diff mbox series

[v4,40/45] powerpc/8xx: Map linear memory with huge pages

Message ID c44f0ab5510474f25123d904cd1f4e5c6aa3c1ac.1589866984.git.christophe.leroy@csgroup.eu
State Under Review
Headers show
Series Use hugepages to map kernel mem on 8xx | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (72bc15d0018ebfbc9c389539d636e2e9a9002b3b)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (249c9b0cd193d983c3a0b00f3fd3b92333bfeebe)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (642b151f45dd54809ea00ecd3976a56c1ec9b53d)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (30df74d67d48949da87e3a5b57c381763e8fd526)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (7b06fb8795ffea9d12be45a172197c3307955479)

Commit Message

Christophe Leroy May 19, 2020, 5:49 a.m. UTC
Map linear memory space with 512k and 8M pages whenever
possible.

Three mappings are performed:
- One for kernel text
- One for RO data
- One for the rest

Separating the mappings is done to be able to update the
protection later when using STRICT_KERNEL_RWX.

The ITLB miss handler now need to also handle huge TLBs
unless kernel text in pinned.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_8xx.S |  4 +--
 arch/powerpc/mm/nohash/8xx.c   | 50 +++++++++++++++++++++++++++++++++-
 2 files changed, 51 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 9a117b9f0998..abb71fad7d6a 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -224,7 +224,7 @@  InstructionTLBMiss:
 3:
 	mtcr	r11
 #endif
-#ifdef CONFIG_HUGETLBFS
+#if defined(CONFIG_HUGETLBFS) || !defined(CONFIG_PIN_TLB_TEXT)
 	lwz	r11, (swapper_pg_dir-PAGE_OFFSET)@l(r10)	/* Get level 1 entry */
 	mtspr	SPRN_MD_TWC, r11
 #else
@@ -234,7 +234,7 @@  InstructionTLBMiss:
 #endif
 	mfspr	r10, SPRN_MD_TWC
 	lwz	r10, 0(r10)	/* Get the pte */
-#ifdef CONFIG_HUGETLBFS
+#if defined(CONFIG_HUGETLBFS) || !defined(CONFIG_PIN_TLB_TEXT)
 	rlwimi	r11, r10, 32 - 9, _PMD_PAGE_512K
 	mtspr	SPRN_MI_TWC, r11
 #endif
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index f8fff1fa72e3..ec3ef75895d8 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -127,20 +127,68 @@  void __init mmu_mapin_immr(void)
 				    PAGE_KERNEL_NCG, MMU_PAGE_512K, true);
 }
 
+static void __init mmu_mapin_ram_chunk(unsigned long offset, unsigned long top,
+				       pgprot_t prot, bool new)
+{
+	unsigned long v = PAGE_OFFSET + offset;
+	unsigned long p = offset;
+
+	WARN_ON(!IS_ALIGNED(offset, SZ_512K) || !IS_ALIGNED(top, SZ_512K));
+
+	for (; p < ALIGN(p, SZ_8M) && p < top; p += SZ_512K, v += SZ_512K)
+		__early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new);
+	for (; p < ALIGN_DOWN(top, SZ_8M) && p < top; p += SZ_8M, v += SZ_8M)
+		__early_map_kernel_hugepage(v, p, prot, MMU_PAGE_8M, new);
+	for (; p < ALIGN_DOWN(top, SZ_512K) && p < top; p += SZ_512K, v += SZ_512K)
+		__early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new);
+
+	if (!new)
+		flush_tlb_kernel_range(PAGE_OFFSET + v, PAGE_OFFSET + top);
+}
+
 unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
 {
+	unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M);
+	unsigned long sinittext = __pa(_sinittext);
+	unsigned long boundary = strict_kernel_rwx_enabled() ? sinittext : etext8;
+	unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M);
+
+	WARN_ON(top < einittext8);
+
 	mmu_mapin_immr();
 
-	return 0;
+	if (__map_without_ltlbs)
+		return 0;
+
+	mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, true);
+	mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL_TEXT, true);
+	mmu_mapin_ram_chunk(einittext8, top, PAGE_KERNEL, true);
+
+	if (top > SZ_32M)
+		memblock_set_current_limit(top);
+
+	block_mapped_ram = top;
+
+	return top;
 }
 
 void mmu_mark_initmem_nx(void)
 {
+	unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M);
+	unsigned long sinittext = __pa(_sinittext);
+	unsigned long boundary = strict_kernel_rwx_enabled() ? sinittext : etext8;
+	unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M);
+
+	mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, false);
+	mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false);
 }
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
 void mmu_mark_rodata_ro(void)
 {
+	unsigned long sinittext = __pa(_sinittext);
+
+	mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false);
 }
 #endif