KVM: PPC: Add @offset to kvmppc_spapr_tce_table

This enables userspace view of TCE tables to start from non-zero offset
on a bus. This will be used for huge DMA windows.

This only changes the internal structure, the user interface needs to
change in order to use an offset.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Alexey Kardashevskiy 2016-03-01 17:54:39 +11:00 committed by Paul Mackerras
parent fe26e52712
commit 14f853f1b2
2 changed files with 6 additions and 2 deletions

View File

@ -184,6 +184,7 @@ struct kvmppc_spapr_tce_table {
u64 liobn; u64 liobn;
struct rcu_head rcu; struct rcu_head rcu;
u32 page_shift; u32 page_shift;
u64 offset; /* in pages */
u64 size; /* window size in pages */ u64 size; /* window size in pages */
struct page *pages[0]; struct page *pages[0];
}; };

View File

@ -75,7 +75,9 @@ long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
unsigned long mask = (1ULL << stt->page_shift) - 1; unsigned long mask = (1ULL << stt->page_shift) - 1;
unsigned long idx = ioba >> stt->page_shift; unsigned long idx = ioba >> stt->page_shift;
if ((ioba & mask) || (idx + npages > stt->size) || (idx + npages < idx)) if ((ioba & mask) || (idx < stt->offset) ||
(idx - stt->offset + npages > stt->size) ||
(idx + npages < idx))
return H_PARAMETER; return H_PARAMETER;
return H_SUCCESS; return H_SUCCESS;
@ -147,6 +149,7 @@ void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
struct page *page; struct page *page;
u64 *tbl; u64 *tbl;
idx -= stt->offset;
page = stt->pages[idx / TCES_PER_PAGE]; page = stt->pages[idx / TCES_PER_PAGE];
tbl = kvmppc_page_address(page); tbl = kvmppc_page_address(page);
@ -335,7 +338,7 @@ long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
if (ret != H_SUCCESS) if (ret != H_SUCCESS)
return ret; return ret;
idx = ioba >> stt->page_shift; idx = (ioba >> stt->page_shift) - stt->offset;
page = stt->pages[idx / TCES_PER_PAGE]; page = stt->pages[idx / TCES_PER_PAGE];
tbl = (u64 *)page_address(page); tbl = (u64 *)page_address(page);