[PATCH v2 07/11] powerpc/64s/hash: Update directMap page counters for Hash

[Ritesh Harjani (IBM)]

Update the directMap page counters for Hash. Hash by default always uses
mmu_linear_psize only, for it's directMap. However, once the kernel has
booted and the dmesg log is wrapped over there is no way of knowing the
kernel linear pagesize with Hash mmu. Features like debug_page_alloc can
make mmu_linear_psize to be PAGE_SIZE instead of PMD / PUD mappings. It
would be easier if we have this info printed in proc meminfo similar to
Radix for debugging purposes.

Cc: Madhavan Srinivasan <maddy at linux.ibm.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Nicholas Piggin <npiggin at gmail.com>
Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
Cc: Paul Mackerras <paulus at ozlabs.org>
Cc: Aneesh Kumar K.V <aneesh.kumar at kernel.org>
Cc: Donet Tom <donettom at linux.ibm.com>
Cc: <linuxppc-dev at lists.ozlabs.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list at gmail.com>
---
 arch/powerpc/mm/book3s64/hash_utils.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index e63befc96708..31162dbad05c 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -47,6 +47,7 @@
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
 #include <asm/page.h>
+#include <asm/pgalloc.h>
 #include <asm/types.h>
 #include <linux/uaccess.h>
 #include <asm/machdep.h>
@@ -449,6 +450,7 @@ static __init void hash_kfence_map_pool(void)
 {
 	unsigned long kfence_pool_start, kfence_pool_end;
 	unsigned long prot = pgprot_val(PAGE_KERNEL);
+	unsigned int pshift = mmu_psize_defs[mmu_linear_psize].shift;
 
 	if (!kfence_pool)
 		return;
@@ -459,6 +461,7 @@ static __init void hash_kfence_map_pool(void)
 	BUG_ON(htab_bolt_mapping(kfence_pool_start, kfence_pool_end,
 				    kfence_pool, prot, mmu_linear_psize,
 				    mmu_kernel_ssize));
+	update_page_count(mmu_linear_psize, KFENCE_POOL_SIZE >> pshift);
 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
 }
 
@@ -1234,6 +1237,7 @@ int hash__create_section_mapping(unsigned long start, unsigned long end,
 				 int nid, pgprot_t prot)
 {
 	int rc;
+	unsigned int pshift = mmu_psize_defs[mmu_linear_psize].shift;
 
 	if (end >= H_VMALLOC_START) {
 		pr_warn("Outside the supported range\n");
@@ -1251,17 +1255,22 @@ int hash__create_section_mapping(unsigned long start, unsigned long end,
 					      mmu_kernel_ssize);
 		BUG_ON(rc2 && (rc2 != -ENOENT));
 	}
+	update_page_count(mmu_linear_psize, (end - start) >> pshift);
 	return rc;
 }
 
 int hash__remove_section_mapping(unsigned long start, unsigned long end)
 {
+	unsigned int pshift = mmu_psize_defs[mmu_linear_psize].shift;
+
 	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
 				     mmu_kernel_ssize);
 
 	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
 		pr_warn("Hash collision while resizing HPT\n");
 
+	if (!rc)
+		update_page_count(mmu_linear_psize, -((end - start) >> pshift));
 	return rc;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
@@ -1304,6 +1313,7 @@ static void __init htab_initialize(void)
 	unsigned long prot;
 	phys_addr_t base = 0, size = 0, end, limit = MEMBLOCK_ALLOC_ANYWHERE;
 	u64 i;
+	unsigned int pshift = mmu_psize_defs[mmu_linear_psize].shift;
 
 	DBG(" -> htab_initialize()\n");
 
@@ -1404,6 +1414,8 @@ static void __init htab_initialize(void)
 
 		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
 				prot, mmu_linear_psize, mmu_kernel_ssize));
+
+		update_page_count(mmu_linear_psize, size >> pshift);
 	}
 	hash_kfence_map_pool();
 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
@@ -1425,6 +1437,8 @@ static void __init htab_initialize(void)
 		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
 					 __pa(tce_alloc_start), prot,
 					 mmu_linear_psize, mmu_kernel_ssize));
+		update_page_count(mmu_linear_psize,
+				  (tce_alloc_end - tce_alloc_start) >> pshift);
 	}
 
 
-- 
2.51.0