From 9764723de613d93b72e95923d25d589f539f07e9 Mon Sep 17 00:00:00 2001 From: Mikko Perttunen Date: Fri, 1 Sep 2023 14:15:07 +0300 Subject: [PATCH] gpu: host1x: Add locking in channel allocation Add locking around channel allocation to avoid race conditions. Signed-off-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20230901111510.663401-1-cyndis@kapsi.fi --- drivers/gpu/host1x/channel.c | 7 +++++++ drivers/gpu/host1x/channel.h | 3 +++ 2 files changed, 10 insertions(+) diff --git a/drivers/gpu/host1x/channel.c b/drivers/gpu/host1x/channel.c index 2d0051d6314c..79501c957532 100644 --- a/drivers/gpu/host1x/channel.c +++ b/drivers/gpu/host1x/channel.c @@ -27,6 +27,8 @@ int host1x_channel_list_init(struct host1x_channel_list *chlist, return -ENOMEM; } + mutex_init(&chlist->lock); + return 0; } @@ -104,8 +106,11 @@ static struct host1x_channel *acquire_unused_channel(struct host1x *host) unsigned int max_channels = host->info->nb_channels; unsigned int index; + mutex_lock(&chlist->lock); + index = find_first_zero_bit(chlist->allocated_channels, max_channels); if (index >= max_channels) { + mutex_unlock(&chlist->lock); dev_err(host->dev, "failed to find free channel\n"); return NULL; } @@ -114,6 +119,8 @@ static struct host1x_channel *acquire_unused_channel(struct host1x *host) set_bit(index, chlist->allocated_channels); + mutex_unlock(&chlist->lock); + return &chlist->channels[index]; } diff --git a/drivers/gpu/host1x/channel.h b/drivers/gpu/host1x/channel.h index 39044ff6c3aa..b23a8071fbd0 100644 --- a/drivers/gpu/host1x/channel.h +++ b/drivers/gpu/host1x/channel.h @@ -10,6 +10,7 @@ #include #include +#include #include "cdma.h" @@ -18,6 +19,8 @@ struct host1x_channel; struct host1x_channel_list { struct host1x_channel *channels; + + struct mutex lock; unsigned long *allocated_channels; };