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-rw-r--r--drivers/virtio/Kconfig11
-rw-r--r--drivers/virtio/virtio.c11
-rw-r--r--drivers/virtio/virtio_balloon.c92
-rw-r--r--drivers/virtio/virtio_mmio.c163
4 files changed, 243 insertions, 34 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 1a61939b85f..f38b17a86c3 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -46,4 +46,15 @@ config VIRTIO_BALLOON
If unsure, say N.
+config VIRTIO_MMIO_CMDLINE_DEVICES
+ bool "Memory mapped virtio devices parameter parsing"
+ depends on VIRTIO_MMIO
+ ---help---
+ Allow virtio-mmio devices instantiation via the kernel command line
+ or module parameters. Be aware that using incorrect parameters (base
+ address in particular) can crash your system - you have been warned.
+ See Documentation/kernel-parameters.txt for details.
+
+ If unsure, say 'N'.
+
endmenu
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 984c501c258..f3558070e37 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -2,9 +2,10 @@
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
#include <linux/module.h>
+#include <linux/idr.h>
/* Unique numbering for virtio devices. */
-static unsigned int dev_index;
+static DEFINE_IDA(virtio_index_ida);
static ssize_t device_show(struct device *_d,
struct device_attribute *attr, char *buf)
@@ -193,7 +194,11 @@ int register_virtio_device(struct virtio_device *dev)
dev->dev.bus = &virtio_bus;
/* Assign a unique device index and hence name. */
- dev->index = dev_index++;
+ err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
+ if (err < 0)
+ goto out;
+
+ dev->index = err;
dev_set_name(&dev->dev, "virtio%u", dev->index);
/* We always start by resetting the device, in case a previous
@@ -208,6 +213,7 @@ int register_virtio_device(struct virtio_device *dev)
/* device_register() causes the bus infrastructure to look for a
* matching driver. */
err = device_register(&dev->dev);
+out:
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;
@@ -217,6 +223,7 @@ EXPORT_SYMBOL_GPL(register_virtio_device);
void unregister_virtio_device(struct virtio_device *dev)
{
device_unregister(&dev->dev);
+ ida_simple_remove(&virtio_index_ida, dev->index);
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 05f0a80818a..bfbc15ca38d 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -28,6 +28,13 @@
#include <linux/slab.h>
#include <linux/module.h>
+/*
+ * Balloon device works in 4K page units. So each page is pointed to by
+ * multiple balloon pages. All memory counters in this driver are in balloon
+ * page units.
+ */
+#define VIRTIO_BALLOON_PAGES_PER_PAGE (PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT)
+
struct virtio_balloon
{
struct virtio_device *vdev;
@@ -42,8 +49,13 @@ struct virtio_balloon
/* Waiting for host to ack the pages we released. */
struct completion acked;
- /* The pages we've told the Host we're not using. */
+ /* Number of balloon pages we've told the Host we're not using. */
unsigned int num_pages;
+ /*
+ * The pages we've told the Host we're not using.
+ * Each page on this list adds VIRTIO_BALLOON_PAGES_PER_PAGE
+ * to num_pages above.
+ */
struct list_head pages;
/* The array of pfns we tell the Host about. */
@@ -66,7 +78,13 @@ static u32 page_to_balloon_pfn(struct page *page)
BUILD_BUG_ON(PAGE_SHIFT < VIRTIO_BALLOON_PFN_SHIFT);
/* Convert pfn from Linux page size to balloon page size. */
- return pfn >> (PAGE_SHIFT - VIRTIO_BALLOON_PFN_SHIFT);
+ return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE;
+}
+
+static struct page *balloon_pfn_to_page(u32 pfn)
+{
+ BUG_ON(pfn % VIRTIO_BALLOON_PAGES_PER_PAGE);
+ return pfn_to_page(pfn / VIRTIO_BALLOON_PAGES_PER_PAGE);
}
static void balloon_ack(struct virtqueue *vq)
@@ -96,12 +114,23 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
wait_for_completion(&vb->acked);
}
+static void set_page_pfns(u32 pfns[], struct page *page)
+{
+ unsigned int i;
+
+ /* Set balloon pfns pointing at this page.
+ * Note that the first pfn points at start of the page. */
+ for (i = 0; i < VIRTIO_BALLOON_PAGES_PER_PAGE; i++)
+ pfns[i] = page_to_balloon_pfn(page) + i;
+}
+
static void fill_balloon(struct virtio_balloon *vb, size_t num)
{
/* We can only do one array worth at a time. */
num = min(num, ARRAY_SIZE(vb->pfns));
- for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {
+ for (vb->num_pfns = 0; vb->num_pfns < num;
+ vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) {
struct page *page = alloc_page(GFP_HIGHUSER | __GFP_NORETRY |
__GFP_NOMEMALLOC | __GFP_NOWARN);
if (!page) {
@@ -113,9 +142,9 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num)
msleep(200);
break;
}
- vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
+ set_page_pfns(vb->pfns + vb->num_pfns, page);
+ vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE;
totalram_pages--;
- vb->num_pages++;
list_add(&page->lru, &vb->pages);
}
@@ -130,8 +159,9 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned int num)
{
unsigned int i;
- for (i = 0; i < num; i++) {
- __free_page(pfn_to_page(pfns[i]));
+ /* Find pfns pointing at start of each page, get pages and free them. */
+ for (i = 0; i < num; i += VIRTIO_BALLOON_PAGES_PER_PAGE) {
+ __free_page(balloon_pfn_to_page(pfns[i]));
totalram_pages++;
}
}
@@ -143,11 +173,12 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
/* We can only do one array worth at a time. */
num = min(num, ARRAY_SIZE(vb->pfns));
- for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {
+ for (vb->num_pfns = 0; vb->num_pfns < num;
+ vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) {
page = list_first_entry(&vb->pages, struct page, lru);
list_del(&page->lru);
- vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
- vb->num_pages--;
+ set_page_pfns(vb->pfns + vb->num_pfns, page);
+ vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
}
/*
@@ -234,11 +265,14 @@ static void virtballoon_changed(struct virtio_device *vdev)
static inline s64 towards_target(struct virtio_balloon *vb)
{
- u32 v;
+ __le32 v;
+ s64 target;
+
vb->vdev->config->get(vb->vdev,
offsetof(struct virtio_balloon_config, num_pages),
&v, sizeof(v));
- return (s64)v - vb->num_pages;
+ target = le32_to_cpu(v);
+ return target - vb->num_pages;
}
static void update_balloon_size(struct virtio_balloon *vb)
@@ -347,20 +381,25 @@ out:
return err;
}
-static void __devexit virtballoon_remove(struct virtio_device *vdev)
+static void remove_common(struct virtio_balloon *vb)
{
- struct virtio_balloon *vb = vdev->priv;
-
- kthread_stop(vb->thread);
-
/* There might be pages left in the balloon: free them. */
while (vb->num_pages)
leak_balloon(vb, vb->num_pages);
+ update_balloon_size(vb);
/* Now we reset the device so we can clean up the queues. */
- vdev->config->reset(vdev);
+ vb->vdev->config->reset(vb->vdev);
- vdev->config->del_vqs(vdev);
+ vb->vdev->config->del_vqs(vb->vdev);
+}
+
+static void __devexit virtballoon_remove(struct virtio_device *vdev)
+{
+ struct virtio_balloon *vb = vdev->priv;
+
+ kthread_stop(vb->thread);
+ remove_common(vb);
kfree(vb);
}
@@ -374,17 +413,11 @@ static int virtballoon_freeze(struct virtio_device *vdev)
* function is called.
*/
- while (vb->num_pages)
- leak_balloon(vb, vb->num_pages);
- update_balloon_size(vb);
-
- /* Ensure we don't get any more requests from the host */
- vdev->config->reset(vdev);
- vdev->config->del_vqs(vdev);
+ remove_common(vb);
return 0;
}
-static int restore_common(struct virtio_device *vdev)
+static int virtballoon_restore(struct virtio_device *vdev)
{
struct virtio_balloon *vb = vdev->priv;
int ret;
@@ -397,11 +430,6 @@ static int restore_common(struct virtio_device *vdev)
update_balloon_size(vb);
return 0;
}
-
-static int virtballoon_restore(struct virtio_device *vdev)
-{
- return restore_common(vdev);
-}
#endif
static unsigned int features[] = {
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 01d6dc250d5..453db0c403d 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -6,6 +6,50 @@
* This module allows virtio devices to be used over a virtual, memory mapped
* platform device.
*
+ * The guest device(s) may be instantiated in one of three equivalent ways:
+ *
+ * 1. Static platform device in board's code, eg.:
+ *
+ * static struct platform_device v2m_virtio_device = {
+ * .name = "virtio-mmio",
+ * .id = -1,
+ * .num_resources = 2,
+ * .resource = (struct resource []) {
+ * {
+ * .start = 0x1001e000,
+ * .end = 0x1001e0ff,
+ * .flags = IORESOURCE_MEM,
+ * }, {
+ * .start = 42 + 32,
+ * .end = 42 + 32,
+ * .flags = IORESOURCE_IRQ,
+ * },
+ * }
+ * };
+ *
+ * 2. Device Tree node, eg.:
+ *
+ * virtio_block@1e000 {
+ * compatible = "virtio,mmio";
+ * reg = <0x1e000 0x100>;
+ * interrupts = <42>;
+ * }
+ *
+ * 3. Kernel module (or command line) parameter. Can be used more than once -
+ * one device will be created for each one. Syntax:
+ *
+ * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>]
+ * where:
+ * <size> := size (can use standard suffixes like K, M or G)
+ * <baseaddr> := physical base address
+ * <irq> := interrupt number (as passed to request_irq())
+ * <id> := (optional) platform device id
+ * eg.:
+ * virtio_mmio.device=0x100@0x100b0000:48 \
+ * virtio_mmio.device=1K@0x1001e000:74
+ *
+ *
+ *
* Registers layout (all 32-bit wide):
*
* offset d. name description
@@ -42,6 +86,8 @@
* See the COPYING file in the top-level directory.
*/
+#define pr_fmt(fmt) "virtio-mmio: " fmt
+
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@@ -449,6 +495,122 @@ static int __devexit virtio_mmio_remove(struct platform_device *pdev)
+/* Devices list parameter */
+
+#if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
+
+static struct device vm_cmdline_parent = {
+ .init_name = "virtio-mmio-cmdline",
+};
+
+static int vm_cmdline_parent_registered;
+static int vm_cmdline_id;
+
+static int vm_cmdline_set(const char *device,
+ const struct kernel_param *kp)
+{
+ int err;
+ struct resource resources[2] = {};
+ char *str;
+ long long int base;
+ int processed, consumed = 0;
+ struct platform_device *pdev;
+
+ resources[0].flags = IORESOURCE_MEM;
+ resources[1].flags = IORESOURCE_IRQ;
+
+ resources[0].end = memparse(device, &str) - 1;
+
+ processed = sscanf(str, "@%lli:%u%n:%d%n",
+ &base, &resources[1].start, &consumed,
+ &vm_cmdline_id, &consumed);
+
+ if (processed < 2 || processed > 3 || str[consumed])
+ return -EINVAL;
+
+ resources[0].start = base;
+ resources[0].end += base;
+ resources[1].end = resources[1].start;
+
+ if (!vm_cmdline_parent_registered) {
+ err = device_register(&vm_cmdline_parent);
+ if (err) {
+ pr_err("Failed to register parent device!\n");
+ return err;
+ }
+ vm_cmdline_parent_registered = 1;
+ }
+
+ pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
+ vm_cmdline_id,
+ (unsigned long long)resources[0].start,
+ (unsigned long long)resources[0].end,
+ (int)resources[1].start);
+
+ pdev = platform_device_register_resndata(&vm_cmdline_parent,
+ "virtio-mmio", vm_cmdline_id++,
+ resources, ARRAY_SIZE(resources), NULL, 0);
+ if (IS_ERR(pdev))
+ return PTR_ERR(pdev);
+
+ return 0;
+}
+
+static int vm_cmdline_get_device(struct device *dev, void *data)
+{
+ char *buffer = data;
+ unsigned int len = strlen(buffer);
+ struct platform_device *pdev = to_platform_device(dev);
+
+ snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n",
+ pdev->resource[0].end - pdev->resource[0].start + 1ULL,
+ (unsigned long long)pdev->resource[0].start,
+ (unsigned long long)pdev->resource[1].start,
+ pdev->id);
+ return 0;
+}
+
+static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
+{
+ buffer[0] = '\0';
+ device_for_each_child(&vm_cmdline_parent, buffer,
+ vm_cmdline_get_device);
+ return strlen(buffer) + 1;
+}
+
+static struct kernel_param_ops vm_cmdline_param_ops = {
+ .set = vm_cmdline_set,
+ .get = vm_cmdline_get,
+};
+
+device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR);
+
+static int vm_unregister_cmdline_device(struct device *dev,
+ void *data)
+{
+ platform_device_unregister(to_platform_device(dev));
+
+ return 0;
+}
+
+static void vm_unregister_cmdline_devices(void)
+{
+ if (vm_cmdline_parent_registered) {
+ device_for_each_child(&vm_cmdline_parent, NULL,
+ vm_unregister_cmdline_device);
+ device_unregister(&vm_cmdline_parent);
+ vm_cmdline_parent_registered = 0;
+ }
+}
+
+#else
+
+static void vm_unregister_cmdline_devices(void)
+{
+}
+
+#endif
+
/* Platform driver */
static struct of_device_id virtio_mmio_match[] = {
@@ -475,6 +637,7 @@ static int __init virtio_mmio_init(void)
static void __exit virtio_mmio_exit(void)
{
platform_driver_unregister(&virtio_mmio_driver);
+ vm_unregister_cmdline_devices();
}
module_init(virtio_mmio_init);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-21 18:37:39 +0000