linux-kernel - [PATCH v5 3/4] x86/boot: Get the max address from SRAT

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Date:   Fri, 15 Nov 2019 09:49:16 -0500
From:   Masayoshi Mizuma <msys.mizuma@...il.com>
To:     Borislav Petkov <bp@...en8.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Baoquan He <bhe@...hat.com>
Cc:     Masayoshi Mizuma <msys.mizuma@...il.com>,
        Masayoshi Mizuma <m.mizuma@...fujitsu.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v5 3/4] x86/boot: Get the max address from SRAT

From: Masayoshi Mizuma <m.mizuma@...fujitsu.com>

Get the max address from SRAT and write it into boot_params->max_addr.

Acked-by: Baoquan He <bhe@...hat.com>
Signed-off-by: Masayoshi Mizuma <m.mizuma@...fujitsu.com>
---
 arch/x86/boot/compressed/acpi.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index a0f81438a0fd..47db706656e0 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -362,17 +362,32 @@ static unsigned long get_acpi_srat_table(void)
 	return 0;
 }
 
-static void subtable_parse(struct acpi_subtable_header *sub_table, int *num)
+/**
+ * subtable_parse - Cache the immovable memory regions into the
+ * immovable_mem array and update the index of the array.
+ *
+ * Return the end physical address of hotpluggable region.
+ * The system memory can be extended to the address by hotplug.
+ */
+static unsigned long subtable_parse(struct acpi_subtable_header *sub_table,
+				    int *num)
 {
 	struct acpi_srat_mem_affinity *ma;
+	unsigned long addr = 0;
 
 	ma = (struct acpi_srat_mem_affinity *)sub_table;
 
-	if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) {
-		immovable_mem[*num].start = ma->base_address;
-		immovable_mem[*num].size = ma->length;
-		(*num)++;
+	if (ma->length) {
+		if (ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)
+			addr = ma->base_address + ma->length;
+		else {
+			immovable_mem[*num].start = ma->base_address;
+			immovable_mem[*num].size = ma->length;
+			(*num)++;
+		}
 	}
+
+	return addr;
 }
 
 /**
@@ -391,6 +406,7 @@ int count_immovable_mem_regions(void)
 	struct acpi_subtable_header *sub_table;
 	struct acpi_table_header *table_header;
 	char arg[MAX_ACPI_ARG_LENGTH];
+	unsigned long max_addr = 0, addr;
 	int num = 0;
 
 	if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
@@ -409,7 +425,9 @@ int count_immovable_mem_regions(void)
 		sub_table = (struct acpi_subtable_header *)table;
 		if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
 
-			subtable_parse(sub_table, &num);
+			addr = subtable_parse(sub_table, &num);
+			if (addr > max_addr)
+				max_addr = addr;
 
 			if (num >= MAX_NUMNODES*2) {
 				debug_putstr("Too many immovable memory regions, aborting.\n");
@@ -418,6 +436,9 @@ int count_immovable_mem_regions(void)
 		}
 		table += sub_table->length;
 	}
+
+	boot_params->max_addr = max_addr;
+
 	return num;
 }
 #endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */
-- 
2.20.1