On Fri, Sep 22, 2017 at 07:26:10PM +0100, James Morse wrote: > diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h > new file mode 100644 > index 000000000000..ed329e01a301 > --- /dev/null > +++ b/arch/arm64/include/asm/sdei.h > @@ -0,0 +1,63 @@ > +/* > + * Copyright (C) 2017 ARM Ltd. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +#ifndef __ASM_SDEI_H > +#define __ASM_SDEI_H > + > +/* Values for sdei_exit_mode */ > +#define SDEI_EXIT_HVC 0 > +#define SDEI_EXIT_SMC 1 > + > +#define SDEI_STACK_SIZE IRQ_STACK_SIZE > + > +#ifndef __ASSEMBLY__ > + > +#include <linux/linkage.h> > +#include <linux/types.h> > + > +#include <asm/virt.h> > + > +extern unsigned long sdei_exit_mode; > + > +/* Software Delegated Exception entry point from firmware*/ > +asmlinkage void __sdei_asm_handler(unsigned long event_num, unsigned long arg, > + unsigned long pc, unsigned long pstate); > + > +/* > + * The above entry point does the minimum to call C code. This function does > + * anything else, before calling the driver. > + */ > +struct sdei_registered_event; > +asmlinkage unsigned long __sdei_handler(struct pt_regs *regs, > + struct sdei_registered_event *arg); > + > +extern unsigned long sdei_arch_get_entry_point(int conduit); Nitpick: drop the "extern" here. > diff --git a/arch/arm64/kernel/sdei-entry.S b/arch/arm64/kernel/sdei-entry.S > new file mode 100644 > index 000000000000..cf12f8da0789 > --- /dev/null > +++ b/arch/arm64/kernel/sdei-entry.S > @@ -0,0 +1,122 @@ > +/* > + * Software Delegated Exception entry point from firmware to the kernel. > + * > + * Copyright (C) 2017 ARM Ltd. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/linkage.h> > + > +#include <asm/alternative.h> > +#include <asm/asm-offsets.h> > +#include <asm/assembler.h> > +#include <asm/memory.h> > +#include <asm/ptrace.h> > +#include <asm/sdei.h> > +#include <uapi/linux/sdei.h> > + > +/* > + * Software Delegated Exception entry point. > + * > + * x0: Event number Currently the only event number is 0. Shall we plan for having other events in the future or we just ignore this argument? > + * x1: struct sdei_registered_event argument from registration time. > + * x2: interrupted PC > + * x3: interrupted PSTATE [...] > +/* > + * __sdei_handler() returns one of: > + * SDEI_EV_HANDLED - success, return to the interrupted context. > + * SDEI_EV_FAILED - failure, return this error code to firmare. > + * virtual-address - success, return to this address. > + */ > +static __kprobes unsigned long _sdei_handler(struct pt_regs *regs, > + struct sdei_registered_event *arg) > +{ > + u32 mode; > + int i, err = 0; > + int clobbered_registers = 4; Maybe const int here if you want to avoid magic numbers in the 'for' loop below. Otherwise it looks like some variable you intend to modify in this function. > + u64 elr = read_sysreg(elr_el1); > + u32 kernel_mode = read_sysreg(CurrentEL) | 1; /* +SPSel */ > + unsigned long vbar = read_sysreg(vbar_el1); > + > + /* Retrieve the missing registers values */ > + for (i = 0; i < clobbered_registers; i++) { > + /* from within the handler, this call always succeeds */ > + sdei_api_event_context(i, ®s->regs[i]); > + } > + > + /* > + * We didn't take an exception to get here, set PAN. UAO will be cleared > + * by sdei_event_handler()s set_fs(USER_DS) call. > + */ > + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, > + CONFIG_ARM64_PAN)); Can you use uaccess_disable() directly? > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig > index d8a9859f6102..1f6633b337aa 100644 > --- a/drivers/firmware/Kconfig > +++ b/drivers/firmware/Kconfig > @@ -50,6 +50,7 @@ config ARM_SCPI_POWER_DOMAIN > > config ARM_SDE_INTERFACE > bool "ARM Software Delegated Exception Interface (SDEI)" > + depends on ARM64 > help > The Software Delegated Exception Interface (SDEI) is an ARM > standard for registering callbacks from the platform firmware > diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c > index 4b3c7fd99c34..3ea6a19ae439 100644 > --- a/drivers/firmware/arm_sdei.c > +++ b/drivers/firmware/arm_sdei.c > @@ -154,6 +154,7 @@ int sdei_api_event_context(u32 query, u64 *result) > return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0, > result); > } > +NOKPROBE_SYMBOL(sdei_api_event_context); Should this be part of the patch introducing arm_sdei.c? > > static int sdei_api_event_get_info(u32 event, u32 info, u64 *result) > { > diff --git a/include/linux/sdei.h b/include/linux/sdei.h > index bb3dd000771e..df3fe6373e32 100644 > --- a/include/linux/sdei.h > +++ b/include/linux/sdei.h > @@ -32,6 +32,8 @@ enum sdei_conduit_types { > CONDUIT_HVC, > }; > > +#include <asm/sdei.h> > + > /* Arch code should override this to set the entry point from firmware... */ > #ifndef sdei_arch_get_entry_point > #define sdei_arch_get_entry_point(conduit) (0) Same here. This should not be built before the Kconfig change anyway. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
