riscv: Split SiFive CLINT support between SPL and U-Boot proper
At present there is only one Kconfig option CONFIG_SIFIVE_CLINT to
control the enabling of SiFive CLINT support in both SPL (M-mode)
and U-Boot proper (S-mode). So for a typical SPL config that the
SiFive CLINT driver is enabled in both SPL and U-Boot proper, that
means the S-mode U-Boot tries to access the memory-mapped CLINT
registers directly, instead of the normal 'rdtime' instruction.
This was not a problem before, as the hardware does not forbid the
access from S-mode. However this becomes an issue now with OpenSBI
commit 8b569803475e ("lib: utils/sys: Add CLINT memregion in the root domain")
that the SiFive CLINT register space is protected by PMP for M-mode
access only. U-Boot proper does not boot any more with the latest
OpenSBI, that access exceptions are fired forever from U-Boot when
trying to read the timer value via the SiFive CLINT driver in U-Boot.
To solve this, we need to split current SiFive CLINT support between
SPL and U-Boot proper, using 2 separate Kconfig options.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
index eb5c48c..2ebdeab 100644
--- a/drivers/timer/Makefile
+++ b/drivers/timer/Makefile
@@ -19,7 +19,7 @@
obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o
obj-$(CONFIG_ROCKCHIP_TIMER) += rockchip_timer.o
obj-$(CONFIG_SANDBOX_TIMER) += sandbox_timer.o
-obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint_timer.o
+obj-$(CONFIG_$(SPL_)SIFIVE_CLINT) += sifive_clint_timer.o
obj-$(CONFIG_STI_TIMER) += sti-timer.o
obj-$(CONFIG_STM32_TIMER) += stm32_timer.o
obj-$(CONFIG_X86_TSC_TIMER) += tsc_timer.o