[PATCH 3/5] Extend e820_table to hold information about memory encryption

[Martin Fernandez <martin.fernandez@eclypsium.com>]

Add a new member in e820_entry to hold whether an entry is able to do
hardware memory encryption or not.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
---
 arch/x86/include/asm/e820/api.h   |  2 ++
 arch/x86/include/asm/e820/types.h |  1 +
 arch/x86/kernel/e820.c            | 32 +++++++++++++++++++++++++++++--
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
index e8f58ddd06d9..f3a09b6afca1 100644
--- a/arch/x86/include/asm/e820/api.h
+++ b/arch/x86/include/asm/e820/api.h
@@ -18,6 +18,8 @@ extern void e820__range_add   (u64 start, u64 size, enum e820_type type);
 extern u64  e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
 extern u64  e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);
 
+extern void e820__mark_regions_as_crypto_capable(u64 start, u64 size);
+
 extern void e820__print_table(char *who);
 extern int  e820__update_table(struct e820_table *table);
 extern void e820__update_table_print(void);
diff --git a/arch/x86/include/asm/e820/types.h b/arch/x86/include/asm/e820/types.h
index 314f75d886d0..231c9ad9a9c3 100644
--- a/arch/x86/include/asm/e820/types.h
+++ b/arch/x86/include/asm/e820/types.h
@@ -56,6 +56,7 @@ struct e820_entry {
 	u64			addr;
 	u64			size;
 	enum e820_type		type;
+	bool			crypto_capable;
 } __attribute__((packed));
 
 /*
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index bc0657f0deed..3e0aaa5525e0 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -176,6 +176,7 @@ static void __init __e820__range_add(struct e820_table *table, u64 start, u64 si
 	table->entries[x].addr = start;
 	table->entries[x].size = size;
 	table->entries[x].type = type;
+	table->entries[x].crypto_capable = false;
 	table->nr_entries++;
 }
 
@@ -184,6 +185,19 @@ void __init e820__range_add(u64 start, u64 size, enum e820_type type)
 	__e820__range_add(e820_table, start, size, type);
 }
 
+void __init e820__mark_regions_as_crypto_capable(u64 start, u64 size)
+{
+	int i;
+	u64 end = start + size;
+
+	for (i = 0; i < e820_table->nr_entries; i++) {
+		struct e820_entry *const entry = &e820_table->entries[i];
+
+		if (entry->addr >= start && entry->addr + entry->size <= end)
+			entry->crypto_capable = true;
+	}
+}
+
 static void __init e820_print_type(enum e820_type type)
 {
 	switch (type) {
@@ -211,6 +225,8 @@ void __init e820__print_table(char *who)
 			e820_table->entries[i].addr + e820_table->entries[i].size - 1);
 
 		e820_print_type(e820_table->entries[i].type);
+		pr_cont("%s",
+			e820_table->entries[i].crypto_capable ? "; crypto-capable" : "");
 		pr_cont("\n");
 	}
 }
@@ -327,6 +343,8 @@ int __init e820__update_table(struct e820_table *table)
 	unsigned long long last_addr;
 	u32 new_nr_entries, overlap_entries;
 	u32 i, chg_idx, chg_nr;
+	bool current_crypto;
+	bool last_crypto = false;
 
 	/* If there's only one memory region, don't bother: */
 	if (table->nr_entries < 2)
@@ -388,13 +406,17 @@ int __init e820__update_table(struct e820_table *table)
 		 * 1=usable, 2,3,4,4+=unusable)
 		 */
 		current_type = 0;
+		current_crypto = false;
 		for (i = 0; i < overlap_entries; i++) {
+			current_crypto = current_crypto || overlap_list[i]->crypto_capable;
 			if (overlap_list[i]->type > current_type)
 				current_type = overlap_list[i]->type;
 		}
 
 		/* Continue building up new map based on this information: */
-		if (current_type != last_type || e820_nomerge(current_type)) {
+		if (current_type != last_type ||
+		    current_crypto != last_crypto ||
+		    e820_nomerge(current_type)) {
 			if (last_type != 0)	 {
 				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
 				/* Move forward only if the new size was non-zero: */
@@ -406,6 +428,9 @@ int __init e820__update_table(struct e820_table *table)
 			if (current_type != 0)	{
 				new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
 				new_entries[new_nr_entries].type = current_type;
+				new_entries[new_nr_entries].crypto_capable = current_crypto;
+
+				last_crypto = current_crypto;
 				last_addr = change_point[chg_idx]->addr;
 			}
 			last_type = current_type;
@@ -1321,7 +1346,10 @@ void __init e820__memblock_setup(void)
 		if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
 			continue;
 
-		memblock_add(entry->addr, entry->size);
+		if (entry->crypto_capable)
+			memblock_add_crypto_capable(entry->addr, entry->size);
+		else
+			memblock_add(entry->addr, entry->size);
 	}
 
 	/* Throw away partial pages: */
-- 
2.30.2