[RFC PATCH v2 1/2] lib: sbi: Add shared memory region support
Inochi Amaoto
inochiama at outlook.com
Wed Jan 10 16:35:32 PST 2024
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 at 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 --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 at 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 at 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;
+}
--
2.43.0
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