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From: Gregory CLEMENT <gregory.clement@free-electrons.com>
To: "David S. Miller" <davem@davemloft.net>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Florian Fainelli <f.fainelli@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Gregory CLEMENT <gregory.clement@free-electrons.com>,
	linux-arm-kernel@lists.infradead.org,
	Lior Amsalem <alior@marvell.com>,
	Nadav Haklai <nadavh@marvell.com>,
	Marcin Wojtas <mw@semihalf.com>,
	Simon Guinot <simon.guinot@sequanux.org>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	Willy Tarreau <w@1wt.eu>, Timor Kardashov <timork@marvell.com>,
	Dmitri Epshtein <dima@marvell.com>,
	Sebastian Careba <nitroshift@yahoo.com>
Subject: [PATCH v5 net-next 09/10] net: add a hardware buffer management helper API
Date: Thu, 10 Mar 2016 11:09:17 +0100	[thread overview]
Message-ID: <1457604558-1121-10-git-send-email-gregory.clement@free-electrons.com> (raw)
In-Reply-To: <1457604558-1121-1-git-send-email-gregory.clement@free-electrons.com>

This basic implementation allows to share code between driver using
hardware buffer management. As the code is hardware agnostic, there is
few helpers, most of the optimization brought by the an HW BM has to be
done at driver level.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 include/net/hwbm.h | 28 ++++++++++++++++++
 net/Kconfig        |  3 ++
 net/core/Makefile  |  1 +
 net/core/hwbm.c    | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 119 insertions(+)
 create mode 100644 include/net/hwbm.h
 create mode 100644 net/core/hwbm.c

diff --git a/include/net/hwbm.h b/include/net/hwbm.h
new file mode 100644
index 000000000000..47d08662501b
--- /dev/null
+++ b/include/net/hwbm.h
@@ -0,0 +1,28 @@
+#ifndef _HWBM_H
+#define _HWBM_H
+
+struct hwbm_pool {
+	/* Capacity of the pool */
+	int size;
+	/* Size of the buffers managed */
+	int frag_size;
+	/* Number of buffers currently used by this pool */
+	int buf_num;
+	/* constructor called during alocation */
+	int (*construct)(struct hwbm_pool *bm_pool, void *buf);
+	/* protect acces to the buffer counter*/
+	spinlock_t lock;
+	/* private data */
+	void *priv;
+};
+#ifdef CONFIG_HWBM
+void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf);
+int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp);
+int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp);
+#else
+void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {}
+int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) { return 0; }
+int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)
+{ return 0; }
+#endif /* CONFIG_HWBM */
+#endif /* _HWBM_H */
diff --git a/net/Kconfig b/net/Kconfig
index 174354618f8a..f50c8af4308b 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -253,6 +253,9 @@ config XPS
 	depends on SMP
 	default y
 
+config HWBM
+       bool
+
 config SOCK_CGROUP_DATA
 	bool
 	default n
diff --git a/net/core/Makefile b/net/core/Makefile
index 0b835de04de3..57e6dd81c6be 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_NET_PTP_CLASSIFY) += ptp_classifier.o
 obj-$(CONFIG_CGROUP_NET_PRIO) += netprio_cgroup.o
 obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o
 obj-$(CONFIG_LWTUNNEL) += lwtunnel.o
+obj-$(CONFIG_HWBM) += hwbm.o
diff --git a/net/core/hwbm.c b/net/core/hwbm.c
new file mode 100644
index 000000000000..941c28486896
--- /dev/null
+++ b/net/core/hwbm.c
@@ -0,0 +1,87 @@
+/* Support for hardware buffer manager.
+ *
+ * Copyright (C) 2016 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ *  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.
+ */
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/skbuff.h>
+#include <net/hwbm.h>
+
+void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf)
+{
+	if (likely(bm_pool->frag_size <= PAGE_SIZE))
+		skb_free_frag(buf);
+	else
+		kfree(buf);
+}
+EXPORT_SYMBOL_GPL(hwbm_buf_free);
+
+/* Refill processing for HW buffer management */
+int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp)
+{
+	int frag_size = bm_pool->frag_size;
+	void *buf;
+
+	if (likely(frag_size <= PAGE_SIZE))
+		buf = netdev_alloc_frag(frag_size);
+	else
+		buf = kmalloc(frag_size, gfp);
+
+	if (!buf)
+		return -ENOMEM;
+
+	if (bm_pool->construct)
+		if (bm_pool->construct(bm_pool, buf)) {
+			hwbm_buf_free(bm_pool, buf);
+			return -ENOMEM;
+		}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hwbm_pool_refill);
+
+int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)
+{
+	int err, i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bm_pool->lock, flags);
+	if (bm_pool->buf_num == bm_pool->size) {
+		pr_warn("pool already filled\n");
+		return bm_pool->buf_num;
+	}
+
+	if (buf_num + bm_pool->buf_num > bm_pool->size) {
+		pr_warn("cannot allocate %d buffers for pool\n",
+			buf_num);
+		return 0;
+	}
+
+	if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
+		pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
+			buf_num,  bm_pool->buf_num);
+		return 0;
+	}
+
+	for (i = 0; i < buf_num; i++) {
+		err = hwbm_pool_refill(bm_pool, gfp);
+		if (err < 0)
+			break;
+	}
+
+	/* Update BM driver with number of buffers added to pool */
+	bm_pool->buf_num += i;
+
+	pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);
+	spin_unlock_irqrestore(&bm_pool->lock, flags);
+
+	return i;
+}
+EXPORT_SYMBOL_GPL(hwbm_pool_add);
-- 
2.5.0

  parent reply	other threads:[~2016-03-10 10:10 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-10 10:09 [PATCH v5 net-next 00/10] API set for HW Buffer management Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 01/10] misc: sram: add optional ioremap without write combining Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 02/10] ARM: dts: armada-38x: add buffer manager nodes Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 03/10] ARM: dts: armada-38x: enable buffer manager support on Armada 38x boards Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 04/10] ARM: dts: armada-xp: add buffer manager nodes Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 05/10] ARM: dts: armada-xp: enable buffer manager support on Armada XP boards Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 06/10] ARM: dts: armada-xp-openblocks-ax3-4: Add BM support Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 07/10] bus: mvebu-mbus: provide api for obtaining IO and DRAM window information Gregory CLEMENT
2016-03-10 10:09 ` [PATCH v5 net-next 08/10] net: mvneta: bm: add support for hardware buffer management Gregory CLEMENT
2016-03-10 10:09 ` Gregory CLEMENT [this message]
2016-03-10 10:09 ` [PATCH v5 net-next 10/10] net: mvneta: Use the new hwbm framework Gregory CLEMENT
2016-03-14  2:02 ` [PATCH v5 net-next 00/10] API set for HW Buffer management David Miller

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