LinuxKPI: upstream a collection of drm-kmod conflicting changes

The upcoming in-kernel implementations for LinuxKPI based on work on
iwlwifi (and other wireless drivers) conflicts in a few places with
the drm-kmod graphics work outside the base system.

In order to transition smoothly extract the conflicting bits.
This included "unaligned" accessor functions, sg_pcopy_from_buffer(),
IS_*() macros (to be further restricted in the future), power management
bits (possibly no longer conflicting with DRM), and other minor changes.

Obtained-from:  bz_iwlwifi
Sponsored-by:   The FreeBSD Foundation
MFC after:	3 days
Reviewed by:	kib, hselasky, manu, bdragon (looked at earlier versions)
Differential Revision: https://reviews.freebsd.org/D26598

6 files changed, 241 insertions, 0 deletions

diff --git a/sys/compat/linuxkpi/common/include/asm/unaligned.h b/sys/compat/linuxkpi/common/include/asm/unaligned.h
new file mode 100644
index 000000000000..7597f00f7596
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/asm/unaligned.h
@@ -0,0 +1,78 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Björn Zeeb under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_ASM_UNALIGNED_H
+#define	_ASM_UNALIGNED_H
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+static __inline uint32_t
+get_unaligned_le32(const void *p)
+{
+
+	return (le32_to_cpup((const __le32 *)p));
+}
+
+static __inline void
+put_unaligned_le32(__le32 v, void *p)
+{
+	__le32 x;
+
+	x = cpu_to_le32(v);
+	memcpy(p, &x, sizeof(x));
+}
+
+static __inline void
+put_unaligned_le64(__le64 v, void *p)
+{
+	__le64 x;
+
+	x = cpu_to_le64(v);
+	memcpy(p, &x, sizeof(x));
+}
+
+static __inline uint16_t
+get_unaligned_be16(const void *p)
+{
+
+	return (be16_to_cpup((const __be16 *)p));
+}
+
+static __inline uint32_t
+get_unaligned_be32(const void *p)
+{
+
+	return (be32_to_cpup((const __be32 *)p));
+}
+
+#endif	/* _ASM_UNALIGNED_H */
diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h
index 9b0a2df72322..daef6216a151 100644
--- a/sys/compat/linuxkpi/common/include/linux/kernel.h
+++ b/sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -593,4 +593,46 @@ linux_ratelimited(linux_ratelimit_t *rl)
 #define	TAINT_WARN	0
 #define	test_taint(x)	(0)
 
+/*
+ * Checking if an option is defined would be easy if we could do CPP inside CPP.
+ * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with.  In either
+ * case the defined value is "1". A more general -Dxxx=<c> case will require
+ * more effort to deal with all possible "true" values. Hope we do not have
+ * to do this as well.
+ * The real problem is the undefined case.  To avoid this problem we do the
+ * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1"
+ * by having a #define for yyy_1 which is "ignore,".
+ * Otherwise we will just get "yyy".
+ * Need to be careful about variable substitutions in macros though.
+ * This way we make a (true, false) problem a (don't care, true, false) or a
+ * (don't care true, false).  Then we can use a variadic macro to only select
+ * the always well known and defined argument #2.  And that seems to be
+ * exactly what we need.  Use 1 for true and 0 for false to also allow
+ * #if IS_*() checks pre-compiler checks which do not like #if true.
+ */
+#define ___XAB_1		dontcare,
+#define ___IS_XAB(_ignore, _x, ...)	(_x)
+#define	__IS_XAB(_x)		___IS_XAB(_x 1, 0)
+#define	_IS_XAB(_x)		__IS_XAB(__CONCAT(___XAB_, _x))
+
+/* This is if CONFIG_ccc=y. */
+#define	IS_BUILTIN(_x)		_IS_XAB(_x)
+/* This is if CONFIG_ccc=m. */
+#define	IS_MODULE(_x)		_IS_XAB(_x ## _MODULE)
+/* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */
+#define	IS_ENABLED(_x)		(IS_BUILTIN(_x) || IS_MODULE(_x))
+/*
+ * This is weird case.  If the CONFIG_ccc is builtin (=y) this returns true;
+ * or if the CONFIG_ccc is a module (=m) and the caller is built as a module
+ * (-DMODULE defined) this returns true, but if the callers is not a module
+ * (-DMODULE not defined, which means caller is BUILTIN) then it returns
+ * false.  In other words, a module can reach the kernel, a module can reach
+ * a module, but the kernel cannot reach a module, and code never compiled
+ * cannot be reached either.
+ * XXX -- I'd hope the module-to-module case would be handled by a proper
+ * module dependency definition (MODULE_DEPEND() in FreeBSD).
+ */
+#define	IS_REACHABLE(_x)	(IS_BUILTIN(_x) || \
+				    (IS_MODULE(_x) && IS_BUILTIN(MODULE)))
+
 #endif	/* _LINUX_KERNEL_H_ */
diff --git a/sys/compat/linuxkpi/common/include/linux/kobject.h b/sys/compat/linuxkpi/common/include/linux/kobject.h
index bd9e1c4ec6f5..403ec1495c32 100644
--- a/sys/compat/linuxkpi/common/include/linux/kobject.h
+++ b/sys/compat/linuxkpi/common/include/linux/kobject.h
@@ -41,6 +41,8 @@
 struct kobject;
 struct sysctl_oid;
 
+#define	KOBJ_CHANGE		0x01
+
 struct kobj_type {
 	void (*release)(struct kobject *kobj);
 	const struct sysfs_ops *sysfs_ops;
@@ -151,4 +153,16 @@ int	kobject_set_name(struct kobject *kobj, const char *fmt, ...);
 int	kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype,
 	    struct kobject *parent, const char *fmt, ...);
 
+static __inline void
+kobject_uevent_env(struct kobject *kobj, int action, char *envp[])
+{
+
+	/*
+	 * iwlwifi(4) sends an INACCESSIBLE event when it detects that the card
+	 * (pice endpoint) is gone and it attempts a removal cleanup.
+	 * Not sure if we do anything related to udev/sysfs at the moment or
+	 * need a shortcut or simply ignore it (for now).
+	 */
+}
+
 #endif /* _LINUX_KOBJECT_H_ */
diff --git a/sys/compat/linuxkpi/common/include/linux/lockdep.h b/sys/compat/linuxkpi/common/include/linux/lockdep.h
index d2b3d4485dde..a86157ba5924 100644
--- a/sys/compat/linuxkpi/common/include/linux/lockdep.h
+++ b/sys/compat/linuxkpi/common/include/linux/lockdep.h
@@ -42,6 +42,7 @@ struct lock_class_key {
 #define	lockdep_set_class_and_name(lock, key, name)
 #define	lockdep_set_current_reclaim_state(g) do { } while (0)
 #define	lockdep_clear_current_reclaim_state() do { } while (0)
+#define	lockdep_init_map(_map, _name, _key, _x) do { } while(0)
 
 #ifdef INVARIANTS
 #define	lockdep_assert_held(m) do {					\
diff --git a/sys/compat/linuxkpi/common/include/linux/pm.h b/sys/compat/linuxkpi/common/include/linux/pm.h
new file mode 100644
index 000000000000..6b8a7e768a8c
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/pm.h
@@ -0,0 +1,52 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ *
+ * This software was developed by Björn Zeeb under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LINUXKPI_LINUX_PM_H
+#define	_LINUXKPI_LINUX_PM_H
+
+#ifdef CONFIG_PM_SLEEP
+#define	SIMPLE_DEV_PM_OPS(_name, _suspendfunc, _resumefunc)	\
+const struct dev_pm_ops _name = {				\
+        .suspend	= _suspendfunc,				\
+        .resume		= _resumefunc,				\
+        .freeze		= _suspendfunc,				\
+        .thaw		= _resumefunc,				\
+        .poweroff	= _suspendfunc,				\
+        .restore	= _resumefunc,				\
+}
+#else
+#define	SIMPLE_DEV_PM_OPS(_name, _suspendfunc, _resumefunc)	\
+const struct dev_pm_ops _name = {				\
+}
+#endif
+
+#endif	/* _LINUXKPI_LINUX_PM_H */
diff --git a/sys/compat/linuxkpi/common/include/linux/scatterlist.h b/sys/compat/linuxkpi/common/include/linux/scatterlist.h
index 9104cb8dd78a..ebf0632f6f58 100644
--- a/sys/compat/linuxkpi/common/include/linux/scatterlist.h
+++ b/sys/compat/linuxkpi/common/include/linux/scatterlist.h
@@ -32,6 +32,9 @@
 #ifndef	_LINUX_SCATTERLIST_H_
 #define	_LINUX_SCATTERLIST_H_
 
+#include <sys/types.h>
+#include <sys/sf_buf.h>
+
 #include <linux/page.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
@@ -479,4 +482,55 @@ sg_page_iter_page(struct sg_page_iter *piter)
 	return (nth_page(sg_page(piter->sg), piter->sg_pgoffset));
 }
 
+static __inline size_t
+sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
+    const void *buf, size_t buflen, off_t skip)
+{
+	struct sg_page_iter piter;
+	struct page *page;
+	struct sf_buf *sf;
+	size_t len, copied;
+	char *p, *b;
+
+	if (buflen == 0)
+		return (0);
+
+	b = __DECONST(char *, buf);
+	copied = 0;
+	sched_pin();
+	for_each_sg_page(sgl, &piter, nents, 0) {
+
+		/* Skip to the start. */
+		if (piter.sg->length <= skip) {
+			skip -= piter.sg->length;
+			continue;
+		}
+
+		/* See how much to copy. */
+		KASSERT(((piter.sg->length - skip) != 0 && (buflen != 0)),
+		    ("%s: sg len %u - skip %ju || buflen %zu is 0\n",
+		    __func__, piter.sg->length, (uintmax_t)skip, buflen));
+		len = min(piter.sg->length - skip, buflen);
+
+		page = sg_page_iter_page(&piter);
+		sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT);
+		if (sf == NULL)
+			break;
+		p = (char *)sf_buf_kva(sf) + piter.sg_pgoffset + skip;
+		memcpy(p, b, len);
+		sf_buf_free(sf);
+
+		copied += len;
+		/* Either we exactly filled the page, or we are done. */
+		buflen -= len;
+		if (buflen == 0)
+			break;
+		skip -= len;
+		b += len;
+	}
+	sched_unpin();
+
+	return (copied);
+}
+
 #endif					/* _LINUX_SCATTERLIST_H_ */