mm: percpu: add generic pcpu_populate_pte() function

With NEED_PER_CPU_PAGE_FIRST_CHUNK enabled, we need a function to
populate pte, this patch adds a generic pcpu populate pte function,
pcpu_populate_pte(), which is marked __weak and used on most
architectures, but it is overridden on x86, which has its own
implementation.

Link: https://lkml.kernel.org/r/20211216112359.103822-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 46 deletions

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a0c55c6e3023..f7cf408217c5 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -787,51 +787,6 @@ static __init int pcpu_cpu_to_node(int cpu)
 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(__per_cpu_offset);
 
-static void __init pcpu_populate_pte(unsigned long addr)
-{
-	pgd_t *pgd = pgd_offset_k(addr);
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
-
-	p4d = p4d_offset(pgd, addr);
-	if (p4d_none(*p4d)) {
-		pud_t *new;
-
-		new = memblock_alloc(PUD_TABLE_SIZE, PUD_TABLE_SIZE);
-		if (!new)
-			goto err_alloc;
-		p4d_populate(&init_mm, p4d, new);
-	}
-
-	pud = pud_offset(p4d, addr);
-	if (pud_none(*pud)) {
-		pmd_t *new;
-
-		new = memblock_alloc(PMD_TABLE_SIZE, PMD_TABLE_SIZE);
-		if (!new)
-			goto err_alloc;
-		pud_populate(&init_mm, pud, new);
-	}
-
-	pmd = pmd_offset(pud, addr);
-	if (!pmd_present(*pmd)) {
-		pte_t *new;
-
-		new = memblock_alloc(PTE_TABLE_SIZE, PTE_TABLE_SIZE);
-		if (!new)
-			goto err_alloc;
-		pmd_populate_kernel(&init_mm, pmd, new);
-	}
-
-	return;
-
-err_alloc:
-	panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n",
-	      __func__, PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
-}
-
-
 void __init setup_per_cpu_areas(void)
 {
 	const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
@@ -860,7 +815,7 @@ void __init setup_per_cpu_areas(void)
 	}
 
 	if (rc < 0)
-		rc = pcpu_page_first_chunk(0, pcpu_cpu_to_node, pcpu_populate_pte);
+		rc = pcpu_page_first_chunk(0, pcpu_cpu_to_node);
 	if (rc < 0)
 		panic("cannot initialize percpu area (err=%d)", rc);