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authorMark Brown <broonie@linaro.org>2013-07-22 11:16:51 +0100
committerMark Brown <broonie@linaro.org>2013-07-22 11:16:51 +0100
commit9f6772da061814c2962aeb7d79231f7510dba313 (patch)
treee0c4a856204af6adff125ee61fe1f3059cada71b /Documentation
parentd998ec4860d366424a55059093bb022beb38a61d (diff)
parent0f4a56e16d5fc9028b62ba529177a3109513e111 (diff)
Merge tag 'v3.10.2' into linux-linaro-lsk-androidlsk-android
This is the 3.10.2 stable release
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/parisc/registers8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/parisc/registers b/Documentation/parisc/registers
index dd3caddd1ad..10c7d1730f5 100644
--- a/Documentation/parisc/registers
+++ b/Documentation/parisc/registers
@@ -78,6 +78,14 @@ Shadow Registers used by interruption handler code
TOC enable bit 1
=========================================================================
+
+The PA-RISC architecture defines 7 registers as "shadow registers".
+Those are used in RETURN FROM INTERRUPTION AND RESTORE instruction to reduce
+the state save and restore time by eliminating the need for general register
+(GR) saves and restores in interruption handlers.
+Shadow registers are the GRs 1, 8, 9, 16, 17, 24, and 25.
+
+=========================================================================
Register usage notes, originally from John Marvin, with some additional
notes from Randolph Chung.