xen/arm: switch find_domU_holes to rangesets

remove_shm_holes_for_domU() is unnecessarily complex: it re-creates the
extended regions from scratch.

Move the rangeset into find_domU_holes() and create the extended regions
only once. This makes is simpler to further manipulate the rangeset for
removing other regions.

Remove now-unused remove_shm_holes_for_domU().

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/arch/arm/domain_build.c

@@ -933,34 +933,58 @@ static int __init find_domU_holes(const struct kernel_info *kinfo,
                                   struct membanks *ext_regions)
 {
     unsigned int i;
-    uint64_t bankend;
     const uint64_t bankbase[] = GUEST_RAM_BANK_BASES;
     const uint64_t banksize[] = GUEST_RAM_BANK_SIZES;
     const struct membanks *kinfo_mem = kernel_info_get_mem_const(kinfo);
-    int res = -ENOENT;
+    struct rangeset *mem_holes;
+    int res;
+
+    mem_holes = rangeset_new(NULL, NULL, 0);
+    if ( !mem_holes )
+        return -ENOMEM;
 
     for ( i = 0; i < GUEST_RAM_BANKS; i++ )
     {
-        struct membank *ext_bank = &(ext_regions->bank[ext_regions->nr_banks]);
+        uint64_t bankend, start, size = 0;
 
-        ext_bank->start = ROUNDUP(bankbase[i] + kinfo_mem->bank[i].size, SZ_2M);
+        start = ROUNDUP(bankbase[i] + kinfo_mem->bank[i].size, SZ_2M);
 
         bankend = ~0ULL >> (64 - p2m_ipa_bits);
         bankend = min(bankend, bankbase[i] + banksize[i] - 1);
-        if ( bankend > ext_bank->start )
-            ext_bank->size = bankend - ext_bank->start + 1;
+
+        if ( bankend > start )
+            size = bankend - start + 1;
 
         /* 64MB is the minimum size of an extended region */
-        if ( ext_bank->size < MB(64) )
+        if ( size < MB(64) )
             continue;
-        ext_regions->nr_banks++;
-        res = 0;
+
+        res = rangeset_add_range(mem_holes, PFN_DOWN(start), PFN_DOWN(bankend));
+        if ( res )
+        {
+            printk(XENLOG_ERR "Failed to add: %#"PRIx64"->%#"PRIx64"\n",
+                   start, start + size - 1);
+            goto out;
+        }
     }
 
+    /* Remove static shared memory regions */
+    res = remove_shm_from_rangeset(kinfo, mem_holes);
     if ( res )
-        return res;
+        goto out;
 
-    return remove_shm_holes_for_domU(kinfo, ext_regions);
+    res = rangeset_report_ranges(mem_holes, 0,
+                                 PFN_DOWN((1ULL << p2m_ipa_bits) - 1),
+                                 add_ext_regions, ext_regions);
+    if ( res )
+        ext_regions->nr_banks = 0;
+    else if ( !ext_regions->nr_banks )
+        res = -ENOENT;
+
+ out:
+    rangeset_destroy(mem_holes);
+
+    return res;
 }
 
 static int __init find_host_extended_regions(const struct kernel_info *kinfo,

xen/arch/arm/include/asm/static-shmem.h

@@ -27,9 +27,6 @@ void init_sharedmem_pages(void);
 int remove_shm_from_rangeset(const struct kernel_info *kinfo,
                              struct rangeset *rangeset);
 
-int remove_shm_holes_for_domU(const struct kernel_info *kinfo,
-                              struct membanks *ext_regions);
-
 int make_shm_resv_memory_node(const struct kernel_info *kinfo, int addrcells,
                               int sizecells);
 
@@ -73,12 +70,6 @@ static inline int remove_shm_from_rangeset(const struct kernel_info *kinfo,
     return 0;
 }
 
-static inline int remove_shm_holes_for_domU(const struct kernel_info *kinfo,
-                                            struct membanks *ext_regions)
-{
-    return 0;
-}
-
 static inline int make_shm_resv_memory_node(const struct kernel_info *kinfo,
                                             int addrcells, int sizecells)
 {

xen/arch/arm/static-shmem.c

@@ -822,71 +822,6 @@ int __init remove_shm_from_rangeset(const struct kernel_info *kinfo,
     return 0;
 }
 
-int __init remove_shm_holes_for_domU(const struct kernel_info *kinfo,
-                                     struct membanks *ext_regions)
-{
-    const struct membanks *shm_mem = kernel_info_get_shm_mem_const(kinfo);
-    struct rangeset *guest_holes;
-    unsigned int i;
-    paddr_t start;
-    paddr_t end;
-    int res;
-
-    /* No static shared memory region. */
-    if ( shm_mem->nr_banks == 0 )
-        return 0;
-
-    dt_dprintk("Remove static shared memory holes from extended regions of DomU\n");
-
-    guest_holes = rangeset_new(NULL, NULL, 0);
-    if ( !guest_holes )
-        return -ENOMEM;
-
-    /* Copy extended regions sets into the rangeset */
-    for ( i = 0; i < ext_regions->nr_banks; i++ )
-    {
-        start = ext_regions->bank[i].start;
-        end = start + ext_regions->bank[i].size;
-
-        res = rangeset_add_range(guest_holes, PFN_DOWN(start),
-                                 PFN_DOWN(end - 1));
-        if ( res )
-        {
-            printk(XENLOG_ERR
-                   "Failed to add: %#"PRIpaddr"->%#"PRIpaddr", error: %d\n",
-                   start, end, res);
-            goto out;
-        }
-    }
-
-    /* Remove static shared memory regions */
-    res = remove_shm_from_rangeset(kinfo, guest_holes);
-    if ( res )
-        goto out;
-
-    /*
-     * Take the interval of memory starting from the first extended region bank
-     * start address and ending to the end of the last extended region bank.
-     */
-    i = ext_regions->nr_banks - 1;
-    start = ext_regions->bank[0].start;
-    end = ext_regions->bank[i].start + ext_regions->bank[i].size - 1;
-
-    /* Reset original extended regions to hold new value */
-    ext_regions->nr_banks = 0;
-    res = rangeset_report_ranges(guest_holes, PFN_DOWN(start), PFN_DOWN(end),
-                                 add_ext_regions, ext_regions);
-    if ( res )
-        ext_regions->nr_banks = 0;
-    else if ( !ext_regions->nr_banks )
-        res = -ENOENT;
-
- out:
-    rangeset_destroy(guest_holes);
-
-    return res;
-}
-
 void __init shm_mem_node_fill_reg_range(const struct kernel_info *kinfo,
                                         __be32 *reg, int *nr_cells,
                                         int addrcells, int sizecells)