arch/riscv/kernel/clint.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2019 Christoph Hellwig.
   4  */
   5
   6 #include <linux/io.h>
   7 #include <linux/of_address.h>
   8 #include <linux/types.h>
   9 #include <asm/clint.h>
  10 #include <asm/csr.h>
  11 #include <asm/timex.h>
  12 #include <asm/smp.h>
  13
  14 /*
  15  * This is the layout used by the SiFive clint, which is also shared by the qemu
  16  * virt platform, and the Kendryte KD210 at least.
  17  */
  18 #define CLINT_IPI_OFF           0
  19 #define CLINT_TIME_CMP_OFF      0x4000
  20 #define CLINT_TIME_VAL_OFF      0xbff8
  21
  22 u32 __iomem *clint_ipi_base;
  23
  24 void clint_init_boot_cpu(void)
  25 {
  26         struct device_node *np;
  27         void __iomem *base;
  28
  29         np = of_find_compatible_node(NULL, NULL, "riscv,clint0");
  30         if (!np) {
  31                 panic("clint not found");
  32                 return;
  33         }
  34
  35         base = of_iomap(np, 0);
  36         if (!base)
  37                 panic("could not map CLINT");
  38
  39         clint_ipi_base = base + CLINT_IPI_OFF;
  40         riscv_time_cmp = base + CLINT_TIME_CMP_OFF;
  41         riscv_time_val = base + CLINT_TIME_VAL_OFF;
  42
  43         clint_clear_ipi(boot_cpu_hartid);
  44 }