diff options
| -rw-r--r-- | arch/riscv/Kconfig | 4 | ||||
| -rw-r--r-- | arch/riscv/cpu/cpu.c | 9 | ||||
| -rw-r--r-- | arch/riscv/cpu/start.S | 134 | ||||
| -rw-r--r-- | arch/riscv/include/asm/csr.h | 1 | ||||
| -rw-r--r-- | arch/riscv/lib/asm-offsets.c | 1 |
5 files changed, 147 insertions, 2 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 9da609b33b1..3a4470daf3f 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -144,4 +144,8 @@ config SBI_IPI default y if RISCV_SMODE depends on SMP +config STACK_SIZE_SHIFT + int + default 13 + endmenu diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c index e662140427a..c32de8a4c3e 100644 --- a/arch/riscv/cpu/cpu.c +++ b/arch/riscv/cpu/cpu.c @@ -12,10 +12,17 @@ #include <dm/uclass-internal.h> /* - * prior_stage_fdt_address must be stored in the data section since it is used + * The variables here must be stored in the data section since they are used * before the bss section is available. */ phys_addr_t prior_stage_fdt_address __attribute__((section(".data"))); +u32 hart_lottery __attribute__((section(".data"))) = 0; + +/* + * The main hart running U-Boot has acquired available_harts_lock until it has + * finished initialization of global data. + */ +u32 available_harts_lock = 1; static inline bool supports_extension(char ext) { diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S index bcc0ff696dc..f55b8cbc371 100644 --- a/arch/riscv/cpu/start.S +++ b/arch/riscv/cpu/start.S @@ -13,6 +13,7 @@ #include <config.h> #include <common.h> #include <elf.h> +#include <asm/csr.h> #include <asm/encoding.h> #include <generated/asm-offsets.h> @@ -45,6 +46,23 @@ _start: /* mask all interrupts */ csrw MODE_PREFIX(ie), zero +#ifdef CONFIG_SMP + /* check if hart is within range */ + /* tp: hart id */ + li t0, CONFIG_NR_CPUS + bge tp, t0, hart_out_of_bounds_loop +#endif + +#ifdef CONFIG_SMP + /* set xSIE bit to receive IPIs */ +#ifdef CONFIG_RISCV_MMODE + li t0, MIE_MSIE +#else + li t0, SIE_SSIE +#endif + csrs MODE_PREFIX(ie), t0 +#endif + /* * Set stackpointer in internal/ex RAM to call board_init_f */ @@ -56,7 +74,30 @@ call_board_init_f: call_board_init_f_0: mv a0, sp jal board_init_f_alloc_reserve + + /* + * Set global data pointer here for all harts, uninitialized at this + * point. + */ + mv gp, a0 + + /* setup stack */ +#ifdef CONFIG_SMP + /* tp: hart id */ + slli t0, tp, CONFIG_STACK_SIZE_SHIFT + sub sp, a0, t0 +#else mv sp, a0 +#endif + + /* + * Pick hart to initialize global data and run U-Boot. The other harts + * wait for initialization to complete. + */ + la t0, hart_lottery + li s2, 1 + amoswap.w s2, t1, 0(t0) + bnez s2, wait_for_gd_init la t0, prior_stage_fdt_address SREG s1, 0(t0) @@ -66,6 +107,33 @@ call_board_init_f_0: /* save the boot hart id to global_data */ SREG tp, GD_BOOT_HART(gp) + la t0, available_harts_lock + fence rw, w + amoswap.w zero, zero, 0(t0) + +wait_for_gd_init: + la t0, available_harts_lock + li t1, 1 +1: amoswap.w t1, t1, 0(t0) + fence r, rw + bnez t1, 1b + + /* register available harts in the available_harts mask */ + li t1, 1 + sll t1, t1, tp + LREG t2, GD_AVAILABLE_HARTS(gp) + or t2, t2, t1 + SREG t2, GD_AVAILABLE_HARTS(gp) + + fence rw, w + amoswap.w zero, zero, 0(t0) + + /* + * Continue on hart lottery winner, others branch to + * secondary_hart_loop. + */ + bnez s2, secondary_hart_loop + /* Enable cache */ jal icache_enable jal dcache_enable @@ -95,7 +163,14 @@ relocate_code: *Set up the stack */ stack_setup: +#ifdef CONFIG_SMP + /* tp: hart id */ + slli t0, tp, CONFIG_STACK_SIZE_SHIFT + sub sp, s2, t0 +#else mv sp, s2 +#endif + la t0, _start sub t6, s4, t0 /* t6 <- relocation offset */ beq t0, s4, clear_bss /* skip relocation */ @@ -175,13 +250,30 @@ clear_bss: add t0, t0, t6 /* t0 <- rel __bss_start in RAM */ la t1, __bss_end /* t1 <- rel __bss_end in FLASH */ add t1, t1, t6 /* t1 <- rel __bss_end in RAM */ - beq t0, t1, call_board_init_r + beq t0, t1, relocate_secondary_harts clbss_l: SREG zero, 0(t0) /* clear loop... */ addi t0, t0, REGBYTES bne t0, t1, clbss_l +relocate_secondary_harts: +#ifdef CONFIG_SMP + /* send relocation IPI */ + la t0, secondary_hart_relocate + add a0, t0, t6 + + /* store relocation offset */ + mv s5, t6 + + mv a1, s2 + mv a2, s3 + jal smp_call_function + + /* restore relocation offset */ + mv t6, s5 +#endif + /* * We are done. Do not return, instead branch to second part of board * initialization, now running from RAM. @@ -202,3 +294,43 @@ call_board_init_r: * jump to it ... */ jr t4 /* jump to board_init_r() */ + +#ifdef CONFIG_SMP +hart_out_of_bounds_loop: + /* Harts in this loop are out of bounds, increase CONFIG_NR_CPUS. */ + wfi + j hart_out_of_bounds_loop +#endif + +#ifdef CONFIG_SMP +/* SMP relocation entry */ +secondary_hart_relocate: + /* a1: new sp */ + /* a2: new gd */ + /* tp: hart id */ + + /* setup stack */ + slli t0, tp, CONFIG_STACK_SIZE_SHIFT + sub sp, a1, t0 + + /* update global data pointer */ + mv gp, a2 +#endif + +secondary_hart_loop: + wfi + +#ifdef CONFIG_SMP + csrr t0, MODE_PREFIX(ip) +#ifdef CONFIG_RISCV_MMODE + andi t0, t0, MIE_MSIE +#else + andi t0, t0, SIE_SSIE +#endif + beqz t0, secondary_hart_loop + + mv a0, tp + jal handle_ipi +#endif + + j secondary_hart_loop diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index 86136f542c7..644e6baa157 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -46,6 +46,7 @@ #endif /* Interrupt Enable and Interrupt Pending flags */ +#define MIE_MSIE _AC(0x00000008, UL) /* Software Interrupt Enable */ #define SIE_SSIE _AC(0x00000002, UL) /* Software Interrupt Enable */ #define SIE_STIE _AC(0x00000020, UL) /* Timer Interrupt Enable */ diff --git a/arch/riscv/lib/asm-offsets.c b/arch/riscv/lib/asm-offsets.c index e0b71f56919..f998402bd1b 100644 --- a/arch/riscv/lib/asm-offsets.c +++ b/arch/riscv/lib/asm-offsets.c @@ -14,6 +14,7 @@ int main(void) { DEFINE(GD_BOOT_HART, offsetof(gd_t, arch.boot_hart)); + DEFINE(GD_AVAILABLE_HARTS, offsetof(gd_t, arch.available_harts)); return 0; } |