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path: root/drivers/irqchip/irq-gic-v3-its.c
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Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its.c')
-rw-r--r--drivers/irqchip/irq-gic-v3-its.c48
1 files changed, 25 insertions, 23 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index cfb9b4e5f914..35500801dc2b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1,18 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013-2017 ARM Limited, All Rights Reserved.
* Author: Marc Zyngier <marc.zyngier@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/acpi.h>
@@ -744,32 +733,43 @@ static void its_flush_cmd(struct its_node *its, struct its_cmd_block *cmd)
}
static int its_wait_for_range_completion(struct its_node *its,
- struct its_cmd_block *from,
+ u64 prev_idx,
struct its_cmd_block *to)
{
- u64 rd_idx, from_idx, to_idx;
+ u64 rd_idx, to_idx, linear_idx;
u32 count = 1000000; /* 1s! */
- from_idx = its_cmd_ptr_to_offset(its, from);
+ /* Linearize to_idx if the command set has wrapped around */
to_idx = its_cmd_ptr_to_offset(its, to);
+ if (to_idx < prev_idx)
+ to_idx += ITS_CMD_QUEUE_SZ;
+
+ linear_idx = prev_idx;
while (1) {
+ s64 delta;
+
rd_idx = readl_relaxed(its->base + GITS_CREADR);
- /* Direct case */
- if (from_idx < to_idx && rd_idx >= to_idx)
- break;
+ /*
+ * Compute the read pointer progress, taking the
+ * potential wrap-around into account.
+ */
+ delta = rd_idx - prev_idx;
+ if (rd_idx < prev_idx)
+ delta += ITS_CMD_QUEUE_SZ;
- /* Wrapped case */
- if (from_idx >= to_idx && rd_idx >= to_idx && rd_idx < from_idx)
+ linear_idx += delta;
+ if (linear_idx >= to_idx)
break;
count--;
if (!count) {
- pr_err_ratelimited("ITS queue timeout (%llu %llu %llu)\n",
- from_idx, to_idx, rd_idx);
+ pr_err_ratelimited("ITS queue timeout (%llu %llu)\n",
+ to_idx, linear_idx);
return -1;
}
+ prev_idx = rd_idx;
cpu_relax();
udelay(1);
}
@@ -786,6 +786,7 @@ void name(struct its_node *its, \
struct its_cmd_block *cmd, *sync_cmd, *next_cmd; \
synctype *sync_obj; \
unsigned long flags; \
+ u64 rd_idx; \
\
raw_spin_lock_irqsave(&its->lock, flags); \
\
@@ -807,10 +808,11 @@ void name(struct its_node *its, \
} \
\
post: \
+ rd_idx = readl_relaxed(its->base + GITS_CREADR); \
next_cmd = its_post_commands(its); \
raw_spin_unlock_irqrestore(&its->lock, flags); \
\
- if (its_wait_for_range_completion(its, cmd, next_cmd)) \
+ if (its_wait_for_range_completion(its, rd_idx, next_cmd)) \
pr_err_ratelimited("ITS cmd %ps failed\n", builder); \
}