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>
This commit is contained in:
Bin Meng 2021-05-11 20:04:12 +08:00 committed by Leo Yu-Chi Liang
parent 2b039940f3
commit a6d7e8c914
6 changed files with 14 additions and 6 deletions

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@ -158,7 +158,14 @@ config DMA_ADDR_T_64BIT
config SIFIVE_CLINT
bool
depends on RISCV_MMODE || SPL_RISCV_MMODE
depends on RISCV_MMODE
help
The SiFive CLINT block holds memory-mapped control and status registers
associated with software and timer interrupts.
config SPL_SIFIVE_CLINT
bool
depends on SPL_RISCV_MMODE
help
The SiFive CLINT block holds memory-mapped control and status registers
associated with software and timer interrupts.

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@ -11,7 +11,7 @@ config SIFIVE_FU540
imply CPU
imply CPU_RISCV
imply RISCV_TIMER if (RISCV_SMODE || SPL_RISCV_SMODE)
imply SIFIVE_CLINT if (RISCV_MMODE || SPL_RISCV_MMODE)
imply SPL_SIFIVE_CLINT
imply CMD_CPU
imply SPL_CPU
imply SPL_OPENSBI

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@ -8,7 +8,8 @@ config GENERIC_RISCV
imply CPU
imply CPU_RISCV
imply RISCV_TIMER if (RISCV_SMODE || SPL_RISCV_SMODE)
imply SIFIVE_CLINT if (RISCV_MMODE || SPL_RISCV_MMODE)
imply SIFIVE_CLINT if RISCV_MMODE
imply SPL_SIFIVE_CLINT if SPL_RISCV_MMODE
imply CMD_CPU
imply SPL_CPU
imply SPL_OPENSBI

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@ -18,7 +18,7 @@
struct arch_global_data {
long boot_hart; /* boot hart id */
phys_addr_t firmware_fdt_addr;
#ifdef CONFIG_SIFIVE_CLINT
#if CONFIG_IS_ENABLED(SIFIVE_CLINT)
void __iomem *clint; /* clint base address */
#endif
#ifdef CONFIG_ANDES_PLIC

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@ -11,7 +11,7 @@ obj-$(CONFIG_CMD_BOOTI) += bootm.o image.o
obj-$(CONFIG_CMD_GO) += boot.o
obj-y += cache.o
ifeq ($(CONFIG_$(SPL_)RISCV_MMODE),y)
obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint.o
obj-$(CONFIG_$(SPL_)SIFIVE_CLINT) += sifive_clint.o
obj-$(CONFIG_ANDES_PLIC) += andes_plic.o
else
obj-$(CONFIG_SBI) += sbi.o

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@ -19,7 +19,7 @@ obj-$(CONFIG_RENESAS_OSTM_TIMER) += ostm_timer.o
obj-$(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