Some of the upcoming SBI extensions (such as SSE) will directly
update register state so improve the prototype of ecall handler
to accommodate this. Further, this flexibility allows us to
push the trap redirection from sbi_ecall_handler() to the
sbi_ecall_legacy_handler().
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
When an extension implements a probe function it means there's a
chance that the extension is not available. Use this function in the
register_extensions callback to determine if the extension should be
registered at all. Where the probe implementation is simple, just
open code the check.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The vendor extension ID range is large, but at runtime at most
a single ID will be available. Narrow the range in the
register_extensions callback. After narrowing, we no longer
need to check that the extension ID is correct in the other
callbacks, as those callbacks will never be invoked with
anything other than the single ID.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Rather than registering all extensions on their behalf in
sbi_ecall_init(), introduce another extension callback and
invoke that instead. For now, implement each callback by
simply registering the extension, which means this patch
has no intended functional change. In later patches, extension
callbacks will be modified to choose when to register and to
possibly narrow the extension ID range prior to registering.
When an extension range needs to remove IDs, leaving gaps, then
multiple invocations of sbi_ecall_register_extension() may be
used. In summary, later patches for current extensions and the
introductions of future extensions will use the new callback to
ensure that only valid extension IDs from the initial range,
which are also available, will be registered.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
As-per the SBI specification, the lower 24bits of the SBI vendor
extension id is same as lower 24bits of the mvendorid CSR.
We update the SBI vendor extension id checking based on above.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
We had added args pointer in ecall handler to ensure that ecall
handler only implements functionality and does not deal with
SBI calling convention. This also helped us to keep SBI calling
convention related code in one place at sbi_ecall_handler().
The Keystone Enclavce project needs access to the trap regsiters
in their ecall handler so that they can context switch enclaves
in custom SBI calls. To help the Keystone Enclave project, we
replace the args pointer in ecall handler parameter with a const
pointer to trap registers.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We remove mcause, scratch and hartid parameters from various
functions for ecall handling because we can always get current
HART id and current scratch pointer using just one CSR access.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch factor-out SBI vendor extension into its own source
for better modularity of SBI implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
