Implement Linux alloc_page/__free_page and kmap_atomic/kunmap_atomic.


(riastradh)

@@ -1,4 +1,4 @@
-/*	$NetBSD: drm_module.c,v 1.1.2.3 2013/07/24 03:14:31 riastradh Exp $	*/
+/*	$NetBSD: drm_module.c,v 1.1.2.4 2013/07/24 03:31:12 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -30,13 +30,15 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drm_module.c,v 1.1.2.3 2013/07/24 03:14:31 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drm_module.c,v 1.1.2.4 2013/07/24 03:31:12 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/device.h>
 #include <sys/module.h>
 #include <sys/systm.h>
 
+#include <linux/highmem.h>
+
 /*
  * XXX I2C stuff should be moved to a separate drm2edid module.
  *
@@ -63,12 +65,19 @@
 
 	switch (cmd) {
 	case MODULE_CMD_INIT:
+		error = linux_kmap_init();
+		if (error) {
+			aprint_error("drm: unable to initialize linux kmap:"
+			    " %d", error);
+			return error;
+		}
 #ifdef _MODULE
 		error = config_init_component(cfdriver_ioconf_drm,
 		    cfattach_ioconf_drm, cfdata_ioconf_drm);
 		if (error) {
 			aprint_error("drm: unable to init component: %d\n",
 			    error);
+			linux_kmap_fini();
 			return error;
 		}
 		error = devsw_attach("drm", NULL, &bmajor,
@@ -78,6 +87,7 @@
 			    error);
 			(void)config_fini_component(cfdriver_ioconf_drm,
 			    cfattach_ioconf_drm, cfdata_ioconf_drm);
+			linux_kmap_fini();
 			return error;
 		}
 #endif
@@ -94,6 +104,7 @@
 			/* XXX Now what?  Reattach the devsw?  */
 			return error;
 #endif
+		linux_kmap_fini();
 		return 0;
 
 	default:

@@ -1,4 +1,4 @@
-/*	$NetBSD: gfp.h,v 1.1.2.1 2013/07/24 03:30:42 riastradh Exp $	*/
+/*	$NetBSD: gfp.h,v 1.1.2.2 2013/07/24 03:31:12 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -61,8 +61,8 @@
 #define	__GFP_ZERO		__BIT(12)
 
 /* XXX Make the nm output a little more greppable...  */
-#define	alloc_page	linux_gfp_alloc_page
-#define	__free_page	linux_gfp___free_page
+#define	alloc_page	linux_alloc_page
+#define	__free_page	linux___free_page
 
 struct page;
 struct page *	alloc_page(gfp_t);

@@ -1,4 +1,4 @@
-/*	$NetBSD: highmem.h,v 1.1.2.1 2013/07/24 00:33:12 riastradh Exp $	*/
+/*	$NetBSD: highmem.h,v 1.1.2.2 2013/07/24 03:31:12 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -31,5 +31,23 @@
 
 #ifndef _LINUX_HIGHMEM_H_
 #define _LINUX_HIGHMEM_H_
+
+#include <sys/types.h>
+#include <sys/queue.h>
+
+#include <uvm/uvm_extern.h>
+
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
+
+/* XXX Make the nm output a little more greppable...  */
+#define	kmap_atomic	linux_kmap_atomic
+#define	kunmap_atomic	linux_kunmap_atomic
+
+int	linux_kmap_init(void);
+void	linux_kmap_fini(void);
+
+void *	kmap_atomic(struct page *);
+void	kunmap_atomic(void *);
 
 #endif  /* _LINUX_HIGHMEM_H_ */

/*	$NetBSD: linux_gfp.c,v 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $	*/

/*-
 * Copyright (c) 2013 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Taylor R. Campbell.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_gfp.c,v 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $");

#include <sys/types.h>
#include <sys/queue.h>

#include <uvm/uvm_extern.h>

#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/mm_types.h>

struct page *
alloc_page(gfp_t gfp)
{
	paddr_t low = 0;
	paddr_t high = ~(paddr_t)0;
	struct pglist pglist;
	struct vm_page *vm_page;
	int error;

	if (ISSET(gfp, __GFP_DMA32))
		high = 0xffffffff;

	error = uvm_pglistalloc(PAGE_SIZE, low, high, PAGE_SIZE, PAGE_SIZE,
	    &pglist, 1, ISSET(gfp, __GFP_WAIT));
	if (error)
		return NULL;

	vm_page = TAILQ_FIRST(&pglist);
	TAILQ_REMOVE(&pglist, vm_page, pageq.queue);	/* paranoia */
	KASSERT(TAILQ_EMPTY(&pglist));

	return container_of(vm_page, struct page, p_vmp);
}

void
__free_page(struct page *page)
{
	struct pglist pglist = TAILQ_HEAD_INITIALIZER(pglist);

	TAILQ_INSERT_TAIL(&pglist, &page->p_vmp, pageq.queue);

	uvm_pglistfree(&pglist);
}

/*	$NetBSD: linux_kmap.c,v 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $	*/

/*-
 * Copyright (c) 2013 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Taylor R. Campbell.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_kmap.c,v 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $");

#include <sys/types.h>
#include <sys/mutex.h>

#include <uvm/uvm_extern.h>

#include <linux/highmem.h>

/*
 * XXX Kludgerific implementation of Linux kmap_atomic, which is
 * required not to fail.  To accomodate this, we reserve one page of
 * kva at boot (or load) and limit the system to at most kmap_atomic in
 * use at a time.
 */

static kmutex_t linux_kmap_atomic_lock;
static vaddr_t linux_kmap_atomic_vaddr;

int
linux_kmap_init(void)
{

	/* IPL_VM is needed to block pmap_kenter_pa.  */
	mutex_init(&linux_kmap_atomic_lock, MUTEX_DEFAULT, IPL_VM);

	linux_kmap_atomic_vaddr = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
	    (UVM_KMF_VAONLY | UVM_KMF_WAITVA));

	KASSERT(linux_kmap_atomic_vaddr != 0);
	KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL));

	return 0;
}

void
linux_kmap_fini(void)
{

	KASSERT(linux_kmap_atomic_vaddr != 0);
	KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL));

	uvm_km_free(kernel_map, linux_kmap_atomic_vaddr, PAGE_SIZE,
	    (UVM_KMF_VAONLY | UVM_KMF_WAITVA));

	mutex_destroy(&linux_kmap_atomic_lock);
}

void *
kmap_atomic(struct page *page)
{

	mutex_spin_enter(&linux_kmap_atomic_lock);

	KASSERT(linux_kmap_atomic_vaddr != 0);
	KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL));

	const vaddr_t vaddr = linux_kmap_atomic_vaddr;
	const paddr_t paddr = uvm_vm_page_to_phys(&page->p_vmp);
	const int prot = (VM_PROT_READ | VM_PROT_WRITE);
	const int flags = 0;
	pmap_kenter_pa(vaddr, paddr, prot, flags);
	pmap_update(pmap_kernel());

	return (void *)vaddr;
}

void
kunmap_atomic(void *addr)
{
	const vaddr_t vaddr = (vaddr_t)addr;

	KASSERT(linux_kmap_atomic_vaddr == vaddr);
	KASSERT(pmap_extract(pmap_kernel(), vaddr, NULL));

	pmap_kremove(vaddr, PAGE_SIZE);
	pmap_update(pmap_kernel());

	mutex_spin_exit(&linux_kmap_atomic_lock);
}

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.1.2.35 2013/07/24 03:11:44 riastradh Exp $
+# $NetBSD: Makefile,v 1.1.2.36 2013/07/24 03:31:12 riastradh Exp $
 
 .include "../Makefile.inc"
 .include "Makefile.inc"
@@ -51,6 +51,8 @@
 
 # XXX The following should be in a separate Linux compatibility module,
 # or modules.
+SRCS+=	linux_gfp.c
+SRCS+=	linux_kmap.c
 SRCS+=	linux_i2c.c
 SRCS+=	linux_idr.c
 SRCS+=	linux_list_sort.c