s390/mm: fix direct map accounting

Commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled") did not
implement direct map accounting in the early page table setup code. In
result the reported values are bogus now:

$cat /proc/meminfo
...
DirectMap4k:        5120 kB
DirectMap1M:    18446744073709546496 kB
DirectMap2G:           0 kB

Fix this by adding the missing accounting. The result looks sane again:

$cat /proc/meminfo
...
DirectMap4k:        6156 kB
DirectMap1M:     2091008 kB
DirectMap2G:     6291456 kB

Fixes: bb1520d581a3 ("s390/mm: start kernel with DAT enabled")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c
index df91d9065f7e96256ae636f54347536707c029c5..acb1f8b53105bdb557c99776c76e842fbc74e13f 100644 (file)
--- a/arch/s390/boot/vmem.c
+++ b/arch/s390/boot/vmem.c
@@ -13,6 +13,10 @@
 
 unsigned long __bootdata_preserved(s390_invalid_asce);
 
+#ifdef CONFIG_PROC_FS
+atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
+#endif
+
 #define init_mm                        (*(struct mm_struct *)vmlinux.init_mm_off)
 #define swapper_pg_dir         vmlinux.swapper_pg_dir_off
 #define invalid_pg_dir         vmlinux.invalid_pg_dir_off
@@ -267,6 +271,7 @@ static bool can_large_pmd(pmd_t *pm_dir, unsigned long addr, unsigned long end)
 static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long end,
                                 enum populate_mode mode)
 {
+       unsigned long pages = 0;
        pte_t *pte, entry;
 
        pte = pte_offset_kernel(pmd, addr);
@@ -277,14 +282,17 @@ static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long e
                        entry = __pte(_pa(addr, PAGE_SIZE, mode));
                        entry = set_pte_bit(entry, PAGE_KERNEL_EXEC);
                        set_pte(pte, entry);
+                       pages++;
                }
        }
+       if (mode == POPULATE_DIRECT)
+               update_page_count(PG_DIRECT_MAP_4K, pages);
 }
 
 static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long end,
                                 enum populate_mode mode)
 {
-       unsigned long next;
+       unsigned long next, pages = 0;
        pmd_t *pmd, entry;
        pte_t *pte;
 
@@ -298,6 +306,7 @@ static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long e
                                entry = __pmd(_pa(addr, _SEGMENT_SIZE, mode));
                                entry = set_pmd_bit(entry, SEGMENT_KERNEL_EXEC);
                                set_pmd(pmd, entry);
+                               pages++;
                                continue;
                        }
                        pte = boot_pte_alloc();
@@ -307,12 +316,14 @@ static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long e
                }
                pgtable_pte_populate(pmd, addr, next, mode);
        }
+       if (mode == POPULATE_DIRECT)
+               update_page_count(PG_DIRECT_MAP_1M, pages);
 }
 
 static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long end,
                                 enum populate_mode mode)
 {
-       unsigned long next;
+       unsigned long next, pages = 0;
        pud_t *pud, entry;
        pmd_t *pmd;
 
@@ -326,6 +337,7 @@ static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long e
                                entry = __pud(_pa(addr, _REGION3_SIZE, mode));
                                entry = set_pud_bit(entry, REGION3_KERNEL_EXEC);
                                set_pud(pud, entry);
+                               pages++;
                                continue;
                        }
                        pmd = boot_crst_alloc(_SEGMENT_ENTRY_EMPTY);
@@ -335,6 +347,8 @@ static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long e
                }
                pgtable_pmd_populate(pud, addr, next, mode);
        }
+       if (mode == POPULATE_DIRECT)
+               update_page_count(PG_DIRECT_MAP_2G, pages);
 }
 
 static void pgtable_p4d_populate(pgd_t *pgd, unsigned long addr, unsigned long end,

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2c70b4d1263d2057ab9932945fa6d1b4c5269bcf..acbe1ac2d57161704ec0f8cfc66470c987ea41df 100644 (file)
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -34,7 +34,7 @@ enum {
        PG_DIRECT_MAP_MAX
 };
 
-extern atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
+extern atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
 
 static inline void update_page_count(int level, long count)
 {

diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 7838e9c70000b9c6f1aef82631800f6b38e33457..77f31791044d551a12b02aec645ff4c7c1756e59 100644 (file)
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -41,7 +41,7 @@ void __storage_key_init_range(unsigned long start, unsigned long end)
 }
 
 #ifdef CONFIG_PROC_FS
-atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
+atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
 
 void arch_report_meminfo(struct seq_file *m)
 {