xen/arm: mmu: move MMU specific P2M code to mmu/p2m.{c,h}

Current P2M implementation is designed for MMU system only.
We move the MMU-specific codes into mmu/p2m.c, and only keep generic
codes in p2m.c, like VMID allocator, etc. We also move MMU-specific
definitions and declarations to mmu/p2m.h, such as p2m_tlb_flush_sync().
Also expose previously static functions p2m_vmid_allocator_init(),
p2m_alloc_vmid() for further MPU usage. Since with the code movement
p2m_free_vmid() is now used in two files, also expose p2m_free_vmid().

With the code movement, global variable max_vmid is used in multiple
files instead of a single file (and will be used in MPU P2M
implementation), declare it in the header and remove the "static" of
this variable.

Also, since p2m_invalidate_root() should be MMU only and after the
code movement the only caller of p2m_invalidate_root() outside of
mmu/p2m.c is arch_domain_creation_finished(), creating a new function
named p2m_domain_creation_finished() in mmu/p2m.c for the original
code in arch_domain_creation_finished(), and marking
p2m_invalidate_root() as static.

Take the opportunity to fix the incorrect coding style when possible.
When there is bit shift in macros, take the opportunity to add the
missing 'U' as a compliance of MISRA.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/domain.c

@@ -870,16 +870,7 @@ int arch_domain_soft_reset(struct domain *d)
 
 void arch_domain_creation_finished(struct domain *d)
 {
-    /*
-     * To avoid flushing the whole guest RAM on the first Set/Way, we
-     * invalidate the P2M to track what has been accessed.
-     *
-     * This is only turned when IOMMU is not used or the page-table are
-     * not shared because bit[0] (e.g valid bit) unset will result
-     * IOMMU fault that could be not fixed-up.
-     */
-    if ( !iommu_use_hap_pt(d) )
-        p2m_invalidate_root(p2m_get_hostp2m(d));
+    p2m_domain_creation_finished(d);
 }
 
 static int is_guest_pv32_psr(uint32_t psr)

xen/arch/arm/include/asm/mmu/p2m.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __ARM_MMU_P2M_H__
+#define __ARM_MMU_P2M_H__
+
+extern unsigned int p2m_root_order;
+extern unsigned int p2m_root_level;
+#define P2M_ROOT_ORDER p2m_root_order
+#define P2M_ROOT_LEVEL p2m_root_level
+#define P2M_ROOT_PAGES    (1U << P2M_ROOT_ORDER)
+
+struct p2m_domain;
+void p2m_force_tlb_flush_sync(struct p2m_domain *p2m);
+void p2m_tlb_flush_sync(struct p2m_domain *p2m);
+
+void p2m_clear_root_pages(struct p2m_domain *p2m);
+
+#endif /* __ARM_MMU_P2M_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

xen/arch/arm/include/asm/p2m.h

@@ -14,10 +14,19 @@
 /* Holds the bit size of IPAs in p2m tables.  */
 extern unsigned int p2m_ipa_bits;
 
-extern unsigned int p2m_root_order;
-extern unsigned int p2m_root_level;
-#define P2M_ROOT_ORDER    p2m_root_order
-#define P2M_ROOT_LEVEL p2m_root_level
+#define MAX_VMID_8_BIT  (1UL << 8)
+#define MAX_VMID_16_BIT (1UL << 16)
+
+#define INVALID_VMID 0 /* VMID 0 is reserved */
+
+#ifdef CONFIG_ARM_64
+extern unsigned int max_vmid;
+/* VMID is by default 8 bit width on AArch64 */
+#define MAX_VMID       max_vmid
+#else
+/* VMID is always 8 bit width on AArch32 */
+#define MAX_VMID        MAX_VMID_8_BIT
+#endif
 
 struct domain;
 
@@ -156,6 +165,12 @@ typedef enum {
 #endif
 #include <xen/p2m-common.h>
 
+#if defined(CONFIG_MMU)
+# include <asm/mmu/p2m.h>
+#else
+# error "Unknown memory management layout"
+#endif
+
 static inline bool arch_acquire_resource_check(struct domain *d)
 {
     /*
@@ -180,6 +195,10 @@ void p2m_altp2m_check(struct vcpu *v, uint16_t idx)
  */
 void p2m_restrict_ipa_bits(unsigned int ipa_bits);
 
+void p2m_vmid_allocator_init(void);
+int p2m_alloc_vmid(struct domain *d);
+void p2m_free_vmid(struct domain *d);
+
 /* Second stage paging setup, to be called on all CPUs */
 void setup_virt_paging(void);
 
@@ -242,8 +261,6 @@ static inline int p2m_is_write_locked(struct p2m_domain *p2m)
     return rw_is_write_locked(&p2m->lock);
 }
 
-void p2m_tlb_flush_sync(struct p2m_domain *p2m);
-
 /* Look up the MFN corresponding to a domain's GFN. */
 mfn_t p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t);
 
@@ -271,8 +288,7 @@ int p2m_set_entry(struct p2m_domain *p2m,
 
 bool p2m_resolve_translation_fault(struct domain *d, gfn_t gfn);
 
-void p2m_clear_root_pages(struct p2m_domain *p2m);
-void p2m_invalidate_root(struct p2m_domain *p2m);
+void p2m_domain_creation_finished(struct domain *d);
 
 /*
  * Clean & invalidate caches corresponding to a region [start,end) of guest

xen/arch/arm/mmu/Makefile

@@ -1,3 +1,4 @@
+obj-y += p2m.o
 obj-y += pt.o
 obj-y += setup.o
 obj-y += smpboot.o