On Thu, Jul 09, 2026 at 11:26:02PM +0530, Rahul Pathak wrote: > SBI MPXY interface implements the SBI MPXY > extension to interact with supported message > protocols for platform management and control > > Signed-off-by: Rahul Pathak <[email protected]> > --- > arch/riscv/Kconfig | 9 + > arch/riscv/include/asm/sbi.h | 268 ++++++++++++++++++ > arch/riscv/lib/Makefile | 1 + > arch/riscv/lib/sbi_mpxy.c | 529 +++++++++++++++++++++++++++++++++++ > 4 files changed, 807 insertions(+) > create mode 100644 arch/riscv/lib/sbi_mpxy.c >
... > diff --git a/arch/riscv/lib/sbi_mpxy.c b/arch/riscv/lib/sbi_mpxy.c > new file mode 100644 > index 00000000000..f95cedaabac > --- /dev/null > +++ b/arch/riscv/lib/sbi_mpxy.c > @@ -0,0 +1,529 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * SBI MPXY (Message Proxy) Generic Library > + * > + * Copyright (c) 2026, Rahul Pathak <[email protected]> > + */ ... > + > +/** > + * sbi_mpxy_read_attrs() - Read a contiguous range of channel attributes > + * > + * @chan: Target channel > + * @base_attr_id: First attribute ID in the range > + * @attr_count: Number of attributes to read > + * @attrs_buf: Output buffer (attr_count u32 words) > + */ > +int sbi_mpxy_read_attrs(struct mpxy_channel *chan, u32 base_attr_id, > + u32 attr_count, u32 *attrs_buf) > +{ > + struct sbiret ret; > + __le32 *shmem; > + u32 end_id; > + int i; > + > + if (!chan || !attr_count || !attrs_buf) > + return -EINVAL; > + > + if (attr_count > mpxy_ctx.shmem_size / sizeof(u32)) > + return -EINVAL; > + > + shmem = (__le32 *)shmem_base(); > + if (!shmem) > + return -ENXIO; > + > + end_id = base_attr_id + attr_count - 1; > + > + if (base_attr_id < SBI_MPXY_ATTR_STD_ATTR_MAX_IDX) { > + /* Standard attributes */ > + if (end_id >= SBI_MPXY_ATTR_STD_ATTR_MAX_IDX) > + return -EINVAL; > + > + ret = sbi_ecall(SBI_EXT_MPXY, SBI_EXT_MPXY_READ_ATTRS, > + chan->channel_id, base_attr_id, attr_count, > + 0, 0, 0); > + if (ret.error) > + return -EINVAL; > + > + for (i = 0; i < attr_count; i++) > + attrs_buf[i] = le32_to_cpu(shmem[i]); > + > + return 0; > + } > + > + if (base_attr_id >= SBI_MPXY_ATTR_MSGPROTO_ATTR_START && > + end_id < SBI_MPXY_ATTR_MSGPROTO_ATTR_END) { > + /* Protocol-specific attributes */ > + if (!chan->proto || !chan->proto->readattr) > + return -ENOSYS; > + > + ret = sbi_ecall(SBI_EXT_MPXY, SBI_EXT_MPXY_READ_ATTRS, > + chan->channel_id, base_attr_id, attr_count, > + 0, 0, 0); > + if (ret.error) > + return -EINVAL; > + > + for (i = 0; i < attr_count; i++) > + attrs_buf[i] = le32_to_cpu(shmem[i]); Shouldn't you call the ->readattr() callback here instead of manually doing the read? Also, I'm not quite sure I understand what purpose those callbacks serve. >From what I'm seeing, attributes are always read/write using SBI_EXT_MPXY_[READ|WRITE]_ATTRS because the transport layer is always mpxy. Would a non-RPMI protocol do something different? Thanks, Charles
