cache.h

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/*
 * Copyright 2022 Carlo Caione <ccaione@baylibre.com>
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_ARCH_ARM64_CACHE_H_
#define ZEPHYR_INCLUDE_ARCH_ARM64_CACHE_H_
 
#ifndef _ASMLANGUAGE
 
#include <zephyr/types.h>
#include <zephyr/sys/util.h>
#include <zephyr/sys/barrier.h>
#include <zephyr/arch/cpu.h>
#include <errno.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define K_CACHE_WB              BIT(0)
#define K_CACHE_INVD            BIT(1)
#define K_CACHE_WB_INVD         (K_CACHE_WB | K_CACHE_INVD)
 
#if defined(CONFIG_DCACHE)
 
#define CTR_EL0_DMINLINE_SHIFT          16
#define CTR_EL0_DMINLINE_MASK           BIT_MASK(4)
#define CTR_EL0_CWG_SHIFT               24
#define CTR_EL0_CWG_MASK                BIT_MASK(4)
 
/* clidr_el1 */
#define CLIDR_EL1_LOC_SHIFT             24
#define CLIDR_EL1_LOC_MASK              BIT_MASK(3)
#define CLIDR_EL1_CTYPE_SHIFT(level)    ((level) * 3)
#define CLIDR_EL1_CTYPE_MASK            BIT_MASK(3)
 
/* ccsidr_el1 */
#define CCSIDR_EL1_LN_SZ_SHIFT          0
#define CCSIDR_EL1_LN_SZ_MASK           BIT_MASK(3)
#define CCSIDR_EL1_WAYS_SHIFT           3
#define CCSIDR_EL1_WAYS_MASK            BIT_MASK(10)
#define CCSIDR_EL1_SETS_SHIFT           13
#define CCSIDR_EL1_SETS_MASK            BIT_MASK(15)
 
#define dc_ops(op, val)                                                 \
({                                                                      \
        __asm__ volatile ("dc " op ", %0" :: "r" (val) : "memory");     \
})
 
static size_t dcache_line_size;
 
static ALWAYS_INLINE size_t arch_dcache_line_size_get(void)
{
        uint64_t ctr_el0;
        uint32_t dminline;
 
        if (dcache_line_size) {
                return dcache_line_size;
        }
 
        ctr_el0 = read_sysreg(CTR_EL0);
 
        dminline = (ctr_el0 >> CTR_EL0_DMINLINE_SHIFT) & CTR_EL0_DMINLINE_MASK;
 
        dcache_line_size = 4 << dminline;
 
        return dcache_line_size;
}
 
/*
 * operation for data cache by virtual address to PoC
 * ops:  K_CACHE_INVD: invalidate
 *       K_CACHE_WB: clean
 *       K_CACHE_WB_INVD: clean and invalidate
 */
static ALWAYS_INLINE int arm64_dcache_range(void *addr, size_t size, int op)
{
        size_t line_size;
        uintptr_t start_addr = (uintptr_t)addr;
        uintptr_t end_addr = start_addr + size;
 
        if (op != K_CACHE_INVD && op != K_CACHE_WB && op != K_CACHE_WB_INVD) {
                return -ENOTSUP;
        }
 
        line_size = arch_dcache_line_size_get();
 
        /*
         * For the data cache invalidate operation, clean and invalidate
         * the partial cache lines at both ends of the given range to
         * prevent data corruption.
         *
         * For example (assume cache line size is 64 bytes):
         * There are 2 consecutive 32-byte buffers, which can be cached in
         * one line like below.
         *                      +------------------+------------------+
         *       Cache line:    | buffer 0 (dirty) |     buffer 1     |
         *                      +------------------+------------------+
         * For the start address not aligned case, when invalidate the
         * buffer 1, the full cache line will be invalidated, if the buffer
         * 0 is dirty, its data will be lost.
         * The same logic applies to the not aligned end address.
         */
        if (op == K_CACHE_INVD) {
                if (end_addr & (line_size - 1)) {
                        end_addr &= ~(line_size - 1);
                        dc_ops("civac", end_addr);
                }
 
                if (start_addr & (line_size - 1)) {
                        start_addr &= ~(line_size - 1);
                        if (start_addr == end_addr) {
                                goto done;
                        }
                        dc_ops("civac", start_addr);
                        start_addr += line_size;
                }
        }
 
        /* Align address to line size */
        start_addr &= ~(line_size - 1);
 
        while (start_addr < end_addr) {
                if (op == K_CACHE_INVD) {
                        dc_ops("ivac", start_addr);
                } else if (op == K_CACHE_WB) {
                        dc_ops("cvac", start_addr);
                } else if (op == K_CACHE_WB_INVD) {
                        dc_ops("civac", start_addr);
                }
 
                start_addr += line_size;
        }
 
done:
        barrier_dsync_fence_full();
 
        return 0;
}
 
/*
 * operation for all data cache
 * ops:  K_CACHE_INVD: invalidate
 *       K_CACHE_WB: clean
 *       K_CACHE_WB_INVD: clean and invalidate
 */
static ALWAYS_INLINE int arm64_dcache_all(int op)
{
        uint32_t clidr_el1, csselr_el1, ccsidr_el1;
        uint8_t loc, ctype, cache_level, line_size, way_pos;
        uint32_t max_ways, max_sets, dc_val, set, way;
 
        if (op != K_CACHE_INVD && op != K_CACHE_WB && op != K_CACHE_WB_INVD) {
                return -ENOTSUP;
        }
 
        /* Data barrier before start */
        barrier_dsync_fence_full();
 
        clidr_el1 = read_clidr_el1();
 
        loc = (clidr_el1 >> CLIDR_EL1_LOC_SHIFT) & CLIDR_EL1_LOC_MASK;
        if (!loc) {
                return 0;
        }
 
        for (cache_level = 0; cache_level < loc; cache_level++) {
                ctype = (clidr_el1 >> CLIDR_EL1_CTYPE_SHIFT(cache_level))
                                & CLIDR_EL1_CTYPE_MASK;
                /* No data cache, continue */
                if (ctype < 2) {
                        continue;
                }
 
                /* select cache level */
                csselr_el1 = cache_level << 1;
                write_csselr_el1(csselr_el1);
                barrier_isync_fence_full();
 
                ccsidr_el1 = read_ccsidr_el1();
                line_size = (ccsidr_el1 >> CCSIDR_EL1_LN_SZ_SHIFT
                                & CCSIDR_EL1_LN_SZ_MASK) + 4;
                max_ways = (ccsidr_el1 >> CCSIDR_EL1_WAYS_SHIFT)
                                & CCSIDR_EL1_WAYS_MASK;
                max_sets = (ccsidr_el1 >> CCSIDR_EL1_SETS_SHIFT)
                                & CCSIDR_EL1_SETS_MASK;
                /* 32-log2(ways), bit position of way in DC operand */
                way_pos = __builtin_clz(max_ways);
 
                for (set = 0; set <= max_sets; set++) {
                        for (way = 0; way <= max_ways; way++) {
                                /* way number, aligned to pos in DC operand */
                                dc_val = way << way_pos;
                                /* cache level, aligned to pos in DC operand */
                                dc_val |= csselr_el1;
                                /* set number, aligned to pos in DC operand */
                                dc_val |= set << line_size;
 
                                if (op == K_CACHE_INVD) {
                                        dc_ops("isw", dc_val);
                                } else if (op == K_CACHE_WB_INVD) {
                                        dc_ops("cisw", dc_val);
                                } else if (op == K_CACHE_WB) {
                                        dc_ops("csw", dc_val);
                                }
                        }
                }
        }
 
        /* Restore csselr_el1 to level 0 */
        write_csselr_el1(0);
        barrier_dsync_fence_full();
        barrier_isync_fence_full();
 
        return 0;
}
 
static ALWAYS_INLINE int arch_dcache_flush_all(void)
{
        return arm64_dcache_all(K_CACHE_WB);
}
 
static ALWAYS_INLINE int arch_dcache_invd_all(void)
{
        return arm64_dcache_all(K_CACHE_INVD);
}
 
static ALWAYS_INLINE int arch_dcache_flush_and_invd_all(void)
{
        return arm64_dcache_all(K_CACHE_WB_INVD);
}
 
static ALWAYS_INLINE int arch_dcache_flush_range(void *addr, size_t size)
{
        return arm64_dcache_range(addr, size, K_CACHE_WB);
}
 
static ALWAYS_INLINE int arch_dcache_invd_range(void *addr, size_t size)
{
        return arm64_dcache_range(addr, size, K_CACHE_INVD);
}
 
static ALWAYS_INLINE int arch_dcache_flush_and_invd_range(void *addr, size_t size)
{
        return arm64_dcache_range(addr, size, K_CACHE_WB_INVD);
}
 
static ALWAYS_INLINE void arch_dcache_enable(void)
{
        /* nothing */
}
 
static ALWAYS_INLINE void arch_dcache_disable(void)
{
        /* nothing */
}
 
#endif /* CONFIG_DCACHE */
 
#if defined(CONFIG_ICACHE)
 
static ALWAYS_INLINE size_t arch_icache_line_size_get(void)
{
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_flush_all(void)
{
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_invd_all(void)
{
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_flush_and_invd_all(void)
{
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_flush_range(void *addr, size_t size)
{
        ARG_UNUSED(addr);
        ARG_UNUSED(size);
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_invd_range(void *addr, size_t size)
{
        ARG_UNUSED(addr);
        ARG_UNUSED(size);
        return -ENOTSUP;
}
 
static ALWAYS_INLINE int arch_icache_flush_and_invd_range(void *addr, size_t size)
{
        ARG_UNUSED(addr);
        ARG_UNUSED(size);
        return -ENOTSUP;
}
 
static ALWAYS_INLINE void arch_icache_enable(void)
{
        /* nothing */
}
 
static ALWAYS_INLINE void arch_icache_disable(void)
{
        /* nothing */
}
 
#endif /* CONFIG_ICACHE */
 
#ifdef __cplusplus
}
#endif
 
#endif /* _ASMLANGUAGE */
 
#endif /* ZEPHYR_INCLUDE_ARCH_ARM64_CACHE_H_ */