Nicholas Piggin <npig...@gmail.com> writes:
> This option increases the number of SLB misses by limiting the number of
> kernel SLB entries, and increased flushing of cached lookaside information.
> This helps stress test difficult to hit paths in the kernel.
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
....
> +{
> + unsigned long slbie_data = get_paca()->slb_cache[index];
> + unsigned long ksp = get_paca()->kstack;
> +
> + slbie_data <<= SID_SHIFT;
> + slbie_data |= 0xc000000000000000ULL;
> + if ((ksp & slb_esid_mask(mmu_kernel_ssize)) == slbie_data)
> + return;
> + slbie_data |= mmu_kernel_ssize << SLBIE_SSIZE_SHIFT;
> +
> + asm volatile("slbie %0" : : "r" (slbie_data));
> +}
> +
> +static void slb_cache_slbie(unsigned int index)
May be slb_cache_slbie_user()? Similar to _kernel above?
> +{
> + unsigned long slbie_data = get_paca()->slb_cache[index];
> +
> + slbie_data <<= SID_SHIFT;
> + slbie_data |= user_segment_size(slbie_data) << SLBIE_SSIZE_SHIFT;
> + slbie_data |= SLBIE_C; /* user slbs have C=1 */
> +
> + asm volatile("slbie %0" : : "r" (slbie_data));
> +}
>
> /* Flush all user entries from the segment table of the current processor. */
> void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
> @@ -414,8 +449,14 @@ void switch_slb(struct task_struct *tsk, struct
> mm_struct *mm)
> * which would update the slb_cache/slb_cache_ptr fields in the PACA.
> */
> hard_irq_disable();
> - asm volatile("isync" : : : "memory");
> - if (cpu_has_feature(CPU_FTR_ARCH_300)) {
> + isync();
> + if (torture_slb()) {
> + __slb_flush_and_restore_bolted(0);
s/0/SLIBA_IH_ALL or something like that?
> + isync();
> + get_paca()->slb_cache_ptr = 0;
> + get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
> +
> + } else if (cpu_has_feature(CPU_FTR_ARCH_300)) {
> /*
> * SLBIA IH=3 invalidates all Class=1 SLBEs and their
> * associated lookaside structures, which matches what
> @@ -423,47 +464,36 @@ void switch_slb(struct task_struct *tsk, struct
> mm_struct *mm)
> * cache.
> */
> asm volatile(PPC_SLBIA(3));
-aneesh
