From a27d76f4517d56a6471def2f76687e83fd2a7923 Mon Sep 17 00:00:00 2001
From: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Date: Mon, 29 Jul 2024 16:53:18 +0100
Subject: [PATCH 1342/1350] numa/emulation: Check emulated zones around the CMA
 window

... Make sure CMA zones do not straddle the emulated NUMA nodes ...

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
---
 drivers/base/numa_emulation.c |  5 +++++
 include/linux/cma.h           | 10 ++++++++++
 mm/cma.c                      | 36 +++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

--- a/drivers/base/numa_emulation.c
+++ b/drivers/base/numa_emulation.c
@@ -7,6 +7,7 @@
  * Author: Maíra Canal <mcanal@igalia.com>
  * Author: Tvrtko Ursulin <tursulin@igalia.com>
  */
+#include <linux/cma.h>
 #include <linux/memblock.h>
 
 #include "numa_emulation.h"
@@ -55,6 +56,10 @@ int __init numa_emu_init(void)
 		if (i == (emu_nodes - 1) && e != end)
 			e = end;
 
+		ret = cma_check_range(&s, &e);
+		if (ret)
+			return ret;
+
 		pr_info("Faking a node at [mem %pap-%pap]\n", &s, &e);
 		ret = numa_add_memblk(i, s, e + 1);
 		if (ret) {
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -56,4 +56,14 @@ extern bool cma_release(struct cma *cma,
 extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
 
 extern void cma_reserve_pages_on_error(struct cma *cma);
+
+#ifdef CONFIG_CMA
+extern int cma_check_range(u64 *start, u64 *end);
+#else
+static inline int cma_check_range(u64 *start, u64 *end)
+{
+	return 0;
+}
+#endif
+
 #endif
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -587,3 +587,39 @@ int cma_for_each_area(int (*it)(struct c
 
 	return 0;
 }
+
+struct cma_check_range_data {
+	u64 start, end;
+};
+
+static int check_range(struct cma *cma_, void *data)
+{
+	struct cma_check_range_data *range = data;
+	struct cma_check_range_data cma;
+	bool starts_in_range;
+	bool ends_in_range;
+
+	cma.start = cma_get_base(cma_);
+	cma.end = cma.start + cma_get_size(cma_) - 1;
+
+	starts_in_range = cma.start >= range->start && cma.start <= range->end;
+	ends_in_range = cma.end >= range->start && cma.end <= range->end;
+
+	if (starts_in_range == ends_in_range)
+		return 0;
+
+	pr_notice("CMA %s [%llx-%llx] straddles range [%llx-%llx]\n",
+		  cma_->name, cma.start, cma.end, range->start, range->end);
+
+	return -EINVAL;
+}
+
+int cma_check_range(u64 *start, u64 *end)
+{
+	struct cma_check_range_data range = {
+		.start = *start,
+		.end = *end,
+	};
+
+	return cma_for_each_area(check_range, &range);
+}