Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 292 insertions, 0 deletions

diff --git a/src/VBox/Runtime/r0drv/linux/waitqueue-r0drv-linux.h b/src/VBox/Runtime/r0drv/linux/waitqueue-r0drv-linux.h
new file mode 100644
index 00000000..4ef87a59
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/linux/waitqueue-r0drv-linux.h
@@ -0,0 +1,292 @@
+/* $Id: waitqueue-r0drv-linux.h $ */
+/** @file
+ * IPRT - Linux Ring-0 Driver Helpers for Abstracting Wait Queues,
+ */
+
+/*
+ * Copyright (C) 2006-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#ifndef IPRT_INCLUDED_SRC_r0drv_linux_waitqueue_r0drv_linux_h
+#define IPRT_INCLUDED_SRC_r0drv_linux_waitqueue_r0drv_linux_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include "the-linux-kernel.h"
+
+#include <iprt/asm-math.h>
+#include <iprt/err.h>
+#include <iprt/string.h>
+#include <iprt/time.h>
+
+/** The resolution (nanoseconds) specified when using
+ *  schedule_hrtimeout_range. */
+#define RTR0SEMLNXWAIT_RESOLUTION   50000
+
+
+/**
+ * Kernel mode Linux wait state structure.
+ */
+typedef struct RTR0SEMLNXWAIT
+{
+    /** The wait queue entry. */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 14)  /* 4.13.0 and openSUSE */
+    wait_queue_entry_t WaitQE;
+#else
+    wait_queue_t    WaitQE;
+#endif
+    /** The absolute timeout given as nano seconds since the start of the
+     *  monotonic clock. */
+    uint64_t        uNsAbsTimeout;
+    /** The timeout in nano seconds relative to the start of the wait. */
+    uint64_t        cNsRelTimeout;
+    /** The native timeout value. */
+    union
+    {
+#ifdef IPRT_LINUX_HAS_HRTIMER
+        /** The timeout when fHighRes is true. Absolute, so no updating. */
+        ktime_t     KtTimeout;
+#endif
+        /** The timeout when fHighRes is false.  Updated after waiting. */
+        long        lTimeout;
+    } u;
+    /** Set if we use high resolution timeouts. */
+    bool            fHighRes;
+    /** Set if it's an indefinite wait. */
+    bool            fIndefinite;
+    /** Set if we've already timed out.
+     * Set by rtR0SemLnxWaitDoIt and read by rtR0SemLnxWaitHasTimedOut. */
+    bool            fTimedOut;
+    /** TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE. */
+    int             iWaitState;
+    /** The wait queue. */
+    wait_queue_head_t *pWaitQueue;
+} RTR0SEMLNXWAIT;
+/** Pointer to a linux wait state. */
+typedef RTR0SEMLNXWAIT *PRTR0SEMLNXWAIT;
+
+
+/**
+ * Initializes a wait.
+ *
+ * The caller MUST check the wait condition BEFORE calling this function or the
+ * timeout logic will be flawed.
+ *
+ * @returns VINF_SUCCESS or VERR_TIMEOUT.
+ * @param   pWait               The wait structure.
+ * @param   fFlags              The wait flags.
+ * @param   uTimeout            The timeout.
+ * @param   pWaitQueue          The wait queue head.
+ */
+DECLINLINE(int) rtR0SemLnxWaitInit(PRTR0SEMLNXWAIT pWait, uint32_t fFlags, uint64_t uTimeout,
+                                   wait_queue_head_t *pWaitQueue)
+{
+    /*
+     * Process the flags and timeout.
+     */
+    if (!(fFlags & RTSEMWAIT_FLAGS_INDEFINITE))
+    {
+/** @todo optimize: millisecs -> nanosecs -> millisec -> jiffies */
+        if (fFlags & RTSEMWAIT_FLAGS_MILLISECS)
+            uTimeout = uTimeout < UINT64_MAX / RT_US_1SEC * RT_US_1SEC
+                     ? uTimeout * RT_US_1SEC
+                     : UINT64_MAX;
+        if (uTimeout == UINT64_MAX)
+            fFlags |= RTSEMWAIT_FLAGS_INDEFINITE;
+        else
+        {
+            uint64_t u64Now;
+            if (fFlags & RTSEMWAIT_FLAGS_RELATIVE)
+            {
+                if (uTimeout == 0)
+                    return VERR_TIMEOUT;
+
+                u64Now = RTTimeSystemNanoTS();
+                pWait->cNsRelTimeout = uTimeout;
+                pWait->uNsAbsTimeout = u64Now + uTimeout;
+                if (pWait->uNsAbsTimeout < u64Now) /* overflow */
+                    fFlags |= RTSEMWAIT_FLAGS_INDEFINITE;
+            }
+            else
+            {
+                u64Now = RTTimeSystemNanoTS();
+                if (u64Now >= uTimeout)
+                    return VERR_TIMEOUT;
+
+                pWait->cNsRelTimeout = uTimeout - u64Now;
+                pWait->uNsAbsTimeout = uTimeout;
+            }
+        }
+    }
+
+    if (!(fFlags & RTSEMWAIT_FLAGS_INDEFINITE))
+    {
+        pWait->fIndefinite      = false;
+#ifdef IPRT_LINUX_HAS_HRTIMER
+        if (   (fFlags & (RTSEMWAIT_FLAGS_NANOSECS | RTSEMWAIT_FLAGS_ABSOLUTE))
+            || pWait->cNsRelTimeout < RT_NS_1SEC / HZ * 4)
+        {
+            pWait->fHighRes     = true;
+# if BITS_PER_LONG < 64
+            if (   KTIME_SEC_MAX <= LONG_MAX
+                && pWait->uNsAbsTimeout >= KTIME_SEC_MAX * RT_NS_1SEC_64 + (RT_NS_1SEC - 1))
+                fFlags |= RTSEMWAIT_FLAGS_INDEFINITE;
+            else
+# endif
+                pWait->u.KtTimeout  = ns_to_ktime(pWait->uNsAbsTimeout);
+        }
+        else
+#endif
+        {
+            uint64_t cJiffies = ASMMultU64ByU32DivByU32(pWait->cNsRelTimeout, HZ, RT_NS_1SEC);
+            if (cJiffies >= MAX_JIFFY_OFFSET)
+                fFlags |= RTSEMWAIT_FLAGS_INDEFINITE;
+            else
+            {
+                pWait->u.lTimeout   = (long)cJiffies;
+                pWait->fHighRes     = false;
+            }
+        }
+    }
+
+    if (fFlags & RTSEMWAIT_FLAGS_INDEFINITE)
+    {
+        pWait->fIndefinite      = true;
+        pWait->fHighRes         = false;
+        pWait->uNsAbsTimeout    = UINT64_MAX;
+        pWait->cNsRelTimeout    = UINT64_MAX;
+        pWait->u.lTimeout       = LONG_MAX;
+    }
+
+    pWait->fTimedOut   = false;
+
+    /*
+     * Initialize the wait queue related bits.
+     */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 39)
+    init_wait((&pWait->WaitQE));
+#else
+    RT_ZERO(pWait->WaitQE);
+    init_waitqueue_entry((&pWait->WaitQE), current);
+#endif
+    pWait->pWaitQueue = pWaitQueue;
+    pWait->iWaitState = fFlags & RTSEMWAIT_FLAGS_INTERRUPTIBLE
+                      ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
+
+    return VINF_SUCCESS;
+}
+
+
+/**
+ * Prepares the next wait.
+ *
+ * This must be called before rtR0SemLnxWaitDoIt, and the caller should check
+ * the exit conditions in-between the two calls.
+ *
+ * @param   pWait               The wait structure.
+ */
+DECLINLINE(void) rtR0SemLnxWaitPrepare(PRTR0SEMLNXWAIT pWait)
+{
+    /* Make everything thru schedule*() atomic scheduling wise. (Is this correct?) */
+    prepare_to_wait(pWait->pWaitQueue, &pWait->WaitQE, pWait->iWaitState);
+}
+
+
+/**
+ * Do the actual wait.
+ *
+ * @param   pWait               The wait structure.
+ */
+DECLINLINE(void) rtR0SemLnxWaitDoIt(PRTR0SEMLNXWAIT pWait)
+{
+    if (pWait->fIndefinite)
+        schedule();
+#ifdef IPRT_LINUX_HAS_HRTIMER
+    else if (pWait->fHighRes)
+    {
+        int rc = schedule_hrtimeout_range(&pWait->u.KtTimeout, HRTIMER_MODE_ABS, RTR0SEMLNXWAIT_RESOLUTION);
+        if (!rc)
+            pWait->fTimedOut = true;
+    }
+#endif
+    else
+    {
+        pWait->u.lTimeout = schedule_timeout(pWait->u.lTimeout);
+        if (pWait->u.lTimeout <= 0)
+            pWait->fTimedOut = true;
+    }
+    after_wait((&pWait->WaitQE));
+}
+
+
+/**
+ * Checks if a linux wait was interrupted.
+ *
+ * @returns true / false
+ * @param   pWait               The wait structure.
+ * @remarks This shall be called before the first rtR0SemLnxWaitDoIt().
+ */
+DECLINLINE(bool) rtR0SemLnxWaitWasInterrupted(PRTR0SEMLNXWAIT pWait)
+{
+    return pWait->iWaitState == TASK_INTERRUPTIBLE
+        && signal_pending(current);
+}
+
+
+/**
+ * Checks if a linux wait has timed out.
+ *
+ * @returns true / false
+ * @param   pWait               The wait structure.
+ */
+DECLINLINE(bool) rtR0SemLnxWaitHasTimedOut(PRTR0SEMLNXWAIT pWait)
+{
+    return pWait->fTimedOut;
+}
+
+
+/**
+ * Deletes a linux wait.
+ *
+ * @param   pWait               The wait structure.
+ */
+DECLINLINE(void) rtR0SemLnxWaitDelete(PRTR0SEMLNXWAIT pWait)
+{
+    finish_wait(pWait->pWaitQueue, &pWait->WaitQE);
+}
+
+
+/**
+ * Gets the max resolution of the timeout machinery.
+ *
+ * @returns Resolution specified in nanoseconds.
+ */
+DECLINLINE(uint32_t) rtR0SemLnxWaitGetResolution(void)
+{
+#ifdef IPRT_LINUX_HAS_HRTIMER
+    return RTR0SEMLNXWAIT_RESOLUTION;
+#else
+    return RT_NS_1SEC / HZ; /* ns */
+#endif
+}
+
+#endif /* !IPRT_INCLUDED_SRC_r0drv_linux_waitqueue_r0drv_linux_h */
+