1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
new file mode 100644
index 000000000..f202ac7f4
--- /dev/null
+++ b/drivers/hv/hv.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * 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 <clocksource/hyperv_timer.h>
+#include <asm/mshyperv.h>
+#include "hyperv_vmbus.h"
+
+/* The one and only */
+struct hv_context hv_context;
+
+/*
+ * 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;
+	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;
+}
+
+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->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;
+		}
+	}
+
+	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);
+
+		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.
+ */
+void hv_synic_enable_regs(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)
+		>> HV_HYP_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)
+		>> HV_HYP_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 = hv_get_vector();
+	shared_sint.masked = false;
+	shared_sint.auto_eoi = hv_recommend_using_aeoi();
+	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);
+}
+
+int hv_synic_init(unsigned int cpu)
+{
+	hv_synic_enable_regs(cpu);
+
+	hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
+
+	return 0;
+}
+
+/*
+ * hv_synic_cleanup - Cleanup routine for hv_synic_init().
+ */
+void hv_synic_disable_regs(unsigned int cpu)
+{
+	union hv_synic_sint shared_sint;
+	union hv_synic_simp simp;
+	union hv_synic_siefp siefp;
+	union hv_synic_scontrol sctrl;
+
+	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);
+}
+
+int hv_synic_cleanup(unsigned int cpu)
+{
+	struct vmbus_channel *channel, *sc;
+	bool channel_found = false;
+
+	/*
+	 * Hyper-V does not provide a way to change the connect CPU once
+	 * it is set; we must prevent the connect CPU from going offline
+	 * while the VM is running normally. But in the panic or kexec()
+	 * path where the vmbus is already disconnected, the CPU must be
+	 * allowed to shut down.
+	 */
+	if (cpu == VMBUS_CONNECT_CPU &&
+	    vmbus_connection.conn_state == CONNECTED)
+		return -EBUSY;
+
+	/*
+	 * 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
+	 * fail; this will effectively prevent CPU offlining.
+	 *
+	 * TODO: Re-bind the channels to different CPUs.
+	 */
+	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;
+		}
+		list_for_each_entry(sc, &channel->sc_list, sc_list) {
+			if (sc->target_cpu == cpu) {
+				channel_found = true;
+				break;
+			}
+		}
+		if (channel_found)
+			break;
+	}
+	mutex_unlock(&vmbus_connection.channel_mutex);
+
+	if (channel_found && vmbus_connection.conn_state == CONNECTED)
+		return -EBUSY;
+
+	hv_stimer_legacy_cleanup(cpu);
+
+	hv_synic_disable_regs(cpu);
+
+	return 0;
+}