From patchwork Mon Oct 8 04:18:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Peter A. G. Crosthwaite" X-Patchwork-Id: 189892 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8E1882C0176 for ; Mon, 8 Oct 2012 15:40:48 +1100 (EST) Received: from localhost ([::1]:54781 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TL4pN-00047X-0z for incoming@patchwork.ozlabs.org; Mon, 08 Oct 2012 00:20:25 -0400 Received: from eggs.gnu.org ([208.118.235.92]:41577) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TL4oa-0002dv-HQ for qemu-devel@nongnu.org; Mon, 08 Oct 2012 00:19:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TL4oZ-0006r9-0j for qemu-devel@nongnu.org; Mon, 08 Oct 2012 00:19:36 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:46947) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TL4oY-0006Zk-Qc for qemu-devel@nongnu.org; Mon, 08 Oct 2012 00:19:34 -0400 Received: by mail-pa0-f45.google.com with SMTP id fb10so3627987pad.4 for ; Sun, 07 Oct 2012 21:19:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :in-reply-to:references:x-gm-message-state; bh=l7L2up7jX0j/WWzBlOom5ICVQDoJMWyAHLhxhDYquqA=; b=PYpqxbSayU4qGMzdcRNJGcA2yfeGuRumfqnyY5qTi2YWEpXS9MegiBklJ51r4wjsjq wCMXW4yW7PX293QUlCq3hXOOuO2y1fE8x8U9awgJuGRQ2wq7APZAN02/l6viAMKu2xy4 wp1qGXVtWgCwz+fP+A9uWBBa0eE3Hr2lJXaTCnFtVQCqgUs0tfsFLx1w1bRigq+vvZlS OLkS8ZxnjXNJ3Kw0LyrKoWZet32QTX5Xp9dscZcAzxcyLfXXGieN27DSKpxov88ZNkyU DTZ/vM263asCe3WViu0qpesPIDa0LUwI8bRb5N8z4jZlTC6hcE9/t33fe9eYq5haO7jd XpZg== Received: by 10.68.190.233 with SMTP id gt9mr49590244pbc.137.1349669974398; Sun, 07 Oct 2012 21:19:34 -0700 (PDT) Received: from localhost ([124.148.20.9]) by mx.google.com with ESMTPS id pw9sm10057650pbb.42.2012.10.07.21.19.31 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 07 Oct 2012 21:19:33 -0700 (PDT) From: Peter Crosthwaite To: qemu-devel@nongnu.org, edgar.iglesias@gmail.com, peter.maydell@linaro.org Date: Mon, 8 Oct 2012 14:18:20 +1000 Message-Id: X-Mailer: git-send-email 1.7.0.4 In-Reply-To: References: In-Reply-To: References: X-Gm-Message-State: ALoCoQnFw54k2MpOZFbrUvtfGkwSLTOxZaZfPkxRHsTspoRa8Y4/8eqERP2ToBVaLL9iQlNJnrKo X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.220.45 Cc: "Peter A. G. Crosthwaite" Subject: [Qemu-devel] [PATCH v9 06/13] hw: Added generic FIFO API. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Peter A. G. Crosthwaite Added a FIFO API that can be used to create and operate byte FIFOs. Signed-off-by: Peter A. G. Crosthwaite --- Changed since v8: Added documentation. Fixed copy paste error on VMSD name string hw/Makefile.objs | 1 + hw/fifo.c | 78 ++++++++++++++++++++++++++++++++++++++++++ hw/fifo.h | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 178 insertions(+), 0 deletions(-) create mode 100644 hw/fifo.c create mode 100644 hw/fifo.h diff --git a/hw/Makefile.objs b/hw/Makefile.objs index b59c749..66abbb2 100644 --- a/hw/Makefile.objs +++ b/hw/Makefile.objs @@ -35,6 +35,7 @@ common-obj-$(CONFIG_APPLESMC) += applesmc.o common-obj-$(CONFIG_SMARTCARD) += ccid-card-passthru.o common-obj-$(CONFIG_SMARTCARD_NSS) += ccid-card-emulated.o common-obj-$(CONFIG_I8259) += i8259_common.o i8259.o +common-obj-y += fifo.o # PPC devices common-obj-$(CONFIG_PREP_PCI) += prep_pci.o diff --git a/hw/fifo.c b/hw/fifo.c new file mode 100644 index 0000000..68a955a --- /dev/null +++ b/hw/fifo.c @@ -0,0 +1,78 @@ +/* + * Generic FIFO component, implemented as a circular buffer. + * + * Copyright (c) 2012 Peter A. G. Crosthwaite + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see . + */ + +#include "fifo.h" + +void fifo8_create(Fifo8 *fifo, uint32_t capacity) +{ + fifo->data = g_new(uint8_t, capacity); + fifo->capacity = capacity; + fifo->head = 0; + fifo->num = 0; +} + +void fifo8_destroy(Fifo8 *fifo) +{ + g_free(fifo->data); +} + +void fifo8_push(Fifo8 *fifo, uint8_t data) +{ + if (fifo->num == fifo->capacity) { + abort(); + } + fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; + fifo->num++; +} + +uint8_t fifo8_pop(Fifo8 *fifo) +{ + uint8_t ret; + + if (fifo->num == 0) { + abort(); + } + ret = fifo->data[fifo->head++]; + fifo->head %= fifo->capacity; + fifo->num--; + return ret; +} + +void fifo8_reset(Fifo8 *fifo) +{ + fifo->num = 0; +} + +bool fifo8_is_empty(Fifo8 *fifo) +{ + return (fifo->num == 0); +} + +bool fifo8_is_full(Fifo8 *fifo) +{ + return (fifo->num == fifo->capacity); +} + +const VMStateDescription vmstate_fifo8 = { + .name = "Fifo8", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), + VMSTATE_UINT32(head, Fifo8), + VMSTATE_UINT32(num, Fifo8), + VMSTATE_END_OF_LIST() + } +}; diff --git a/hw/fifo.h b/hw/fifo.h new file mode 100644 index 0000000..f23890a --- /dev/null +++ b/hw/fifo.h @@ -0,0 +1,99 @@ +#ifndef FIFO_H +#define FIFO_H + +#include "hw.h" + +typedef struct { + /* All fields are private */ + uint8_t *data; + uint32_t capacity; + uint32_t head; + uint32_t num; +} Fifo8; + +/** + * fifo8_create: + * @fifo: struct Fifo8 to initialise with new FIFO + * @capacity: capacity of the newly created FIFO + * + * Create a FIFO of the specified size. Clients should call fifo8_destroy() + * when finished using the fifo. The FIFO is initially empty. + */ + +void fifo8_create(Fifo8 *fifo, uint32_t capacity); + +/** + * fifo8_destroy: + * @fifo: FIFO to cleanup + * + * Cleanup a FIFO created with fifo8_create(). Frees memory created for FIFO + *storage. The FIFO is no longer usable after this has been called. + */ + +void fifo8_destroy(Fifo8 *fifo); + +/** + * fifo8_push: + * @fifo: FIFO to push to + * @data: data byte to push + * + * Push a data byte to the FIFO. Behaviour is undefined if the FIFO is full. + * Clients are responsible for checking for fullness using fifo8_is_full(). + */ + +void fifo8_push(Fifo8 *fifo, uint8_t data); + +/** + * fifo8_pop: + * @fifo: fifo to pop from + * + * Pop a data byte from the FIFO. Behaviour is undefined if the FIFO is empty. + * Clients are responsible for checking for emptyness using fifo8_is_empty(). + * + * Returns: The popped data byte. + */ + +uint8_t fifo8_pop(Fifo8 *fifo); + +/** + * fifo8_reset: + * @fifo: FIFO to reset + * + * Reset a FIFO. All data is discarded and the FIFO is emptied. + */ + +void fifo8_reset(Fifo8 *fifo); + +/** + * fifo8_is_empty: + * @fifo: FIFO to check + * + * Check if a FIFO is empty. + * + * Returns: True if the fifo is empty, false otherwise. + */ + +bool fifo8_is_empty(Fifo8 *fifo); + +/** + * fifo8_is_full: + * @fifo: FIFO to check + * + * Check if a FIFO is full. + * + * Returns: True if the fifo is full, false otherwise. + */ + +bool fifo8_is_full(Fifo8 *fifo); + +extern const VMStateDescription vmstate_fifo8; + +#define VMSTATE_FIFO8(_field, _state) { \ + .name = (stringify(_field)), \ + .size = sizeof(Fifo8), \ + .vmsd = &vmstate_fifo8, \ + .flags = VMS_STRUCT, \ + .offset = vmstate_offset_value(_state, _field, Fifo8), \ +} + +#endif /* FIFO_H */