Hi,
On 12/03/2025 13:52, Luca Fancellu wrote:
Introduce variables and functions used in the common Arm code by
MPU memory management subsystem, provide struct page_info and
the MPU implementation for helpers and macros used in the common
arm code.
Moving virt_to_page helper to mmu/mpu part is not easy as it needs
visibility of 'struct page_info', so protect it with CONFIG_MMU
and provide the MPU variant in the #else branch.
Have you considered including "asm/{mmu,mpu}/mm.h" **after** struct
page_info is declared?
Introduce FRAMETABLE_NR that is required for 'pdx_group_valid' in
pdx.c.
Maybe clarify in the commit message that the frametable will be setup at
a later stage?
Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
---
xen/arch/arm/include/asm/mm.h | 18 ++++++++++++++++++
xen/arch/arm/include/asm/mpu/layout.h | 3 +++
xen/arch/arm/include/asm/mpu/mm.h | 3 +++
xen/arch/arm/mpu/mm.c | 4 ++++
4 files changed, 28 insertions(+)
diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h
index e7767cdab493..c96d33aceaf0 100644
--- a/xen/arch/arm/include/asm/mm.h
+++ b/xen/arch/arm/include/asm/mm.h
@@ -341,6 +341,8 @@ static inline uint64_t gvirt_to_maddr(vaddr_t va, paddr_t
*pa,
#define virt_to_mfn(va) __virt_to_mfn(va)
#define mfn_to_virt(mfn) __mfn_to_virt(mfn)
+#ifdef CONFIG_MMU
+
/* Convert between Xen-heap virtual addresses and page-info structures. */
static inline struct page_info *virt_to_page(const void *v)
{
@@ -355,6 +357,22 @@ static inline struct page_info *virt_to_page(const void *v)
return frame_table + pdx - frametable_base_pdx;
}
+#else /* !CONFIG_MMU */
+
+/* Convert between virtual address to page-info structure. */
+static inline struct page_info *virt_to_page(const void *v)
+{
+ unsigned long pdx;
+
+ pdx = paddr_to_pdx(virt_to_maddr(v));
+ ASSERT(pdx >= frametable_base_pdx);
+ ASSERT(pdx < frametable_pdx_end);
+
+ return frame_table + pdx - frametable_base_pdx;
+}
+
+#endif /* CONFIG_MMU */
+
static inline void *page_to_virt(const struct page_info *pg)
{
return mfn_to_virt(mfn_x(page_to_mfn(pg)));
diff --git a/xen/arch/arm/include/asm/mpu/layout.h
b/xen/arch/arm/include/asm/mpu/layout.h
index 248e55f8882d..c46b634c9c15 100644
--- a/xen/arch/arm/include/asm/mpu/layout.h
+++ b/xen/arch/arm/include/asm/mpu/layout.h
@@ -3,6 +3,9 @@
#ifndef __ARM_MPU_LAYOUT_H__
#define __ARM_MPU_LAYOUT_H__
+#define FRAMETABLE_SIZE GB(32)
I guess you copied the value for the MMU code for arm64. But is this
value still sensible for MPU? What about arm32?
In any case, some documentation would be useful.
+#define FRAMETABLE_NR (FRAMETABLE_SIZE / sizeof(*frame_table))
+
#define XEN_START_ADDRESS CONFIG_XEN_START_ADDRESS
/*
diff --git a/xen/arch/arm/include/asm/mpu/mm.h
b/xen/arch/arm/include/asm/mpu/mm.h
index 57f1e558fd44..2219c9979548 100644
--- a/xen/arch/arm/include/asm/mpu/mm.h
+++ b/xen/arch/arm/include/asm/mpu/mm.h
@@ -5,6 +5,9 @@
#include <xen/macros.h>
+extern struct page_info *frame_table;
+extern unsigned long frametable_pdx_end;
+
#define virt_to_maddr(va) ({ \
(paddr_t)va; \
})
diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c
index a11e017d8a96..4036dd62eeeb 100644
--- a/xen/arch/arm/mpu/mm.c
+++ b/xen/arch/arm/mpu/mm.c
@@ -3,6 +3,10 @@
#include <xen/lib.h>
#include <xen/init.h>
#include <xen/sizes.h>
+#include <xen/mm.h>
+
+struct page_info *frame_table;
+unsigned long __read_mostly frametable_pdx_end;
static void __init __maybe_unused build_assertions(void)
{
Cheers,
--
Julien Grall
