iommu/arm-smmu-v3: Fix soft lockup triggered by arm_smmu_mm_invalidate_range

In the Linux kernel, the following vulnerability has been resolved:

iommu/arm-smmu-v3: Fix soft lockup triggered by arm_smmu_mm_invalidate_range

When running an SVA case, the following soft lockup is triggered:

--------------------------------------------------------------------

watchdog: BUG: soft lockup - CPU#244 stuck for 26s!

pstate: 83400009 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)

pc : arm_smmu_cmdq_issue_cmdlist+0x178/0xa50

lr : arm_smmu_cmdq_issue_cmdlist+0x150/0xa50

sp : ffff8000d83ef290

x29: ffff8000d83ef290 x28: 000000003b9aca00 x27: 0000000000000000

x26: ffff8000d83ef3c0 x25: da86c0812194a0e8 x24: 0000000000000000

x23: 0000000000000040 x22: ffff8000d83ef340 x21: ffff0000c63980c0

x20: 0000000000000001 x19: ffff0000c6398080 x18: 0000000000000000

x17: 0000000000000000 x16: 0000000000000000 x15: ffff3000b4a3bbb0

x14: ffff3000b4a30888 x13: ffff3000b4a3cf60 x12: 0000000000000000

x11: 0000000000000000 x10: 0000000000000000 x9 : ffffc08120e4d6bc

x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000048cfa

x5 : 0000000000000000 x4 : 0000000000000001 x3 : 000000000000000a

x2 : 0000000080000000 x1 : 0000000000000000 x0 : 0000000000000001

Call trace:

arm_smmu_cmdq_issue_cmdlist+0x178/0xa50

__arm_smmu_tlb_inv_range+0x118/0x254

arm_smmu_tlb_inv_range_asid+0x6c/0x130

arm_smmu_mm_invalidate_range+0xa0/0xa4

__mmu_notifier_invalidate_range_end+0x88/0x120

unmap_vmas+0x194/0x1e0

unmap_region+0xb4/0x144

do_mas_align_munmap+0x290/0x490

do_mas_munmap+0xbc/0x124

__vm_munmap+0xa8/0x19c

__arm64_sys_munmap+0x28/0x50

invoke_syscall+0x78/0x11c

el0_svc_common.constprop.0+0x58/0x1c0

do_el0_svc+0x34/0x60

el0_svc+0x2c/0xd4

el0t_64_sync_handler+0x114/0x140

el0t_64_sync+0x1a4/0x1a8

--------------------------------------------------------------------

Note that since 6.6-rc1 the arm_smmu_mm_invalidate_range above is renamed

to "arm_smmu_mm_arch_invalidate_secondary_tlbs", yet the problem remains.

The commit 06ff87bae8d3 ("arm64: mm: remove unused functions and variable

protoypes") fixed a similar lockup on the CPU MMU side. Yet, it can occur

to SMMU too, since arm_smmu_mm_arch_invalidate_secondary_tlbs() is called

typically next to MMU tlb flush function, e.g.

tlb_flush_mmu_tlbonly {

tlb_flush {

__flush_tlb_range {

// check MAX_TLBI_OPS

}

}

mmu_notifier_arch_invalidate_secondary_tlbs {

arm_smmu_mm_arch_invalidate_secondary_tlbs {

// does not check MAX_TLBI_OPS

}

}

}

Clone a CMDQ_MAX_TLBI_OPS from the MAX_TLBI_OPS in tlbflush.h, since in an

SVA case SMMU uses the CPU page table, so it makes sense to align with the

tlbflush code. Then, replace per-page TLBI commands with a single per-asid

TLBI command, if the request size hits this threshold.