diff options
| author | Atish Patra <atish.patra@wdc.com> | 2019-04-01 17:04:05 -0700 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2019-04-03 09:57:42 +0530 |
| commit | 8334a88c632b5bd3abd33fa8c9b9b4c04f0b12c8 (patch) | |
| tree | 7ddcc59943bd9a718945057ec202fee91bf016c8 | |
| parent | 14dadeab09654b8ccde0f95a5283874bd43ea711 (diff) | |
lib: Add a fifo implementation.
Implement a fifo to accomodate outstanding IPIs for a specific hart
at the same time.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
| -rw-r--r-- | include/sbi/sbi_fifo.h | 32 | ||||
| -rw-r--r-- | lib/objects.mk | 4 | ||||
| -rw-r--r-- | lib/sbi_fifo.c | 82 |
3 files changed, 118 insertions, 0 deletions
diff --git a/include/sbi/sbi_fifo.h b/include/sbi/sbi_fifo.h new file mode 100644 index 0000000..ba9769b --- /dev/null +++ b/include/sbi/sbi_fifo.h @@ -0,0 +1,32 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2019 Western Digital Corporation or its affiliates. + * + * Authors: + * Atish Patra<atish.patra@wdc.com> + * + */ + +#ifndef __SBI_FIFO_H__ +#define __SBI_FIFO_H__ + +#include <sbi/riscv_locks.h> +#include <sbi/sbi_types.h> + +struct sbi_fifo { + int head; + int tail; + spinlock_t qlock; + unsigned long entrysize; + unsigned long num_entries; + void *queue; +}; + +int sbi_fifo_dequeue(struct sbi_fifo *fifo, void *data); +int sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data); +void sbi_fifo_init(struct sbi_fifo *fifo, unsigned long entries, + unsigned long entrysize); +bool sbi_fifo_is_empty(struct sbi_fifo *fifo); +bool sbi_fifo_is_full(struct sbi_fifo *fifo); +#endif diff --git a/lib/objects.mk b/lib/objects.mk index ebee592..137d7f0 100644 --- a/lib/objects.mk +++ b/lib/objects.mk @@ -15,6 +15,7 @@ lib-objs-y += riscv_locks.o lib-objs-y += sbi_console.o lib-objs-y += sbi_ecall.o lib-objs-y += sbi_emulate_csr.o +lib-objs-y += sbi_fifo.o lib-objs-y += sbi_hart.o lib-objs-y += sbi_illegal_insn.o lib-objs-y += sbi_init.o @@ -23,3 +24,6 @@ lib-objs-y += sbi_misaligned_ldst.o lib-objs-y += sbi_system.o lib-objs-y += sbi_timer.o lib-objs-y += sbi_trap.o + +# External Libraries to include +PLATFORM_INCLUDE_LIBC=y diff --git a/lib/sbi_fifo.c b/lib/sbi_fifo.c new file mode 100644 index 0000000..9d9a5b9 --- /dev/null +++ b/lib/sbi_fifo.c @@ -0,0 +1,82 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2019 Western Digital Corporation or its affiliates. + * + * Authors: + * Atish Patra<atish.patra@wdc.com> + * + */ +#include <sbi/riscv_locks.h> +#include <sbi/sbi_fifo.h> +#include <plat/string.h> + +void sbi_fifo_init(struct sbi_fifo *fifo, unsigned long entries, + unsigned long size) +{ + fifo->head = -1; + fifo->tail = -1; + fifo->num_entries = entries; + fifo->entrysize = size; + SPIN_LOCK_INIT(&fifo->qlock); + memset(fifo->queue, 0, entries * size); +} + +bool sbi_fifo_is_full(struct sbi_fifo *fifo) +{ + if (((fifo->head == fifo->num_entries-1) && fifo->tail == 0) || + (fifo->tail == fifo->head + 1)) { + return TRUE; + } + return FALSE; +} + +bool sbi_fifo_is_empty(struct sbi_fifo *fifo) +{ + if (fifo->head == -1) + return TRUE; + return FALSE; +} + +int sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data) +{ + if (!fifo || !data) + return -1; + spin_lock(&fifo->qlock); + if (sbi_fifo_is_full(fifo)) { + spin_unlock(&fifo->qlock); + return -1; + } + if (fifo->tail == -1) + fifo->tail = 0; + fifo->head = (fifo->head + 1) % fifo->num_entries; + memcpy(fifo->queue + fifo->head * fifo->entrysize, data, + fifo->entrysize); + spin_unlock(&fifo->qlock); + + return 0; +} + +int sbi_fifo_dequeue(struct sbi_fifo *fifo, void *data) +{ + if (!fifo || !data) + return -1; + + spin_lock(&fifo->qlock); + if (sbi_fifo_is_empty(fifo)) { + spin_unlock(&fifo->qlock); + return -1; + } + memcpy(data, fifo->queue + fifo->tail * fifo->entrysize, + fifo->entrysize); + + if (fifo->tail == fifo->head) { + fifo->tail = -1; + fifo->head = -1; + } else { + fifo->tail = (fifo->tail + 1) % fifo->num_entries; + } + spin_unlock(&fifo->qlock); + + return 0; +} |