From: Sebastian Andrzej Siewior <[email protected]> v3.18.138-rt116-rc1 stable review patch. If anyone has any objections, please let me know.
----------- [ Upstream commit 5c1b4cd70e2ca0c81038b65babe6dc66086322e0 ] 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: [email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Tom Zanussi <[email protected]> Conflicts: arch/powerpc/platforms/pseries/iommu.c --- 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 05a2c9eefc08..acc6f64f0cb8 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -36,6 +36,7 @@ #include <linux/crash_dump.h> #include <linux/memory.h> #include <linux/of.h> +#include <linux/locallock.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/rtas.h> @@ -177,6 +178,7 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum, } 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, @@ -197,7 +199,8 @@ 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 = __get_cpu_var(tce_page); @@ -208,7 +211,7 @@ 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, tcenum, npages, uaddr, direction, attrs); } @@ -242,7 +245,7 @@ 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; @@ -397,13 +400,14 @@ static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn, u64 rc = 0; long l, limit; - 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 = __get_cpu_var(tce_page); if (!tcep) { tcep = (__be64 *)__get_free_page(GFP_ATOMIC); if (!tcep) { - local_irq_enable(); + local_unlock_irq(tcp_page_lock); return -ENOMEM; } __get_cpu_var(tce_page) = tcep; @@ -449,7 +453,7 @@ 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; } -- 2.14.1
