diff options
Diffstat (limited to 'arch/riscv/kernel/head.S')
| -rw-r--r-- | arch/riscv/kernel/head.S | 133 |
1 files changed, 121 insertions, 12 deletions
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 0f1ba17e476f..271860fc2c3f 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -11,6 +11,7 @@ #include <asm/thread_info.h> #include <asm/page.h> #include <asm/csr.h> +#include <asm/hwcap.h> #include <asm/image.h> __INIT @@ -39,16 +40,30 @@ ENTRY(_start) .word RISCV_HEADER_VERSION .word 0 .dword 0 - .asciz RISCV_IMAGE_MAGIC - .word 0 + .ascii RISCV_IMAGE_MAGIC .balign 4 + .ascii RISCV_IMAGE_MAGIC2 .word 0 .global _start_kernel _start_kernel: /* Mask all interrupts */ - csrw CSR_SIE, zero - csrw CSR_SIP, zero + csrw CSR_IE, zero + csrw CSR_IP, zero + +#ifdef CONFIG_RISCV_M_MODE + /* flush the instruction cache */ + fence.i + + /* Reset all registers except ra, a0, a1 */ + call reset_regs + + /* + * The hartid in a0 is expected later on, and we have no firmware + * to hand it to us. + */ + csrr a0, CSR_MHARTID +#endif /* CONFIG_RISCV_M_MODE */ /* Load the global pointer */ .option push @@ -61,7 +76,14 @@ _start_kernel: * floating point in kernel space */ li t0, SR_FS - csrc sstatus, t0 + csrc CSR_STATUS, t0 + +#ifdef CONFIG_SMP + li t0, CONFIG_NR_CPUS + blt a0, t0, .Lgood_cores + tail .Lsecondary_park +.Lgood_cores: +#endif /* Pick one hart to run the main boot sequence */ la a3, hart_lottery @@ -89,18 +111,24 @@ clear_bss_done: la sp, init_thread_union + THREAD_SIZE mv a0, s1 call setup_vm +#ifdef CONFIG_MMU la a0, early_pg_dir call relocate +#endif /* CONFIG_MMU */ /* Restore C environment */ la tp, init_task sw zero, TASK_TI_CPU(tp) la sp, init_thread_union + THREAD_SIZE +#ifdef CONFIG_KASAN + call kasan_early_init +#endif /* Start the kernel */ call parse_dtb tail start_kernel +#ifdef CONFIG_MMU relocate: /* Relocate return address */ li a1, PAGE_OFFSET @@ -111,7 +139,7 @@ relocate: /* Point stvec to virtual address of intruction after satp write */ la a2, 1f add a2, a2, a1 - csrw CSR_STVEC, a2 + csrw CSR_TVEC, a2 /* Compute satp for kernel page tables, but don't load it yet */ srl a2, a0, PAGE_SHIFT @@ -133,7 +161,7 @@ relocate: 1: /* Set trap vector to spin forever to help debug */ la a0, .Lsecondary_park - csrw CSR_STVEC, a0 + csrw CSR_TVEC, a0 /* Reload the global pointer */ .option push @@ -151,15 +179,13 @@ relocate: sfence.vma ret +#endif /* CONFIG_MMU */ .Lsecondary_start: #ifdef CONFIG_SMP - li a1, CONFIG_NR_CPUS - bgeu a0, a1, .Lsecondary_park - /* Set trap vector to spin forever to help debug */ la a3, .Lsecondary_park - csrw CSR_STVEC, a3 + csrw CSR_TVEC, a3 slli a3, a0, LGREG la a1, __cpu_up_stack_pointer @@ -179,19 +205,102 @@ relocate: beqz tp, .Lwait_for_cpu_up fence +#ifdef CONFIG_MMU /* Enable virtual memory and relocate to virtual address */ la a0, swapper_pg_dir call relocate +#endif tail smp_callin #endif +END(_start) + +#ifdef CONFIG_RISCV_M_MODE +ENTRY(reset_regs) + li sp, 0 + li gp, 0 + li tp, 0 + li t0, 0 + li t1, 0 + li t2, 0 + li s0, 0 + li s1, 0 + li a2, 0 + li a3, 0 + li a4, 0 + li a5, 0 + li a6, 0 + li a7, 0 + li s2, 0 + li s3, 0 + li s4, 0 + li s5, 0 + li s6, 0 + li s7, 0 + li s8, 0 + li s9, 0 + li s10, 0 + li s11, 0 + li t3, 0 + li t4, 0 + li t5, 0 + li t6, 0 + csrw CSR_SCRATCH, 0 + +#ifdef CONFIG_FPU + csrr t0, CSR_MISA + andi t0, t0, (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D) + beqz t0, .Lreset_regs_done + + li t1, SR_FS + csrs CSR_STATUS, t1 + fmv.s.x f0, zero + fmv.s.x f1, zero + fmv.s.x f2, zero + fmv.s.x f3, zero + fmv.s.x f4, zero + fmv.s.x f5, zero + fmv.s.x f6, zero + fmv.s.x f7, zero + fmv.s.x f8, zero + fmv.s.x f9, zero + fmv.s.x f10, zero + fmv.s.x f11, zero + fmv.s.x f12, zero + fmv.s.x f13, zero + fmv.s.x f14, zero + fmv.s.x f15, zero + fmv.s.x f16, zero + fmv.s.x f17, zero + fmv.s.x f18, zero + fmv.s.x f19, zero + fmv.s.x f20, zero + fmv.s.x f21, zero + fmv.s.x f22, zero + fmv.s.x f23, zero + fmv.s.x f24, zero + fmv.s.x f25, zero + fmv.s.x f26, zero + fmv.s.x f27, zero + fmv.s.x f28, zero + fmv.s.x f29, zero + fmv.s.x f30, zero + fmv.s.x f31, zero + csrw fcsr, 0 + /* note that the caller must clear SR_FS */ +#endif /* CONFIG_FPU */ +.Lreset_regs_done: + ret +END(reset_regs) +#endif /* CONFIG_RISCV_M_MODE */ + +.section ".text", "ax",@progbits .align 2 .Lsecondary_park: /* We lack SMP support or have too many harts, so park this hart */ wfi j .Lsecondary_park -END(_start) __PAGE_ALIGNED_BSS /* Empty zero page */ |
