Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h

Break out parts of mshyperv.h that are ISA independent into a
separate file in include/asm-generic. This move facilitates
ARM64 code reusing these definitions and avoids code
duplication. No functionality or behavior is changed.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 180 insertions, 0 deletions

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
new file mode 100644
index 000000000000..0becb7d9704d
--- /dev/null
+++ b/include/asm-generic/mshyperv.h
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Linux-specific definitions for managing interactions with Microsoft's
+ * Hyper-V hypervisor. The definitions in this file are architecture
+ * independent. See arch/<arch>/include/asm/mshyperv.h for definitions
+ * that are specific to architecture <arch>.
+ *
+ * Definitions that are specified in the Hyper-V Top Level Functional
+ * Spec (TLFS) should not go in this file, but should instead go in
+ * hyperv-tlfs.h.
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author : Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef _ASM_GENERIC_MSHYPERV_H
+#define _ASM_GENERIC_MSHYPERV_H
+
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/cpumask.h>
+#include <asm/ptrace.h>
+#include <asm/hyperv-tlfs.h>
+
+struct ms_hyperv_info {
+	u32 features;
+	u32 misc_features;
+	u32 hints;
+	u32 nested_features;
+	u32 max_vp_index;
+	u32 max_lp_index;
+};
+extern struct ms_hyperv_info ms_hyperv;
+
+extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
+extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+
+
+/* Generate the guest OS identifier as described in the Hyper-V TLFS */
+static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
+				       __u64 d_info2)
+{
+	__u64 guest_id = 0;
+
+	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
+	guest_id |= (d_info1 << 48);
+	guest_id |= (kernel_version << 16);
+	guest_id |= d_info2;
+
+	return guest_id;
+}
+
+
+/* Free the message slot and signal end-of-message if required */
+static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
+{
+	/*
+	 * On crash we're reading some other CPU's message page and we need
+	 * to be careful: this other CPU may already had cleared the header
+	 * and the host may already had delivered some other message there.
+	 * In case we blindly write msg->header.message_type we're going
+	 * to lose it. We can still lose a message of the same type but
+	 * we count on the fact that there can only be one
+	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
+	 * on crash.
+	 */
+	if (cmpxchg(&msg->header.message_type, old_msg_type,
+		    HVMSG_NONE) != old_msg_type)
+		return;
+
+	/*
+	 * The cmxchg() above does an implicit memory barrier to
+	 * ensure the write to MessageType (ie set to
+	 * HVMSG_NONE) happens before we read the
+	 * MessagePending and EOMing. Otherwise, the EOMing
+	 * will not deliver any more messages since there is
+	 * no empty slot
+	 */
+	if (msg->header.message_flags.msg_pending) {
+		/*
+		 * This will cause message queue rescan to
+		 * possibly deliver another msg from the
+		 * hypervisor
+		 */
+		hv_signal_eom();
+	}
+}
+
+void hv_setup_vmbus_irq(void (*handler)(void));
+void hv_remove_vmbus_irq(void);
+void hv_enable_vmbus_irq(void);
+void hv_disable_vmbus_irq(void);
+
+void hv_setup_kexec_handler(void (*handler)(void));
+void hv_remove_kexec_handler(void);
+void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
+void hv_remove_crash_handler(void);
+
+#if IS_ENABLED(CONFIG_HYPERV)
+/*
+ * Hypervisor's notion of virtual processor ID is different from
+ * Linux' notion of CPU ID. This information can only be retrieved
+ * in the context of the calling CPU. Setup a map for easy access
+ * to this information.
+ */
+extern u32 *hv_vp_index;
+extern u32 hv_max_vp_index;
+
+/* Sentinel value for an uninitialized entry in hv_vp_index array */
+#define VP_INVAL	U32_MAX
+
+/**
+ * hv_cpu_number_to_vp_number() - Map CPU to VP.
+ * @cpu_number: CPU number in Linux terms
+ *
+ * This function returns the mapping between the Linux processor
+ * number and the hypervisor's virtual processor number, useful
+ * in making hypercalls and such that talk about specific
+ * processors.
+ *
+ * Return: Virtual processor number in Hyper-V terms
+ */
+static inline int hv_cpu_number_to_vp_number(int cpu_number)
+{
+	return hv_vp_index[cpu_number];
+}
+
+static inline int cpumask_to_vpset(struct hv_vpset *vpset,
+				    const struct cpumask *cpus)
+{
+	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
+
+	/* valid_bank_mask can represent up to 64 banks */
+	if (hv_max_vp_index / 64 >= 64)
+		return 0;
+
+	/*
+	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
+	 * structs are not cleared between calls, we risk flushing unneeded
+	 * vCPUs otherwise.
+	 */
+	for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
+		vpset->bank_contents[vcpu_bank] = 0;
+
+	/*
+	 * Some banks may end up being empty but this is acceptable.
+	 */
+	for_each_cpu(cpu, cpus) {
+		vcpu = hv_cpu_number_to_vp_number(cpu);
+		if (vcpu == VP_INVAL)
+			return -1;
+		vcpu_bank = vcpu / 64;
+		vcpu_offset = vcpu % 64;
+		__set_bit(vcpu_offset, (unsigned long *)
+			  &vpset->bank_contents[vcpu_bank]);
+		if (vcpu_bank >= nr_bank)
+			nr_bank = vcpu_bank + 1;
+	}
+	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
+	return nr_bank;
+}
+
+void hyperv_report_panic(struct pt_regs *regs, long err);
+void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
+bool hv_is_hyperv_initialized(void);
+void hyperv_cleanup(void);
+#else /* CONFIG_HYPERV */
+static inline bool hv_is_hyperv_initialized(void) { return false; }
+static inline void hyperv_cleanup(void) {}
+#endif /* CONFIG_HYPERV */
+
+#if IS_ENABLED(CONFIG_HYPERV)
+extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
+extern void hv_remove_stimer0_irq(int irq);
+#endif
+
+#endif