here... */
- if (!cons_input.used_len)
- return 0;
-
- /* You want more than we have to give? Well, try wanting less! */
- if (cons_input.used_len - cons_offset < count)
- count = cons_input.used_len - cons_offset;
-
- /* Copy across to their buffer and increment offset. */
- memcpy(buf, inbuf + cons_offset, count);
- cons_offset += count;
-
- /* Finished? Zero offset, and reset cons_input so Host will use it
- * again. */
- if (cons_offset == cons_input.used_len) {
- cons_offset = 0;
- cons_input.used_len = 0;
- }
- return count;
-}
-/*:*/
-
-static struct hv_ops lguest_cons = {
- .get_chars = get_chars,
- .put_chars = put_chars,
-};
-
-/*D:320 Console drivers are initialized very early so boot messages can go
- * out. At this stage, the console is output-only. Our driver checks we're a
- * Guest, and if so hands hvc_instantiate() the console number (0), priority
- * (0), and the struct hv_ops containing the put_chars() function. */
-static int __init cons_init(void)
-{
- if (strcmp(pv_info.name, "lguest") != 0)
- return 0;
-
- return hvc_instantiate(0, 0, &lguest_cons);
-}
-console_initcall(cons_init);
-
-/*D:370 To set up and manage our virtual console, we call hvc_alloc() and
- * stash the result in the private pointer of the "struct lguest_device".
- * Since we never remove the console device we never need this pointer again,
- * but using ->private is considered good form, and you never know who's going
- * to copy your driver.
- *
- * Once the console is set up, we bind our input buffer ready for input. */
-static int lguestcons_probe(struct lguest_device *lgdev)
-{
- int err;
-
- /* The first argument of hvc_alloc() is the virtual console number, so
- * we use zero. The second argument is the interrupt number.
- *
- * The third argument is a "struct hv_ops" containing the put_chars()
- * and get_chars() pointers. The final argument is the output buffer
- * size: we use 256 and expect the Host to have room for us to send
- * that much. */
- lgdev->private = hvc_alloc(0, lgdev_irq(lgdev), &lguest_cons, 256);
- if (IS_ERR(lgdev->private))
- return PTR_ERR(lgdev->private);
-
- /* We bind a single DMA buffer at key LGUEST_CONSOLE_DMA_KEY.
- * "cons_input" is that statically-initialized global DMA buffer we saw
- * above, and we also give the interrupt we want. */
- err = lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY, &cons_input, 1,
- lgdev_irq(lgdev));
- if (err)
- printk("lguest console: failed to bind buffer.\n");
- return err;
-}
-/* Note the use of lgdev_irq() for the interrupt number. We tell hvc_alloc()
- * to expect input when this interrupt is triggered, and then tell
- * lguest_bind_dma() that is the interrupt to send us when input comes in. */
-
-/*D:360 From now on the console driver follows standard Guest driver form:
- * register_lguest_driver() registers the device type and probe function, and
- * the probe function sets up the device.
- *
- * The standard "struct lguest_driver": */
-static struct lguest_driver lguestcons_drv = {
- .name = "lguestcons",
- .owner = THIS_MODULE,
- .device_type = LGUEST_DEVICE_T_CONSOLE,
- .probe = lguestcons_probe,
-};
-
-/* The standard init function */
-static int __init hvc_lguest_init(void)
-{
- return register_lguest_driver(&lguestcons_drv);
-}
-module_init(hvc_lguest_init);
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
new file mode 100644
index 000000000000..100e8a201e3a
--- /dev/null
+++ b/drivers/char/virtio_console.c
@@ -0,0 +1,225 @@
+/*D:300
+ * The Guest console driver
+ *
+ * Writing console drivers is one of the few remaining Dark Arts in Linux.
+ * Fortunately for us, the path of virtual consoles has been well-trodden by
+ * the PowerPC folks, who wrote "hvc_console.c" to generically support any
+ * virtual console. We use that infrastructure which only requires us to write
+ * the basic put_chars and get_chars functions and call the right register
+ * functions.
+ :*/
+
+/*M:002 The console can be flooded: while the Guest is processing input the
+ * Host can send more. Buffering in the Host could alleviate this, but it is a
+ * difficult problem in general. :*/
+/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/virtio.h>
+#include <linux/virtio_console.h>
+#include "hvc_console.h"
+
+/*D:340 These represent our input and output console queues, and the virtio
+ * operations for them. */
+static struct virtqueue *in_vq, *out_vq;
+static struct virtio_device *vdev;
+
+/* This is our input buffer, and how much data is left in it. */
+static unsigned int in_len;
+static char *in, *inbuf;
+
+/* The operations for our console. */
+static struct hv_ops virtio_cons;
+
+/*D:310 The put_chars() callback is pretty straightforward.
+ *
+ * We turn the characters into a scatter-gather list, add it to the output
+ * queue and then kick the Host. Then we sit here waiting for it to finish:
+ * inefficient in theory, but in practice implementations will do it
+ * immediately (lguest's Launcher does). */
+static int put_chars(u32 vtermno, const char *buf, int count)
+{
+ struct scatterlist sg[1];
+ unsigned int len;
+
+ /* This is a convenient routine to initialize a single-elem sg list */
+ sg_init_one(sg, buf, count);
+
+ /* add_buf wants a token to identify this buffer: we hand it any
+ * non-NULL pointer, since there's only ever one buffer. */
+ if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) == 0) {
+ /* Tell Host to go! */
+ out_vq->vq_ops->kick(out_vq);
+ /* Chill out until it's done with the buffer. */
+ while (!out_vq->vq_ops->get_buf(out_vq, &len))
+ cpu_relax();
+ }
+
+ /* We're expected to return the amount of data we wrote: all of it. */
+ return count;
+}
+
+/* Create a scatter-gather list representing our input buffer and put it in the
+ * queue. */
+static void add_inbuf(void)
+{
+ struct scatterlist sg[1];
+ sg_init_one(sg, inbuf, PAGE_SIZE);
+
+ /* We should always be able to add one buffer to an empty queue. */
+ if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) != 0)
+ BUG();
+ in_vq->vq_ops->kick(in_vq);
+}
+
+/*D:350 get_chars() is the callback from the hvc_console infrastructure when
+ * an interrupt is received.
+ *
+ * Most of the code deals with the fact that the hvc_console() infrastructure
+ * only asks us for 16 bytes at a time. We keep in_offset and in_used fields
+ * for partially-filled buffers. */
+static int get_chars(u32 vtermno, char *buf, int count)
+{
+ /* If we don't have an input queue yet, we can't get input. */
+ BUG_ON(!in_vq);
+
+ /* No buffer? Try to get one. */
+ if (!in_len) {
+ in = in_vq->vq_ops->get_buf(in_vq, &in_len);
+ if (!in)
+ return 0;
+ }
+
+ /* You want more than we have to give? Well, try wanting less! */
+ if (in_len < count)
+ count = in_len;
+
+ /* Copy across to their buffer and increment offset. */
+ memcpy(buf, in, count);
+ in += count;
+ in_len -= count;
+
+ /* Finished? Re-register buffer so Host will use it again. */
+ if (in_len == 0)
+ add_inbuf();
+
+ return count;
+}
+/*:*/
+
+/*D:320 Console drivers are initialized very early so boot messages can go out,
+ * so we do things slightly differently from the generic virtio initialization
+ * of the net and block drivers.
+ *
+ * At this stage, the console is output-only. It's too early to set up a
+ * virtqueue, so we let the drivers do some boutique early-output thing. */
+int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
+{
+ virtio_cons.put_chars = put_chars;
+ return hvc_instantiate(0, 0, &virtio_cons);
+}
+
+/*D:370 Once we're further in boot, we get probed like any other virtio device.
+ * At this stage we set up the output virtqueue.
+ *
+ * To set up and manage our virtual console, we call hvc_alloc(). Since we
+ * never remove the console device we never need this pointer again.
+ *
+ * Finally we put our input buffer in the input queue, ready to receive. */
+static int virtcons_probe(struct virtio_device *dev)
+{
+ int err;
+ struct hvc_struct *hvc;
+
+ vdev = dev;
+
+ /* This is the scratch page we use to receive console input */
+ inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!inbuf) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /* Find the input queue. */
+ /* FIXME: This is why we want to wean off hvc: we do nothing
+ * when input comes in. */
+ in_vq = vdev->config->find_vq(vdev, NULL);
+ if (IS_ERR(in_vq)) {
+ err = PTR_ERR(in_vq);
+ goto free;
+ }
+
+ out_vq = vdev->config->find_vq(vdev, NULL);
+ if (IS_ERR(out_vq)) {
+ err = PTR_ERR(out_vq);
+ goto free_in_vq;
+ }
+
+ /* Start using the new console output. */
+ virtio_cons.get_chars = get_chars;
+ virtio_cons.put_chars = put_chars;
+
+ /* The first argument of hvc_alloc() is the virtual console number, so
+ * we use zero. The second argument is the interrupt number; we
+ * currently leave this as zero: it would be better not to use the
+ * hvc mechanism and fix this (FIXME!).
+ *
+ * The third argument is a "struct hv_ops" containing the put_chars()
+ * and get_chars() pointers. The final argument is the output buffer
+ * size: we can do any size, so we put PAGE_SIZE here. */
+ hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE);
+ if (IS_ERR(hvc)) {
+ err = PTR_ERR(hvc);
+ goto free_out_vq;
+ }
+
+ /* Register the input buffer the first time. */
+ add_inbuf();
+ return 0;
+
+free_out_vq:
+ vdev->config->del_vq(out_vq);
+free_in_vq:
+ vdev->config->del_vq(in_vq);
+free:
+ kfree(inbuf);
+fail:
+ return err;
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtio_console = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtcons_probe,
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtio_console);
+}
+module_init(init);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio console driver");
+MODULE_LICENSE("GPL");