From cf977b1af9ec67fabcc6a625589c49c52d07b11d Mon Sep 17 00:00:00 2001
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
Date: Wed, 18 Dec 2019 11:42:30 -0500
Subject: [PATCH] kexec: add variant helper functions for handling memory
 regions

mem_regions_alloc_and_add() and mem_regions_alloc_and_exclude() are
functionally equivalent to, respectively, mem_regions_add() and
mem_regions_exclude() except the formers will re-allocate memory
dynamically when no more entries are available in 'ranges' array.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
---
 kexec/mem_regions.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 kexec/mem_regions.h |  7 +++++++
 2 files changed, 49 insertions(+)

diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c
index 50c8abc..ad7d3f1 100644
--- a/kexec/mem_regions.c
+++ b/kexec/mem_regions.c
@@ -125,3 +125,45 @@ int mem_regions_exclude(struct memory_ranges *ranges,
 	}
 	return 0;
 }
+
+#define KEXEC_MEMORY_RANGES 16
+
+int mem_regions_alloc_and_add(struct memory_ranges *ranges,
+			      unsigned long long base,
+			      unsigned long long length, int type)
+{
+	void *new_ranges;
+
+	if (ranges->size >= ranges->max_size) {
+		new_ranges = realloc(ranges->ranges,
+				sizeof(struct memory_range) *
+				(ranges->max_size + KEXEC_MEMORY_RANGES));
+		if (!new_ranges)
+			return -1;
+
+		ranges->ranges = new_ranges;
+		ranges->max_size += KEXEC_MEMORY_RANGES;
+	}
+
+	return mem_regions_add(ranges, base, length, type);
+}
+
+int mem_regions_alloc_and_exclude(struct memory_ranges *ranges,
+				  const struct memory_range *range)
+{
+	void *new_ranges;
+
+	/* for safety, we should have at least one free entry in ranges */
+	if (ranges->size >= ranges->max_size) {
+		new_ranges = realloc(ranges->ranges,
+				sizeof(struct memory_range) *
+				(ranges->max_size + KEXEC_MEMORY_RANGES));
+		if (!new_ranges)
+			return -1;
+
+		ranges->ranges = new_ranges;
+		ranges->max_size += KEXEC_MEMORY_RANGES;
+	}
+
+	return mem_regions_exclude(ranges, range);
+}
diff --git a/kexec/mem_regions.h b/kexec/mem_regions.h
index ae9e972..e306d67 100644
--- a/kexec/mem_regions.h
+++ b/kexec/mem_regions.h
@@ -12,4 +12,11 @@ int mem_regions_exclude(struct memory_ranges *ranges,
 int mem_regions_add(struct memory_ranges *ranges, unsigned long long base,
                     unsigned long long length, int type);
 
+int mem_regions_alloc_and_exclude(struct memory_ranges *ranges,
+				  const struct memory_range *range);
+
+int mem_regions_alloc_and_add(struct memory_ranges *ranges,
+			      unsigned long long base,
+			      unsigned long long length, int type);
+
 #endif