kernel.git/arch/powerpc/kernel/entry_32.S, branch linux-5.13.y

powerpc/32: Manage KUAP in C

2021-03-29T02:22:11Z

Move all KUAP management in C. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/199365ddb58d579daf724815f2d0acb91cc49d19.1615552867.git.christophe.leroy@csgroup.eu

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: Return directly from power_save_ppc32_restore()

2021-03-29T02:22:10Z

transfer_to_handler_cont: is now just a blr. Directly perform blr in power_save_ppc32_restore(). Also remove useless setting of r11 in e500 version of power_save_ppc32_restore(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e337506e08a4df95b11d2290104b92f0dcdb5548.1615552867.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: 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: Only restore non volatile registers when required

2021-03-29T02:22:09Z

Until now, non volatile registers were restored everytime they were saved, ie using EXC_XFER_STD meant saving and restoring them while EXC_XFER_LITE meant neither saving not restoring them. Now that they are always saved, EXC_XFER_STD means to restore them and EXC_XFER_LITE means to not restore them. Most of the users of EXC_XFER_STD only need to retrieve the non volatile registers. For them there is no need to restore the non volatile registers as they have not been modified. Only very few exceptions require non volatile registers restore. Opencode the few places which require saving of non volatile registers. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d1cb12d8023cc6afc1f07150565571373c04945c.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: Call bad_page_fault() from do_page_fault()

2021-03-29T02:22:08Z

Now that non volatile registers are saved at all time, no need to split bad_page_fault() out of do_page_fault(). Remove handle_page_fault() and use do_page_fault() directly. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/cfb95be8863204cc2bf45a22ea44dd1d0dc16b7f.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