[PATCH 073/120] MIPS: PS2: IOP: Heap memory allocate and free

[Fredrik Noring <noring@nocrew.org>]

The IOP heap memory operations are serviced by an IOP module linked from
read-only memory (ROM).

Signed-off-by: Fredrik Noring <noring@nocrew.org>
---
 arch/mips/include/asm/mach-ps2/iop-heap.h | 19 +++++
 drivers/ps2/Makefile                      |  1 +
 drivers/ps2/iop-heap.c                    | 90 +++++++++++++++++++++++
 3 files changed, 110 insertions(+)
 create mode 100644 arch/mips/include/asm/mach-ps2/iop-heap.h
 create mode 100644 drivers/ps2/iop-heap.c

diff --git a/arch/mips/include/asm/mach-ps2/iop-heap.h b/arch/mips/include/asm/mach-ps2/iop-heap.h
new file mode 100644
index 000000000000..ee96e2ffba83
--- /dev/null
+++ b/arch/mips/include/asm/mach-ps2/iop-heap.h
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PlayStation 2 input/output processor (IOP) heap memory
+ *
+ * Copyright (C) 2019 Fredrik Noring
+ */
+
+#ifndef __ASM_MACH_PS2_IOP_HEAP_H
+#define __ASM_MACH_PS2_IOP_HEAP_H
+
+#include <linux/types.h>
+
+#include <asm/mach-ps2/iop.h>
+
+iop_addr_t iop_alloc(size_t nbyte);
+
+int iop_free(iop_addr_t baddr);
+
+#endif /* __ASM_MACH_PS2_IOP_HEAP_H */
diff --git a/drivers/ps2/Makefile b/drivers/ps2/Makefile
index b04e4d3c3374..02a5756cb059 100644
--- a/drivers/ps2/Makefile
+++ b/drivers/ps2/Makefile
@@ -1,3 +1,4 @@
+obj-m				+= iop-heap.o
 obj-m				+= iop-memory.o
 obj-m				+= iop-module.o
 obj-m				+= iop-registers.o
diff --git a/drivers/ps2/iop-heap.c b/drivers/ps2/iop-heap.c
new file mode 100644
index 000000000000..f803401f59e5
--- /dev/null
+++ b/drivers/ps2/iop-heap.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PlayStation 2 input/output processor (IOP) heap memory
+ *
+ * Copyright (C) 2019 Fredrik Noring
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/module.h>
+
+#include <asm/mach-ps2/iop-error.h>
+#include <asm/mach-ps2/iop-heap.h>
+#include <asm/mach-ps2/sif.h>
+
+/**
+ * enum iop_heap_rpc_ops - I/O processor (IOP) heap RPC operations
+ * @rpo_alloc: allocate IOP memory
+ * @rpo_free: free IOP memory
+ * @rpo_load: FIXME
+ */
+enum iop_heap_rpc_ops {
+	rpo_alloc = 1,
+	rpo_free  = 2,
+	rpo_load  = 3,
+};
+
+static struct sif_rpc_client iop_heap_rpc;
+
+/**
+ * iop_alloc - allocate IOP memory
+ * @nbyte: number of bytes to allocate
+ *
+ * Context: sleep
+ * Return: IOP address, or zero if the allocation failed
+ */
+iop_addr_t iop_alloc(size_t nbyte)
+{
+	const u32 size_arg = nbyte;
+	u32 iop_addr;
+
+	if (size_arg != nbyte)
+		return 0;
+
+	return sif_rpc(&iop_heap_rpc, rpo_alloc,
+		&size_arg, sizeof(size_arg),
+		&iop_addr, sizeof(iop_addr)) < 0 ? 0 : iop_addr;
+}
+EXPORT_SYMBOL(iop_alloc);
+
+/**
+ * iop_free - free previously allocated IOP memory
+ * @baddr: IOP address, or zero
+ *
+ * Context: sleep
+ * Return: 0 on success, otherwise a negative error number
+ */
+int iop_free(iop_addr_t baddr)
+{
+	const u32 addr_arg = baddr;
+	s32 status;
+	int err;
+
+	if (!baddr)
+		return 0;
+
+	err = sif_rpc(&iop_heap_rpc, rpo_free,
+		&addr_arg, sizeof(addr_arg),
+		&status, sizeof(status));
+
+	return err < 0 ? err : errno_for_iop_error(status);
+}
+EXPORT_SYMBOL(iop_free);
+
+static int __init iop_heap_init(void)
+{
+	return sif_rpc_bind(&iop_heap_rpc, SIF_SID_HEAP);
+}
+
+static void __exit iop_heap_exit(void)
+{
+	sif_rpc_unbind(&iop_heap_rpc);
+}
+
+module_init(iop_heap_init);
+module_exit(iop_heap_exit);
+
+MODULE_DESCRIPTION("PlayStation 2 input/output processor (IOP) heap memory");
+MODULE_AUTHOR("Fredrik Noring");
+MODULE_LICENSE("GPL");
-- 
2.21.0