diff mbox

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

Message ID 1446244918-12089-6-git-send-email-ira.weiny@intel.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Ira Weiny Oct. 30, 2015, 10:41 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

Or Gerlitz Nov. 12, 2015, 5:58 a.m. UTC | #1
On Sat, Oct 31, 2015 at 12:41 AM,  <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.

So this is an wholy orthogonal mechanism for memory registrations or
de-registrations vs
what's supported by the upstream RDMA stack to which this driver
attempts to be a HW provider, right?

Ira, Mike - why do that?

2. Greg - I read an earlier comment you made that a driver in staging
need to be 1st
and most **fixed** with patches such that the TODO items to get it out
of staging are
addressed. I see here every day long train of features going into this
driver, should the
focus need to be elsewhere, according to the staging guidelines?

Or.


>  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(-)
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Greg Kroah-Hartman Nov. 20, 2015, 1:06 a.m. UTC | #2
On Thu, Nov 12, 2015 at 07:58:54AM +0200, Or Gerlitz wrote:
> On Sat, Oct 31, 2015 at 12:41 AM,  <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.
> 
> So this is an wholy orthogonal mechanism for memory registrations or
> de-registrations vs
> what's supported by the upstream RDMA stack to which this driver
> attempts to be a HW provider, right?
> 
> Ira, Mike - why do that?
> 
> 2. Greg - I read an earlier comment you made that a driver in staging
> need to be 1st
> and most **fixed** with patches such that the TODO items to get it out
> of staging are
> addressed. I see here every day long train of features going into this
> driver, should the
> focus need to be elsewhere, according to the staging guidelines?

I've already complained about this, supposedly these are things that are
needed to get it out of staging...

And yes, you are correct.

thanks,

greg k-h
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Or Gerlitz Nov. 20, 2015, 8:21 a.m. UTC | #3
On Fri, Nov 20, 2015 at 3:06 AM, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> On Thu, Nov 12, 2015 at 07:58:54AM +0200, Or Gerlitz wrote:
>> On Sat, Oct 31, 2015 at 12:41 AM,  <ira.weiny@intel.com> wrote:

>> So this is an wholy orthogonal mechanism for memory registrations or
>> de-registrations vs what's supported by the upstream RDMA stack to which this driver
>> attempts to be a HW provider, right?

>> Ira, Mike - why do that?

>> 2. Greg - I read an earlier comment you made that a driver in staging need to be 1st
>> and most **fixed** with patches such that the TODO items to get it out
>> of staging are addressed. I see here every day long train of features going into this
>> driver, should the focus need to be elsewhere, according to the staging guidelines?

> I've already complained about this, supposedly these are things that are
> needed to get it out of staging...

Greg,

When the driver was picked by Doug to staging, the only major comment
he has was the need to come up with shared code that implements IBTA
transport in SW -- to avoid the code duplication between ipath, qib and hfi1

Indeed, work has been started to do that, but since hfi1 is in staging,
none of the patches applied on it deal with that comment. I guess it
should be OK that people sends cleanup once the driver is already there,
buy should it be so heavily patched with new features? Mike? Doug?

> And yes, you are correct.

I know...
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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 */