Module Name: src Committed By: riastradh Date: Sun Dec 26 16:14:34 UTC 2021
Modified Files: src/sys/external/bsd/drm2/linux: linux_ww_mutex.c Log Message: drm: Allow ww_mutex_lock after ww_acquire_done if we already hold it. In other words, if ww_mutex_lock would return -EALREADY, that's OK and does not warrant an assertion. PR kern/56557 To generate a diff of this commit: cvs rdiff -u -r1.12 -r1.13 src/sys/external/bsd/drm2/linux/linux_ww_mutex.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/external/bsd/drm2/linux/linux_ww_mutex.c diff -u src/sys/external/bsd/drm2/linux/linux_ww_mutex.c:1.12 src/sys/external/bsd/drm2/linux/linux_ww_mutex.c:1.13 --- src/sys/external/bsd/drm2/linux/linux_ww_mutex.c:1.12 Fri Dec 24 15:25:03 2021 +++ src/sys/external/bsd/drm2/linux/linux_ww_mutex.c Sun Dec 26 16:14:34 2021 @@ -1,4 +1,4 @@ -/* $NetBSD: linux_ww_mutex.c,v 1.12 2021/12/24 15:25:03 riastradh Exp $ */ +/* $NetBSD: linux_ww_mutex.c,v 1.13 2021/12/26 16:14:34 riastradh Exp $ */ /*- * Copyright (c) 2014 The NetBSD Foundation, Inc. @@ -30,7 +30,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: linux_ww_mutex.c,v 1.12 2021/12/24 15:25:03 riastradh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: linux_ww_mutex.c,v 1.13 2021/12/26 16:14:34 riastradh Exp $"); #include <sys/types.h> #include <sys/atomic.h> @@ -108,6 +108,21 @@ ww_acquire_done(struct ww_acquire_ctx *c ctx->wwx_acquire_done = true; } +static void +ww_acquire_done_check(struct ww_mutex *mutex, struct ww_acquire_ctx *ctx) +{ + + /* + * If caller has invoked ww_acquire_done, we must already hold + * this mutex. + */ + KASSERT(mutex_owned(&mutex->wwm_lock)); + KASSERTMSG((!ctx->wwx_acquire_done || + (mutex->wwm_state == WW_CTX && mutex->wwm_u.ctx == ctx)), + "ctx %p done acquiring locks, refusing to acquire %p", + ctx, mutex); +} + void ww_acquire_fini(struct ww_acquire_ctx *ctx) { @@ -552,8 +567,6 @@ ww_mutex_lock(struct ww_mutex *mutex, st KASSERTMSG((ctx->wwx_owner == curlwp), "ctx %p owned by %p, not self (%p)", ctx, ctx->wwx_owner, curlwp); - KASSERTMSG(!ctx->wwx_acquire_done, - "ctx %p done acquiring locks, can't acquire more", ctx); KASSERTMSG((ctx->wwx_acquired != ~0U), "ctx %p finished, can't be used any more", ctx); KASSERTMSG((ctx->wwx_class == mutex->wwm_class), @@ -561,6 +574,7 @@ ww_mutex_lock(struct ww_mutex *mutex, st ctx, ctx->wwx_class, mutex, mutex->wwm_class); mutex_enter(&mutex->wwm_lock); + ww_acquire_done_check(mutex, ctx); retry: switch (mutex->wwm_state) { case WW_UNLOCKED: WW_WANTLOCK(mutex); @@ -673,8 +687,6 @@ ww_mutex_lock_interruptible(struct ww_mu KASSERTMSG((ctx->wwx_owner == curlwp), "ctx %p owned by %p, not self (%p)", ctx, ctx->wwx_owner, curlwp); - KASSERTMSG(!ctx->wwx_acquire_done, - "ctx %p done acquiring locks, can't acquire more", ctx); KASSERTMSG((ctx->wwx_acquired != ~0U), "ctx %p finished, can't be used any more", ctx); KASSERTMSG((ctx->wwx_class == mutex->wwm_class), @@ -682,6 +694,7 @@ ww_mutex_lock_interruptible(struct ww_mu ctx, ctx->wwx_class, mutex, mutex->wwm_class); mutex_enter(&mutex->wwm_lock); + ww_acquire_done_check(mutex, ctx); retry: switch (mutex->wwm_state) { case WW_UNLOCKED: WW_WANTLOCK(mutex); @@ -795,8 +808,6 @@ ww_mutex_lock_slow(struct ww_mutex *mute KASSERTMSG((ctx->wwx_owner == curlwp), "ctx %p owned by %p, not self (%p)", ctx, ctx->wwx_owner, curlwp); - KASSERTMSG(!ctx->wwx_acquire_done, - "ctx %p done acquiring locks, can't acquire more", ctx); KASSERTMSG((ctx->wwx_acquired != ~0U), "ctx %p finished, can't be used any more", ctx); KASSERTMSG((ctx->wwx_acquired == 0), @@ -807,6 +818,7 @@ ww_mutex_lock_slow(struct ww_mutex *mute ctx, ctx->wwx_class, mutex, mutex->wwm_class); mutex_enter(&mutex->wwm_lock); + ww_acquire_done_check(mutex, ctx); retry: switch (mutex->wwm_state) { case WW_UNLOCKED: mutex->wwm_state = WW_CTX; @@ -874,8 +886,6 @@ ww_mutex_lock_slow_interruptible(struct KASSERTMSG((ctx->wwx_owner == curlwp), "ctx %p owned by %p, not self (%p)", ctx, ctx->wwx_owner, curlwp); - KASSERTMSG(!ctx->wwx_acquire_done, - "ctx %p done acquiring locks, can't acquire more", ctx); KASSERTMSG((ctx->wwx_acquired != ~0U), "ctx %p finished, can't be used any more", ctx); KASSERTMSG((ctx->wwx_acquired == 0), @@ -886,6 +896,7 @@ ww_mutex_lock_slow_interruptible(struct ctx, ctx->wwx_class, mutex, mutex->wwm_class); mutex_enter(&mutex->wwm_lock); + ww_acquire_done_check(mutex, ctx); retry: switch (mutex->wwm_state) { case WW_UNLOCKED: mutex->wwm_state = WW_CTX;