hv/mod_irq: split irq.c into arch/x86/irq.c and common/irq.c

The common irq file is responsible for managing the central
irq_desc data structure and provides the following APIs for
host interrupt handling.
- init_interrupt()
- reserve_irq_num()
- request_irq()
- free_irq()
- set_irq_trigger_mode()
- do_irq()

API prototypes, constant and data structures belonging to common
interrupt handling are all moved into include/common/irq.h.

Conversely, the following arch specific APIs are added which are
called from the common code at various points:
- init_irq_descs_arch()
- setup_irqs_arch()
- init_interrupt_arch()
- free_irq_arch()
- request_irq_arch()
- pre_irq_arch()
- post_irq_arch()

Tracked-On: #5825
Signed-off-by: Peter Fang <peter.fang@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>

hypervisor/include/common/irq.h

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2021 Intel Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef COMMON_IRQ_H
+#define COMMON_IRQ_H
+
+#include <types.h>
+#include <spinlock.h>
+
+#include <arch/x86/irq.h>
+
+/**
+ * @file common/irq.h
+ *
+ * @brief public APIs for common IRQ handling
+ */
+
+#define NR_IRQS			256U
+#define IRQ_INVALID		0xffffffffU
+
+#define IRQ_ALLOC_BITMAP_SIZE	INT_DIV_ROUNDUP(NR_IRQS, 64U)
+
+#define IRQF_NONE	(0U)
+#define IRQF_LEVEL	(1U << 1U)	/* 1: level trigger; 0: edge trigger */
+#define IRQF_PT		(1U << 2U)	/* 1: for passthrough dev */
+
+extern uint64_t irq_alloc_bitmap[IRQ_ALLOC_BITMAP_SIZE];
+
+typedef void (*irq_action_t)(uint32_t irq, void *priv_data);
+
+/**
+ * @brief Interrupt descriptor
+ *
+ * Any field change in below required lock protection with irqsave
+ */
+struct irq_desc {
+	uint32_t irq;		/**< index to irq_desc_base */
+
+	void *arch_data;	/**< arch-specific data */
+
+	irq_action_t action;	/**< callback registered from component */
+	void *priv_data;	/**< irq_action private data */
+	uint32_t flags;		/**< flags for trigger mode/ptdev */
+
+	spinlock_t lock;
+};
+
+/**
+ * @defgroup phys_int_ext_apis Physical Interrupt External Interfaces
+ *
+ * This is a group that includes Physical Interrupt External Interfaces.
+ *
+ * @{
+ */
+
+/**
+ * @brief Reserve an interrupt num
+ *
+ * Reserved interrupt num will not be available for dynamic IRQ allocations.
+ * This is normally used by the hypervisor for static IRQ mappings and/or
+ * arch specific, e.g. IOAPIC, interrupts during initialization.
+ *
+ * @param[in]	req_irq	irq_num to be reserved
+ *
+ * @retval >=0 on success, IRQ_INVALID on failure
+ */
+uint32_t reserve_irq_num(uint32_t req_irq);
+
+/**
+ * @brief Request an interrupt
+ *
+ * Request interrupt num if not specified, and register irq action for the
+ * specified/allocated irq.
+ *
+ * @param[in]	req_irq	irq_num to request, if IRQ_INVALID, a free irq
+ *		number will be allocated
+ * @param[in]	action_fn	Function to be called when the IRQ occurs
+ * @param[in]	priv_data	Private data for action function.
+ * @param[in]	flags	Interrupt type flags, including:
+ *			IRQF_NONE;
+ *			IRQF_LEVEL - 1: level trigger; 0: edge trigger;
+ *			IRQF_PT    - 1: for passthrough dev
+ *
+ * @retval >=0 on success
+ * @retval IRQ_INVALID on failure
+ */
+int32_t request_irq(uint32_t req_irq, irq_action_t action_fn, void *priv_data,
+			uint32_t flags);
+
+/**
+ * @brief Free an interrupt
+ *
+ * Free irq num and unregister the irq action.
+ *
+ * @param[in]	irq	irq_num to be freed
+ */
+void free_irq(uint32_t irq);
+
+/**
+ * @brief Set interrupt trigger mode
+ *
+ * Set the irq trigger mode: edge-triggered or level-triggered
+ *
+ * @param[in]	irq	irq_num of interrupt to be set
+ * @param[in]	is_level_triggered	Trigger mode to set
+ */
+void set_irq_trigger_mode(uint32_t irq, bool is_level_triggered);
+
+/**
+ * @brief Process an IRQ
+ *
+ * To process an IRQ, an action callback will be called if registered.
+ *
+ * @param irq     irq_num to be processed
+ */
+void do_irq(const uint32_t irq);
+
+/**
+ * @brief Initialize interrupt
+ *
+ * To do interrupt initialization for a cpu, will be called for each physical cpu.
+ *
+ * @param[in]	pcpu_id The id of physical cpu to initialize
+ */
+void init_interrupt(uint16_t pcpu_id);
+
+
+/**
+ * @}
+ */
+/* End of phys_int_ext_apis */
+
+#endif /* COMMON_IRQ_H */