1 files changed, 442 insertions, 0 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
new file mode 100644
index 000000000..08bcefca3
--- /dev/null
+++ b/drivers/hv/hv.c
@@ -0,0 +1,442 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/hyperv.h>
+#include <linux/version.h>
+#include <linux/random.h>
+#include <linux/clockchips.h>
+#include <asm/mshyperv.h>
+#include "hyperv_vmbus.h"
+
+/* The one and only */
+struct hv_context hv_context = {
+	.synic_initialized	= false,
+};
+
+/*
+ * If false, we're using the old mechanism for stimer0 interrupts
+ * where it sends a VMbus message when it expires. The old
+ * mechanism is used when running on older versions of Hyper-V
+ * that don't support Direct Mode. While Hyper-V provides
+ * four stimer's per CPU, Linux uses only stimer0.
+ */
+static bool direct_mode_enabled;
+static int stimer0_irq;
+static int stimer0_vector;
+
+#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
+#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
+#define HV_MIN_DELTA_TICKS 1
+
+/*
+ * hv_init - Main initialization routine.
+ *
+ * This routine must be called before any other routines in here are called
+ */
+int hv_init(void)
+{
+	hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
+	if (!hv_context.cpu_context)
+		return -ENOMEM;
+
+	direct_mode_enabled = ms_hyperv.misc_features &
+			HV_STIMER_DIRECT_MODE_AVAILABLE;
+	return 0;
+}
+
+/*
+ * hv_post_message - Post a message using the hypervisor message IPC.
+ *
+ * This involves a hypercall.
+ */
+int hv_post_message(union hv_connection_id connection_id,
+		  enum hv_message_type message_type,
+		  void *payload, size_t payload_size)
+{
+	struct hv_input_post_message *aligned_msg;
+	struct hv_per_cpu_context *hv_cpu;
+	u64 status;
+
+	if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
+		return -EMSGSIZE;
+
+	hv_cpu = get_cpu_ptr(hv_context.cpu_context);
+	aligned_msg = hv_cpu->post_msg_page;
+	aligned_msg->connectionid = connection_id;
+	aligned_msg->reserved = 0;
+	aligned_msg->message_type = message_type;
+	aligned_msg->payload_size = payload_size;
+	memcpy((void *)aligned_msg->payload, payload, payload_size);
+
+	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
+
+	/* Preemption must remain disabled until after the hypercall
+	 * so some other thread can't get scheduled onto this cpu and
+	 * corrupt the per-cpu post_msg_page
+	 */
+	put_cpu_ptr(hv_cpu);
+
+	return status & 0xFFFF;
+}
+
+/*
+ * ISR for when stimer0 is operating in Direct Mode.  Direct Mode
+ * does not use VMbus or any VMbus messages, so process here and not
+ * in the VMbus driver code.
+ */
+
+static void hv_stimer0_isr(void)
+{
+	struct hv_per_cpu_context *hv_cpu;
+
+	hv_cpu = this_cpu_ptr(hv_context.cpu_context);
+	hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt);
+	add_interrupt_randomness(stimer0_vector);
+}
+
+static int hv_ce_set_next_event(unsigned long delta,
+				struct clock_event_device *evt)
+{
+	u64 current_tick;
+
+	WARN_ON(!clockevent_state_oneshot(evt));
+
+	current_tick = hyperv_cs->read(NULL);
+	current_tick += delta;
+	hv_init_timer(0, current_tick);
+	return 0;
+}
+
+static int hv_ce_shutdown(struct clock_event_device *evt)
+{
+	hv_init_timer(0, 0);
+	hv_init_timer_config(0, 0);
+	if (direct_mode_enabled)
+		hv_disable_stimer0_percpu_irq(stimer0_irq);
+
+	return 0;
+}
+
+static int hv_ce_set_oneshot(struct clock_event_device *evt)
+{
+	union hv_timer_config timer_cfg;
+
+	timer_cfg.as_uint64 = 0;
+	timer_cfg.enable = 1;
+	timer_cfg.auto_enable = 1;
+	if (direct_mode_enabled) {
+		/*
+		 * When it expires, the timer will directly interrupt
+		 * on the specified hardware vector/IRQ.
+		 */
+		timer_cfg.direct_mode = 1;
+		timer_cfg.apic_vector = stimer0_vector;
+		hv_enable_stimer0_percpu_irq(stimer0_irq);
+	} else {
+		/*
+		 * When it expires, the timer will generate a VMbus message,
+		 * to be handled by the normal VMbus interrupt handler.
+		 */
+		timer_cfg.direct_mode = 0;
+		timer_cfg.sintx = VMBUS_MESSAGE_SINT;
+	}
+	hv_init_timer_config(0, timer_cfg.as_uint64);
+	return 0;
+}
+
+static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
+{
+	dev->name = "Hyper-V clockevent";
+	dev->features = CLOCK_EVT_FEAT_ONESHOT;
+	dev->cpumask = cpumask_of(cpu);
+	dev->rating = 1000;
+	/*
+	 * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
+	 * result in clockevents_config_and_register() taking additional
+	 * references to the hv_vmbus module making it impossible to unload.
+	 */
+
+	dev->set_state_shutdown = hv_ce_shutdown;
+	dev->set_state_oneshot = hv_ce_set_oneshot;
+	dev->set_next_event = hv_ce_set_next_event;
+}
+
+
+int hv_synic_alloc(void)
+{
+	int cpu;
+	struct hv_per_cpu_context *hv_cpu;
+
+	/*
+	 * First, zero all per-cpu memory areas so hv_synic_free() can
+	 * detect what memory has been allocated and cleanup properly
+	 * after any failures.
+	 */
+	for_each_present_cpu(cpu) {
+		hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
+		memset(hv_cpu, 0, sizeof(*hv_cpu));
+	}
+
+	hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
+					 GFP_KERNEL);
+	if (hv_context.hv_numa_map == NULL) {
+		pr_err("Unable to allocate NUMA map\n");
+		goto err;
+	}
+
+	for_each_present_cpu(cpu) {
+		hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
+
+		tasklet_init(&hv_cpu->msg_dpc,
+			     vmbus_on_msg_dpc, (unsigned long) hv_cpu);
+
+		hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
+					  GFP_KERNEL);
+		if (hv_cpu->clk_evt == NULL) {
+			pr_err("Unable to allocate clock event device\n");
+			goto err;
+		}
+		hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
+
+		hv_cpu->synic_message_page =
+			(void *)get_zeroed_page(GFP_ATOMIC);
+		if (hv_cpu->synic_message_page == NULL) {
+			pr_err("Unable to allocate SYNIC message page\n");
+			goto err;
+		}
+
+		hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
+		if (hv_cpu->synic_event_page == NULL) {
+			pr_err("Unable to allocate SYNIC event page\n");
+			goto err;
+		}
+
+		hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
+		if (hv_cpu->post_msg_page == NULL) {
+			pr_err("Unable to allocate post msg page\n");
+			goto err;
+		}
+
+		INIT_LIST_HEAD(&hv_cpu->chan_list);
+	}
+
+	if (direct_mode_enabled &&
+	    hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
+				hv_stimer0_isr))
+		goto err;
+
+	return 0;
+err:
+	/*
+	 * Any memory allocations that succeeded will be freed when
+	 * the caller cleans up by calling hv_synic_free()
+	 */
+	return -ENOMEM;
+}
+
+
+void hv_synic_free(void)
+{
+	int cpu;
+
+	for_each_present_cpu(cpu) {
+		struct hv_per_cpu_context *hv_cpu
+			= per_cpu_ptr(hv_context.cpu_context, cpu);
+
+		kfree(hv_cpu->clk_evt);
+		free_page((unsigned long)hv_cpu->synic_event_page);
+		free_page((unsigned long)hv_cpu->synic_message_page);
+		free_page((unsigned long)hv_cpu->post_msg_page);
+	}
+
+	kfree(hv_context.hv_numa_map);
+}
+
+/*
+ * hv_synic_init - Initialize the Synthetic Interrupt Controller.
+ *
+ * If it is already initialized by another entity (ie x2v shim), we need to
+ * retrieve the initialized message and event pages.  Otherwise, we create and
+ * initialize the message and event pages.
+ */
+int hv_synic_init(unsigned int cpu)
+{
+	struct hv_per_cpu_context *hv_cpu
+		= per_cpu_ptr(hv_context.cpu_context, cpu);
+	union hv_synic_simp simp;
+	union hv_synic_siefp siefp;
+	union hv_synic_sint shared_sint;
+	union hv_synic_scontrol sctrl;
+
+	/* Setup the Synic's message page */
+	hv_get_simp(simp.as_uint64);
+	simp.simp_enabled = 1;
+	simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
+		>> PAGE_SHIFT;
+
+	hv_set_simp(simp.as_uint64);
+
+	/* Setup the Synic's event page */
+	hv_get_siefp(siefp.as_uint64);
+	siefp.siefp_enabled = 1;
+	siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
+		>> PAGE_SHIFT;
+
+	hv_set_siefp(siefp.as_uint64);
+
+	/* Setup the shared SINT. */
+	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
+	shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
+	shared_sint.masked = false;
+	if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
+		shared_sint.auto_eoi = false;
+	else
+		shared_sint.auto_eoi = true;
+
+	hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
+	/* Enable the global synic bit */
+	hv_get_synic_state(sctrl.as_uint64);
+	sctrl.enable = 1;
+
+	hv_set_synic_state(sctrl.as_uint64);
+
+	hv_context.synic_initialized = true;
+
+	/*
+	 * Register the per-cpu clockevent source.
+	 */
+	if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)
+		clockevents_config_and_register(hv_cpu->clk_evt,
+						HV_TIMER_FREQUENCY,
+						HV_MIN_DELTA_TICKS,
+						HV_MAX_MAX_DELTA_TICKS);
+	return 0;
+}
+
+/*
+ * hv_synic_clockevents_cleanup - Cleanup clockevent devices
+ */
+void hv_synic_clockevents_cleanup(void)
+{
+	int cpu;
+
+	if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
+		return;
+
+	if (direct_mode_enabled)
+		hv_remove_stimer0_irq(stimer0_irq);
+
+	for_each_present_cpu(cpu) {
+		struct hv_per_cpu_context *hv_cpu
+			= per_cpu_ptr(hv_context.cpu_context, cpu);
+
+		clockevents_unbind_device(hv_cpu->clk_evt, cpu);
+	}
+}
+
+/*
+ * hv_synic_cleanup - Cleanup routine for hv_synic_init().
+ */
+int hv_synic_cleanup(unsigned int cpu)
+{
+	union hv_synic_sint shared_sint;
+	union hv_synic_simp simp;
+	union hv_synic_siefp siefp;
+	union hv_synic_scontrol sctrl;
+	struct vmbus_channel *channel, *sc;
+	bool channel_found = false;
+	unsigned long flags;
+
+	if (!hv_context.synic_initialized)
+		return -EFAULT;
+
+	/*
+	 * Search for channels which are bound to the CPU we're about to
+	 * cleanup. In case we find one and vmbus is still connected we need to
+	 * fail, this will effectively prevent CPU offlining. There is no way
+	 * we can re-bind channels to different CPUs for now.
+	 */
+	mutex_lock(&vmbus_connection.channel_mutex);
+	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
+		if (channel->target_cpu == cpu) {
+			channel_found = true;
+			break;
+		}
+		spin_lock_irqsave(&channel->lock, flags);
+		list_for_each_entry(sc, &channel->sc_list, sc_list) {
+			if (sc->target_cpu == cpu) {
+				channel_found = true;
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&channel->lock, flags);
+		if (channel_found)
+			break;
+	}
+	mutex_unlock(&vmbus_connection.channel_mutex);
+
+	if (channel_found && vmbus_connection.conn_state == CONNECTED)
+		return -EBUSY;
+
+	/* Turn off clockevent device */
+	if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
+		struct hv_per_cpu_context *hv_cpu
+			= this_cpu_ptr(hv_context.cpu_context);
+
+		clockevents_unbind_device(hv_cpu->clk_evt, cpu);
+		hv_ce_shutdown(hv_cpu->clk_evt);
+	}
+
+	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
+	shared_sint.masked = 1;
+
+	/* Need to correctly cleanup in the case of SMP!!! */
+	/* Disable the interrupt */
+	hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
+	hv_get_simp(simp.as_uint64);
+	simp.simp_enabled = 0;
+	simp.base_simp_gpa = 0;
+
+	hv_set_simp(simp.as_uint64);
+
+	hv_get_siefp(siefp.as_uint64);
+	siefp.siefp_enabled = 0;
+	siefp.base_siefp_gpa = 0;
+
+	hv_set_siefp(siefp.as_uint64);
+
+	/* Disable the global synic bit */
+	hv_get_synic_state(sctrl.as_uint64);
+	sctrl.enable = 0;
+	hv_set_synic_state(sctrl.as_uint64);
+
+	return 0;
+}