drm/nouveau/mmu: implement base for new vm management

This is the first chunk of the new VMM code that provides the structures
needed to describe a GPU virtual address-space layout, as well as common
interfaces to handle VMM creation, and connecting instances to a VMM.

The constructor now allocates the PD itself, rather than having the user
handle that manually.  This won't/can't be used until after all backends
have been ported to these interfaces, so a little bit of memory will be
wasted on Fermi and newer for a couple of commits in the series.

Compatibility has been hacked into the old code to allow each GPU backend
to be ported individually.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 111 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h
new file mode 100644
index 000000000000..46cc194b2003
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.h
@@ -0,0 +1,111 @@
+#ifndef __NVKM_VMM_H__
+#define __NVKM_VMM_H__
+#include "priv.h"
+#include <core/memory.h>
+
+struct nvkm_vmm_pt {
+	/* Some GPUs have a mapping level with a dual page tables to
+	 * support large and small pages in the same address-range.
+	 *
+	 * We track the state of both page tables in one place, which
+	 * is why there's multiple PT pointers/refcounts here.
+	 */
+	struct nvkm_mmu_pt *pt[2];
+	u32 refs[2];
+
+	/* Page size handled by this PT.
+	 *
+	 * Tesla backend needs to know this when writinge PDEs,
+	 * otherwise unnecessary.
+	 */
+	u8 page;
+
+	/* Entire page table sparse.
+	 *
+	 * Used to propagate sparseness to child page tables.
+	 */
+	bool sparse:1;
+
+	/* Tracking for page directories.
+	 *
+	 * The array is indexed by PDE, and will either point to the
+	 * child page table, or indicate the PDE is marked as sparse.
+	 **/
+#define NVKM_VMM_PDE_INVALID(pde) IS_ERR_OR_NULL(pde)
+#define NVKM_VMM_PDE_SPARSED(pde) IS_ERR(pde)
+#define NVKM_VMM_PDE_SPARSE       ERR_PTR(-EBUSY)
+	struct nvkm_vmm_pt **pde;
+
+	/* Tracking for dual page tables.
+	 *
+	 * There's one entry for each LPTE, keeping track of whether
+	 * there are valid SPTEs in the same address-range.
+	 *
+	 * This information is used to manage LPTE state transitions.
+	 */
+#define NVKM_VMM_PTE_SPARSE 0x80
+#define NVKM_VMM_PTE_VALID  0x40
+#define NVKM_VMM_PTE_SPTES  0x3f
+	u8 pte[];
+};
+
+struct nvkm_vmm_desc_func {
+};
+
+struct nvkm_vmm_desc {
+	enum {
+		PGD,
+		PGT,
+		SPT,
+		LPT,
+	} type;
+	u8 bits;	/* VMA bits covered by PT. */
+	u8 size;	/* Bytes-per-PTE. */
+	u32 align;	/* PT address alignment. */
+	const struct nvkm_vmm_desc_func *func;
+};
+
+struct nvkm_vmm_page {
+	u8 shift;
+	const struct nvkm_vmm_desc *desc;
+#define NVKM_VMM_PAGE_SPARSE                                               0x01
+#define NVKM_VMM_PAGE_VRAM                                                 0x02
+#define NVKM_VMM_PAGE_HOST                                                 0x04
+#define NVKM_VMM_PAGE_COMP                                                 0x08
+#define NVKM_VMM_PAGE_Sxxx                                (NVKM_VMM_PAGE_SPARSE)
+#define NVKM_VMM_PAGE_xVxx                                  (NVKM_VMM_PAGE_VRAM)
+#define NVKM_VMM_PAGE_SVxx             (NVKM_VMM_PAGE_Sxxx | NVKM_VMM_PAGE_VRAM)
+#define NVKM_VMM_PAGE_xxHx                                  (NVKM_VMM_PAGE_HOST)
+#define NVKM_VMM_PAGE_SxHx             (NVKM_VMM_PAGE_Sxxx | NVKM_VMM_PAGE_HOST)
+#define NVKM_VMM_PAGE_xVHx             (NVKM_VMM_PAGE_xVxx | NVKM_VMM_PAGE_HOST)
+#define NVKM_VMM_PAGE_SVHx             (NVKM_VMM_PAGE_SVxx | NVKM_VMM_PAGE_HOST)
+#define NVKM_VMM_PAGE_xVxC             (NVKM_VMM_PAGE_xVxx | NVKM_VMM_PAGE_COMP)
+#define NVKM_VMM_PAGE_SVxC             (NVKM_VMM_PAGE_SVxx | NVKM_VMM_PAGE_COMP)
+#define NVKM_VMM_PAGE_xxHC             (NVKM_VMM_PAGE_xxHx | NVKM_VMM_PAGE_COMP)
+#define NVKM_VMM_PAGE_SxHC             (NVKM_VMM_PAGE_SxHx | NVKM_VMM_PAGE_COMP)
+	u8 type;
+};
+
+struct nvkm_vmm_func {
+	int (*join)(struct nvkm_vmm *, struct nvkm_memory *inst);
+	void (*part)(struct nvkm_vmm *, struct nvkm_memory *inst);
+
+	u64 page_block;
+	const struct nvkm_vmm_page page[];
+};
+
+int nvkm_vmm_new_(const struct nvkm_vmm_func *, struct nvkm_mmu *,
+		  u32 pd_header, u64 addr, u64 size, struct lock_class_key *,
+		  const char *name, struct nvkm_vmm **);
+int nvkm_vmm_ctor(const struct nvkm_vmm_func *, struct nvkm_mmu *,
+		  u32 pd_header, u64 addr, u64 size, struct lock_class_key *,
+		  const char *name, struct nvkm_vmm *);
+void nvkm_vmm_dtor(struct nvkm_vmm *);
+
+struct nvkm_vmm_user {
+	struct nvkm_sclass base;
+	int (*ctor)(struct nvkm_mmu *, u64 addr, u64 size, void *args, u32 argc,
+		    struct lock_class_key *, const char *name,
+		    struct nvkm_vmm **);
+};
+#endif