From 9f0877fc85a299ad0c6d9c2e2eec411e3ce87d8c Mon Sep 17 00:00:00 2001 From: "Wesley W. Terpstra" Date: Fri, 3 Nov 2017 11:42:52 -0700 Subject: [PATCH] sdboot: support SMP boot --- bootrom/sdboot/head.S | 3 + bootrom/sdboot/include/smp.h | 142 +++++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+) create mode 100644 bootrom/sdboot/include/smp.h diff --git a/bootrom/sdboot/head.S b/bootrom/sdboot/head.S index 88adfbb..14fa740 100644 --- a/bootrom/sdboot/head.S +++ b/bootrom/sdboot/head.S @@ -1,13 +1,16 @@ // See LICENSE for license details. #include +#include #include "common.h" .section .text.init .option norvc .globl _prog_start _prog_start: + smp_pause(s1, s2) li sp, (PAYLOAD_DEST + 0x7fff000) call main + smp_resume(s1, s2) csrr a0, mhartid la a1, dtb li s1, PAYLOAD_DEST diff --git a/bootrom/sdboot/include/smp.h b/bootrom/sdboot/include/smp.h new file mode 100644 index 0000000..145ceb3 --- /dev/null +++ b/bootrom/sdboot/include/smp.h @@ -0,0 +1,142 @@ +#ifndef SIFIVE_SMP +#define SIFIVE_SMP +#include "platform.h" + +// The maximum number of HARTs this code supports +#ifndef MAX_HARTS +#define MAX_HARTS 32 +#endif +#define CLINT_END_HART_IPI CLINT_CTRL_ADDR + (MAX_HARTS*4) +#define CLINT1_END_HART_IPI CLINT1_CTRL_ADDR + (MAX_HARTS*4) + +// The hart that non-SMP tests should run on +#ifndef NONSMP_HART +#define NONSMP_HART 0 +#endif + +/* If your test cannot handle multiple-threads, use this: + * smp_disable(reg1) + */ +#define smp_disable(reg1, reg2) \ + csrr reg1, mhartid ;\ + li reg2, NONSMP_HART ;\ + beq reg1, reg2, hart0_entry ;\ +42: ;\ + wfi ;\ + j 42b ;\ +hart0_entry: + +/* If your test needs to temporarily block multiple-threads, do this: + * smp_pause(reg1, reg2) + * ... single-threaded work ... + * smp_resume(reg1, reg2) + * ... multi-threaded work ... + */ + +#define smp_pause(reg1, reg2) \ + li reg2, 0x8 ;\ + csrw mie, reg2 ;\ + li reg1, NONSMP_HART ;\ + csrr reg2, mhartid ;\ + bne reg1, reg2, 42f + +#ifdef CLINT1_CTRL_ADDR +// If a second CLINT exists, then make sure we: +// 1) Trigger a software interrupt on all harts of both CLINTs. +// 2) Locate your own hart's software interrupt pending register and clear it. +// 3) Wait for all harts on both CLINTs to clear their software interrupt +// pending register. +// WARNING: This code makes these assumptions, which are only true for Fadu as +// of now: +// 1) hart0 uses CLINT0 at offset 0 +// 2) hart2 uses CLINT1 at offset 0 +// 3) hart3 uses CLINT1 at offset 1 +// 4) There are no other harts or CLINTs in the system. +#define smp_resume(reg1, reg2) \ + /* Trigger software interrupt on CLINT0 */ \ + li reg1, CLINT_CTRL_ADDR ;\ +41: ;\ + li reg2, 1 ;\ + sw reg2, 0(reg1) ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT_END_HART_IPI ;\ + blt reg1, reg2, 41b ;\ + /* Trigger software interrupt on CLINT1 */ \ + li reg1, CLINT1_CTRL_ADDR ;\ +41: ;\ + li reg2, 1 ;\ + sw reg2, 0(reg1) ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT1_END_HART_IPI ;\ + blt reg1, reg2, 41b ;\ + /* Wait to receive software interrupt */ \ +42: ;\ + wfi ;\ + csrr reg2, mip ;\ + andi reg2, reg2, 0x8 ;\ + beqz reg2, 42b ;\ + /* Clear own software interrupt bit */ \ + csrr reg2, mhartid ;\ + bnez reg2, 41f; \ + /* hart0 case: Use CLINT0 */ \ + li reg1, CLINT_CTRL_ADDR ;\ + slli reg2, reg2, 2 ;\ + add reg2, reg2, reg1 ;\ + sw zero, 0(reg2) ;\ + j 42f; \ +41: \ + /* hart 2, 3 case: Use CLINT1 and remap hart IDs to 0 and 1 */ \ + li reg1, CLINT1_CTRL_ADDR ;\ + addi reg2, reg2, -2; \ + slli reg2, reg2, 2 ;\ + add reg2, reg2, reg1 ;\ + sw zero, 0(reg2) ; \ +42: \ + /* Wait for all software interrupt bits to be cleared on CLINT0 */ \ + li reg1, CLINT_CTRL_ADDR ;\ +41: ;\ + lw reg2, 0(reg1) ;\ + bnez reg2, 41b ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT_END_HART_IPI ;\ + blt reg1, reg2, 41b; \ + /* Wait for all software interrupt bits to be cleared on CLINT1 */ \ + li reg1, CLINT1_CTRL_ADDR ;\ +41: ;\ + lw reg2, 0(reg1) ;\ + bnez reg2, 41b ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT1_END_HART_IPI ;\ + blt reg1, reg2, 41b; \ + /* End smp_resume() */ + +#else + +#define smp_resume(reg1, reg2) \ + li reg1, CLINT_CTRL_ADDR ;\ +41: ;\ + li reg2, 1 ;\ + sw reg2, 0(reg1) ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT_END_HART_IPI ;\ + blt reg1, reg2, 41b ;\ +42: ;\ + wfi ;\ + csrr reg2, mip ;\ + andi reg2, reg2, 0x8 ;\ + beqz reg2, 42b ;\ + li reg1, CLINT_CTRL_ADDR ;\ + csrr reg2, mhartid ;\ + slli reg2, reg2, 2 ;\ + add reg2, reg2, reg1 ;\ + sw zero, 0(reg2) ;\ +41: ;\ + lw reg2, 0(reg1) ;\ + bnez reg2, 41b ;\ + addi reg1, reg1, 4 ;\ + li reg2, CLINT_END_HART_IPI ;\ + blt reg1, reg2, 41b + +#endif /* ifdef CLINT1_CTRL_ADDR */ + +#endif -- 2.30.2