kernel.git/arch/powerpc/kernel/head_32.h, branch linux-5.13.y

powerpc/32s: Move KUEP locking/unlocking in C

2021-03-29T02:22:10Z

This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500

2021-03-29T02:22:10Z

Only book3s/32 and e500 have significative work to do in prepare_transfer_to_handler. Other 32 bit have nothing to do at all. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b5e29ca0e557c11340415a13fe8b107189d315e1.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Save remaining registers in exception prolog

2021-03-29T02:22:10Z

Save non volatile registers, XER, CTR, MSR and NIP in exception prolog. Also assign proper value to r2 and r3 there. For now, recalculate thread pointer in prepare_transfer_to_handler. It will disappear once KUAP is ported to C. And remove the comment which is now completely wrong. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/56f0cde9dd0362edf2ddba4d887552013eee7329.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Refactor saving of volatile registers in exception prologs

2021-03-29T02:22:10Z

Exception prologs all do the same at the end: - Save trapno in stack - Mark stack with exception marker - Save r0 - Save r3 to r8 Refactor that into a COMMON_EXCEPTION_PROLOG_END macro. At the same time use r1 instead of r11. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e1c45d2e895e0693c42d2a6840df1105a148efea.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Remove the xfer parameter in EXCEPTION() macro

2021-03-29T02:22:09Z

The xfer parameter is not used anymore, remove it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/17c7d68bd18f7d2f1ab24a1a20d9ed33bbcda741.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE

2021-03-29T02:22:09Z

In order to get more control in exception prolog, dismantle all non standard exception macros, finishing with EXC_XFER_STD and EXC_XFER_LITE and EXC_XFER_TEMPLATE. Also remove transfer_to_handler_full and ret_from_except and ret_from_except_full as they are not used anymore. Last parameter of EXCEPTION() is now ignored, will be removed in a later patch to avoid too much churn. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ca5795d04a220586b7037dbbbe6951dfa9e768eb.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs

2021-03-29T02:22:09Z

In order to increase flexibility, add a macro that will for now call transfer_to_handler. As transfer_to_handler doesn't do the actual transfer anymore, also name it prepare_transfer_to_handler. The following patches will progressively remove the use of transfer_to_handler label. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7f757c52518ab1d7b27ad5113b10f860e803f467.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Save trap number on stack in exception prolog

2021-03-29T02:22:08Z

Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Set regs parameter in r3 in transfer_to_handler

2021-03-29T02:22:08Z

All exception handlers take regs as first parameter. Instead of setting r3 just before each call to a handler, set it in transfer_to_handler. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/f994a379bb895a2cbd518cb82460ad3f3d3ccdf5.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Always save non volatile registers on exception entry

2021-03-29T02:22:07Z

In preparation of handling exception entry and exit in C, in order to simplify the handling, always save non volatile registers when entering an exception. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3ce8ced87a4f1467fa36fcc50763d53b45e466c1.1615552867.git.christophe.leroy@csgroup.eu