[PATCH v4 16/30] xen/riscv: introduce p2m.h

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
Changes in V4:
 - update the comment above p2m_type_t. RISC-V has only 2 free for use bits in 
PTE, not 4 as Arm.
 - update the comment after p2m_ram_rw: s/guest/domain/ as this also applies 
for dom0.
 - return INVALID_MFN in gfn_to_mfn() instead of mfn(0).
 - drop PPC changes.
---
Changes in V3:
 - add SPDX
 - drop unneeded for now p2m types.
 - return false in all functions implemented with BUG() inside.
 - update the commit message
---
Changes in V2:
 - Nothing changed. Only rebase.
---
 xen/arch/riscv/include/asm/p2m.h | 102 +++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 xen/arch/riscv/include/asm/p2m.h

diff --git a/xen/arch/riscv/include/asm/p2m.h b/xen/arch/riscv/include/asm/p2m.h
new file mode 100644
index 0000000000..8ad020974f
--- /dev/null
+++ b/xen/arch/riscv/include/asm/p2m.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_RISCV_P2M_H__
+#define __ASM_RISCV_P2M_H__
+
+#include <asm/page-bits.h>
+
+#define paddr_bits PADDR_BITS
+
+/*
+ * List of possible type for each page in the p2m entry.
+ * The number of available bit per page in the pte for this purpose is 2 bits.
+ * So it's possible to only have 4 fields. If we run out of value in the
+ * future, it's possible to use higher value for pseudo-type and don't store
+ * them in the p2m entry.
+ */
+typedef enum {
+    p2m_invalid = 0,    /* Nothing mapped here */
+    p2m_ram_rw,         /* Normal read/write domain RAM */
+} p2m_type_t;
+
+#include <xen/p2m-common.h>
+
+static inline int get_page_and_type(struct page_info *page,
+                                    struct domain *domain,
+                                    unsigned long type)
+{
+    BUG_ON("unimplemented");
+    return -EINVAL;
+}
+
+/* Look up a GFN and take a reference count on the backing page. */
+typedef unsigned int p2m_query_t;
+#define P2M_ALLOC    (1u<<0)   /* Populate PoD and paged-out entries */
+#define P2M_UNSHARE  (1u<<1)   /* Break CoW sharing */
+
+static inline struct page_info *get_page_from_gfn(
+    struct domain *d, unsigned long gfn, p2m_type_t *t, p2m_query_t q)
+{
+    BUG_ON("unimplemented");
+    return NULL;
+}
+
+static inline void memory_type_changed(struct domain *d)
+{
+    BUG_ON("unimplemented");
+}
+
+
+static inline int guest_physmap_mark_populate_on_demand(struct domain *d, 
unsigned long gfn,
+                                                        unsigned int order)
+{
+    return -EOPNOTSUPP;
+}
+
+static inline int guest_physmap_add_entry(struct domain *d,
+                            gfn_t gfn,
+                            mfn_t mfn,
+                            unsigned long page_order,
+                            p2m_type_t t)
+{
+    BUG_ON("unimplemented");
+    return -EINVAL;
+}
+
+/* Untyped version for RAM only, for compatibility */
+static inline int __must_check
+guest_physmap_add_page(struct domain *d, gfn_t gfn, mfn_t mfn,
+                       unsigned int page_order)
+{
+    return guest_physmap_add_entry(d, gfn, mfn, page_order, p2m_ram_rw);
+}
+
+static inline mfn_t gfn_to_mfn(struct domain *d, gfn_t gfn)
+{
+    BUG_ON("unimplemented");
+    return INVALID_MFN;
+}
+
+static inline bool arch_acquire_resource_check(struct domain *d)
+{
+    /*
+     * The reference counting of foreign entries in set_foreign_p2m_entry()
+     * is supported on RISCV.
+     */
+    return true;
+}
+
+static inline void p2m_altp2m_check(struct vcpu *v, uint16_t idx)
+{
+    /* Not supported on RISCV. */
+}
+
+#endif /* __ASM_RISCV_P2M_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.43.0