From: harry <harry@hebutterworth.freeserve.co.uk>
To: xen-devel@lists.xensource.com
Subject: [PATCH][2/17] USB virt 2.6 split driver---xenidc buffer resource provider
Date: Mon, 21 Nov 2005 13:18:45 +0000 [thread overview]
Message-ID: <1132579125.31295.113.camel@localhost.localdomain> (raw)
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This patch implements a resource pool for buffer resources used by the
xenidc transport which is in turn used by the USB driver.
Signed-off-by: Harry Butterworth <butterwo@uk.ibm.com>
[-- Attachment #2: p2-xenidc-buffer-resource-provider.patch --]
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diff -r 7adcceaaf851 -r 1e2c0ff9c46a linux-2.6-xen-sparse/drivers/xen/xenidc/Makefile
--- a/linux-2.6-xen-sparse/drivers/xen/xenidc/Makefile Sun Nov 20 14:53:27 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/xenidc/Makefile Sun Nov 20 14:53:55 2005
@@ -3,3 +3,4 @@
xenidc-objs =
xenidc-objs += xenidc_callback.o
xenidc-objs += xenidc_work.o
+xenidc-objs += xenidc_buffer_resource_provider.o
diff -r 7adcceaaf851 -r 1e2c0ff9c46a linux-2.6-xen-sparse/drivers/xen/xenidc/xenidc_buffer_resource_provider.c
--- /dev/null Sun Nov 20 14:53:27 2005
+++ b/linux-2.6-xen-sparse/drivers/xen/xenidc/xenidc_buffer_resource_provider.c Sun Nov 20 14:53:55 2005
@@ -0,0 +1,443 @@
+/*****************************************************************************/
+/* Xen inter-domain communication buffer resource provider. */
+/* */
+/* Copyright (c) 2005 Harry Butterworth IBM Corporation */
+/* */
+/* 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. */
+/* */
+/* 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. */
+/* */
+/* You should have received a copy of the GNU General Public License along */
+/* with this program; if not, write to the Free Software Foundation, Inc., */
+/* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
+/* */
+/*****************************************************************************/
+/*****************************************************************************/
+/* Based on */
+/* */
+/* arch/xen/drivers/blkback/blkback.c */
+/* */
+/* original copyright notice follows... */
+/*****************************************************************************/
+/******************************************************************************
+ * arch/xen/drivers/blkif/backend/main.c
+ *
+ * Back-end of the driver for virtual block devices. This portion of the
+ * driver exports a 'unified' block-device interface that can be accessed
+ * by any operating system that implements a compatible front end. A
+ * reference front-end implementation can be found in:
+ * arch/xen/drivers/blkif/frontend
+ *
+ * Copyright (c) 2003-2004, Keir Fraser & Steve Hand
+ * Copyright (c) 2005, Christopher Clark
+ */
+
+#include <asm/pgalloc.h>
+#include <linux/spinlock.h>
+#include <asm-xen/balloon.h>
+#include <asm-xen/driver_util.h>
+#include <asm-xen/xenidc_buffer_resource_provider.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include "xenidc_trace.h"
+
+struct xenidc_buffer_resource_provider_struct {
+ spinlock_t lock;
+ xenidc_buffer_resource_list resource_allocation;
+ xenidc_buffer_resource_list free_resources;
+ struct list_head page_list;
+ grant_ref_t grant_ref_pool;
+ struct page *page;
+ unsigned long mmap_vstart;
+ struct list_head empty_page_range_list;
+ struct list_head *empty_page_range_link;
+};
+
+static int xenidc_buffer_resource_provider_init_or_exit
+ (xenidc_buffer_resource_provider * provider, int exit) {
+ trace1("%p", provider);
+
+ {
+ int return_value = 0;
+
+ if (exit) {
+ goto EXIT;
+ }
+
+ spin_lock_init(&provider->lock);
+
+ provider->free_resources = xenidc_buffer_resource_list_null();
+
+ INIT_LIST_HEAD(&provider->page_list);
+
+ {
+ int i;
+
+ for (i = 0; i < provider->resource_allocation.pages;
+ i++) {
+ void *page =
+ (void *)__get_free_page(GFP_KERNEL);
+
+ if (page == NULL) {
+ return_value = -ENOMEM;
+
+ goto EXIT_NO_PAGE;
+ }
+
+ xenidc_buffer_resource_provider_free_page
+ (provider, page);
+ }
+ }
+
+ if (provider->resource_allocation.grant_references != 0) {
+ return_value = gnttab_alloc_grant_references
+ (provider->resource_allocation.grant_references,
+ &provider->grant_ref_pool);
+
+ if (return_value != 0) {
+ trace0
+ ("failed to allocate grant reference pool");
+
+ goto EXIT_NO_GRANT_REF;
+ }
+
+ provider->free_resources.grant_references =
+ provider->resource_allocation.grant_references;
+ }
+
+ if (provider->resource_allocation.empty_page_ranges != 0) {
+ provider->page = balloon_alloc_empty_page_range
+ (provider->resource_allocation.empty_page_ranges
+ *
+ provider->resource_allocation.
+ empty_page_range_page_count);
+
+ if (provider->page == NULL) {
+ return_value = -ENOMEM;
+
+ goto EXIT_NO_EMPTY_PAGE_RANGE;
+ }
+
+ provider->mmap_vstart =
+ (unsigned long)
+ pfn_to_kaddr(page_to_pfn(provider->page));
+
+ INIT_LIST_HEAD(&provider->empty_page_range_list);
+
+ provider->empty_page_range_link = vmalloc
+ (sizeof(struct list_head)
+ * provider->resource_allocation.empty_page_ranges);
+
+ if (provider->empty_page_range_link == NULL) {
+ return_value = -ENOMEM;
+
+ goto EXIT_NO_EMPTY_PAGE_RANGE_LINK;
+ }
+
+ {
+ int i;
+
+ for (i = 0;
+ i <
+ provider->resource_allocation.
+ empty_page_ranges; i++) {
+ struct list_head *link =
+ &provider->empty_page_range_link[i];
+
+ INIT_LIST_HEAD(link);
+
+ list_add(link,
+ &provider->
+ empty_page_range_list);
+ }
+ }
+
+ provider->free_resources.empty_page_ranges =
+ provider->resource_allocation.empty_page_ranges;
+
+ provider->free_resources.empty_page_range_page_count =
+ provider->resource_allocation.
+ empty_page_range_page_count;
+ }
+
+ return 0;
+
+ EXIT:
+
+ if (provider->resource_allocation.empty_page_ranges != 0) {
+ vfree(provider->empty_page_range_link);
+
+ EXIT_NO_EMPTY_PAGE_RANGE_LINK:
+
+ balloon_dealloc_empty_page_range
+ (provider->page,
+ provider->resource_allocation.empty_page_ranges
+ *
+ provider->resource_allocation.
+ empty_page_range_page_count);
+ }
+
+ EXIT_NO_EMPTY_PAGE_RANGE:
+
+ if (provider->resource_allocation.grant_references != 0) {
+ gnttab_free_grant_references(provider->grant_ref_pool);
+ }
+
+ EXIT_NO_GRANT_REF:
+
+ EXIT_NO_PAGE:
+
+ while (!list_empty(&provider->page_list)) {
+ free_page
+ ((unsigned long)
+ xenidc_buffer_resource_provider_allocate_page
+ (provider)
+ );
+ }
+
+ return return_value;
+ }
+}
+
+xenidc_buffer_resource_provider *xenidc_allocate_buffer_resource_provider
+ (xenidc_buffer_resource_list resource_allocation) {
+ trace();
+
+ {
+ xenidc_buffer_resource_provider *provider =
+ (xenidc_buffer_resource_provider *)
+ vmalloc(sizeof(xenidc_buffer_resource_provider));
+
+ if (provider != NULL) {
+ provider->resource_allocation = resource_allocation;
+
+ if (xenidc_buffer_resource_provider_init_or_exit
+ (provider, 0)
+ != 0) {
+ vfree(provider);
+
+ provider = NULL;
+ }
+ }
+
+ return provider;
+ }
+}
+
+void xenidc_free_buffer_resource_provider
+ (xenidc_buffer_resource_provider * provider) {
+ trace();
+
+ (void)xenidc_buffer_resource_provider_init_or_exit(provider, 1);
+
+ vfree(provider);
+}
+
+xenidc_buffer_resource_list
+ xenidc_buffer_resource_provider_query_free_resources
+ (xenidc_buffer_resource_provider * provider) {
+ trace();
+
+ {
+ xenidc_buffer_resource_list list;
+
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ list = provider->free_resources;
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+
+ return list;
+ }
+}
+
+void *xenidc_buffer_resource_provider_allocate_page
+ (xenidc_buffer_resource_provider * provider) {
+ trace();
+
+ {
+ struct list_head *link;
+
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ provider->free_resources.pages--;
+
+ link = provider->page_list.next;
+
+ trace1("%p", link);
+
+ list_del(link);
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+
+ return link;
+ }
+}
+
+void xenidc_buffer_resource_provider_free_page
+ (xenidc_buffer_resource_provider * provider, void *page) {
+ trace1("%p", page);
+
+ {
+ struct list_head *link = page;
+
+ INIT_LIST_HEAD(link);
+
+ {
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ provider->free_resources.pages++;
+
+ list_add(link, &provider->page_list);
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+ }
+ }
+}
+
+grant_ref_t xenidc_buffer_resource_provider_allocate_grant_reference
+ (xenidc_buffer_resource_provider * provider) {
+ trace();
+
+ {
+ grant_ref_t reference;
+
+ {
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ provider->free_resources.grant_references--;
+
+ reference =
+ gnttab_claim_grant_reference(&provider->
+ grant_ref_pool);
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+ }
+
+ return reference;
+ }
+}
+
+void xenidc_buffer_resource_provider_free_grant_reference
+ (xenidc_buffer_resource_provider * provider, grant_ref_t reference) {
+ trace();
+
+ {
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ gnttab_release_grant_reference(&provider->grant_ref_pool,
+ reference);
+
+ provider->free_resources.grant_references++;
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+ }
+}
+
+unsigned long xenidc_buffer_resource_provider_allocate_empty_page_range
+ (xenidc_buffer_resource_provider * provider, unsigned long page_count) {
+ trace();
+
+ {
+ unsigned long page_range;
+
+ {
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ {
+ struct list_head *link =
+ provider->empty_page_range_list.next;
+
+ list_del_init(link);
+
+ provider->free_resources.empty_page_ranges--;
+
+ page_range =
+ (provider->mmap_vstart
+ +
+ (PAGE_SIZE
+ *
+ provider->resource_allocation.
+ empty_page_range_page_count
+ *
+ (((unsigned long)link
+ -
+ (unsigned long)provider->
+ empty_page_range_link)
+ / sizeof(struct list_head)
+ )
+ )
+ );
+ }
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+ }
+
+ return page_range;
+ }
+}
+
+void xenidc_buffer_resource_provider_free_empty_page_range
+ (xenidc_buffer_resource_provider * provider, unsigned long page_range) {
+ trace();
+
+ {
+ int i = ((page_range - provider->mmap_vstart)
+ /
+ (PAGE_SIZE
+ *
+ provider->resource_allocation.
+ empty_page_range_page_count)
+ );
+
+ unsigned long flags;
+
+ spin_lock_irqsave(&provider->lock, flags);
+
+ list_add
+ (&provider->empty_page_range_link[i],
+ &provider->empty_page_range_list);
+
+ provider->free_resources.empty_page_ranges++;
+
+ spin_unlock_irqrestore(&provider->lock, flags);
+ }
+}
+
+void xenidc_buffer_resource_list_trace(xenidc_buffer_resource_list list)
+{
+ trace();
+
+ printk
+ (KERN_INFO
+ "xenidc %s: "
+ "pages:%d; "
+ "grant_references:%d; "
+ "empty_page_ranges:%d; "
+ "empty_page_range_page_count:%d\n",
+ __PRETTY_FUNCTION__,
+ list.pages,
+ list.grant_references,
+ list.empty_page_ranges, list.empty_page_range_page_count);
+}
diff -r 7adcceaaf851 -r 1e2c0ff9c46a linux-2.6-xen-sparse/include/asm-xen/xenidc_buffer_resource_provider.h
--- /dev/null Sun Nov 20 14:53:27 2005
+++ b/linux-2.6-xen-sparse/include/asm-xen/xenidc_buffer_resource_provider.h Sun Nov 20 14:53:55 2005
@@ -0,0 +1,138 @@
+/*****************************************************************************/
+/* Xen inter-domain communication buffer resource provider. */
+/* */
+/* Copyright (c) 2005 Harry Butterworth IBM Corporation */
+/* */
+/* 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. */
+/* */
+/* 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. */
+/* */
+/* You should have received a copy of the GNU General Public License along */
+/* with this program; if not, write to the Free Software Foundation, Inc., */
+/* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
+/* */
+/*****************************************************************************/
+/* */
+/* The main point of this buffer resource provider code is to make it */
+/* possible to write some other generic code to manipulate various types of */
+/* buffers and keep the other code independent of any buffer-type-specific */
+/* resource management. */
+/* */
+/* The initial implementation of this code provides sets of resources to */
+/* clients in isolated per-client pools but this code provides a centralised */
+/* point of buffer resource management so it will be easy to implement a */
+/* more efficient version which maintains isolation for a base set of */
+/* resources to avoid deadlock and then shares additional resources between */
+/* clients. */
+
+#ifndef __ASM_XEN_XENIDC_BUFFER_RESOURCE_PROVIDER_H__
+#define __ASM_XEN_XENIDC_BUFFER_RESOURCE_PROVIDER_H__
+
+#include <asm/types.h>
+#include <asm-xen/gnttab.h>
+
+/* A xenidc_buffer_resource_list describes a set of resources, sometimes a */
+/* set of resources required for an operation and sometimes a set of */
+/* resources available to perform operations. */
+
+typedef struct xenidc_buffer_resource_list_struct xenidc_buffer_resource_list;
+
+struct xenidc_buffer_resource_list_struct {
+ u32 pages;
+ u32 grant_references;
+ u32 empty_page_ranges;
+ u32 empty_page_range_page_count;
+};
+
+/* xenidc_buffer_resource_list_null returns a list specifying no resources. */
+
+static inline xenidc_buffer_resource_list xenidc_buffer_resource_list_null(void)
+{
+ xenidc_buffer_resource_list list;
+
+ memset(&list, 0, sizeof(list));
+
+ return list;
+}
+
+/* xenidc_buffer_resource_list_subset_of returns true iff the resource */
+/* requirements specified by list 'a' are met by the resources available in */
+/* list 'b'. */
+
+static inline int xenidc_buffer_resource_list_subset_of
+ (xenidc_buffer_resource_list * a, xenidc_buffer_resource_list * b) {
+ return ((a->pages <= b->pages)
+ && (a->grant_references <= b->grant_references)
+ && (a->empty_page_ranges <= b->empty_page_ranges)
+ &&
+ (a->empty_page_range_page_count <=
+ b->empty_page_range_page_count)
+ );
+}
+
+/* xenidc_buffer_resource_list_plus_equals adds the resource requirements */
+/* specified by list 'b' to the resource requirements specified by list 'a' */
+/* such that the resulting list 'a' specifies a set of resources sufficient */
+/* to meet the sum of the requirements of the original 'a' list and 'b' lists.*/
+
+static inline void xenidc_buffer_resource_list_plus_equals
+ (xenidc_buffer_resource_list * a, xenidc_buffer_resource_list * b) {
+ a->pages += b->pages;
+ a->grant_references += b->grant_references;
+ a->empty_page_ranges += b->empty_page_ranges;
+
+ if (b->empty_page_range_page_count > a->empty_page_range_page_count) {
+ a->empty_page_range_page_count = b->empty_page_range_page_count;
+ }
+}
+
+/* Clients allocate a xenidc_buffer_resource_provider to provide themselves */
+/* with a pool of resources. */
+
+typedef struct xenidc_buffer_resource_provider_struct
+ xenidc_buffer_resource_provider;
+
+extern xenidc_buffer_resource_provider *xenidc_allocate_buffer_resource_provider
+ (xenidc_buffer_resource_list resource_allocation);
+
+extern void xenidc_free_buffer_resource_provider
+ (xenidc_buffer_resource_provider * provider);
+
+/* Find out what resources are currently free for allocation. */
+
+extern xenidc_buffer_resource_list
+ xenidc_buffer_resource_provider_query_free_resources
+ (xenidc_buffer_resource_provider * provider);
+
+/* Resource-type specific allocate/free functions. */
+
+extern void *xenidc_buffer_resource_provider_allocate_page
+ (xenidc_buffer_resource_provider * provider);
+
+extern void xenidc_buffer_resource_provider_free_page
+ (xenidc_buffer_resource_provider * provider, void *page);
+
+extern grant_ref_t xenidc_buffer_resource_provider_allocate_grant_reference
+ (xenidc_buffer_resource_provider * provider);
+
+extern void xenidc_buffer_resource_provider_free_grant_reference
+ (xenidc_buffer_resource_provider * provider, grant_ref_t reference);
+
+extern unsigned long xenidc_buffer_resource_provider_allocate_empty_page_range
+ (xenidc_buffer_resource_provider * provider, unsigned long page_count);
+
+extern void xenidc_buffer_resource_provider_free_empty_page_range
+ (xenidc_buffer_resource_provider * provider, unsigned long page_range);
+
+/* xenidc_buffer_resource_list_trace is used for debugging and printks a dump */
+/* of the resource list. */
+
+extern void xenidc_buffer_resource_list_trace(xenidc_buffer_resource_list list);
+
+#endif
[-- Attachment #3: Type: text/plain, Size: 138 bytes --]
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next reply other threads:[~2005-11-21 13:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-21 13:18 harry [this message]
2005-11-21 20:18 ` [PATCH][2/17] USB virt 2.6 split driver---xenidc buffer resource provider Muli Ben-Yehuda
2005-11-21 21:30 ` Harry Butterworth
2005-11-22 10:55 ` Muli Ben-Yehuda
2005-11-22 11:11 ` harry
2005-11-22 11:12 ` Keir Fraser
2005-11-22 11:22 ` Muli Ben-Yehuda
2005-11-22 12:06 ` Keir Fraser
2005-11-22 12:14 ` *** SPAM *** " harry
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