[XEN RFC PATCH 28/40] xen/x86: decouple nodes_cover_memory with E820 map

[Wei Chen <wei.chen@xxxxxxx>]

We will reuse nodes_cover_memory for Arm to check its bootmem
info. So we introduce two arch helpers to get memory map's
entry number and specified entry's range:
    arch_get_memory_bank_number
    arch_get_memory_bank_range

Depends above two helpers, we make nodes_cover_memory become
architecture independent.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 xen/arch/x86/numa.c    | 18 ++++++++++++++++++
 xen/arch/x86/srat.c    |  8 +++-----
 xen/include/xen/numa.h |  4 ++++
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/numa.c b/xen/arch/x86/numa.c
index 6908738305..8b43be4aa7 100644
--- a/xen/arch/x86/numa.c
+++ b/xen/arch/x86/numa.c
@@ -128,6 +128,24 @@ unsigned int __init arch_get_dma_bitsize(void)
                  + PAGE_SHIFT, 32);
 }
 
+uint32_t __init arch_meminfo_get_nr_bank(void)
+{
+       return e820.nr_map;
+}
+
+int __init arch_meminfo_get_ram_bank_range(int bank,
+       unsigned long long *start, unsigned long long *end)
+{
+       if (e820.map[bank].type != E820_RAM || !start || !end) {
+               return -1;
+       }
+
+       *start = e820.map[bank].addr;
+       *end = e820.map[bank].addr + e820.map[bank].size;
+
+       return 0;
+}
+
 static void dump_numa(unsigned char key)
 {
     s_time_t now = NOW();
diff --git a/xen/arch/x86/srat.c b/xen/arch/x86/srat.c
index 6d68b8a614..2298353846 100644
--- a/xen/arch/x86/srat.c
+++ b/xen/arch/x86/srat.c
@@ -316,18 +316,16 @@ acpi_numa_memory_affinity_init(const struct 
acpi_srat_mem_affinity *ma)
 static int __init nodes_cover_memory(void)
 {
        int i;
+       uint32_t nr_banks = arch_meminfo_get_nr_bank();
 
-       for (i = 0; i < e820.nr_map; i++) {
+       for (i = 0; i < nr_banks; i++) {
                int j, found;
                unsigned long long start, end;
 
-               if (e820.map[i].type != E820_RAM) {
+               if (arch_meminfo_get_ram_bank_range(i, &start, &end)) {
                        continue;
                }
 
-               start = e820.map[i].addr;
-               end = e820.map[i].addr + e820.map[i].size;
-
                do {
                        found = 0;
                        for_each_node_mask(j, memory_nodes_parsed)
diff --git a/xen/include/xen/numa.h b/xen/include/xen/numa.h
index 0475823b13..6d18059bcd 100644
--- a/xen/include/xen/numa.h
+++ b/xen/include/xen/numa.h
@@ -89,6 +89,10 @@ static inline void clear_node_cpumask(int cpu)
        cpumask_clear_cpu(cpu, &node_to_cpumask[cpu_to_node(cpu)]);
 }
 
+extern uint32_t arch_meminfo_get_nr_bank(void);
+extern int arch_meminfo_get_ram_bank_range(int bank,
+    unsigned long long *start, unsigned long long *end);
+
 #endif /* CONFIG_NUMA */
 
 #endif /* _XEN_NUMA_H */
-- 
2.25.1