Some IPIs may already be pending when U-Boot is started. This could be a
problem if a secondary hart tries to handle an IPI before the boot hart has
initialized the IPI device.
To be specific, the Kendryte K210 ROM-based bootloader does not clear IPIs
before passing control to U-Boot. Without this patch, the secondary hart
jumps to address 0x0 as soon as it enters secondary_hart_loop, and then
hangs in its trap handler.
This commit introduces a valid bit so secondary harts know when and IPI
originates from U-Boot, and it is safe to use the IPI API. The valid bit is
initialized to 0 by board_init_f_init_reserve. Before this, secondary harts
wait in wait_for_gd_init.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Leo Liang <ycliang@andestech.com>
Without a matching barrier on the write side, the barrier in handle_ipi
does nothing. It was entirely possible for the boot hart to write to addr,
arg0, and arg1 *after* sending the IPI, because there was no barrier on the
sending side.
Fixes: 90ae281437 ("riscv: add option to wait for ack from secondary harts in smp functions")
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Leo Liang <ycliang@andestech.com>
The previous IPI code initialized the device whenever the first call was
made to a riscv_*_ipi function. This made it difficult to determine when
the IPI device was initialized. This patch introduces a new function
riscv_init_ipi. It is called once during arch_cpu_init_dm. In SPL, it is
called in spl_invoke_opensbi. Before this point, no riscv_*_ipi functions
should be called.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
Add a wait option to smp_call_function() to wait for the secondary harts
to acknowledge the call-function request. The request is considered to
be acknowledged once each secondary hart has cleared the corresponding
IPI.
As part of the call-function request, the secondary harts invalidate the
instruction cache after clearing the IPI. This adds a delay between
acknowledgment (clear IPI) and fulfillment (call function) of the
request. We want to use the acknowledgment to be able to judge when the
request has been completed. Remove the delay by clearing the IPI after
cache invalidation and just before calling the function from the
request.
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Rick Chen <rick@andestech.com>
Tested-by: Rick Chen <rick@andestech.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Add the function riscv_get_ipi() for reading the pending status of IPIs.
The supported controllers are Andes' Platform Level Interrupt Controller
(PLIC), the Supervisor Binary Interface (SBI), and SiFive's Core Local
Interruptor (CLINT).
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Rick Chen <rick@andestech.com>
These functions are CPU-related and do not use driver model. Move them to
cpu_func.h
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
When U-Boot boots from flash, during the boot process,
hart_lottery and available_harts_lock variable addresses
point to flash which is not writable. This causes boot
failures on AE350. Introduce a config option CONFIG_XIP
to support such configuration.
Signed-off-by: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Harts on RISC-V boot independently, U-Boot is responsible for managing
them. Functions are called on other harts with smp_call_function(),
which sends inter-processor interrupts (IPIs) to all other available
harts. Available harts are those marked as available in the device tree
and present in the available_harts mask stored in global data. The
available_harts mask is used to register all harts that have entered
U-Boot. Functions are specified with their address and two function
arguments (argument 2 and 3). The first function argument is always the
hart ID of the hart calling the function. On the other harts, the IPI
interrupt handler handle_ipi() must be called on software interrupts to
handle the request and call the specified function.
Functions are stored in the ipi_data data structure. Every hart has its
own data structure in global data. While this is not required at the
moment (all harts are expected to boot Linux), this does allow future
expansion, where other harts may be used for monitoring or other tasks.
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>
