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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
* Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
* Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/list.h>
#include <linux/stringify.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/book3s/64/mmu-hash.h>
#include <asm/mmu_context.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/kvm_host.h>
#include <asm/udbg.h>
#include <asm/iommu.h>
#include <asm/tce.h>
#include <asm/pte-walk.h>
#ifdef CONFIG_BUG
#define WARN_ON_ONCE_RM(condition) ({ \
static bool __section(.data.unlikely) __warned; \
int __ret_warn_once = !!(condition); \
\
if (unlikely(__ret_warn_once && !__warned)) { \
__warned = true; \
pr_err("WARN_ON_ONCE_RM: (%s) at %s:%u\n", \
__stringify(condition), \
__func__, __LINE__); \
dump_stack(); \
} \
unlikely(__ret_warn_once); \
})
#else
#define WARN_ON_ONCE_RM(condition) ({ \
int __ret_warn_on = !!(condition); \
unlikely(__ret_warn_on); \
})
#endif
#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
/*
* Finds a TCE table descriptor by LIOBN.
*
* WARNING: This will be called in real or virtual mode on HV KVM and virtual
* mode on PR KVM
*/
struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
unsigned long liobn)
{
struct kvmppc_spapr_tce_table *stt;
list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list)
if (stt->liobn == liobn)
return stt;
return NULL;
}
EXPORT_SYMBOL_GPL(kvmppc_find_table);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
* Validates TCE address.
* At the moment flags and page mask are validated.
* As the host kernel does not access those addresses (just puts them
* to the table and user space is supposed to process them), we can skip
* checking other things (such as TCE is a guest RAM address or the page
* was actually allocated).
*/
static long kvmppc_rm_tce_validate(struct kvmppc_spapr_tce_table *stt,
unsigned long tce)
{
unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
enum dma_data_direction dir = iommu_tce_direction(tce);
struct kvmppc_spapr_tce_iommu_table *stit;
unsigned long ua = 0;
/* Allow userspace to poison TCE table */
if (dir == DMA_NONE)
return H_SUCCESS;
if (iommu_tce_check_gpa(stt->page_shift, gpa))
return H_PARAMETER;
if (kvmppc_tce_to_ua(stt->kvm, tce, &ua, NULL))
return H_TOO_HARD;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
unsigned long hpa = 0;
struct mm_iommu_table_group_mem_t *mem;
long shift = stit->tbl->it_page_shift;
mem = mm_iommu_lookup_rm(stt->kvm->mm, ua, 1ULL << shift);
if (!mem)
return H_TOO_HARD;
if (mm_iommu_ua_to_hpa_rm(mem, ua, shift, &hpa))
return H_TOO_HARD;
}
return H_SUCCESS;
}
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
/* Note on the use of page_address() in real mode,
*
* It is safe to use page_address() in real mode on ppc64 because
* page_address() is always defined as lowmem_page_address()
* which returns __va(PFN_PHYS(page_to_pfn(page))) which is arithmetic
* operation and does not access page struct.
*
* Theoretically page_address() could be defined different
* but either WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL
* would have to be enabled.
* WANT_PAGE_VIRTUAL is never enabled on ppc32/ppc64,
* HASHED_PAGE_VIRTUAL could be enabled for ppc32 only and only
* if CONFIG_HIGHMEM is defined. As CONFIG_SPARSEMEM_VMEMMAP
* is not expected to be enabled on ppc32, page_address()
* is safe for ppc32 as well.
*
* WARNING: This will be called in real-mode on HV KVM and virtual
* mode on PR KVM
*/
static u64 *kvmppc_page_address(struct page *page)
{
#if defined(HASHED_PAGE_VIRTUAL) || defined(WANT_PAGE_VIRTUAL)
#error TODO: fix to avoid page_address() here
#endif
return (u64 *) page_address(page);
}
/*
* Handles TCE requests for emulated devices.
* Puts guest TCE values to the table and expects user space to convert them.
* Called in both real and virtual modes.
* Cannot fail so kvmppc_tce_validate must be called before it.
*
* WARNING: This will be called in real-mode on HV KVM and virtual
* mode on PR KVM
*/
void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
unsigned long idx, unsigned long tce)
{
struct page *page;
u64 *tbl;
idx -= stt->offset;
page = stt->pages[idx / TCES_PER_PAGE];
tbl = kvmppc_page_address(page);
tbl[idx % TCES_PER_PAGE] = tce;
}
EXPORT_SYMBOL_GPL(kvmppc_tce_put);
long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
unsigned long *ua, unsigned long **prmap)
{
unsigned long gfn = tce >> PAGE_SHIFT;
struct kvm_memory_slot *memslot;
memslot = search_memslots(kvm_memslots(kvm), gfn);
if (!memslot)
return -EINVAL;
*ua = __gfn_to_hva_memslot(memslot, gfn) |
(tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
if (prmap)
*prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
#endif
return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_tce_to_ua);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
static long iommu_tce_xchg_rm(struct mm_struct *mm, struct iommu_table *tbl,
unsigned long entry, unsigned long *hpa,
enum dma_data_direction *direction)
{
long ret;
ret = tbl->it_ops->exchange_rm(tbl, entry, hpa, direction);
if (!ret && ((*direction == DMA_FROM_DEVICE) ||
(*direction == DMA_BIDIRECTIONAL))) {
__be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
/*
* kvmppc_rm_tce_iommu_do_map() updates the UA cache after
* calling this so we still get here a valid UA.
*/
if (pua && *pua)
mm_iommu_ua_mark_dirty_rm(mm, be64_to_cpu(*pua));
}
return ret;
}
static void kvmppc_rm_clear_tce(struct kvm *kvm, struct iommu_table *tbl,
unsigned long entry)
{
unsigned long hpa = 0;
enum dma_data_direction dir = DMA_NONE;
iommu_tce_xchg_rm(kvm->mm, tbl, entry, &hpa, &dir);
}
static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm,
struct iommu_table *tbl, unsigned long entry)
{
struct mm_iommu_table_group_mem_t *mem = NULL;
const unsigned long pgsize = 1ULL << tbl->it_page_shift;
__be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
if (!pua)
/* it_userspace allocation might be delayed */
return H_TOO_HARD;
mem = mm_iommu_lookup_rm(kvm->mm, be64_to_cpu(*pua), pgsize);
if (!mem)
return H_TOO_HARD;
mm_iommu_mapped_dec(mem);
*pua = cpu_to_be64(0);
return H_SUCCESS;
}
static long kvmppc_rm_tce_iommu_do_unmap(struct kvm *kvm,
struct iommu_table *tbl, unsigned long entry)
{
enum dma_data_direction dir = DMA_NONE;
unsigned long hpa
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