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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*/
#include <command.h>
#include <cpu.h>
#include <cpu_func.h>
#include <dm.h>
#include <dm/lists.h>
#include <event.h>
#include <hang.h>
#include <init.h>
#include <log.h>
#include <asm/encoding.h>
#include <asm/system.h>
#include <dm/uclass-internal.h>
#include <linux/bitops.h>
/*
* The variables here must be stored in the data section since they are used
* before the bss section is available.
*/
#if !CONFIG_IS_ENABLED(XIP)
u32 hart_lottery __section(".data") = 0;
#ifdef CONFIG_AVAILABLE_HARTS
/*
* The main hart running U-Boot has acquired available_harts_lock until it has
* finished initialization of global data.
*/
u32 available_harts_lock = 1;
#endif
#endif
static inline bool supports_extension(char ext)
{
#if CONFIG_IS_ENABLED(RISCV_MMODE)
return csr_read(CSR_MISA) & (1 << (ext - 'a'));
#elif CONFIG_CPU
char sext[2] = {ext};
struct udevice *dev;
const char *isa;
int ret, i;
uclass_find_first_device(UCLASS_CPU, &dev);
if (!dev) {
debug("unable to find the RISC-V cpu device\n");
return false;
}
ret = dev_read_stringlist_search(dev, "riscv,isa-extensions", sext);
if (ret >= 0)
return true;
/*
* Only if the property is not found (ENODATA) is the fallback to
* riscv,isa used, otherwise the extension is not present in this
* CPU.
*/
if (ret != -ENODATA)
return false;
isa = dev_read_string(dev, "riscv,isa");
if (!isa)
return false;
/*
* Skip the first 4 characters (rv32|rv64).
*/
for (i = 4; i < sizeof(isa); i++) {
switch (isa[i]) {
case 's':
case 'x':
case 'z':
case '_':
case '\0':
/*
* Any of these characters mean the single
* letter extensions have all been consumed.
*/
return false;
default:
if (isa[i] == ext)
return true;
}
}
return false;
#else /* !CONFIG_CPU */
#warning "There is no way to determine the available extensions in S-mode."
#warning "Please convert your board to use the RISC-V CPU driver."
return false;
#endif /* CONFIG_CPU */
}
static int riscv_cpu_probe(void)
{
#ifdef CONFIG_CPU
int ret;
/* probe cpus so that RISC-V timer can be bound */
ret = cpu_probe_all();
if (ret)
return log_msg_ret("RISC-V cpus probe failed\n", ret);
#endif
return 0;
}
EVENT_SPY_SIMPLE(EVT_DM_POST_INIT_R, riscv_cpu_probe);
/*
* This is called on secondary harts just after the IPI is init'd. Currently
* there's nothing to do, since we just need to clear any existing IPIs, and
* that is handled by the sending of an ipi itself.
*/
#if CONFIG_IS_ENABLED(SMP)
static void dummy_pending_ipi_clear(ulong hart, ulong arg0, ulong arg1)
{
}
#endif
int riscv_cpu_setup(void)
{
int __maybe_unused ret;
/* Enable FPU */
if (supports_extension('d') || supports_extension('f')) {
csr_set(MODE_PREFIX(status), MSTATUS_FS);
csr_write(CSR_FCSR, 0);
}
if (CONFIG_IS_ENABLED(RISCV_MMODE)) {
/*
* Enable perf counters for cycle, time,
* and instret counters only
*/
if (supports_extension('u')) {
#ifdef CONFIG_RISCV_PRIV_1_9
csr_write(CSR_MSCOUNTEREN, GENMASK(2, 0));
csr_write(CSR_MUCOUNTEREN, GENMASK(2, 0));
#else
csr_write(CSR_MCOUNTEREN, GENMASK(2, 0));
#endif
}
/* Disable paging */
if (supports_extension('s'))
#ifdef CONFIG_RISCV_PRIV_1_9
csr_read_clear(CSR_MSTATUS, SR_VM);
#else
csr_write(CSR_SATP, 0);
#endif
}
#if CONFIG_IS_ENABLED(SMP)
ret = riscv_init_ipi();
if (ret)
return ret;
/*
* Clear all pending IPIs on secondary harts. We don't do anything on
* the boot hart, since we never send an IPI to ourselves, and no
* interrupts are enabled
*/
ret = smp_call_function((ulong)dummy_pending_ipi_clear, 0, 0, 0);
if (ret)
return ret;
#endif
return 0;
}
EVENT_SPY_SIMPLE(EVT_DM_POST_INIT_F, riscv_cpu_setup);
int arch_early_init_r(void)
{
if (IS_ENABLED(CONFIG_SYSRESET_SBI))
device_bind_driver(gd->dm_root, "sbi-sysreset",
"sbi-sysreset", NULL);
return 0;
}
/**
* harts_early_init() - A callback function called by start.S to configure
* feature settings of each hart.
*
* In a multi-core system, memory access shall be careful here, it shall
* take care of race conditions.
*/
__weak void harts_early_init(void)
{
}
#if !CONFIG_IS_ENABLED(SYSRESET)
void reset_cpu(void)
{
printf("resetting ...\n");
printf("reset not supported yet\n");
hang();
}
#endif
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