Introduce ZynqMP IPI implementation

Previously, ZynqMP IPI in ATF is only for ZynqMP PM,
This patch is to have a ZynqMP IPI implementation to handle
both ZynqMP PM IPI requirement and IPI mailbox service requirement
which will be introduced next.

We control IPI agents registers access but not IPI buffers access in
this implementation. Each IPI mailbox user will directly access the
IPI buffers.

Signed-off-by: Wendy Liang <jliang@xilinx.com>
diff --git a/plat/xilinx/zynqmp/platform.mk b/plat/xilinx/zynqmp/platform.mk
index cb3b442..a31e31d 100644
--- a/plat/xilinx/zynqmp/platform.mk
+++ b/plat/xilinx/zynqmp/platform.mk
@@ -71,6 +71,7 @@
 				plat/xilinx/zynqmp/plat_startup.c		\
 				plat/xilinx/zynqmp/plat_topology.c		\
 				plat/xilinx/zynqmp/sip_svc_setup.c		\
+				plat/xilinx/zynqmp/zynqmp_ipi.c		\
 				plat/xilinx/zynqmp/pm_service/pm_svc_main.c	\
 				plat/xilinx/zynqmp/pm_service/pm_api_sys.c	\
 				plat/xilinx/zynqmp/pm_service/pm_ipi.c		\
diff --git a/plat/xilinx/zynqmp/zynqmp_ipi.c b/plat/xilinx/zynqmp/zynqmp_ipi.c
new file mode 100644
index 0000000..755a3b7
--- /dev/null
+++ b/plat/xilinx/zynqmp/zynqmp_ipi.c
@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * Zynq UltraScale+ MPSoC IPI agent registers access management
+ */
+
+#include <bakery_lock.h>
+#include <debug.h>
+#include <errno.h>
+#include <mmio.h>
+#include <runtime_svc.h>
+#include <string.h>
+#include "zynqmp_ipi.h"
+#include "../zynqmp_private.h"
+
+/*********************************************************************
+ * Macros definitions
+ ********************************************************************/
+
+/* IPI registers base address */
+#define IPI_REGS_BASE   0xFF300000U
+
+/* IPI registers offsets macros */
+#define IPI_TRIG_OFFSET 0x00U
+#define IPI_OBR_OFFSET  0x04U
+#define IPI_ISR_OFFSET  0x10U
+#define IPI_IMR_OFFSET  0x14U
+#define IPI_IER_OFFSET  0x18U
+#define IPI_IDR_OFFSET  0x1CU
+
+/* IPI register start offset */
+#define IPI_REG_BASE(I) (zynqmp_ipi_table[(I)].ipi_reg_base)
+
+/* IPI register bit mask */
+#define IPI_BIT_MASK(I) (zynqmp_ipi_table[(I)].ipi_bit_mask)
+
+/* IPI secure check */
+#define IPI_SECURE_MASK  0x1U
+#define IPI_IS_SECURE(I) ((zynqmp_ipi_table[(I)].secure_only & \
+			   IPI_SECURE_MASK) ? 1 : 0)
+
+/*********************************************************************
+ * Struct definitions
+ ********************************************************************/
+
+/* structure to maintain IPI configuration information */
+struct zynqmp_ipi_config {
+	unsigned int ipi_bit_mask;
+	unsigned int ipi_reg_base;
+	unsigned char secure_only;
+};
+
+/* Zynqmp ipi configuration table */
+const static struct zynqmp_ipi_config zynqmp_ipi_table[] = {
+	/* APU IPI */
+	{
+		.ipi_bit_mask = 0x1,
+		.ipi_reg_base = 0xFF300000,
+		.secure_only = 0,
+	},
+	/* RPU0 IPI */
+	{
+		.ipi_bit_mask = 0x100,
+		.ipi_reg_base = 0xFF310000,
+		.secure_only = 0,
+	},
+	/* RPU1 IPI */
+	{
+		.ipi_bit_mask = 0x200,
+		.ipi_reg_base = 0xFF320000,
+		.secure_only = 0,
+	},
+	/* PMU0 IPI */
+	{
+		.ipi_bit_mask = 0x10000,
+		.ipi_reg_base = 0xFF330000,
+		.secure_only = IPI_SECURE_MASK,
+	},
+	/* PMU1 IPI */
+	{
+		.ipi_bit_mask = 0x20000,
+		.ipi_reg_base = 0xFF331000,
+		.secure_only = IPI_SECURE_MASK,
+	},
+	/* PMU2 IPI */
+	{
+		.ipi_bit_mask = 0x40000,
+		.ipi_reg_base = 0xFF332000,
+		.secure_only = IPI_SECURE_MASK,
+	},
+	/* PMU3 IPI */
+	{
+		.ipi_bit_mask = 0x80000,
+		.ipi_reg_base = 0xFF333000,
+		.secure_only = IPI_SECURE_MASK,
+	},
+	/* PL0 IPI */
+	{
+		.ipi_bit_mask = 0x1000000,
+		.ipi_reg_base = 0xFF340000,
+		.secure_only = 0,
+	},
+	/* PL1 IPI */
+	{
+		.ipi_bit_mask = 0x2000000,
+		.ipi_reg_base = 0xFF350000,
+		.secure_only = 0,
+	},
+	/* PL2 IPI */
+	{
+		.ipi_bit_mask = 0x4000000,
+		.ipi_reg_base = 0xFF360000,
+		.secure_only = 0,
+	},
+	/* PL3 IPI */
+	{
+		.ipi_bit_mask = 0x8000000,
+		.ipi_reg_base = 0xFF370000,
+		.secure_only = 0,
+	},
+};
+
+/* is_ipi_mb_within_range() - verify if IPI mailbox is within range
+ *
+ * @local  - local IPI ID
+ * @remote - remote IPI ID
+ *
+ * return - 1 if within range, 0 if not
+ */
+static inline int is_ipi_mb_within_range(uint32_t local, uint32_t remote)
+{
+	int ret = 1;
+	uint32_t ipi_total = ARRAY_SIZE(zynqmp_ipi_table);
+
+	if (remote >= ipi_total || local >= ipi_total)
+		ret = 0;
+
+	return ret;
+}
+
+/**
+ * ipi_mb_validate() - validate IPI mailbox access
+ *
+ * @local  - local IPI ID
+ * @remote - remote IPI ID
+ * @is_secure - indicate if the requester is from secure software
+ *
+ * return - 0 success, negative value for errors
+ */
+int ipi_mb_validate(uint32_t local, uint32_t remote, unsigned int is_secure)
+{
+	int ret = 0;
+
+	if (!is_ipi_mb_within_range(local, remote))
+		ret = -EINVAL;
+	else if (IPI_IS_SECURE(local) && !is_secure)
+		ret = -EPERM;
+	else if (IPI_IS_SECURE(remote) && !is_secure)
+		ret = -EPERM;
+
+	return ret;
+}
+
+/**
+ * ipi_mb_open() - Open IPI mailbox.
+ *
+ * @local  - local IPI ID
+ * @remote - remote IPI ID
+ *
+ */
+void ipi_mb_open(uint32_t local, uint32_t remote)
+{
+	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
+		      IPI_BIT_MASK(remote));
+	mmio_write_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET,
+		      IPI_BIT_MASK(remote));
+}
+
+/**
+ * ipi_mb_release() - Open IPI mailbox.
+ *
+ * @local  - local IPI ID
+ * @remote - remote IPI ID
+ *
+ */
+void ipi_mb_release(uint32_t local, uint32_t remote)
+{
+	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
+		      IPI_BIT_MASK(remote));
+}
+
+/**
+ * ipi_mb_enquire_status() - Enquire IPI mailbox status
+ *
+ * @local  - local IPI ID
+ * @remote - remote IPI ID
+ *
+ * return - 0 idle, positive value for pending sending or receiving,
+ *          negative value for errors
+ */
+int ipi_mb_enquire_status(uint32_t local, uint32_t remote)
+{
+	int ret = 0;
+	uint32_t status;
+
+	status = mmio_read_32(IPI_REG_BASE(local) + IPI_OBR_OFFSET);
+	if (status & IPI_BIT_MASK(remote))
+		ret |= IPI_MB_STATUS_SEND_PENDING;
+	status = mmio_read_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET);
+	if (status & IPI_BIT_MASK(remote))
+		ret |= IPI_MB_STATUS_RECV_PENDING;
+
+	return ret;
+}
+
+/* ipi_mb_notify() - Trigger IPI mailbox notification
+ *
+ * @local - local IPI ID
+ * @remote - remote IPI ID
+ * @is_blocking - if to trigger the notification in blocking mode or not.
+ *
+ * It sets the remote bit in the IPI agent trigger register.
+ *
+ */
+void ipi_mb_notify(uint32_t local, uint32_t remote, uint32_t is_blocking)
+{
+	uint32_t status;
+
+	mmio_write_32(IPI_REG_BASE(local) + IPI_TRIG_OFFSET,
+		      IPI_BIT_MASK(remote));
+	if (is_blocking) {
+		do {
+			status = mmio_read_32(IPI_REG_BASE(local) +
+					      IPI_OBR_OFFSET);
+		} while (status & IPI_BIT_MASK(remote));
+	}
+}
+
+/* ipi_mb_ack() - Ack IPI mailbox notification from the other end
+ *
+ * @local - local IPI ID
+ * @remote - remote IPI ID
+ *
+ * It will clear the remote bit in the isr register.
+ *
+ */
+void ipi_mb_ack(uint32_t local, uint32_t remote)
+{
+	mmio_write_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET,
+		      IPI_BIT_MASK(remote));
+}
+
+/* ipi_mb_disable_irq() - Disable IPI mailbox notification interrupt
+ *
+ * @local - local IPI ID
+ * @remote - remote IPI ID
+ *
+ * It will mask the remote bit in the idr register.
+ *
+ */
+void ipi_mb_disable_irq(uint32_t local, uint32_t remote)
+{
+	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
+		      IPI_BIT_MASK(remote));
+}
+
+/* ipi_mb_enable_irq() - Enable IPI mailbox notification interrupt
+ *
+ * @local - local IPI ID
+ * @remote - remote IPI ID
+ *
+ * It will mask the remote bit in the idr register.
+ *
+ */
+void ipi_mb_enable_irq(uint32_t local, uint32_t remote)
+{
+	mmio_write_32(IPI_REG_BASE(local) + IPI_IER_OFFSET,
+		      IPI_BIT_MASK(remote));
+}
diff --git a/plat/xilinx/zynqmp/zynqmp_ipi.h b/plat/xilinx/zynqmp/zynqmp_ipi.h
new file mode 100644
index 0000000..0544ddb
--- /dev/null
+++ b/plat/xilinx/zynqmp/zynqmp_ipi.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/* ZynqMP IPI management enums and defines */
+
+#ifndef _ZYNQMP_IPI_H_
+#define _ZYNQMP_IPI_H_
+
+#include <stdint.h>
+
+/*********************************************************************
+ * IPI agent IDs macros
+ ********************************************************************/
+#define IPI_ID_APU	0U
+#define IPI_ID_RPU0	1U
+#define IPI_ID_RPU1	2U
+#define IPI_ID_PMU0	3U
+#define IPI_ID_PMU1	4U
+#define IPI_ID_PMU2	5U
+#define IPI_ID_PMU3	6U
+#define IPI_ID_PL0	7U
+#define IPI_ID_PL1	8U
+#define IPI_ID_PL2	9U
+#define IPI_ID_PL3	10U
+
+/*********************************************************************
+ * IPI mailbox status macros
+ ********************************************************************/
+#define IPI_MB_STATUS_IDLE		0
+#define IPI_MB_STATUS_SEND_PENDING	1
+#define IPI_MB_STATUS_RECV_PENDING	2
+
+/*********************************************************************
+ * IPI mailbox call is secure or not macros
+ ********************************************************************/
+#define IPI_MB_CALL_NOTSECURE	0
+#define IPI_MB_CALL_SECURE	1
+
+/*********************************************************************
+ * IPI APIs declarations
+ ********************************************************************/
+
+/* Validate IPI mailbox access */
+int ipi_mb_validate(uint32_t local, uint32_t remote, unsigned int is_secure);
+
+/* Open the IPI mailbox */
+void ipi_mb_open(uint32_t local, uint32_t remote);
+
+/* Release the IPI mailbox */
+void ipi_mb_release(uint32_t local, uint32_t remote);
+
+/* Enquire IPI mailbox status */
+int ipi_mb_enquire_status(uint32_t local, uint32_t remote);
+
+/* Trigger notification on the IPI mailbox */
+void ipi_mb_notify(uint32_t local, uint32_t remote, uint32_t is_blocking);
+
+/* Ack IPI mailbox notification */
+void ipi_mb_ack(uint32_t local, uint32_t remote);
+
+/* Disable IPI mailbox notification interrupt */
+void ipi_mb_disable_irq(uint32_t local, uint32_t remote);
+
+/* Enable IPI mailbox notification interrupt */
+void ipi_mb_enable_irq(uint32_t local, uint32_t remote);
+
+#endif /* _ZYNQMP_IPI_H_ */