On Tue, Aug 27, 2024 at 09:20:14PM +0800, Xi Ruoyao wrote:
> + register long ret asm("a0");
> + register long int nr asm("a7") = __NR_getrandom;
The first line is `long` and the second line is `long int` here. Just
call them both `long` like usual?
> struct loongarch_vdso_data {
> struct vdso_pcpu_data pdata[NR_CPUS];
> +#ifdef CONFIG_VDSO_GETRANDOM
> + struct vdso_rng_data rng_data;
> +#endif
If VSO_GETRANDOM is selected unconditionally for the arch, why the ifdef
here?
> +obj-vdso-$(CONFIG_VDSO_GETRANDOM) += vgetrandom.o vgetrandom-chacha.o
Likewise, same question here.
> + /* copy[3] = "expa" */
> + li.w copy3, 0x6b206574
Might want to mention why you're doing this.
/* copy[3] = "expa", because it was clobbered by the i index. */
Or something like that.
But on the topic of those constants,
> + li.w copy0, 0x61707865
> + li.w copy1, 0x3320646e
> + li.w copy2, 0x79622d32
What if you avoid doing this,
> +
> + ld.w cnt_lo, counter, 0
> + ld.w cnt_hi, counter, 4
> +
> +.Lblock:
> + /* state[0,1,2,3] = "expand 32-byte k" */
> + move state0, copy0
> + move state1, copy1
> + move state2, copy2
Use li.w here with the integer literals,
> + /* copy[3] = "expa" */
> + li.w copy3, 0x6b206574
Skip this,
> + add.w state0, state0, copy0
> + add.w state1, state1, copy1
> + add.w state2, state2, copy2
> + add.w state3, state3, copy3
And then use addi.w here with the integer literals instead?
I don't know anything about loongarch, so just guessing.
BTW, can you confirm that this passes the test in test_vdso_chacha?
