Re: [RFC PATCH 10/10] PPC: BOOK3S: Disable/Enable TM looking at the ibm,pa-features device tree entry

2014-01-29 Thread Alexander Graf 

On 01/28/2014 05:44 PM, Aneesh Kumar K.V wrote:

Runtime disable transactional memory feature looking at pa-features
device tree entry. We need to do this so that we can run a kernel
built with TM config in PR mode. For PR guest we provide a device
tree entry with TM feature disabled in pa-features

Signed-off-by: Aneesh Kumar K.V aneesh.ku...@linux.vnet.ibm.com


We need to be able to run kernels without this patch, so better fix TM 
for good - worst case by always aborting transactions.



Alex


---
  arch/powerpc/kernel/prom.c | 5 +
  1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fa0ad8aafbcc..de8c2caf1024 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -160,6 +160,11 @@ static struct ibm_pa_feature {
{CPU_FTR_NODSISRALIGN, 0, 0,1, 1, 1},
{0, MMU_FTR_CI_LARGE_PAGE, 0,   1, 2, 0},
{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
+   /*
+* We should use CPU_FTR_TM_COMP so that if we disable TM, it won't get
+* enabled via device tree
+*/
+   {CPU_FTR_TM_COMP, 0, 0, 22, 0, 0},
  };
  
  static void __init scan_features(unsigned long node, unsigned char *ftrs,


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[RFC PATCH 10/10] PPC: BOOK3S: Disable/Enable TM looking at the ibm, pa-features device tree entry

2014-01-28 Thread Aneesh Kumar K.V 
Runtime disable transactional memory feature looking at pa-features
device tree entry. We need to do this so that we can run a kernel
built with TM config in PR mode. For PR guest we provide a device
tree entry with TM feature disabled in pa-features

Signed-off-by: Aneesh Kumar K.V aneesh.ku...@linux.vnet.ibm.com
---
 arch/powerpc/kernel/prom.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fa0ad8aafbcc..de8c2caf1024 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -160,6 +160,11 @@ static struct ibm_pa_feature {
{CPU_FTR_NODSISRALIGN, 0, 0,1, 1, 1},
{0, MMU_FTR_CI_LARGE_PAGE, 0,   1, 2, 0},
{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
+   /*
+* We should use CPU_FTR_TM_COMP so that if we disable TM, it won't get
+* enabled via device tree
+*/
+   {CPU_FTR_TM_COMP, 0, 0, 22, 0, 0},
 };
 
 static void __init scan_features(unsigned long node, unsigned char *ftrs,
-- 
1.8.5.3

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