[Xen-devel] [PATCH MM-PART2 RESEND v2 15/19] xen/arm: mm: Introduce DEFINE_PAGE_TABLE{, S} and use it

[Julien Grall <julien.grall@xxxxxxx>]

We have multiple static page-tables defined in arch/arm/mm.c. The
current way to define them is difficult to read and does not help when
making modification.

Two new helpers DEFINE_PAGE_TABLES (to define multiple page-tables) and
DEFINE_PAGE_TABLE (alias of DEFINE_PAGE_TABLES(..., 1)) are introduced
and now used to define static page-tables.

Note that DEFINE_PAGE_TABLES() alignment differs from what is currently
used for allocating page-tables. This is fine because page-tables are
only required to be aligned to a page-size.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---
    Changes in v2:
        - Patch in replacement of "Use the shorter version
        __aligned(PAGE_SIZE) to align page-tables".
---
 xen/arch/arm/mm.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 6db7dda0da..9a5f2e1c3f 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -50,6 +50,11 @@ struct domain *dom_xen, *dom_io, *dom_cow;
 #undef mfn_to_virt
 #define mfn_to_virt(mfn) __mfn_to_virt(mfn_x(mfn))
 
+#define DEFINE_PAGE_TABLES(name, nr)                    \
+lpae_t __aligned(PAGE_SIZE) name[LPAE_ENTRIES * (nr)]
+
+#define DEFINE_PAGE_TABLE(name) DEFINE_PAGE_TABLES(name, 1)
+
 /* Static start-of-day pagetables that we use before the allocators
  * are up. These are used by all CPUs during bringup before switching
  * to the CPUs own pagetables.
@@ -73,13 +78,13 @@ struct domain *dom_xen, *dom_io, *dom_cow;
  * Finally, if EARLY_PRINTK is enabled then xen_fixmap will be mapped
  * by the CPU once it has moved off the 1:1 mapping.
  */
-lpae_t boot_pgtable[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+DEFINE_PAGE_TABLE(boot_pgtable);
 #ifdef CONFIG_ARM_64
-lpae_t boot_first[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
-lpae_t boot_first_id[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+DEFINE_PAGE_TABLE(boot_first);
+DEFINE_PAGE_TABLE(boot_first_id);
 #endif
-lpae_t boot_second[LPAE_ENTRIES]  __attribute__((__aligned__(4096)));
-lpae_t boot_third[LPAE_ENTRIES]  __attribute__((__aligned__(4096)));
+DEFINE_PAGE_TABLE(boot_second);
+DEFINE_PAGE_TABLE(boot_third);
 
 /* Main runtime page tables */
 
@@ -93,8 +98,8 @@ lpae_t boot_third[LPAE_ENTRIES]  
__attribute__((__aligned__(4096)));
 
 #ifdef CONFIG_ARM_64
 #define HYP_PT_ROOT_LEVEL 0
-lpae_t xen_pgtable[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
-lpae_t xen_first[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+static DEFINE_PAGE_TABLE(xen_pgtable);
+static DEFINE_PAGE_TABLE(xen_first);
 #define THIS_CPU_PGTABLE xen_pgtable
 #else
 #define HYP_PT_ROOT_LEVEL 1
@@ -107,17 +112,16 @@ static DEFINE_PER_CPU(lpae_t *, xen_pgtable);
  * DOMHEAP_VIRT_START...DOMHEAP_VIRT_END in 2MB chunks. */
 static DEFINE_PER_CPU(lpae_t *, xen_dommap);
 /* Root of the trie for cpu0, other CPU's PTs are dynamically allocated */
-lpae_t cpu0_pgtable[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+static DEFINE_PAGE_TABLE(cpu0_pgtable);
 /* cpu0's domheap page tables */
-lpae_t cpu0_dommap[LPAE_ENTRIES*DOMHEAP_SECOND_PAGES]
-    __attribute__((__aligned__(4096*DOMHEAP_SECOND_PAGES)));
+static DEFINE_PAGE_TABLES(cpu0_dommap, DOMHEAP_SECOND_PAGES);
 #endif
 
 #ifdef CONFIG_ARM_64
 /* The first page of the first level mapping of the xenheap. The
  * subsequent xenheap first level pages are dynamically allocated, but
  * we need this one to bootstrap ourselves. */
-lpae_t xenheap_first_first[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+static DEFINE_PAGE_TABLE(xenheap_first_first);
 /* The zeroeth level slot which uses xenheap_first_first. Used because
  * setup_xenheap_mappings otherwise relies on mfn_to_virt which isn't
  * valid for a non-xenheap mapping. */
@@ -131,12 +135,12 @@ static __initdata int xenheap_first_first_slot = -1;
  * addresses from 0 to 0x7fffffff. Offsets into it are calculated
  * with second_linear_offset(), not second_table_offset().
  */
-lpae_t xen_second[LPAE_ENTRIES*2] __attribute__((__aligned__(4096*2)));
+static DEFINE_PAGE_TABLES(xen_second, 2);
 /* First level page table used for fixmap */
-lpae_t xen_fixmap[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+DEFINE_PAGE_TABLE(xen_fixmap);
 /* First level page table used to map Xen itself with the XN bit set
  * as appropriate. */
-static lpae_t xen_xenmap[LPAE_ENTRIES] __attribute__((__aligned__(4096)));
+static DEFINE_PAGE_TABLE(xen_xenmap);
 
 /* Non-boot CPUs use this to find the correct pagetables. */
 uint64_t init_ttbr;
-- 
2.11.0


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