bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch b/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch
new file mode 100644
index 0000000000..23811e0b6e
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch
@@ -0,0 +1,84 @@
+From 1c108eaeae73a504ac1b2d882bc1fefb91eecf17 Mon Sep 17 00:00:00 2001
+From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Date: Wed, 11 Sep 2019 20:25:46 +0200
+Subject: [PATCH] mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum
+ zone_type'
+
+commit 734f9246e791d8da278957b2c326d7709b2a97c0 upstream.
+
+These zones usage has evolved with time and the comments were outdated.
+This joins both ZONE_DMA and ZONE_DMA32 explanation and gives up to date
+examples on how they are used on different architectures.
+
+Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Reviewed-by: Christoph Hellwig <hch@lst.de>
+Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
+Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
+---
+ include/linux/mmzone.h | 45 ++++++++++++++++++++++++------------------
+ 1 file changed, 26 insertions(+), 19 deletions(-)
+
+--- a/include/linux/mmzone.h
++++ b/include/linux/mmzone.h
+@@ -358,33 +358,40 @@ struct per_cpu_nodestat {
+ #endif /* !__GENERATING_BOUNDS.H */
+ 
+ enum zone_type {
+-#ifdef CONFIG_ZONE_DMA
+ 	/*
+-	 * ZONE_DMA is used when there are devices that are not able
+-	 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
+-	 * carve out the portion of memory that is needed for these devices.
+-	 * The range is arch specific.
+-	 *
+-	 * Some examples
+-	 *
+-	 * Architecture		Limit
+-	 * ---------------------------
+-	 * parisc, ia64, sparc	<4G
+-	 * s390, powerpc	<2G
+-	 * arm			Various
+-	 * alpha		Unlimited or 0-16MB.
++	 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
++	 * to DMA to all of the addressable memory (ZONE_NORMAL).
++	 * On architectures where this area covers the whole 32 bit address
++	 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
++	 * DMA addressing constraints. This distinction is important as a 32bit
++	 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
++	 * platforms may need both zones as they support peripherals with
++	 * different DMA addressing limitations.
++	 *
++	 * Some examples:
++	 *
++	 *  - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the
++	 *    rest of the lower 4G.
++	 *
++	 *  - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on
++	 *    the specific device.
++	 *
++	 *  - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the
++	 *    lower 4G.
++	 *
++	 *  - powerpc only uses ZONE_DMA, the size, up to 2G, may vary
++	 *    depending on the specific device.
+ 	 *
+-	 * i386, x86_64 and multiple other arches
+-	 * 			<16M.
++	 *  - s390 uses ZONE_DMA fixed to the lower 2G.
++	 *
++	 *  - ia64 and riscv only use ZONE_DMA32.
++	 *
++	 *  - parisc uses neither.
+ 	 */
++#ifdef CONFIG_ZONE_DMA
+ 	ZONE_DMA,
+ #endif
+ #ifdef CONFIG_ZONE_DMA32
+-	/*
+-	 * x86_64 needs two ZONE_DMAs because it supports devices that are
+-	 * only able to do DMA to the lower 16M but also 32 bit devices that
+-	 * can only do DMA areas below 4G.
+-	 */
+ 	ZONE_DMA32,
+ #endif
+ 	/*