cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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copro_fault.c (3640B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * CoProcessor (SPU/AFU) mm fault handler
      4 *
      5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
      6 *
      7 * Author: Arnd Bergmann <arndb@de.ibm.com>
      8 * Author: Jeremy Kerr <jk@ozlabs.org>
      9 */
     10#include <linux/sched.h>
     11#include <linux/mm.h>
     12#include <linux/export.h>
     13#include <asm/reg.h>
     14#include <asm/copro.h>
     15#include <asm/spu.h>
     16#include <misc/cxl-base.h>
     17
     18/*
     19 * This ought to be kept in sync with the powerpc specific do_page_fault
     20 * function. Currently, there are a few corner cases that we haven't had
     21 * to handle fortunately.
     22 */
     23int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
     24		unsigned long dsisr, vm_fault_t *flt)
     25{
     26	struct vm_area_struct *vma;
     27	unsigned long is_write;
     28	int ret;
     29
     30	if (mm == NULL)
     31		return -EFAULT;
     32
     33	if (mm->pgd == NULL)
     34		return -EFAULT;
     35
     36	mmap_read_lock(mm);
     37	ret = -EFAULT;
     38	vma = find_vma(mm, ea);
     39	if (!vma)
     40		goto out_unlock;
     41
     42	if (ea < vma->vm_start) {
     43		if (!(vma->vm_flags & VM_GROWSDOWN))
     44			goto out_unlock;
     45		if (expand_stack(vma, ea))
     46			goto out_unlock;
     47	}
     48
     49	is_write = dsisr & DSISR_ISSTORE;
     50	if (is_write) {
     51		if (!(vma->vm_flags & VM_WRITE))
     52			goto out_unlock;
     53	} else {
     54		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
     55			goto out_unlock;
     56		/*
     57		 * PROT_NONE is covered by the VMA check above.
     58		 * and hash should get a NOHPTE fault instead of
     59		 * a PROTFAULT in case fixup is needed for things
     60		 * like autonuma.
     61		 */
     62		if (!radix_enabled())
     63			WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
     64	}
     65
     66	ret = 0;
     67	*flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
     68	if (unlikely(*flt & VM_FAULT_ERROR)) {
     69		if (*flt & VM_FAULT_OOM) {
     70			ret = -ENOMEM;
     71			goto out_unlock;
     72		} else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
     73			ret = -EFAULT;
     74			goto out_unlock;
     75		}
     76		BUG();
     77	}
     78
     79out_unlock:
     80	mmap_read_unlock(mm);
     81	return ret;
     82}
     83EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
     84
     85#ifdef CONFIG_PPC_64S_HASH_MMU
     86int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
     87{
     88	u64 vsid, vsidkey;
     89	int psize, ssize;
     90
     91	switch (get_region_id(ea)) {
     92	case USER_REGION_ID:
     93		pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
     94		if (mm == NULL)
     95			return 1;
     96		psize = get_slice_psize(mm, ea);
     97		ssize = user_segment_size(ea);
     98		vsid = get_user_vsid(&mm->context, ea, ssize);
     99		vsidkey = SLB_VSID_USER;
    100		break;
    101	case VMALLOC_REGION_ID:
    102		pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
    103		psize = mmu_vmalloc_psize;
    104		ssize = mmu_kernel_ssize;
    105		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
    106		vsidkey = SLB_VSID_KERNEL;
    107		break;
    108	case IO_REGION_ID:
    109		pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
    110		psize = mmu_io_psize;
    111		ssize = mmu_kernel_ssize;
    112		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
    113		vsidkey = SLB_VSID_KERNEL;
    114		break;
    115	case LINEAR_MAP_REGION_ID:
    116		pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
    117		psize = mmu_linear_psize;
    118		ssize = mmu_kernel_ssize;
    119		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
    120		vsidkey = SLB_VSID_KERNEL;
    121		break;
    122	default:
    123		pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
    124		return 1;
    125	}
    126	/* Bad address */
    127	if (!vsid)
    128		return 1;
    129
    130	vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
    131
    132	vsid |= mmu_psize_defs[psize].sllp |
    133		((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
    134
    135	slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
    136	slb->vsid = vsid;
    137
    138	return 0;
    139}
    140EXPORT_SYMBOL_GPL(copro_calculate_slb);
    141
    142void copro_flush_all_slbs(struct mm_struct *mm)
    143{
    144#ifdef CONFIG_SPU_BASE
    145	spu_flush_all_slbs(mm);
    146#endif
    147	cxl_slbia(mm);
    148}
    149EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
    150#endif