u-boot/arch/riscv/lib/andes_plicsw.c
Yu Chien Peter Lin bc35b49a5c riscv: andes_plicsw: Fix IPI during OpenSBI invocation
On some AE350 boards, we need to explicitly initialize the priority
registers to a non-zero value so the boot hart can instruct secondary
harts to jump to OpenSBI.

This patch also updates the information about PLICSW.

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2023-07-06 17:28:08 +08:00

147 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019, Rick Chen <rick@andestech.com>
*
* U-Boot syscon driver for Andes' PLICSW
* The PLICSW block is an Andes-specific design for software interrupts,
* contains memory-mapped priority, enable, claim and pending registers
* similar to RISC-V PLIC.
*/
#include <common.h>
#include <dm.h>
#include <asm/global_data.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/uclass-internal.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/io.h>
#include <asm/syscon.h>
#include <cpu.h>
#include <linux/err.h>
/* pending register */
#define PENDING_REG(base, hart) ((ulong)(base) + 0x1000 + ((hart) / 4) * 4)
/* enable register */
#define ENABLE_REG(base, hart) ((ulong)(base) + 0x2000 + (hart) * 0x80)
/* claim register */
#define CLAIM_REG(base, hart) ((ulong)(base) + 0x200004 + (hart) * 0x1000)
/* priority register */
#define PRIORITY_REG(base) ((ulong)(base) + PLICSW_PRIORITY_BASE)
#define ENABLE_HART_IPI (0x01010101)
#define SEND_IPI_TO_HART(hart) (0x1 << (hart))
#define PLICSW_PRIORITY_BASE 0x4
#define PLICSW_INTERRUPT_PER_HART 0x8
DECLARE_GLOBAL_DATA_PTR;
static int enable_ipi(int hart)
{
unsigned int en;
en = ENABLE_HART_IPI << hart;
writel(en, (void __iomem *)ENABLE_REG(gd->arch.plicsw, hart));
writel(en, (void __iomem *)ENABLE_REG(gd->arch.plicsw + 0x4, hart));
return 0;
}
static void init_priority_ipi(int hart_num)
{
uint32_t *priority = (void *)PRIORITY_REG(gd->arch.plicsw);
for (int i = 0; i < hart_num * PLICSW_INTERRUPT_PER_HART; i++) {
writel(1, &priority[i]);
}
return;
}
int riscv_init_ipi(void)
{
int ret;
int hart_num = 0;
long *base = syscon_get_first_range(RISCV_SYSCON_PLICSW);
ofnode node;
struct udevice *dev;
u32 reg;
if (IS_ERR(base))
return PTR_ERR(base);
gd->arch.plicsw = base;
ret = uclass_find_first_device(UCLASS_CPU, &dev);
if (ret)
return ret;
else if (!dev)
return -ENODEV;
ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
const char *device_type;
device_type = ofnode_read_string(node, "device_type");
if (!device_type)
continue;
if (strcmp(device_type, "cpu"))
continue;
/* skip if hart is marked as not available */
if (!ofnode_is_enabled(node))
continue;
/* read hart ID of CPU */
ret = ofnode_read_u32(node, "reg", &reg);
if (ret == 0)
enable_ipi(reg);
hart_num++;
}
init_priority_ipi(hart_num);
return 0;
}
int riscv_send_ipi(int hart)
{
unsigned int ipi = (SEND_IPI_TO_HART(hart) << (8 * gd->arch.boot_hart));
writel(ipi, (void __iomem *)PENDING_REG(gd->arch.plicsw,
gd->arch.boot_hart));
return 0;
}
int riscv_clear_ipi(int hart)
{
u32 source_id;
source_id = readl((void __iomem *)CLAIM_REG(gd->arch.plicsw, hart));
writel(source_id, (void __iomem *)CLAIM_REG(gd->arch.plicsw, hart));
return 0;
}
int riscv_get_ipi(int hart, int *pending)
{
unsigned int ipi = (SEND_IPI_TO_HART(hart) << (8 * gd->arch.boot_hart));
*pending = readl((void __iomem *)PENDING_REG(gd->arch.plicsw,
gd->arch.boot_hart));
*pending = !!(*pending & ipi);
return 0;
}
static const struct udevice_id andes_plicsw_ids[] = {
{ .compatible = "andestech,plicsw", .data = RISCV_SYSCON_PLICSW },
{ }
};
U_BOOT_DRIVER(andes_plicsw) = {
.name = "andes_plicsw",
.id = UCLASS_SYSCON,
.of_match = andes_plicsw_ids,
.flags = DM_FLAG_PRE_RELOC,
};