linux-kernel - [PATCH v18 13/15] arm64: kexec: remove the pre-kexec PoC maintenance

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Date:   Thu, 30 Sep 2021 14:31:11 +0000
From:   Pasha Tatashin <pasha.tatashin@...een.com>
To:     pasha.tatashin@...een.com, sashal@...nel.org,
        ebiederm@...ssion.com, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org, corbet@....net,
        catalin.marinas@....com, will@...nel.org,
        linux-arm-kernel@...ts.infradead.org, maz@...nel.org,
        james.morse@....com, vladimir.murzin@....com,
        matthias.bgg@...il.com, linux-mm@...ck.org, mark.rutland@....com,
        steve.capper@....com, rfontana@...hat.com, tglx@...utronix.de,
        selindag@...il.com, kernelfans@...il.com, akpm@...ux-foundation.org
Subject: [PATCH v18 13/15] arm64: kexec: remove the pre-kexec PoC maintenance

Now that kexec does its relocations with the MMU enabled, we no longer
need to clean the relocation data to the PoC.

Suggested-by: James Morse <james.morse@....com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
Acked-by: Catalin Marinas <catalin.marinas@....com>
---
 arch/arm64/kernel/machine_kexec.c | 43 -------------------------------
 1 file changed, 43 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 1e9a2a45e016..559d47a3c59c 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -77,48 +77,6 @@ int machine_kexec_prepare(struct kimage *kimage)
 	return 0;
 }
 
-/**
- * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
- */
-static void kexec_list_flush(struct kimage *kimage)
-{
-	kimage_entry_t *entry;
-
-	dcache_clean_inval_poc((unsigned long)kimage,
-			       (unsigned long)kimage + sizeof(*kimage));
-
-	for (entry = &kimage->head; ; entry++) {
-		unsigned int flag;
-		unsigned long addr;
-
-		/* flush the list entries. */
-		dcache_clean_inval_poc((unsigned long)entry,
-				    (unsigned long)entry +
-					    sizeof(kimage_entry_t));
-
-		flag = *entry & IND_FLAGS;
-		if (flag == IND_DONE)
-			break;
-
-		addr = (unsigned long)phys_to_virt(*entry & PAGE_MASK);
-
-		switch (flag) {
-		case IND_INDIRECTION:
-			/* Set entry point just before the new list page. */
-			entry = (kimage_entry_t *)addr - 1;
-			break;
-		case IND_SOURCE:
-			/* flush the source pages. */
-			dcache_clean_inval_poc(addr, addr + PAGE_SIZE);
-			break;
-		case IND_DESTINATION:
-			break;
-		default:
-			BUG();
-		}
-	}
-}
-
 /**
  * kexec_segment_flush - Helper to flush the kimage segments to PoC.
  */
@@ -207,7 +165,6 @@ int machine_kexec_post_load(struct kimage *kimage)
 			       (unsigned long)reloc_code + reloc_size);
 	icache_inval_pou((uintptr_t)reloc_code,
 			 (uintptr_t)reloc_code + reloc_size);
-	kexec_list_flush(kimage);
 	kexec_image_info(kimage);
 
 	return 0;
-- 
2.33.0.800.g4c38ced690-goog