embox

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/**
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 * @file
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 *
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 * @brief Implementation of the RISC-V Core Local Interruptor (CLINT) for interrupt control, including support for SiFive multi-hart architectures.
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 *
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 * @date 05.07.2024
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 * @authored by Suraj Ravindra Sonawane
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 */
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#include <stdint.h>
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#include <drivers/irqctrl.h>
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#include <hal/reg.h>
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#include <asm/interrupts.h>
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#include <drivers/interrupt/riscv_clint.h>
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#define CLINT_ADDR      OPTION_GET(NUMBER, base_addr)
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#define MSIP_OFFSET     OPTION_GET(NUMBER, msip_offset)
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#define MTIMECMP_OFFSET OPTION_GET(NUMBER, mtimecmp_offset)
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#define MTIME_OFFSET    OPTION_GET(NUMBER, mtime_offset)
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#define MSIP_ADDR(hart)       (CLINT_ADDR + MSIP_OFFSET + ((hart) * 4))
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#define MTIMECMP_ADDR(hart)   (CLINT_ADDR + MTIMECMP_OFFSET + ((hart) * 8))
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#define MTIME_ADDR            (CLINT_ADDR + MTIME_OFFSET)
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/**
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 * Initializes the CLINT.
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 *
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 * This function initializes the CLINT by clearing the MSIP (Software Interrupt) and setting MTIMECMP
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 * to its maximum value (0xFFFFFFFFFFFFFFFF).
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 *
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 * @return 0 on success.
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 */
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int clint_init(void) __attribute__((unused));
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int clint_init(void) {
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    // Initial configuration: clear MSIP and set MTIMECMP to max value for all harts
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    for (int hart = 0; hart < 5; hart++) {
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        REG32_STORE(MSIP_ADDR(hart), 0);                 
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        REG64_STORE(MTIMECMP_ADDR(hart), 0xFFFFFFFFFFFFFFFF); 
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    }
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    REG64_STORE(MTIME_ADDR, 0); 
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    enable_software_interrupts();
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    return 0;
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}
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/**
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 * Configures the Software Interrupt (MSIP).
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 *
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 * This function configures the MSIP by writing a specific value (0 or 1) to its address.
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 *
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 * @param value The value (0 or 1) to set for MSIP.
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 * @param hart_id The hart id (only for SiFive CLINT).
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 */
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void clint_configure_msip(uint8_t value
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#ifdef SIFIVE_CLINT
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    , int hart_id
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#endif
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) {
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#ifdef SIFIVE_CLINT
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    REG32_STORE(MSIP_ADDR(hart_id), value & 1);
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#else
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    REG32_STORE(MSIP_ADDR(0), value & 1);
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#endif
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}
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/**
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 * Sets the MTIMECMP register value.
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 *
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 * This function sets the MTIMECMP register to the provided 64-bit value.
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 *
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 * @param value The value to set for MTIMECMP.
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 * @param hart_id The hart id (only for SiFive CLINT).
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 */
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void clint_set_mtimecmp(uint64_t value
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#ifdef SIFIVE_CLINT
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    , int hart_id
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#endif
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) {
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#ifdef SIFIVE_CLINT
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    REG64_STORE(MTIMECMP_ADDR(hart_id), value); // Write 'value' to MTIMECMP_ADDR for the specific hart
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#else
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    REG64_STORE(MTIMECMP_ADDR(0), value);
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#endif
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}
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/**
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 * Retrieves the current value of MTIME.
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 *
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 * This function reads and returns the current value of MTIME.
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 *
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 * @return The current value of MTIME.
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 */
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uint64_t clint_get_mtime(void) {
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    return REG64_LOAD(MTIME_ADDR);
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}