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@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-14-pasha.tatashin@soleen.comSigned-off-by: Will Deacon <will@kernel.org>

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;