101 lines
3.6 KiB
Diff
101 lines
3.6 KiB
Diff
From dd0d56cb4d2cafeedbb850448b6fe7cd5e954fbb Mon Sep 17 00:00:00 2001
|
|
Message-Id: <dd0d56cb4d2cafeedbb850448b6fe7cd5e954fbb.1601675153.git.zanussi@kernel.org>
|
|
In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
|
|
References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
|
|
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Date: Tue, 26 Mar 2019 18:31:54 +0100
|
|
Subject: [PATCH 261/333] powerpc/pseries/iommu: Use a locallock instead
|
|
local_irq_save()
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
|
|
|
|
The locallock protects the per-CPU variable tce_page. The function
|
|
attempts to allocate memory while tce_page is protected (by disabling
|
|
interrupts).
|
|
|
|
Use local_irq_save() instead of local_irq_disable().
|
|
|
|
Cc: stable-rt@vger.kernel.org
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
|
|
---
|
|
arch/powerpc/platforms/pseries/iommu.c | 16 ++++++++++------
|
|
1 file changed, 10 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
|
|
index b1a08cb760e0..8ef818ad83ec 100644
|
|
--- a/arch/powerpc/platforms/pseries/iommu.c
|
|
+++ b/arch/powerpc/platforms/pseries/iommu.c
|
|
@@ -38,6 +38,7 @@
|
|
#include <linux/of.h>
|
|
#include <linux/iommu.h>
|
|
#include <linux/rculist.h>
|
|
+#include <linux/locallock.h>
|
|
#include <asm/io.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/rtas.h>
|
|
@@ -212,6 +213,7 @@ static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
|
|
}
|
|
|
|
static DEFINE_PER_CPU(__be64 *, tce_page);
|
|
+static DEFINE_LOCAL_IRQ_LOCK(tcp_page_lock);
|
|
|
|
static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
|
|
long npages, unsigned long uaddr,
|
|
@@ -233,7 +235,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
|
|
direction, attrs);
|
|
}
|
|
|
|
- local_irq_save(flags); /* to protect tcep and the page behind it */
|
|
+ /* to protect tcep and the page behind it */
|
|
+ local_lock_irqsave(tcp_page_lock, flags);
|
|
|
|
tcep = __this_cpu_read(tce_page);
|
|
|
|
@@ -244,7 +247,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
|
|
tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
|
|
/* If allocation fails, fall back to the loop implementation */
|
|
if (!tcep) {
|
|
- local_irq_restore(flags);
|
|
+ local_unlock_irqrestore(tcp_page_lock, flags);
|
|
return tce_build_pSeriesLP(tbl->it_index, tcenum,
|
|
tbl->it_page_shift,
|
|
npages, uaddr, direction, attrs);
|
|
@@ -279,7 +282,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
|
|
tcenum += limit;
|
|
} while (npages > 0 && !rc);
|
|
|
|
- local_irq_restore(flags);
|
|
+ local_unlock_irqrestore(tcp_page_lock, flags);
|
|
|
|
if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
|
|
ret = (int)rc;
|
|
@@ -450,13 +453,14 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
|
|
DMA_BIDIRECTIONAL, 0);
|
|
}
|
|
|
|
- local_irq_disable(); /* to protect tcep and the page behind it */
|
|
+ /* to protect tcep and the page behind it */
|
|
+ local_lock_irq(tcp_page_lock);
|
|
tcep = __this_cpu_read(tce_page);
|
|
|
|
if (!tcep) {
|
|
tcep = (__be64 *)__get_free_page(GFP_ATOMIC);
|
|
if (!tcep) {
|
|
- local_irq_enable();
|
|
+ local_unlock_irq(tcp_page_lock);
|
|
return -ENOMEM;
|
|
}
|
|
__this_cpu_write(tce_page, tcep);
|
|
@@ -502,7 +506,7 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
|
|
|
|
/* error cleanup: caller will clear whole range */
|
|
|
|
- local_irq_enable();
|
|
+ local_unlock_irq(tcp_page_lock);
|
|
return rc;
|
|
}
|
|
|
|
--
|
|
2.17.1
|
|
|