Commit Graph

26 Commits

Author SHA1 Message Date
Anup Patel
cb78a48231 lib: sbi_trap: Remove scratch parameter from sbi_trap_redirect()
The scratch parameter of sbi_trap_redirect() is not used hence we
remove it.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-28 13:32:04 +05:30
Xiang Wang
a0c88ddb31 lib: Fix sbi_ecall_register_extension to prevent extension IDs overlap
The original code does not prevent the following scenarios:
> sbi_ecall_register_extension(ext1); /* extension id (70-80) */
> sbi_ecall_register_extension(ext2); /* extension id (50-100) */

Signed-off-by: Xiang Wang <merle@hardenedlinux.org>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-19 10:16:17 +05:30
Bin Meng
650c0e525c lib: sbi: Fix coding style issues
This fixes various coding style issues found in the SBI codes.
No functional changes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-10 10:27:28 +05:30
Atish Patra
e3f69fc1e9 lib: Implement Hart State Management (HSM) SBI extension
This patch adds support HSM extension. The specification is available
at https://github.com/riscv/riscv-sbi-doc.

It allows to implement hart hotplug and fixed ordered hart booting in
supervisor.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-24 18:13:23 +05:30
Atish Patra
1a8ca08cc0 lib: Initialize out value in SBI calls
As per the SBI specification, the return value in sbiret is undefined
if not explicitly described in the function. However, supervisor may
check this value by mistake and get a garbage value.

Initialize it to zero to avoid nasty supervisor bugs.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-13 09:57:22 +05:30
Anup Patel
021b9e7c76 lib: Factor-out SBI base extension
This patch factor-out SBI base 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>
2020-01-22 12:13:47 +05:30
Anup Patel
43ac621ecb lib: Factor-out SBI vendor extension
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>
2020-01-22 12:13:44 +05:30
Anup Patel
161b348e7e lib: Factor-out SBI replacement extensions
This patch factor-out SBI replacement extensions (such as RFENCE,
IPI, and TIME) 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>
2020-01-22 12:13:42 +05:30
Anup Patel
766850222a lib: Factor-out SBI legacy extension
This patch factor-out SBI legacy 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>
2020-01-22 12:13:40 +05:30
Anup Patel
37923c4a66 lib: Add dynamic registration of SBI extensions
This patch extends our SBI ecall implementation to allow
dynamic registration of various SBI extensions. Using this
dynamic registration we can break-up SBI ecall implementation
into multiple files and even register experimental/custom
SBI extensions from platform code.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-01-22 12:13:34 +05:30
Anup Patel
817d50d0d4 lib: Drop _fifo from the name of various sbi_tlb_fifo_xyz() functions
This patch drops _fifo from the name of various sbi_tlb_fifo_xyz()
functions because all these functions deal with remote TLB managment
and FIFO is the per-HART data structure used internally by remote
TLB implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-01-22 12:10:47 +05:30
Anup Patel
a8b4b83b7f lib: Introduce sbi_tlb_fifo_request() API
Instead of directly calling sbi_ipi_send_many(), we introduce
sbi_tlb_fifo_request() for halting a set of HARTs.

This way in future we can assign any IPI event number for remote
FENCE within sbi_tlb.c only.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-01-22 12:10:40 +05:30
Anup Patel
3d2aaac69a lib: Introduce sbi_ipi_send_smode() API
Instead of directly calling sbi_ipi_send_many(), we introduce
sbi_ipi_send_smode() for injecting S-mode software interrupts.

This way in future we can assign any IPI event number for S-mode
IPIs within sbi_ipi.c only.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-01-22 12:10:35 +05:30
Atish Patra
86a31f5437 lib: Implement RFENCE extension
This patch adds RFENCE extension support in OpenSBI.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:23 +05:30
Atish Patra
9777aeef41 lib: Add IPI extension in SBI
This patch adds new IPI extension which replaces ipi related
v0.1 extensions. This also adds a new API for ipi sending as trap
handling is not necessary in v0.2 SBI IPI related extensions.

It also modifies the IPI sending code which now accepts hart mask as a value
instead of S-mode virtual address. Thus, the caller should set it to exact hart
mask value everytime.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:13 +05:30
Atish Patra
109266397a lib: Add TIME extension in SBI
This patch adds support for TIME extension which replaces v0.1
timer extension.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:11 +05:30
Atish Patra
aa0ed1d733 lib: Remove redundant IPI types
We just need to distinguish only between FENCE and non FENCE related
IPIs as all of the fence related requests are handled via fifo now.

Remove the unnecessary IPI types related to individual fence types.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:08 +05:30
Atish Patra
ab14f94a8c lib: Fix probe extension
The break statement is missing in base extension function handling.

Fix the typo.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Xiang Wang <merle@hardenedlinux.org>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-11-26 16:17:52 +05:30
Anup Patel
75f903dd78 lib: Simplify trap parameters in sbi_ecall functions
The out_tcause and out_tval parameters are not sufficient for most
sbi_ecall functions because this will grow in-future when we support
RISC-V hypervisor v0.5 draft. We replace these parameters with out_trap
which is a pointer to struct sbi_trap_info.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-11-21 13:58:14 +05:30
Anup Patel
0e1322bacb lib: Better naming of unpriv APIs for wider use
The unpriv APIs can be useful to external firmware and out-of-tree
platform support code.

This patch adds "sbi_" prefix to unpriv load/store APIs and rename
struct riscv_unpriv to struct sbi_trap_info everywhere. We also
place struct sbi_trap_info in sbi/sbi_trap.h so that we can use
it for sbi_trap_redirect() as well.

Overall, this patch will make naming of unpriv APIs consistent
with other OpenSBI APIs.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-11-21 13:57:33 +05:30
Atish Patra
30f09fbfd1 lib: Provide a platform hook to implement vendor specific SBI extensions.
SBI v0.2 specification allows vendor extensions and it should be
implemented in a independent of the core sbi library.

Introduce a single platform callback that will let platforms handle
all vendor extensions in platform specific code if they want.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:58:51 +05:30
Atish Patra
0790be0f2c lib: Implement SBI v0.2
SBI v0.2 introduces a base specification which is mandatory to
implement for any SBI implementations that is not legacy.

Add support for the base extension.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:56:55 +05:30
Atish Patra
848ed4f644 lib: Remove redundant variable assignment
An ecall handler should only return error if valid SBI function
fails. Otherwise, it should succeed with appropriate error in a0.

Get rid of unnecessary setting of the temporary return variable to
zero for the cases where errors are not expected.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:55:25 +05:30
Atish Patra
26aec6afed lib: Rename existing SBI implementation as 0.1.
Current SBI implementation is now considered as version 0.1 and will be
removed/replaced with newer extension/functions in future.

Rename the existing implementations accordingly to be in sync with the
specification.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
2019-10-03 08:53:52 +05:30
Atish Patra
897a97a6af lib: Fix race conditions in tlb fifo access.
Linux kernel expects tlb flush SBI call to be completely synchronous i.e.
the SBI call should only return once corresponding *fence* instruction is
executed.

OpenSBI manages the outstanding TLB flush requests by keeping them in a
per hart based fifo. However, there are few corner cases that may lead to
race conditions while updating the fifo.

Currently, the caller hart waits for IPI acknowledgement via clint
address which is not a very good method as synchronization on MMIO may not
be supported in every platform. Moreover, the waiter doesn't have any way of
identifying if the IPI is received for specific tlb flush request or any
other IPI. This may lead to unpredictable behavior in supervisor/user space.

Fix this by waiting on individual fifo entries rather than MMIO address.
Currently, a relaxed loop is being used because wfi again involves MMIO write
which would be slower compared to relaxed loop. To avoid deadlock, fifo
is processed every time a hart loops for fifo enqueue or fifo sync to consume
the tlb flush requests sent by other harts.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-08-16 08:42:55 +05:30
Atish Patra
749b0b0932 lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:51 +05:30