This is a note to let you know that I've just added the patch titled parisc: document the shadow registers to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-document-the-shadow-registers.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a83f58bcb24003b9de2364de7c829a263423ead7 Mon Sep 17 00:00:00 2001 From: Helge Deller <deller@xxxxxx> Date: Sat, 29 Jun 2013 13:24:16 +0200 Subject: parisc: document the shadow registers From: Helge Deller <deller@xxxxxx> commit a83f58bcb24003b9de2364de7c829a263423ead7 upstream. Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- Documentation/parisc/registers | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/Documentation/parisc/registers +++ b/Documentation/parisc/registers @@ -78,6 +78,14 @@ Shadow Registers used by interruption h 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. Patches currently in stable-queue which might be from deller@xxxxxx are queue-3.10/parisc-document-the-shadow-registers.patch queue-3.10/parisc-fix-gcc-miscompilation-in-pa_memcpy.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html