diff mbox

[v4,5/9] staging/rdma/hfi1: Add function stubs for TID caching

Message ID 1446245928-12675-6-git-send-email-ira.weiny@intel.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Ira Weiny Oct. 30, 2015, 10:58 p.m. UTC
From: Mitko Haralanov <mitko.haralanov@intel.com>

Add mmu notify helper functions and TID caching function stubs in preparation
for the TID caching implementation.

TID caching makes use of the MMU notifier to allow the driver to respond to the
user freeing memory which is allocated to the HFI.

This patch implements the basic MMU notifier functions to insert, find and
remove buffer pages from memory based on the mmu_notifier being invoked.

In addition it places stubs in place for the main entry points by follow on
code.

Follow up patches will complete the implementation of the interaction with user
space and makes use of these functions.

Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 drivers/staging/rdma/hfi1/Kconfig        |   1 +
 drivers/staging/rdma/hfi1/Makefile       |   2 +-
 drivers/staging/rdma/hfi1/user_exp_rcv.c | 314 +++++++++++++++++++++++++++++++
 drivers/staging/rdma/hfi1/user_exp_rcv.h |   8 +
 4 files changed, 324 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/rdma/hfi1/user_exp_rcv.c

Comments

Greg KH Nov. 7, 2015, 1:02 a.m. UTC | #1
On Fri, Oct 30, 2015 at 06:58:44PM -0400, ira.weiny@intel.com wrote:
> From: Mitko Haralanov <mitko.haralanov@intel.com>
> 
> Add mmu notify helper functions and TID caching function stubs in preparation
> for the TID caching implementation.
> 
> TID caching makes use of the MMU notifier to allow the driver to respond to the
> user freeing memory which is allocated to the HFI.
> 
> This patch implements the basic MMU notifier functions to insert, find and
> remove buffer pages from memory based on the mmu_notifier being invoked.
> 
> In addition it places stubs in place for the main entry points by follow on
> code.
> 
> Follow up patches will complete the implementation of the interaction with user
> space and makes use of these functions.

This patch adds warnings to the build, which isn't ok, so I've stopped
here in this series and just applied the first 4.  Please fix up and
resend the remaining ones.

thanks,

greg k-h
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Ira Weiny Nov. 10, 2015, 12:11 a.m. UTC | #2
On Fri, Nov 06, 2015 at 05:02:35PM -0800, Greg KH wrote:
> On Fri, Oct 30, 2015 at 06:58:44PM -0400, ira.weiny@intel.com wrote:
> > From: Mitko Haralanov <mitko.haralanov@intel.com>
> > 
> > Add mmu notify helper functions and TID caching function stubs in preparation
> > for the TID caching implementation.
> > 
> > TID caching makes use of the MMU notifier to allow the driver to respond to the
> > user freeing memory which is allocated to the HFI.
> > 
> > This patch implements the basic MMU notifier functions to insert, find and
> > remove buffer pages from memory based on the mmu_notifier being invoked.
> > 
> > In addition it places stubs in place for the main entry points by follow on
> > code.
> > 
> > Follow up patches will complete the implementation of the interaction with user
> > space and makes use of these functions.
> 
> This patch adds warnings to the build, which isn't ok, so I've stopped
> here in this series and just applied the first 4.  Please fix up and
> resend the remaining ones.

Ok, patch 7-9 of this series do not depend on this patch nor number 6.  I will
resend those 3 while I figure out what to do about these 2:

staging/rdma/hfi1: Add function stubs for TID caching
staging/rdma/hfi1: Implement Expected Receive TID caching

Frankly this was an attempt to reduce the size of "Implement Expected Receive
TID caching".  I obviously did something wrong.

I really don't know that I can split these up any more without causing issues
with bisecting the code.

Ira

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Greg KH Nov. 10, 2015, 12:18 a.m. UTC | #3
On Mon, Nov 09, 2015 at 07:11:03PM -0500, ira.weiny wrote:
> On Fri, Nov 06, 2015 at 05:02:35PM -0800, Greg KH wrote:
> > On Fri, Oct 30, 2015 at 06:58:44PM -0400, ira.weiny@intel.com wrote:
> > > From: Mitko Haralanov <mitko.haralanov@intel.com>
> > > 
> > > Add mmu notify helper functions and TID caching function stubs in preparation
> > > for the TID caching implementation.
> > > 
> > > TID caching makes use of the MMU notifier to allow the driver to respond to the
> > > user freeing memory which is allocated to the HFI.
> > > 
> > > This patch implements the basic MMU notifier functions to insert, find and
> > > remove buffer pages from memory based on the mmu_notifier being invoked.
> > > 
> > > In addition it places stubs in place for the main entry points by follow on
> > > code.
> > > 
> > > Follow up patches will complete the implementation of the interaction with user
> > > space and makes use of these functions.
> > 
> > This patch adds warnings to the build, which isn't ok, so I've stopped
> > here in this series and just applied the first 4.  Please fix up and
> > resend the remaining ones.
> 
> Ok, patch 7-9 of this series do not depend on this patch nor number 6.  I will
> resend those 3 while I figure out what to do about these 2:
> 
> staging/rdma/hfi1: Add function stubs for TID caching
> staging/rdma/hfi1: Implement Expected Receive TID caching
> 
> Frankly this was an attempt to reduce the size of "Implement Expected Receive
> TID caching".  I obviously did something wrong.
> 
> I really don't know that I can split these up any more without causing issues
> with bisecting the code.

I strongly doubt that you created this new feature all "at once", it
took a set of steps to get to your final destination.  So show that
work, like your math professor told you...

thanks,

greg k-h
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Ira Weiny Nov. 11, 2015, 6:10 a.m. UTC | #4
> > 
> > Ok, patch 7-9 of this series do not depend on this patch nor number 6.  I will
> > resend those 3 while I figure out what to do about these 2:
> > 
> > staging/rdma/hfi1: Add function stubs for TID caching
> > staging/rdma/hfi1: Implement Expected Receive TID caching
> > 
> > Frankly this was an attempt to reduce the size of "Implement Expected Receive
> > TID caching".  I obviously did something wrong.
> > 
> > I really don't know that I can split these up any more without causing issues
> > with bisecting the code.
> 
> I strongly doubt that you created this new feature all "at once", it
> took a set of steps to get to your final destination.  So show that
> work, like your math professor told you...
> 

The original author and I have been going through the code to see what we can
do.  We have identified a couple of other pieces which can be split.

One question.  Is it ok to have functionality which is added which is unused in
a preliminary patch?  I believe this is ok as long as the code compiles but I
just wanted to make sure.  While there are different operations added in this
patch it is broken to not use them as a set.  So we need to have a series which
implement the pieces with a final patch which exposes the set of operations.

Is this acceptable?

Ira

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Dan Carpenter Nov. 11, 2015, 9:31 a.m. UTC | #5
On Wed, Nov 11, 2015 at 01:10:40AM -0500, ira.weiny wrote:
> The original author and I have been going through the code to see what we can
> do.  We have identified a couple of other pieces which can be split.
> 
> One question.  Is it ok to have functionality which is added which is unused in
> a preliminary patch?  I believe this is ok as long as the code compiles but I
> just wanted to make sure.  While there are different operations added in this
> patch it is broken to not use them as a set.  So we need to have a series which
> implement the pieces with a final patch which exposes the set of operations.
> 
> Is this acceptable?

Yeah.  It's fine.  Don't add warnings about unused static functions
though.  Also we like to see a user in the same patchset so don't add
infrastructure first and the user code the next year or whatever.

regards,
dan carpenter

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diff mbox

Patch

diff --git a/drivers/staging/rdma/hfi1/Kconfig b/drivers/staging/rdma/hfi1/Kconfig
index fd25078ee923..bd0249bcf199 100644
--- a/drivers/staging/rdma/hfi1/Kconfig
+++ b/drivers/staging/rdma/hfi1/Kconfig
@@ -1,6 +1,7 @@ 
 config INFINIBAND_HFI1
 	tristate "Intel OPA Gen1 support"
 	depends on X86_64
+	select MMU_NOTIFIER
 	default m
 	---help---
 	This is a low-level driver for Intel OPA Gen1 adapter.
diff --git a/drivers/staging/rdma/hfi1/Makefile b/drivers/staging/rdma/hfi1/Makefile
index 2e5daa6cdcc2..00c47b788666 100644
--- a/drivers/staging/rdma/hfi1/Makefile
+++ b/drivers/staging/rdma/hfi1/Makefile
@@ -10,7 +10,7 @@  obj-$(CONFIG_INFINIBAND_HFI1) += hfi1.o
 hfi1-y := chip.o cq.o device.o diag.o dma.o driver.o eprom.o file_ops.o firmware.o \
 	init.o intr.o keys.o mad.o mmap.o mr.o pcie.o pio.o pio_copy.o \
 	qp.o qsfp.o rc.o ruc.o sdma.o srq.o sysfs.o trace.o twsi.o \
-	uc.o ud.o user_pages.o user_sdma.o verbs_mcast.o verbs.o
+	uc.o ud.o user_exp_rcv.o user_pages.o user_sdma.o verbs_mcast.o verbs.o
 hfi1-$(CONFIG_DEBUG_FS) += debugfs.o
 
 CFLAGS_trace.o = -I$(src)
diff --git a/drivers/staging/rdma/hfi1/user_exp_rcv.c b/drivers/staging/rdma/hfi1/user_exp_rcv.c
new file mode 100644
index 000000000000..d8066c646f0c
--- /dev/null
+++ b/drivers/staging/rdma/hfi1/user_exp_rcv.c
@@ -0,0 +1,314 @@ 
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <asm/page.h>
+
+#include "user_exp_rcv.h"
+#include "trace.h"
+
+
+struct mmu_rb_node {
+	struct rb_node rbnode;
+	unsigned long virt;
+	unsigned long phys;
+	unsigned long len;
+	struct tid_group *grp;
+	u32 rcventry;
+	dma_addr_t dma_addr;
+	bool freed;
+	unsigned npages;
+	struct page *pages[0];
+};
+
+enum mmu_call_types {
+	MMU_INVALIDATE_PAGE = 0,
+	MMU_INVALIDATE_RANGE = 1
+};
+
+static const char * const mmu_types[] = {
+	"PAGE",
+	"RANGE"
+};
+
+static inline int mmu_addr_cmp(struct mmu_rb_node *, unsigned long,
+			       unsigned long);
+static struct mmu_rb_node *mmu_rb_search_by_addr(struct rb_root *,
+						 unsigned long);
+static inline struct mmu_rb_node *mmu_rb_search_by_entry(struct rb_root *,
+							 u32);
+static int mmu_rb_insert_by_addr(struct rb_root *, struct mmu_rb_node *);
+static int mmu_rb_insert_by_entry(struct rb_root *, struct mmu_rb_node *);
+static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
+					unsigned long, unsigned long,
+					enum mmu_call_types);
+static inline void mmu_notifier_page(struct mmu_notifier *, struct mm_struct *,
+				     unsigned long);
+static inline void mmu_notifier_range_start(struct mmu_notifier *,
+					    struct mm_struct *,
+					    unsigned long, unsigned long);
+
+
+static struct mmu_notifier_ops mn_opts = {
+	.invalidate_page = mmu_notifier_page,
+	.invalidate_range_start = mmu_notifier_range_start,
+};
+
+/*
+ * Initialize context and file private data needed for Expected
+ * receive caching. This needs to be done after the context has
+ * been configured with the eager/expected RcvEntry counts.
+ */
+int hfi1_user_exp_rcv_init(struct file *fp)
+{
+	return -EINVAL;
+}
+
+int hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
+{
+	return -EINVAL;
+}
+
+/*
+ * RcvArray entry allocation for Expected Receives is done by the
+ * following algorithm:
+ *
+ * The context keeps 3 lists of groups of RcvArray entries:
+ *   1. List of empty groups - tid_group_list
+ *      This list is created during user context creation and
+ *      contains elements which describe sets (of 8) of empty
+ *      RcvArray entries.
+ *   2. List of partially used groups - tid_used_list
+ *      This list contains sets of RcvArray entries which are
+ *      not completely used up. Another mapping request could
+ *      use some of all of the remaining entries.
+ *   3. List of full groups - tid_full_list
+ *      This is the list where sets that are completely used
+ *      up go.
+ *
+ * An attempt to optimize the usage of RcvArray entries is
+ * made by finding all sets of physically contiguous pages in a
+ * user's buffer.
+ * These physically contiguous sets are further split into
+ * sizes supported by the receive engine of the HFI. The
+ * resulting sets of pages are stored in struct tid_pageset,
+ * which describes the sets as:
+ *    * .count - number of pages in this set
+ *    * .idx - starting index into struct page ** array
+ *                    of this set
+ *
+ * From this point on, the algorithm deals with the page sets
+ * described above. The number of pagesets is divided by the
+ * RcvArray group size to produce the number of full groups
+ * needed.
+ *
+ * Groups from the 3 lists are manipulated using the following
+ * rules:
+ *   1. For each set of 8 pagesets, a complete group from
+ *      tid_group_list is taken, programmed, and moved to
+ *      the tid_full_list list.
+ *   2. For all remaining pagesets:
+ *      2.1 If the tid_used_list is empty and the tid_group_list
+ *          is empty, stop processing pageset and return only
+ *          what has been programmed up to this point.
+ *      2.2 If the tid_used_list is empty and the tid_group_list
+ *          is not empty, move a group from tid_group_list to
+ *          tid_used_list.
+ *      2.3 For each group is tid_used_group, program as much as
+ *          can fit into the group. If the group becomes fully
+ *          used, move it to tid_full_list.
+ */
+int hfi1_user_exp_rcv_setup(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	return -EINVAL;
+}
+
+int hfi1_user_exp_rcv_clear(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	return -EINVAL;
+}
+
+int hfi1_user_exp_rcv_invalid(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	return -EINVAL;
+}
+
+static inline void mmu_notifier_page(struct mmu_notifier *mn,
+				     struct mm_struct *mm, unsigned long addr)
+{
+	mmu_notifier_mem_invalidate(mn, addr, addr + PAGE_SIZE,
+				    MMU_INVALIDATE_PAGE);
+}
+
+static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
+					    struct mm_struct *mm,
+					    unsigned long start,
+					    unsigned long end)
+{
+	mmu_notifier_mem_invalidate(mn, start, end, MMU_INVALIDATE_RANGE);
+}
+
+static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
+					unsigned long start, unsigned long end,
+					enum mmu_call_types type)
+{
+	/* Stub for now */
+	return;
+}
+
+static inline int mmu_addr_cmp(struct mmu_rb_node *node, unsigned long addr,
+			       unsigned long len)
+{
+	if ((addr + len) <= node->virt)
+		return -1;
+	else if (addr >= node->virt && addr < (node->virt + node->len))
+		return 0;
+	else
+		return 1;
+}
+
+static inline int mmu_entry_cmp(struct mmu_rb_node *node, u32 entry)
+{
+	if (entry < node->rcventry)
+		return -1;
+	else if (entry > node->rcventry)
+		return 1;
+	else
+		return 0;
+}
+
+static struct mmu_rb_node *mmu_rb_search_by_addr(struct rb_root *root,
+						 unsigned long addr)
+{
+	struct rb_node *node = root->rb_node;
+
+	while (node) {
+		struct mmu_rb_node *mnode =
+			container_of(node, struct mmu_rb_node, rbnode);
+		/*
+		 * When searching, use at least one page length for size. The
+		 * MMU notifier will not give us anything less than that. We
+		 * also don't need anything more than a page because we are
+		 * guaranteed to have non-overlapping buffers in the tree.
+		 */
+		int result = mmu_addr_cmp(mnode, addr, PAGE_SIZE);
+
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return mnode;
+	}
+	return NULL;
+}
+
+static inline struct mmu_rb_node *mmu_rb_search_by_entry(struct rb_root *root,
+							 u32 index)
+{
+	struct mmu_rb_node *rbnode;
+	struct rb_node *node;
+
+	if (root && !RB_EMPTY_ROOT(root))
+		for (node = rb_first(root); node; node = rb_next(node)) {
+			rbnode = rb_entry(node, struct mmu_rb_node, rbnode);
+			if (rbnode->rcventry == index)
+				return rbnode;
+		}
+	return NULL;
+}
+
+static int mmu_rb_insert_by_entry(struct rb_root *root,
+				  struct mmu_rb_node *node)
+{
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+	while (*new) {
+		struct mmu_rb_node *this =
+			container_of(*new, struct mmu_rb_node, rbnode);
+		int result = mmu_entry_cmp(this, node->rcventry);
+
+		parent = *new;
+		if (result < 0)
+			new = &((*new)->rb_left);
+		else if (result > 0)
+			new = &((*new)->rb_right);
+		else
+			return 1;
+	}
+
+	rb_link_node(&node->rbnode, parent, new);
+	rb_insert_color(&node->rbnode, root);
+	return 0;
+}
+
+static int mmu_rb_insert_by_addr(struct rb_root *root, struct mmu_rb_node *node)
+{
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+	/* Figure out where to put new node */
+	while (*new) {
+		struct mmu_rb_node *this =
+			container_of(*new, struct mmu_rb_node, rbnode);
+		int result = mmu_addr_cmp(this, node->virt, node->len);
+
+		parent = *new;
+		if (result < 0)
+			new = &((*new)->rb_left);
+		else if (result > 0)
+			new = &((*new)->rb_right);
+		else
+			return 1;
+	}
+
+	/* Add new node and rebalance tree. */
+	rb_link_node(&node->rbnode, parent, new);
+	rb_insert_color(&node->rbnode, root);
+
+	return 0;
+}
diff --git a/drivers/staging/rdma/hfi1/user_exp_rcv.h b/drivers/staging/rdma/hfi1/user_exp_rcv.h
index 4f4876e1d353..28ef98a45a1e 100644
--- a/drivers/staging/rdma/hfi1/user_exp_rcv.h
+++ b/drivers/staging/rdma/hfi1/user_exp_rcv.h
@@ -50,6 +50,8 @@ 
  *
  */
 
+#include "hfi.h"
+
 #define EXP_TID_TIDLEN_MASK   0x7FFULL
 #define EXP_TID_TIDLEN_SHIFT  0
 #define EXP_TID_TIDCTRL_MASK  0x3ULL
@@ -71,4 +73,10 @@ 
 		(tid) |= EXP_TID_SET(field, (value));			\
 	} while (0)
 
+int hfi1_user_exp_rcv_init(struct file *);
+int hfi1_user_exp_rcv_free(struct hfi1_filedata *);
+int hfi1_user_exp_rcv_setup(struct file *, struct hfi1_tid_info *);
+int hfi1_user_exp_rcv_clear(struct file *, struct hfi1_tid_info *);
+int hfi1_user_exp_rcv_invalid(struct file *, struct hfi1_tid_info *);
+
 #endif /* _HFI1_USER_EXP_RCV_H */