Re: [patch V4 part 5 02/31] x86/entry: Provide helpers for execute on irqstack

[Thomas Gleixner]

Alexandre Chartre <alexandre.chartre@xxxxxxxxxx> writes:
> On 5/5/20 3:53 PM, Thomas Gleixner wrote:
>> +	__this_cpu_add(irq_count, 1);					\
>> +	asm volatile(							\
>> +		"pushq  %%rbp					\n"	\
>> +		"movq   %%rsp, %%rbp				\n"	\
>> +		"movq	%%rsp, (%[ts])				\n"	\
>> +		"movq	%[ts], %%rsp				\n"	\
>> +		"1:						\n"	\
>> +		"	.pushsection .discard.instr_begin	\n"	\
>> +		"	.long 1b - .				\n"	\
>> +		"	.popsection				\n"	\
>> +		"call	" __ASM_FORM(func) "			\n"	\
>> +		"2:						\n"	\
>> +		"	.pushsection .discard.instr_end		\n"	\
>> +		"	.long 2b - .				\n"	\
>> +		"	.popsection				\n"	\
>> +		"popq	%%rsp					\n"	\
>> +		"leaveq						\n"	\
>> +		:							\
>> +		: [ts] "r" (tos)					\
>> +		: "memory"						\
>> +		);							\
>> +	__this_cpu_sub(irq_count, 1);					\
>> +}
>
> The pushsection/popsection discard.instr_begin/end sequences are used several
> times in asm() statement at different places, so I wonder if it might be worth
> having a macro.

As discussed elsewhere this is going to move to ASM partially and the
various variants are not longer necessary.

Thanks,

        tglx