diff options
| -rw-r--r-- | arch/riscv/Kconfig | 19 | ||||
| -rw-r--r-- | arch/riscv/include/asm/global_data.h | 6 | ||||
| -rw-r--r-- | arch/riscv/include/asm/smp.h | 53 | ||||
| -rw-r--r-- | arch/riscv/lib/Makefile | 1 | ||||
| -rw-r--r-- | arch/riscv/lib/smp.c | 118 |
5 files changed, 197 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 36512a89950..4d7a1155695 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -120,4 +120,23 @@ config RISCV_RDTIME config SYS_MALLOC_F_LEN default 0x1000 +config SMP + bool "Symmetric Multi-Processing" + help + This enables support for systems with more than one CPU. If + you say N here, U-Boot will run on single and multiprocessor + machines, but will use only one CPU of a multiprocessor + machine. If you say Y here, U-Boot will run on many, but not + all, single processor machines. + +config NR_CPUS + int "Maximum number of CPUs (2-32)" + range 2 32 + depends on SMP + default 8 + help + On multiprocessor machines, U-Boot sets up a stack for each CPU. + Stack memory is pre-allocated. U-Boot must therefore know the + maximum number of CPUs that may be present. + endmenu diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h index a3a342c6e1c..80e3165e397 100644 --- a/arch/riscv/include/asm/global_data.h +++ b/arch/riscv/include/asm/global_data.h @@ -10,12 +10,18 @@ #ifndef __ASM_GBL_DATA_H #define __ASM_GBL_DATA_H +#include <asm/smp.h> + /* Architecture-specific global data */ struct arch_global_data { long boot_hart; /* boot hart id */ #ifdef CONFIG_SIFIVE_CLINT void __iomem *clint; /* clint base address */ #endif +#ifdef CONFIG_SMP + struct ipi_data ipi[CONFIG_NR_CPUS]; +#endif + ulong available_harts; }; #include <asm-generic/global_data.h> diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h new file mode 100644 index 00000000000..bc863fdbafb --- /dev/null +++ b/arch/riscv/include/asm/smp.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019 Fraunhofer AISEC, + * Lukas Auer <lukas.auer@aisec.fraunhofer.de> + */ + +#ifndef _ASM_RISCV_SMP_H +#define _ASM_RISCV_SMP_H + +/** + * struct ipi_data - Inter-processor interrupt (IPI) data structure + * + * IPIs are used for SMP support to communicate to other harts what function to + * call. Functions are in the form + * void (*addr)(ulong hart, ulong arg0, ulong arg1). + * + * The function address and the two arguments, arg0 and arg1, are stored in the + * IPI data structure. The hart ID is inserted by the hart handling the IPI and + * calling the function. + * + * @addr: Address of function + * @arg0: First argument of function + * @arg1: Second argument of function + */ +struct ipi_data { + ulong addr; + ulong arg0; + ulong arg1; +}; + +/** + * handle_ipi() - interrupt handler for software interrupts + * + * The IPI interrupt handler must be called to handle software interrupts. It + * calls the function specified in the hart's IPI data structure. + * + * @hart: Hart ID of the current hart + */ +void handle_ipi(ulong hart); + +/** + * smp_call_function() - Call a function on all other harts + * + * Send IPIs with the specified function call to all harts. + * + * @addr: Address of function + * @arg0: First argument of function + * @arg1: Second argument of function + * @return 0 if OK, -ve on error + */ +int smp_call_function(ulong addr, ulong arg0, ulong arg1); + +#endif diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index edfa61690c7..19370f97497 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint.o obj-y += interrupts.o obj-y += reset.o obj-y += setjmp.o +obj-$(CONFIG_SMP) += smp.o # For building EFI apps CFLAGS_$(EFI_CRT0) := $(CFLAGS_EFI) diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c new file mode 100644 index 00000000000..caa292ccd20 --- /dev/null +++ b/arch/riscv/lib/smp.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Fraunhofer AISEC, + * Lukas Auer <lukas.auer@aisec.fraunhofer.de> + */ + +#include <common.h> +#include <dm.h> +#include <asm/barrier.h> +#include <asm/smp.h> + +DECLARE_GLOBAL_DATA_PTR; + +/** + * riscv_send_ipi() - Send inter-processor interrupt (IPI) + * + * Platform code must provide this function. + * + * @hart: Hart ID of receiving hart + * @return 0 if OK, -ve on error + */ +extern int riscv_send_ipi(int hart); + +/** + * riscv_clear_ipi() - Clear inter-processor interrupt (IPI) + * + * Platform code must provide this function. + * + * @hart: Hart ID of hart to be cleared + * @return 0 if OK, -ve on error + */ +extern int riscv_clear_ipi(int hart); + +static int send_ipi_many(struct ipi_data *ipi) +{ + ofnode node, cpus; + u32 reg; + int ret; + + cpus = ofnode_path("/cpus"); + if (!ofnode_valid(cpus)) { + pr_err("Can't find cpus node!\n"); + return -EINVAL; + } + + ofnode_for_each_subnode(node, cpus) { + /* skip if hart is marked as not available in the device tree */ + if (!ofnode_is_available(node)) + continue; + + /* read hart ID of CPU */ + ret = ofnode_read_u32(node, "reg", ®); + if (ret) + continue; + + /* skip if it is the hart we are running on */ + if (reg == gd->arch.boot_hart) + continue; + + if (reg >= CONFIG_NR_CPUS) { + pr_err("Hart ID %d is out of range, increase CONFIG_NR_CPUS\n", + reg); + continue; + } + + /* skip if hart is not available */ + if (!(gd->arch.available_harts & (1 << reg))) + continue; + + gd->arch.ipi[reg].addr = ipi->addr; + gd->arch.ipi[reg].arg0 = ipi->arg0; + gd->arch.ipi[reg].arg1 = ipi->arg1; + + ret = riscv_send_ipi(reg); + if (ret) { + pr_err("Cannot send IPI to hart %d\n", reg); + return ret; + } + } + + return 0; +} + +void handle_ipi(ulong hart) +{ + int ret; + void (*smp_function)(ulong hart, ulong arg0, ulong arg1); + + if (hart >= CONFIG_NR_CPUS) + return; + + ret = riscv_clear_ipi(hart); + if (ret) { + pr_err("Cannot clear IPI of hart %ld\n", hart); + return; + } + + __smp_mb(); + + smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr; + invalidate_icache_all(); + + smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1); +} + +int smp_call_function(ulong addr, ulong arg0, ulong arg1) +{ + int ret = 0; + struct ipi_data ipi; + + ipi.addr = addr; + ipi.arg0 = arg0; + ipi.arg1 = arg1; + + ret = send_ipi_many(&ipi); + + return ret; +} |