We introduce sbi_trap_exit() API which can help non-firmware
(i.e. generic or platform) code to force exit trap/interrupt
handling and resume execution at context pointed by parameter
"const struct sbi_trap_regs *regs".
This new sbi_trap_exit() API will help Keystone Enclave project
to resume execution of enclave from custom SBI call handler.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
On RV32 systems, we have two CSRs for M-mode status (MSTATUS and
MSTATUSH) when H-extension is implemented. This means we have to
save/restore MSTATUSH for RV32 systems only when H-extension is
implemented. The current _trap_handler() has extra instructions
(roughly 10) for conditional save/restore of MSTATUSH CSR.
These extra instructions in RV32 _trap_handler() can be avoided
if we create separate low-level trap handler for RV32 systems
having H-extension. This patch optimizes low-level trap handler
for RV32 systems accordingly.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The FW_PAYLOAD_FDT_PATH compile-time option is replaced by
FW_FDT_PATH compile-time option which is more flexible and
common across all OpenSBI firmwares.
This patch removes FW_PAYLOAD_FDT_PATH and updates related
documentation to use FW_FDT_PATH.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, only FW_PAYLOAD has mechanism to embed external
FDT using FW_PAYLOAD_FDT_PATH compile-time option.
This patch adds a common FW_FDT_PATH compile-time option to
embed external FDT for all OpenSBI firmwares (i.e FW_JUMP,
FW_PAYLOAD, and FW_DYNAMIC).
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, the low-level trap handler (i.e. _trap_handler()) uses
branch instructions to conditionally setup exception stack based
on which mode trap occured.
This patch implements exception stack setup using xor instructions
which is faster with same number of instructions due to lack of
branch instructions.
The new exception stack setup approach can be best described by the
following pseudocode:
Came_From_M_Mode = ((MSTATUS.MPP < PRV_M) ? 1 : 0) - 1;
Exception_Stack = TP ^ (Came_From_M_Mode & (SP ^ TP))
Came_From_M_Mode = 0 ==> Exception_Stack = TP
Came_From_M_Mode = -1 ==> Exception_Stack = SP
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, the fw_platform_init() does not return anything but we can
further improve by allowing fw_platform_init() to return updated FDT
location.
It is certainly not mandatory for fw_platform_init() to return a new
location of FDT (or modify FDT). In fact, the fw_platform_init() can
always return the original FDT location (i.e. 'arg1') unmodified.
This new capability of fw_platform_init() will allow platforms to:
1. Have multiple built-in FDTs and select one
2. Modify FDT before using based on platform specific straps or OTP
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, we are ORing FW_OPTIONS with the options passed by
previous booting stage to fw_dynamic. This causes confusion
because compiling fw_dynamic with FW_OPTIONS=0x2 does not force
enable boot prints as the U-Boot SPL passes options=0x1 in
fw_dyanmic_info.
The best thing to do is always prefer FW_OPTIONS when available.
This is intuitive for OpenSBI users and easy in debugging.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, fw_prev_arg1() is called after fw_platform_init() which
caused builtin DTB to be not available to fw_platform_init().
To allow builtin DTB available to fw_platform_init(), we should
call fw_save_info() and fw_prev_arg1() before fw_platform_init().
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We add optional fw_platform_init() function which will allow
platform specific code to update "struct sbi_platform platform"
before it is used.
The fw_platform_init() can be a regular C function so before
callint it we:
1. zero-out BSS section
2. Setup temporary trap handler to catch bugs
3. Setup temporary stack pointer
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch simplify sbi_trap_handler() API as follows:
1. Remove current hartid local variable because sbi_trap_handler()
itself does not need it.
2. Remove scratch parameter because none of the functions directly
called by sbi_trap_handler() require it.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
A platform can have discontinuous and/or sparse HART ids so we
cannot always assume a set of HARTs with continuous HART ids.
This patch adds support for discontinuous and sparse HART ids by
introducing HART index to HART id table. This table has platform
hart_count entries and it maps HART index to HART id.
The HART index to HART id table has only two restrictions:
1. HART index < sbi_platform hart_count
2. HART id < SBI_HARTMASK_MAX_BITS
Example1:
Let's say we have a platform with 2 HART ids 11 and 22, for such a
a platform:
hart_count = 2
hart_index2id[0] = 11
hart_index2id[1] = 22
Example2:
Let's say we have a platform with 5 HARTs ids 0, 1, 2, 3, and 4
but out of these HART with id 0 is not usable so for such a platform:
hart_count = 5
hart_index2id[0] = -1U
hart_index2id[1] = 1
hart_index2id[2] = 2
hart_index2id[3] = 3
hart_index2id[4] = 4
OR
hart_count = 4
hart_index2id[0] = 1
hart_index2id[1] = 2
hart_index2id[2] = 3
hart_index2id[3] = 4
With HART index to HART id table in place, the hart_disabled()
callback is now redundant so we remove it as well.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch optimizes _hartid_to_scratch() in following ways:
1. Use caller saved registers instead of callee saved registers
so that we don't need to save/restore registers on stack
2. Remove second redundant mul instruction by re-arranging
instructions
Overall, we reduce 9 instructions in _hartid_to_scratch()
implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Move the .align directives after switching the section. We want to align
the start of the current section, not the end of the previous section.
This also obsoletes the misguided workaround of disabling relaxation.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
It has been reported that link address range of previous booting stage
(such as U-Boot SPL) can overlap the link address rage of FW_DYNAMIC.
This means self-relocation in FW_DYNAMIC can potentially corrupt
previous booting stage if any of the secondary HART enter FW_DYNAMIC
before primary HART.
To tackle this, we add preferred boot HART field (i.e boot_hart) in
struct fw_dyanmic_info. We use this field to force secondary HARTs
into relocation wait loop till preferred/primary boot HART enters
FW_DYNAMIC completes self-relocation. If preferred boot HART is not
available then we fall back to relocation lottery approach.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Instead of forcing HART0 to do the relocation and scratch init
work, we should have an atomic lottery to decide which HART does
the relocation and scratch init.
This way any HART can be boot/main HART.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
When hypervisor extension is available, we can get traps from VS/VU
modes. We should be able to force redirect some of these traps to
HS-mode. In other words, we should be able forward traps from VS/VU
mode to HS-mode using sbi_trap_redirect() hence this patch.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When OpenSBI is started from an address not equal to the link address,
it is first relocated to the link address. Hart 0 performs the
relocation and notifies the other harts of its completion with the
_boot_status variable. It uses the copy of the variable relative to the
link address. This copy contains valid data only after relocation has
finished. The waiting harts will therefore read invalid data until
relocation has finished. This can cause them to continue execution too
early.
Fix this by using the _boot_status variable relative to the load address
while OpenSBI has not finished relocation.
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
The boot status is currently hard-coded. Define some macros for it.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
If core-0 have finished _fdt_reloc_done but any of other cores has not
yet left the loop in _wait_relocate_copy_done, they could never leave
the loop because _boot_status is not equal to 1.
When relocation is not required (i.e. _load_start == _link_start), we
can skip two stage wait for secondary HARTs. This means secondary HARTs
can skip the _wait_relocate_copy_done() loop and directly jump to the
_wait_for_boot_hart() loop when no relocation not required.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The old code may corrupt the code of the waiting hart hence this patch
keeps waiting HART within relocation code range at time of relocation.
Signed-off-by: Xiang W <wxjstz@126.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
This patch extends relocation to handle overlapping load and link
addresses.
The updated relocation will work fine in most cases except when the
relocate copy loop itself falls in overlapping load and link addresses.
Signed-off-by: Xiang W <wxjstz@126.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
This patch extends fw_base to relocate to link address whenever
firmware load address is not equal to link address.
The relocation will not work when load start to load end overlap
link start to link end.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
This patch extends existing firmwares (i.e. fw_jump and fw_payload)
to explicitly provide next mode and options to fw_base.
We also introduce fw_save_info() which is called by fw_base very
early on boot HART. This function can be used by existing firmwares
(i.e. fw_jump and fw_payload) to save information passed by previous
booting stage.
Overall, this is a preparatory patch for implementing fw_dynamic.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
When I tried to start opensbi with coreboot, I found that aligning to a 16-byte
boundary would make a copy error.
Corrected to align to an machine word length boundary.
Signed-off-by: Xiang Wang <wxjstz@126.com>
Introduce "options" in "struct sbi_scratch" and firmware can update
it based on optional compile time flags before calling sbi_init().
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Scratch space setup needs to be done once for reboot for each
hart. _start_warm may be called several times if hart hotplug
is implemented.
Move scratch space setup to the beginning so that it is done
only once.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Create a sbi_ipi_data structure that holds unpacked IPI information. At
the same time remove ipi_type from the sbi_scratch struct and use a
fixed offset to access it.
This structure fits in behind the sbi_scratch structure.
This fixes https://github.com/riscv/opensbi/issues/81
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
A warm reset using reset button may put icache and registers
in non-coherent state.
Flush the icache and reset all registers for every hart.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
All the non-boot harts run in a tight loop which may cause a heavy load
on the memory bus. This may delay the boot hart to complete the cold boot
process.
Introduce few nop that will ease up the traffic.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
A warm reset by pressing the reset button may not initialize all the
registers to zero. Do it for every hart during warm boot.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Multi-core communication via memory requires the addition of a barrier
instructions to ensure cache coherency.
Signed-off-by: Xiang Wang <wxjstz@126.com>
This patch extends our low-level trap handler in fw_base.S for
handling M-mode to M-mode traps without overwritting stack.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Some older toolchains may not have all the csr's defined. Update all
the csr functions to use the CSR_ #define values instead of the
toolchain defined values.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
This patch updates copyright header in all files as follows:
1. Makes "SPDX-License-Identifier: BSD-2-Clause" as first line
2. Change copyright year to 2019 for Western Digital
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The secondary hart waits for an IPI signal from the boot hart to
executing boot code (hot boot). As a result, software generated
interrupts have to be enabled for secondary harts before waiting for
the boot hart boot completion IPI signal.
Enabling software generated interrupts (IPI) can be done independently
of the firmware code and moved to libsbi code so that the different
firmware do not have to implement this.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
The tmp0 member was added in struct sbi_scratch to assist
register save/restore at time of trap handling. This tmp0
is not unsed any more hence removing it.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The struct sbi_trap_regs related defines RISCV_TRAP_REGS_xyz should
be in sbi_trap.h so that we can keep these defines in-sync with changes
in struct sbi_trap_regs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The struct sbi_platform related defines RISCV_PLATFORM_xyz should
be in sbi_platform.h so that we can keep these defines in-sync
with changes in struct sbi_platform.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The struct sbi_scratch related defines RISCV_SCRATCH_xyz should
be in sbi_scratch.h so that we can keep these defines in-sync
with changes in struct sbi_scratch.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The fw_common.S is the base firmware extendend by fw_jump and
fw_payload. This patch renames fw_common.S to fw_base.S to
have more clear/intutive name for base firmware.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
