tegra132: split memory range querying to above/below 4GiB

The address map code was originally assuming all carveouts would
be packed together in the upper end of the physical memory
address space. However, the trust zone carveout is always in the
32-bit address space. Therefore, one needs to query memory ranges
by above and below 4GiB with the assumption of carveouts being
packed at the top of *each* resulting range.

BUG=chrome-os-partner:30572
BRANCH=None
TEST=Built and ran through coreboot on rush.

Original-Change-Id: Iab134a049f3726f1ec41fc6626b1a6683d9f5362
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/208101
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
(cherry picked from commit 8d5795fbff36e91906384e10774a32541d358324)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: If15ff48d5a4c81731eb364980b30c8086deb1cca
Reviewed-on: http://review.coreboot.org/8641
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/nvidia/tegra132/addressmap.c

@@ -102,7 +102,7 @@ void carveout_range(int id, uintptr_t *base_mib, size_t *size_mib)
 	}
 }
 
-void memory_range_by_bits(int bits, uintptr_t *base_mib, uintptr_t *end_mib)
+static void memory_in_range(uintptr_t *base_mib, uintptr_t *end_mib)
 {
 	uintptr_t base;
 	uintptr_t end;
@@ -111,11 +111,21 @@ void memory_range_by_bits(int bits, uintptr_t *base_mib, uintptr_t *end_mib)
 	base = CONFIG_SYS_SDRAM_BASE / MiB;
 	end = base + sdram_size_mb();
 
-	if (bits == ADDRESS_SPACE_32_BIT)
+	/* Requested limits out of range. */
-		end = MIN(end, 4096);
+	if (*end_mib <= base || *base_mib >= end) {
+		*end_mib = *base_mib = 0;
+		return;
+	}
+
+	/* Clip region to passed in limits. */
+	if (*end_mib < end)
+		end = *end_mib;
+	if (*base_mib > base)
+		base = *base_mib;
 
 	for (i = 0; i < CARVEOUT_NUM; i++) {
 		uintptr_t carveout_base;
+		uintptr_t carveout_end;
 		size_t carveout_size;
 
 		carveout_range(i, &carveout_base, &carveout_size);
@@ -123,8 +133,10 @@ void memory_range_by_bits(int bits, uintptr_t *base_mib, uintptr_t *end_mib)
 		if (carveout_size == 0)
 			continue;
 
+		carveout_end = carveout_base + carveout_size;
+
 		/* Bypass carveouts out of requested range. */
-		if (carveout_base >= end)
+		if (carveout_base >= end || carveout_end <= base)
 			continue;
 
 		/*
@@ -139,13 +151,27 @@ void memory_range_by_bits(int bits, uintptr_t *base_mib, uintptr_t *end_mib)
 	*end_mib = end;
 }
 
+void memory_in_range_below_4gb(uintptr_t *base_mib, uintptr_t *end_mib)
+{
+	*base_mib = 0;
+	*end_mib = 4096;
+	memory_in_range(base_mib, end_mib);
+}
+
+void memory_in_range_above_4gb(uintptr_t *base_mib, uintptr_t *end_mib)
+{
+	*base_mib = 4096;
+	*end_mib = ~0UL;
+	memory_in_range(base_mib, end_mib);
+}
+
 uintptr_t framebuffer_attributes(size_t *size_mib)
 {
 	uintptr_t begin;
 	uintptr_t end;
 
 	/* Place the framebuffer just below the 32-bit addressable limit. */
-	memory_range_by_bits(ADDRESS_SPACE_32_BIT, &begin, &end);
+	memory_in_range_below_4gb(&begin, &end);
 
 	/*
 	 * Need to take into account that the Trust Zone region is not able to

src/soc/nvidia/tegra132/include/soc/addressmap.h

@@ -84,16 +84,9 @@ enum {
 /* Return total size of DRAM memory configured on the platform. */
 int sdram_size_mb(void);
 
-enum {
+/* Find memory below and above 4GiB boundary repsectively. All units 1MiB. */
-	ADDRESS_SPACE_32_BIT = 32,
+void memory_in_range_below_4gb(uintptr_t *base_mib, uintptr_t *end_mib);
-	ADDRESS_SPACE_64_BIT = 64,
+void memory_in_range_above_4gb(uintptr_t *base_mib, uintptr_t *end_mib);
-};
-
-/*
- * Return the address range of memory for provided address width. The base
- * and end parameters in 1MiB units with end being exclusive to the range.
- */
-void memory_range_by_bits(int bits, uintptr_t *base_mib, uintptr_t *end_mib);
 
 enum {
 	CARVEOUT_TZ,

src/soc/nvidia/tegra132/ramstage.c

@@ -38,7 +38,7 @@ void arm64_soc_init(void)
 	 * Therefore configure the region early. Also, the TZ region can only
 	 * live in 32-bit space.
 	 */
-	memory_range_by_bits(ADDRESS_SPACE_32_BIT, &base, &end);
+	memory_in_range_below_4gb(&base, &end);
 
 	/* Place the TZ area just below current carveout regions. */
 	end -= tz_size_mib;