linux-kernel - [PATCH v6 05/23] powerpc/64e: Consolidate TLB miss handler patching

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Date: Mon, 24 Jun 2024 16:45:31 +0200
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Jason Gunthorpe <jgg@...dia.com>,
	Peter Xu <peterx@...hat.com>,
	Oscar Salvador <osalvador@...e.de>,
	Michael Ellerman <mpe@...erman.id.au>,
	Nicholas Piggin <npiggin@...il.com>
Cc: Christophe Leroy <christophe.leroy@...roup.eu>,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v6 05/23] powerpc/64e: Consolidate TLB miss handler patching

From: Michael Ellerman <mpe@...erman.id.au>

The 64e TLB miss handler patching is done in setup_mmu_htw(), and then
again immediately afterward in early_init_mmu_global(). Consolidate it
into a single location.

Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
 arch/powerpc/mm/nohash/tlb_64e.c | 38 +++++++++++++-------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index 21c4b2442fcf..d83ecf466929 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -169,24 +169,6 @@ static void __init setup_page_sizes(void)
 	}
 }
 
-static void __init setup_mmu_htw(void)
-{
-	/*
-	 * If we want to use HW tablewalk, enable it by patching the TLB miss
-	 * handlers to branch to the one dedicated to it.
-	 */
-
-	switch (book3e_htw_mode) {
-	case PPC_HTW_E6500:
-		extlb_level_exc = EX_TLB_SIZE;
-		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
-		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
-		break;
-	}
-	pr_info("MMU: Book3E HW tablewalk %s\n",
-		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
-}
-
 /*
  * Early initialization of the MMU TLB code
  */
@@ -252,15 +234,25 @@ static void __init early_init_mmu_global(void)
 	/* Look for supported page sizes */
 	setup_page_sizes();
 
-	/* Look for HW tablewalk support */
-	setup_mmu_htw();
-
-	if (book3e_htw_mode == PPC_HTW_NONE) {
-		extlb_level_exc = EX_TLB_SIZE;
+	/*
+	 * If we want to use HW tablewalk, enable it by patching the TLB miss
+	 * handlers to branch to the one dedicated to it.
+	 */
+	extlb_level_exc = EX_TLB_SIZE;
+	switch (book3e_htw_mode) {
+	case PPC_HTW_E6500:
+		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
+		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
+		break;
+	case PPC_HTW_NONE:
 		patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
 		patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e);
+		break;
 	}
 
+	pr_info("MMU: Book3E HW tablewalk %s\n",
+		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
+
 	/* Set the global containing the top of the linear mapping
 	 * for use by the TLB miss code
 	 */
-- 
2.44.0