Commit Graph

7 Commits

Author SHA1 Message Date
Sean Anderson
b8bc120927 riscv: Add option to support RISC-V privileged spec 1.9
Some older processors (notably the Kendryte K210) use an older version of
the RISC-V privileged specification. The primary changes between the old
and new are in virtual memory, and in the merging of three separate counter
enable CSRs.  Using the new CSR on an old processor causes an illegal
instruction exception.  This patch adds an option to use the old CSRs
instead of the new one.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-01 15:01:22 +08:00
Bin Meng
4d2583dba1 riscv: Access CSRs using CSR numbers
We should prefer accessing CSRs using their CSR numbers
because:
1. It compiles fine with older toolchains.
2. We can use latest CSR names in #define macro names of CSR
   numbers as-per RISC-V spec.
3. We can access newly added CSRs even if toolchain does not
   recognize newly added CSRs by name.

This commit is inspired from Linux kernel commit a3182c91ef4e
("RISC-V: Access CSRs using CSR numbers").

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-08-15 13:42:28 +08:00
Bin Meng
268753f8e6 riscv: Sync csr.h with Linux kernel v5.2
This syncs csr.h with Linux kernel 5.2, and imports asm.h that
is required by csr.h.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-08-15 13:42:28 +08:00
Lukas Auer
3dea63c844 riscv: add support for multi-hart systems
On RISC-V, all harts boot independently. To be able to run on a
multi-hart system, U-Boot must be extended with the functionality to
manage all harts in the system. All harts entering U-Boot are registered
in the available_harts mask stored in global data. A hart lottery system
as used in the Linux kernel selects the hart U-Boot runs on. All other
harts are halted. U-Boot can delegate functions to them using
smp_call_function().

Every hart has a valid pointer to the global data structure and a 8KiB
stack by default. The stack size is set with CONFIG_STACK_SIZE_SHIFT.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-04-08 09:44:26 +08:00
Bin Meng
57fe5c64cb riscv: Add indirect stringification to csr_xxx ops
With current csr_xxx ops, we cannot pass a macro to parameter
'csr', hence we need add another level to allow the parameter
to be a macro itself, aka indirect stringification.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18 09:56:27 +08:00
Baruch Siach
5c8fd32b22 Use _AC and UL macros from linux/const.h
Drop the _AC and UL macros from common.h. Linux headers is the original
source of this macro, so keep its definition in the same header.

Update existing users of these macros to include const.h directly.

Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Rick Chen <rick@andestech.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Signed-off-by: Stefan Roese <sr@denx.de>
2018-11-20 13:08:15 +01:00
Bin Meng
2fab2e9c88 riscv: Add a helper routine to print CPU information
This adds a helper routine to print CPU information. Currently
it prints all the instruction set extensions that the processor
core supports.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03 17:47:55 +08:00