diff mbox series

[RFC,v2,1/2] lib: sbi: Add shared memory region support

Message ID IA1PR20MB495392CAB5FD37F511A25E7BBB682@IA1PR20MB4953.namprd20.prod.outlook.com
State Not Applicable
Headers show
Series lib: sbi_pmu: Add PMU snapshot extension | expand

Commit Message

Inochi Amaoto Jan. 11, 2024, 12:35 a.m. UTC 
SBI 2.0 introducts shared memory between SBI and supervisor-mode software,
which is needed by various extension. So add inital support for shared
memory mechanisms.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
---
 include/sbi/sbi_bitops.h |   3 +
 include/sbi/sbi_shm.h    | 129 +++++++++++++++++++++++++++++++++++++++
 lib/sbi/objects.mk       |   1 +
 lib/sbi/sbi_shm.c        | 114 ++++++++++++++++++++++++++++++++++
 4 files changed, 247 insertions(+)
 create mode 100644 include/sbi/sbi_shm.h
 create mode 100644 lib/sbi/sbi_shm.c
diff mbox series

Patch

diff --git a/include/sbi/sbi_bitops.h b/include/sbi/sbi_bitops.h
index 7d90334..19b478a 100644
--- a/include/sbi/sbi_bitops.h
+++ b/include/sbi/sbi_bitops.h
@@ -28,6 +28,9 @@ 
 #define BIT_WORD_OFFSET(bit)	((bit) & (BITS_PER_LONG - 1))
 #define BIT_ALIGN(bit, align)	(((bit) + ((align) - 1)) & ~((align) - 1))
 
+#define IS_BIT_ALIGN(bit, align)	\
+	(((bit) & ((align) - 1)) == 0)
+
 #define GENMASK(h, l) \
 	(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
 
diff --git a/include/sbi/sbi_shm.h b/include/sbi/sbi_shm.h
new file mode 100644
index 0000000..c50753b
--- /dev/null
+++ b/include/sbi/sbi_shm.h
@@ -0,0 +1,129 @@ 
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2024 Inochi Amaoto <inochiama@outlook.com>
+ */
+
+#ifndef __SBI_SHM_H__
+#define __SBI_SHM_H__
+
+#include <sbi/sbi_byteorder.h>
+
+#define SBI_SHMEM_M_READABLE		(1UL << 0)
+#define SBI_SHMEM_M_WRITABLE		(1UL << 1)
+#define SBI_SHMEM_M_EXECUTABLE		(1UL << 2)
+#define SBI_SHMEM_S_READABLE		(1UL << 3)
+#define SBI_SHMEM_S_WRITABLE		(1UL << 4)
+#define SBI_SHMEM_S_EXECUTABLE		(1UL << 5)
+
+#define SBI_SHMEM_M_RW			\
+	(SBI_SHMEM_M_READABLE |		\
+	 SBI_SHMEM_M_WRITABLE)
+#define SBI_SHMEM_M_RWX			\
+	(SBI_SHMEM_M_READABLE |		\
+	 SBI_SHMEM_M_WRITABLE |		\
+	 SBI_SHMEM_M_EXECUTABLE)
+
+#define SBI_SHMEM_S_RW			\
+	(SBI_SHMEM_S_READABLE |		\
+	 SBI_SHMEM_S_WRITABLE)
+#define SBI_SHMEM_S_RWX			\
+	(SBI_SHMEM_S_READABLE |		\
+	 SBI_SHMEM_S_WRITABLE |		\
+	 SBI_SHMEM_S_EXECUTABLE)
+
+#define SBI_SHMEM_S_ACCESS_SHIFT	3
+
+struct sbi_shmem {
+	unsigned long addr;
+	unsigned long size;
+};
+
+int sbi_shmem_region_init(unsigned long lo, unsigned long hi,
+			  unsigned long size, unsigned long align,
+			  struct sbi_shmem *shmem);
+void sbi_shmem_region_clear(struct sbi_shmem *shmem);
+
+int sbi_shmem_region_check(struct sbi_shmem *shmem, unsigned long flags);
+
+int sbi_shmem_raw_read(struct sbi_shmem *shmem, unsigned long offset,
+		       void* value, unsigned long size);
+int sbi_shmem_raw_write(struct sbi_shmem *shmem, unsigned long offset,
+			void* value, unsigned long size);
+
+static inline int sbi_shmem_read_u8(struct sbi_shmem *shmem,
+				    unsigned long offset,
+				    uint8_t* value)
+{
+	return sbi_shmem_raw_read(shmem, offset, value, 1);
+}
+
+static inline int sbi_shmem_read_u16(struct sbi_shmem *shmem,
+				     unsigned long offset,
+				     uint16_t* value)
+{
+	uint16_t tmp;
+	int ret = sbi_shmem_raw_write(shmem, offset, &tmp, 2);
+
+	*value = le16_to_cpu(tmp);
+
+	return ret;
+}
+
+static inline int sbi_shmem_read_u32(struct sbi_shmem *shmem,
+				     unsigned long offset,
+				     uint32_t* value)
+{
+	uint32_t tmp;
+	int ret = sbi_shmem_raw_write(shmem, offset, &tmp, 4);
+
+	*value = le32_to_cpu(tmp);
+
+	return ret;
+}
+
+static inline int sbi_shmem_read_u64(struct sbi_shmem *shmem,
+				     unsigned long offset,
+				     uint64_t* value)
+{
+	uint64_t tmp;
+	int ret = sbi_shmem_raw_write(shmem, offset, &tmp, 8);
+
+	*value = le64_to_cpu(tmp);
+
+	return ret;
+}
+
+static inline int sbi_shmem_write_u8(struct sbi_shmem *shmem,
+				     unsigned long offset,
+				     uint8_t value)
+{
+	return sbi_shmem_raw_write(shmem, offset, &value, 1);
+}
+
+static inline int sbi_shmem_write_u16(struct sbi_shmem *shmem,
+				      unsigned long offset,
+				      uint16_t value)
+{
+	uint16_t tmp = cpu_to_le16(value);
+	return sbi_shmem_raw_write(shmem, offset, &tmp, 2);
+}
+
+static inline int sbi_shmem_write_u32(struct sbi_shmem *shmem,
+				      unsigned long offset,
+				      uint32_t value)
+{
+	uint32_t tmp = cpu_to_le32(value);
+	return sbi_shmem_raw_write(shmem, offset, &tmp, 4);
+}
+
+static inline int sbi_shmem_write_u64(struct sbi_shmem *shmem,
+				      unsigned long offset,
+				      uint64_t value)
+{
+	uint64_t tmp = cpu_to_le64(value);
+	return sbi_shmem_raw_write(shmem, offset, &tmp, 8);
+}
+
+
+#endif // __SBI_SHM_H__
diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk
index c699187..5ffef06 100644
--- a/lib/sbi/objects.mk
+++ b/lib/sbi/objects.mk
@@ -71,6 +71,7 @@  libsbi-objs-y += sbi_misaligned_ldst.o
 libsbi-objs-y += sbi_platform.o
 libsbi-objs-y += sbi_pmu.o
 libsbi-objs-y += sbi_scratch.o
+libsbi-objs-y += sbi_shm.o
 libsbi-objs-y += sbi_string.o
 libsbi-objs-y += sbi_system.o
 libsbi-objs-y += sbi_timer.o
diff --git a/lib/sbi/sbi_shm.c b/lib/sbi/sbi_shm.c
new file mode 100644
index 0000000..213edaf
--- /dev/null
+++ b/lib/sbi/sbi_shm.c
@@ -0,0 +1,114 @@ 
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2024 Inochi Amaoto <inochiama@outlook.com>
+ */
+
+#include <sbi/riscv_barrier.h>
+#include <sbi/sbi_byteorder.h>
+#include <sbi/sbi_domain.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_shm.h>
+#include <sbi/sbi_string.h>
+
+void sbi_shmem_region_clear(struct sbi_shmem *shmem)
+{
+	shmem->addr = 0;
+	shmem->size = 0;
+}
+
+int sbi_shmem_region_init(unsigned long lo, unsigned long hi,
+			  unsigned long size, unsigned long align,
+			  struct sbi_shmem *shmem)
+{
+	if (IS_BIT_ALIGN(lo, align))
+		return SBI_EINVAL;
+
+	if (size == 0)
+		return SBI_EINVAL;
+
+	/* TODO: support address wider than XLEN bits */
+	if (hi)
+		return SBI_EINVALID_ADDR;
+
+	shmem->addr = lo;
+	shmem->size = size;
+
+	return 0;
+}
+
+static int __sbi_shmem_region_check(struct sbi_domain *domain,
+				    struct sbi_shmem *shmem,
+				    unsigned long mode, unsigned long flags)
+{
+	unsigned long access_flags = 0;
+	int ret;
+
+	if (flags & SBI_SHMEM_M_RWX) {
+		if (flags & SBI_SHMEM_M_READABLE)
+			access_flags |= SBI_DOMAIN_READ;
+		if (flags & SBI_SHMEM_M_WRITABLE)
+			access_flags |= SBI_DOMAIN_WRITE;
+		if (flags & SBI_SHMEM_M_EXECUTABLE)
+			access_flags |= SBI_DOMAIN_EXECUTE;
+		ret = sbi_domain_check_addr_range(domain,
+						  shmem->addr, shmem->size,
+						  mode, access_flags);
+		if (!ret)
+			return SBI_EINVALID_ADDR;
+	}
+
+	return 0;
+}
+
+
+int sbi_shmem_region_check(struct sbi_shmem *shmem, unsigned long flags)
+{
+	struct sbi_domain *domain = sbi_domain_thishart_ptr();
+	int ret;
+
+	if (shmem->size == 0)
+		return SBI_EINVAL;
+
+	ret = __sbi_shmem_region_check(domain, shmem, PRV_M, flags);
+	if (ret)
+		return ret;
+
+	ret = __sbi_shmem_region_check(domain, shmem, PRV_S,
+				       flags >> SBI_SHMEM_S_ACCESS_SHIFT);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+
+int sbi_shmem_raw_write(struct sbi_shmem *shmem, unsigned long offset,
+			void* value, unsigned long size)
+{
+	void *pos = (void *)(shmem->addr + offset);
+
+	if (shmem->size <= offset + size)
+		return SBI_EINVAL;
+
+	mb();
+	sbi_memcpy(pos, value, size);
+	wmb();
+
+	return 0;
+}
+
+int sbi_shmem_raw_read(struct sbi_shmem *shmem, unsigned long offset,
+		       void* value, unsigned long size)
+{
+	void *pos = (void *)(shmem->addr + offset);
+
+	if (shmem->size <= offset + size)
+		return SBI_EINVAL;
+
+	rmb();
+	sbi_memcpy(value, pos, size);
+	wmb();
+
+	return 0;
+}