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powerpc/powernv/iommu: Add real mode version of iommu_table_ops::exchange()

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In real mode, TCE tables are invalidated using special
cache-inhibited store instructions which are not available in
virtual mode

This defines and implements exchange_rm() callback. This does not
define set_rm/clear_rm/flush_rm callbacks as there is no user for those -
exchange/exchange_rm are only to be used by KVM for VFIO.

The exchange_rm callback is defined for IODA1/IODA2 powernv platforms.

This replaces list_for_each_entry_rcu with its lockless version as
from now on pnv_pci_ioda2_tce_invalidate() can be called in
the real mode too.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Alexey Kardashevskiy 2017-03-22 15:21:48 +11:00 committed by Michael Ellerman
parent 6b5c19c552
commit a540aa56ba
3 changed files with 57 additions and 1 deletions
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7
arch/powerpc/include/asm/iommu.h
View File

@ -64,6 +64,11 @@ struct iommu_table_ops {
long index,
unsigned long *hpa,
enum dma_data_direction *direction);
/* Real mode */
int (*exchange_rm)(struct iommu_table *tbl,
long index,
unsigned long *hpa,
enum dma_data_direction *direction);
#endif
void (*clear)(struct iommu_table *tbl,
long index, long npages);
@ -208,6 +213,8 @@ extern void iommu_del_device(struct device *dev);
extern int __init tce_iommu_bus_notifier_init(void);
extern long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
unsigned long *hpa, enum dma_data_direction *direction);
extern long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry,
unsigned long *hpa, enum dma_data_direction *direction);
#else
static inline void iommu_register_group(struct iommu_table_group *table_group,
int pci_domain_number,

25
arch/powerpc/kernel/iommu.c
View File

@ -1004,6 +1004,31 @@ long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
}
EXPORT_SYMBOL_GPL(iommu_tce_xchg);
#ifdef CONFIG_PPC_BOOK3S_64
long iommu_tce_xchg_rm(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))) {
struct page *pg = realmode_pfn_to_page(*hpa >> PAGE_SHIFT);
if (likely(pg)) {
SetPageDirty(pg);
} else {
tbl->it_ops->exchange_rm(tbl, entry, hpa, direction);
ret = -EFAULT;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(iommu_tce_xchg_rm);
#endif
int iommu_take_ownership(struct iommu_table *tbl)
{
unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;

26
arch/powerpc/platforms/powernv/pci-ioda.c
View File

@ -1860,6 +1860,17 @@ static int pnv_ioda1_tce_xchg(struct iommu_table *tbl, long index,
return ret;
}
static int pnv_ioda1_tce_xchg_rm(struct iommu_table *tbl, long index,
unsigned long *hpa, enum dma_data_direction *direction)
{
long ret = pnv_tce_xchg(tbl, index, hpa, direction);
if (!ret)
pnv_pci_p7ioc_tce_invalidate(tbl, index, 1, true);
return ret;
}
#endif
static void pnv_ioda1_tce_free(struct iommu_table *tbl, long index,
@ -1874,6 +1885,7 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops = {
.set = pnv_ioda1_tce_build,
#ifdef CONFIG_IOMMU_API
.exchange = pnv_ioda1_tce_xchg,
.exchange_rm = pnv_ioda1_tce_xchg_rm,
#endif
.clear = pnv_ioda1_tce_free,
.get = pnv_tce_get,
@ -1948,7 +1960,7 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
{
struct iommu_table_group_link *tgl;
list_for_each_entry_rcu(tgl, &tbl->it_group_list, next) {
list_for_each_entry_lockless(tgl, &tbl->it_group_list, next) {
struct pnv_ioda_pe *pe = container_of(tgl->table_group,
struct pnv_ioda_pe, table_group);
struct pnv_phb *phb = pe->phb;
@ -2004,6 +2016,17 @@ static int pnv_ioda2_tce_xchg(struct iommu_table *tbl, long index,
return ret;
}
static int pnv_ioda2_tce_xchg_rm(struct iommu_table *tbl, long index,
unsigned long *hpa, enum dma_data_direction *direction)
{
long ret = pnv_tce_xchg(tbl, index, hpa, direction);
if (!ret)
pnv_pci_ioda2_tce_invalidate(tbl, index, 1, true);
return ret;
}
#endif
static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
@ -2024,6 +2047,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
.set = pnv_ioda2_tce_build,
#ifdef CONFIG_IOMMU_API
.exchange = pnv_ioda2_tce_xchg,
.exchange_rm = pnv_ioda2_tce_xchg_rm,
#endif
.clear = pnv_ioda2_tce_free,
.get = pnv_tce_get,