Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 45c00a5..cbcac03 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -50,12 +50,6 @@
 s64 memstart_addr __ro_after_init = -1;
 EXPORT_SYMBOL(memstart_addr);
 
-s64 physvirt_offset __ro_after_init;
-EXPORT_SYMBOL(physvirt_offset);
-
-struct page *vmemmap __ro_after_init;
-EXPORT_SYMBOL(vmemmap);
-
 phys_addr_t arm64_dma_phys_limit __ro_after_init;
 
 #ifdef CONFIG_KEXEC_CORE
@@ -251,6 +245,18 @@
 
 	if (!valid_section(__nr_to_section(pfn_to_section_nr(pfn))))
 		return 0;
+
+	/*
+	 * ZONE_DEVICE memory does not have the memblock entries.
+	 * memblock_is_map_memory() check for ZONE_DEVICE based
+	 * addresses will always fail. Even the normal hotplugged
+	 * memory will never have MEMBLOCK_NOMAP flag set in their
+	 * memblock entries. Skip memblock search for all non early
+	 * memory sections covering all of hotplug memory including
+	 * both normal and ZONE_DEVICE based.
+	 */
+	if (!early_section(__pfn_to_section(pfn)))
+		return pfn_section_valid(__pfn_to_section(pfn), pfn);
 #endif
 	return memblock_is_map_memory(addr);
 }
@@ -321,20 +327,6 @@
 	memstart_addr = round_down(memblock_start_of_DRAM(),
 				   ARM64_MEMSTART_ALIGN);
 
-	physvirt_offset = PHYS_OFFSET - PAGE_OFFSET;
-
-	vmemmap = ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT));
-
-	/*
-	 * If we are running with a 52-bit kernel VA config on a system that
-	 * does not support it, we have to offset our vmemmap and physvirt_offset
-	 * s.t. we avoid the 52-bit portion of the direct linear map
-	 */
-	if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) {
-		vmemmap += (_PAGE_OFFSET(48) - _PAGE_OFFSET(52)) >> PAGE_SHIFT;
-		physvirt_offset = PHYS_OFFSET - _PAGE_OFFSET(48);
-	}
-
 	/*
 	 * Remove the memory that we will not be able to cover with the
 	 * linear mapping. Take care not to clip the kernel which may be
@@ -350,6 +342,16 @@
 	}
 
 	/*
+	 * If we are running with a 52-bit kernel VA config on a system that
+	 * does not support it, we have to place the available physical
+	 * memory in the 48-bit addressable part of the linear region, i.e.,
+	 * we have to move it upward. Since memstart_addr represents the
+	 * physical address of PAGE_OFFSET, we have to *subtract* from it.
+	 */
+	if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52))
+		memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52);
+
+	/*
 	 * Apply the memory limit if it was set. Since the kernel may be loaded
 	 * high up in memory, add back the kernel region that must be accessible
 	 * via the linear mapping.