[PATCH v2 03/10] memory: define reserve_sdram_region helper

Ahmad Fatoum a.fatoum at pengutronix.de
Wed Aug 17 04:42:37 PDT 2022


We use request_sdram_regions both for code that barebox wants to use for
itself (e.g. barebox stack or initrd) and to reserve regions for secure
firmware that barebox shouldn't overwrite. We need to differentiate
between them, so we can apply different caching flags depending on
region, so add a new reserve_sdram_region helper that may be used and
also add an for_each_reserved_region iterator for use in the MMU code
that applied the different caching flags later on.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 include/memory.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/memory.h b/include/memory.h
index 31da5d74d568..ffd66db02ba0 100644
--- a/include/memory.h
+++ b/include/memory.h
@@ -4,6 +4,7 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
+#include <linux/ioport.h>
 
 void mem_malloc_init(void *start, void *end);
 ulong mem_malloc_start(void);
@@ -22,6 +23,9 @@ int barebox_add_memory_bank(const char *name, resource_size_t start,
 				    resource_size_t size);
 
 #define for_each_memory_bank(mem)	list_for_each_entry(mem, &memory_banks, list)
+#define for_each_reserved_region(mem, rsv) \
+	list_for_each_entry(rsv, &(mem)->res->children, sibling) \
+	if (((rsv)->flags & IORESOURCE_BUSY))
 
 struct resource *__request_sdram_region(const char *name, unsigned flags,
 					resource_size_t start, resource_size_t size);
@@ -34,6 +38,14 @@ static inline struct resource *request_sdram_region(const char *name,
 	return __request_sdram_region(name, 0, start, size);
 }
 
+/* use for secure firmware to inhibit speculation */
+static inline struct resource *reserve_sdram_region(const char *name,
+						    resource_size_t start,
+						    resource_size_t size)
+{
+	return __request_sdram_region(name, IORESOURCE_BUSY, start, size);
+}
+
 int release_sdram_region(struct resource *res);
 
 void memory_bank_find_space(struct memory_bank *bank, resource_size_t *retstart,
-- 
2.30.2




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