diff options
Diffstat (limited to 'debian/patches-rt/0260-powerpc-pseries-iommu-Use-a-locallock-instead-local_.patch')
| -rw-r--r-- | debian/patches-rt/0260-powerpc-pseries-iommu-Use-a-locallock-instead-local_.patch | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/debian/patches-rt/0260-powerpc-pseries-iommu-Use-a-locallock-instead-local_.patch b/debian/patches-rt/0260-powerpc-pseries-iommu-Use-a-locallock-instead-local_.patch new file mode 100644 index 000000000..b5d7da2d1 --- /dev/null +++ b/debian/patches-rt/0260-powerpc-pseries-iommu-Use-a-locallock-instead-local_.patch @@ -0,0 +1,93 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Tue, 26 Mar 2019 18:31:54 +0100 +Subject: [PATCH 260/342] powerpc/pseries/iommu: Use a locallock instead + local_irq_save() +Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=8c0eed1d8e078239e15aeb6ebf028c167f62c92f + +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; + } + |