[PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Jing Xiangfeng]

Using two distinct DMA zones turned out to be problematic. Here's an
attempt go back to a saner default.

Ard Biesheuvel (1):
  arm64: mm: Set ZONE_DMA size based on early IORT scan

Nicolas Saenz Julienne (6):
  arm64: mm: Move reserve_crashkernel() into mem_init()
  arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()
  of/address: Introduce of_dma_get_max_cpu_address()
  of: unittest: Add test for of_dma_get_max_cpu_address()
  arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges
  mm: Remove examples from enum zone_type comment

 arch/arm64/mm/init.c      | 22 +++++++++-------
 drivers/acpi/arm64/iort.c | 55 +++++++++++++++++++++++++++++++++++++++
 drivers/of/address.c      | 42 ++++++++++++++++++++++++++++++
 drivers/of/unittest.c     | 18 +++++++++++++
 include/linux/acpi_iort.h |  4 +++
 include/linux/mmzone.h    | 20 --------------
 include/linux/of.h        |  7 +++++
 7 files changed, 139 insertions(+), 29 deletions(-)

-- 
2.25.1

[PATCH stable v5.10 1/7] arm64: mm: Move reserve_crashkernel() into mem_init()

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 0a30c53573b07d5561457e41fb0ab046cd857da5 upstream

crashkernel might reserve memory located in ZONE_DMA. We plan to delay
ZONE_DMA's initialization after unflattening the devicetree and ACPI's
boot table initialization, so move it later in the boot process.
Specifically into bootmem_init() since request_standard_resources()
depends on it.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-2-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 arch/arm64/mm/init.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 00576a960f11..686653e33250 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -386,8 +386,6 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma32_phys_limit = PHYS_MASK + 1;
 
-	reserve_crashkernel();
-
 	reserve_elfcorehdr();
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
@@ -427,6 +425,12 @@ void __init bootmem_init(void)
 	sparse_init();
 	zone_sizes_init(min, max);
 
+	/*
+	 * request_standard_resources() depends on crashkernel's memory being
+	 * reserved, so do it here.
+	 */
+	reserve_crashkernel();
+
 	memblock_dump_all();
 }
 
-- 
2.25.1

Patch "arm64: mm: Move reserve_crashkernel() into mem_init()" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: mm: Move reserve_crashkernel() into mem_init()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-mm-move-reserve_crashkernel-into-mem_init.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:13 +0800
Subject: arm64: mm: Move reserve_crashkernel() into mem_init()
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Jeremy Linton <jeremy.linton@arm.com>
Message-ID: <20210303073319.2215839-2-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 0a30c53573b07d5561457e41fb0ab046cd857da5 upstream

crashkernel might reserve memory located in ZONE_DMA. We plan to delay
ZONE_DMA's initialization after unflattening the devicetree and ACPI's
boot table initialization, so move it later in the boot process.
Specifically into bootmem_init() since request_standard_resources()
depends on it.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-2-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/mm/init.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -386,8 +386,6 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma32_phys_limit = PHYS_MASK + 1;
 
-	reserve_crashkernel();
-
 	reserve_elfcorehdr();
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
@@ -427,6 +425,12 @@ void __init bootmem_init(void)
 	sparse_init();
 	zone_sizes_init(min, max);
 
+	/*
+	 * request_standard_resources() depends on crashkernel's memory being
+	 * reserved, so do it here.
+	 */
+	reserve_crashkernel();
+
 	memblock_dump_all();
 }
 


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 2/7] arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 9804f8c69b04a39d0ba41d19e6bdc6aa91c19725 upstream

zone_dma_bits's initialization happens earlier that it's actually
needed, in arm64_memblock_init(). So move it into the more suitable
zone_sizes_init().

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-3-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 arch/arm64/mm/init.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 686653e33250..7da912bf4222 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -190,6 +190,8 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
 
 #ifdef CONFIG_ZONE_DMA
+	zone_dma_bits = ARM64_ZONE_DMA_BITS;
+	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif
 #ifdef CONFIG_ZONE_DMA32
@@ -376,11 +378,6 @@ void __init arm64_memblock_init(void)
 
 	early_init_fdt_scan_reserved_mem();
 
-	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
-		zone_dma_bits = ARM64_ZONE_DMA_BITS;
-		arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
-	}
-
 	if (IS_ENABLED(CONFIG_ZONE_DMA32))
 		arm64_dma32_phys_limit = max_zone_phys(32);
 	else
-- 
2.25.1

Patch "arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:14 +0800
Subject: arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Jeremy Linton <jeremy.linton@arm.com>
Message-ID: <20210303073319.2215839-3-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 9804f8c69b04a39d0ba41d19e6bdc6aa91c19725 upstream

zone_dma_bits's initialization happens earlier that it's actually
needed, in arm64_memblock_init(). So move it into the more suitable
zone_sizes_init().

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-3-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/mm/init.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -190,6 +190,8 @@ static void __init zone_sizes_init(unsig
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
 
 #ifdef CONFIG_ZONE_DMA
+	zone_dma_bits = ARM64_ZONE_DMA_BITS;
+	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif
 #ifdef CONFIG_ZONE_DMA32
@@ -376,11 +378,6 @@ void __init arm64_memblock_init(void)
 
 	early_init_fdt_scan_reserved_mem();
 
-	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
-		zone_dma_bits = ARM64_ZONE_DMA_BITS;
-		arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS);
-	}
-
 	if (IS_ENABLED(CONFIG_ZONE_DMA32))
 		arm64_dma32_phys_limit = max_zone_phys(32);
 	else


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 3/7] of/address: Introduce of_dma_get_max_cpu_address()

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 964db79d6c186cc2ecc6ae46f98eed7e0ea8cf71 upstream

Introduce of_dma_get_max_cpu_address(), which provides the highest CPU
physical address addressable by all DMA masters in the system. It's
specially useful for setting memory zones sizes at early boot time.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201119175400.9995-4-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 drivers/of/address.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h   |  7 +++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 1c3257a2d4e3..73ddf2540f3f 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
 }
 #endif /* CONFIG_HAS_DMA */
 
+/**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+	phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+	struct of_range_parser parser;
+	phys_addr_t subtree_max_addr;
+	struct device_node *child;
+	struct of_range range;
+	const __be32 *ranges;
+	u64 cpu_end = 0;
+	int len;
+
+	if (!np)
+		np = of_root;
+
+	ranges = of_get_property(np, "dma-ranges", &len);
+	if (ranges && len) {
+		of_dma_range_parser_init(&parser, np);
+		for_each_of_range(&parser, &range)
+			if (range.cpu_addr + range.size > cpu_end)
+				cpu_end = range.cpu_addr + range.size - 1;
+
+		if (max_cpu_addr > cpu_end)
+			max_cpu_addr = cpu_end;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		subtree_max_addr = of_dma_get_max_cpu_address(child);
+		if (max_cpu_addr > subtree_max_addr)
+			max_cpu_addr = subtree_max_addr;
+	}
+
+	return max_cpu_addr;
+}
+
 /**
  * of_dma_is_coherent - Check if device is coherent
  * @np:	device node
diff --git a/include/linux/of.h b/include/linux/of.h
index af655d264f10..0f4e81e6fb23 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id,
 	       const char *map_name, const char *map_mask_name,
 	       struct device_node **target, u32 *id_out);
 
+phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
@@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 id,
 	return -EINVAL;
 }
 
+static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
+{
+	return PHYS_ADDR_MAX;
+}
+
 #define of_match_ptr(_ptr)	NULL
 #define of_match_node(_matches, _node)	NULL
 #endif /* CONFIG_OF */
-- 
2.25.1

Patch "of/address: Introduce of_dma_get_max_cpu_address()" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    of/address: Introduce of_dma_get_max_cpu_address()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     of-address-introduce-of_dma_get_max_cpu_address.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:15 +0800
Subject: of/address: Introduce of_dma_get_max_cpu_address()
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Rob Herring <robh@kernel.org>
Message-ID: <20210303073319.2215839-4-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 964db79d6c186cc2ecc6ae46f98eed7e0ea8cf71 upstream

Introduce of_dma_get_max_cpu_address(), which provides the highest CPU
physical address addressable by all DMA masters in the system. It's
specially useful for setting memory zones sizes at early boot time.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201119175400.9995-4-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/of/address.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h   |    7 +++++++
 2 files changed, 49 insertions(+)

--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1025,6 +1025,48 @@ out:
 #endif /* CONFIG_HAS_DMA */
 
 /**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+	phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+	struct of_range_parser parser;
+	phys_addr_t subtree_max_addr;
+	struct device_node *child;
+	struct of_range range;
+	const __be32 *ranges;
+	u64 cpu_end = 0;
+	int len;
+
+	if (!np)
+		np = of_root;
+
+	ranges = of_get_property(np, "dma-ranges", &len);
+	if (ranges && len) {
+		of_dma_range_parser_init(&parser, np);
+		for_each_of_range(&parser, &range)
+			if (range.cpu_addr + range.size > cpu_end)
+				cpu_end = range.cpu_addr + range.size - 1;
+
+		if (max_cpu_addr > cpu_end)
+			max_cpu_addr = cpu_end;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		subtree_max_addr = of_dma_get_max_cpu_address(child);
+		if (max_cpu_addr > subtree_max_addr)
+			max_cpu_addr = subtree_max_addr;
+	}
+
+	return max_cpu_addr;
+}
+
+/**
  * of_dma_is_coherent - Check if device is coherent
  * @np:	device node
  *
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u3
 	       const char *map_name, const char *map_mask_name,
 	       struct device_node **target, u32 *id_out);
 
+phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
@@ -995,6 +997,11 @@ static inline int of_map_id(struct devic
 	return -EINVAL;
 }
 
+static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
+{
+	return PHYS_ADDR_MAX;
+}
+
 #define of_match_ptr(_ptr)	NULL
 #define of_match_node(_matches, _node)	NULL
 #endif /* CONFIG_OF */


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 4/7] of: unittest: Add test for of_dma_get_max_cpu_address()

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 07d13a1d6120d453c3c1f020578693d072deded5 upstream

Introduce a test for of_dma_get_max_cup_address(), it uses the same DT
data as the rest of dma-ranges unit tests.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201119175400.9995-5-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 drivers/of/unittest.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 06cc988faf78..98cc0163301b 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -869,6 +869,23 @@ static void __init of_unittest_changeset(void)
 #endif
 }
 
+static void __init of_unittest_dma_get_max_cpu_address(void)
+{
+	struct device_node *np;
+	phys_addr_t cpu_addr;
+
+	np = of_find_node_by_path("/testcase-data/address-tests");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	cpu_addr = of_dma_get_max_cpu_address(np);
+	unittest(cpu_addr == 0x4fffffff,
+		 "of_dma_get_max_cpu_address: wrong CPU addr %pad (expecting %x)\n",
+		 &cpu_addr, 0x4fffffff);
+}
+
 static void __init of_unittest_dma_ranges_one(const char *path,
 		u64 expect_dma_addr, u64 expect_paddr)
 {
@@ -3266,6 +3283,7 @@ static int __init of_unittest(void)
 	of_unittest_changeset();
 	of_unittest_parse_interrupts();
 	of_unittest_parse_interrupts_extended();
+	of_unittest_dma_get_max_cpu_address();
 	of_unittest_parse_dma_ranges();
 	of_unittest_pci_dma_ranges();
 	of_unittest_match_node();
-- 
2.25.1

Patch "of: unittest: Add test for of_dma_get_max_cpu_address()" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    of: unittest: Add test for of_dma_get_max_cpu_address()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:16 +0800
Subject: of: unittest: Add test for of_dma_get_max_cpu_address()
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Rob Herring <robh@kernel.org>
Message-ID: <20210303073319.2215839-5-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 07d13a1d6120d453c3c1f020578693d072deded5 upstream

Introduce a test for of_dma_get_max_cup_address(), it uses the same DT
data as the rest of dma-ranges unit tests.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201119175400.9995-5-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/of/unittest.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -869,6 +869,23 @@ static void __init of_unittest_changeset
 #endif
 }
 
+static void __init of_unittest_dma_get_max_cpu_address(void)
+{
+	struct device_node *np;
+	phys_addr_t cpu_addr;
+
+	np = of_find_node_by_path("/testcase-data/address-tests");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	cpu_addr = of_dma_get_max_cpu_address(np);
+	unittest(cpu_addr == 0x4fffffff,
+		 "of_dma_get_max_cpu_address: wrong CPU addr %pad (expecting %x)\n",
+		 &cpu_addr, 0x4fffffff);
+}
+
 static void __init of_unittest_dma_ranges_one(const char *path,
 		u64 expect_dma_addr, u64 expect_paddr)
 {
@@ -3266,6 +3283,7 @@ static int __init of_unittest(void)
 	of_unittest_changeset();
 	of_unittest_parse_interrupts();
 	of_unittest_parse_interrupts_extended();
+	of_unittest_dma_get_max_cpu_address();
 	of_unittest_parse_dma_ranges();
 	of_unittest_pci_dma_ranges();
 	of_unittest_match_node();


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 5/7] arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 8424ecdde7df99d5426e1a1fd9f0fb36f4183032 upstream

We recently introduced a 1 GB sized ZONE_DMA to cater for platforms
incorporating masters that can address less than 32 bits of DMA, in
particular the Raspberry Pi 4, which has 4 or 8 GB of DRAM, but has
peripherals that can only address up to 1 GB (and its PCIe host
bridge can only access the bottom 3 GB)

The DMA layer also needs to be able to allocate memory that is
guaranteed to meet those DMA constraints, for bounce buffering as well
as allocating the backing for consistent mappings. This is why the 1 GB
ZONE_DMA was introduced recently. Unfortunately, it turns out the having
a 1 GB ZONE_DMA as well as a ZONE_DMA32 causes problems with kdump, and
potentially in other places where allocations cannot cross zone
boundaries. Therefore, we should avoid having two separate DMA zones
when possible.

So, with the help of of_dma_get_max_cpu_address() get the topmost
physical address accessible to all DMA masters in system and use that
information to fine-tune ZONE_DMA's size. In the absence of addressing
limited masters ZONE_DMA will span the whole 32-bit address space,
otherwise, in the case of the Raspberry Pi 4 it'll only span the 30-bit
address space, and have ZONE_DMA32 cover the rest of the 32-bit address
space.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20201119175400.9995-6-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 arch/arm64/mm/init.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 7da912bf4222..05a1c2773629 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -42,8 +42,6 @@
 #include <asm/tlb.h>
 #include <asm/alternative.h>
 
-#define ARM64_ZONE_DMA_BITS	30
-
 /*
  * We need to be able to catch inadvertent references to memstart_addr
  * that occur (potentially in generic code) before arm64_memblock_init()
@@ -188,9 +186,11 @@ static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
 static void __init zone_sizes_init(unsigned long min, unsigned long max)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
+	unsigned int __maybe_unused dt_zone_dma_bits;
 
 #ifdef CONFIG_ZONE_DMA
-	zone_dma_bits = ARM64_ZONE_DMA_BITS;
+	dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL));
+	zone_dma_bits = min(32U, dt_zone_dma_bits);
 	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif
-- 
2.25.1

Patch "arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:17 +0800
Subject: arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>
Message-ID: <20210303073319.2215839-6-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 8424ecdde7df99d5426e1a1fd9f0fb36f4183032 upstream

We recently introduced a 1 GB sized ZONE_DMA to cater for platforms
incorporating masters that can address less than 32 bits of DMA, in
particular the Raspberry Pi 4, which has 4 or 8 GB of DRAM, but has
peripherals that can only address up to 1 GB (and its PCIe host
bridge can only access the bottom 3 GB)

The DMA layer also needs to be able to allocate memory that is
guaranteed to meet those DMA constraints, for bounce buffering as well
as allocating the backing for consistent mappings. This is why the 1 GB
ZONE_DMA was introduced recently. Unfortunately, it turns out the having
a 1 GB ZONE_DMA as well as a ZONE_DMA32 causes problems with kdump, and
potentially in other places where allocations cannot cross zone
boundaries. Therefore, we should avoid having two separate DMA zones
when possible.

So, with the help of of_dma_get_max_cpu_address() get the topmost
physical address accessible to all DMA masters in system and use that
information to fine-tune ZONE_DMA's size. In the absence of addressing
limited masters ZONE_DMA will span the whole 32-bit address space,
otherwise, in the case of the Raspberry Pi 4 it'll only span the 30-bit
address space, and have ZONE_DMA32 cover the rest of the 32-bit address
space.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20201119175400.9995-6-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/mm/init.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -42,8 +42,6 @@
 #include <asm/tlb.h>
 #include <asm/alternative.h>
 
-#define ARM64_ZONE_DMA_BITS	30
-
 /*
  * We need to be able to catch inadvertent references to memstart_addr
  * that occur (potentially in generic code) before arm64_memblock_init()
@@ -188,9 +186,11 @@ static phys_addr_t __init max_zone_phys(
 static void __init zone_sizes_init(unsigned long min, unsigned long max)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
+	unsigned int __maybe_unused dt_zone_dma_bits;
 
 #ifdef CONFIG_ZONE_DMA
-	zone_dma_bits = ARM64_ZONE_DMA_BITS;
+	dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL));
+	zone_dma_bits = min(32U, dt_zone_dma_bits);
 	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 6/7] arm64: mm: Set ZONE_DMA size based on early IORT scan

[Jing Xiangfeng]

From: Ard Biesheuvel <ardb@kernel.org>

commit 2b8652936f0ca9ca2e6c984ae76c7bfcda1b3f22 upstream

We recently introduced a 1 GB sized ZONE_DMA to cater for platforms
incorporating masters that can address less than 32 bits of DMA, in
particular the Raspberry Pi 4, which has 4 or 8 GB of DRAM, but has
peripherals that can only address up to 1 GB (and its PCIe host
bridge can only access the bottom 3 GB)

Instructing the DMA layer about these limitations is straight-forward,
even though we had to fix some issues regarding memory limits set in
the IORT for named components, and regarding the handling of ACPI _DMA
methods. However, the DMA layer also needs to be able to allocate
memory that is guaranteed to meet those DMA constraints, for bounce
buffering as well as allocating the backing for consistent mappings.

This is why the 1 GB ZONE_DMA was introduced recently. Unfortunately,
it turns out the having a 1 GB ZONE_DMA as well as a ZONE_DMA32 causes
problems with kdump, and potentially in other places where allocations
cannot cross zone boundaries. Therefore, we should avoid having two
separate DMA zones when possible.

So let's do an early scan of the IORT, and only create the ZONE_DMA
if we encounter any devices that need it. This puts the burden on
the firmware to describe such limitations in the IORT, which may be
redundant (and less precise) if _DMA methods are also being provided.
However, it should be noted that this situation is highly unusual for
arm64 ACPI machines. Also, the DMA subsystem still gives precedence to
the _DMA method if implemented, and so we will not lose the ability to
perform streaming DMA outside the ZONE_DMA if the _DMA method permits
it.

[nsaenz: unified implementation with DT's counterpart]

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-7-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 arch/arm64/mm/init.c      |  5 +++-
 drivers/acpi/arm64/iort.c | 55 +++++++++++++++++++++++++++++++++++++++
 include/linux/acpi_iort.h |  4 +++
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 05a1c2773629..b913844ab740 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -29,6 +29,7 @@
 #include <linux/kexec.h>
 #include <linux/crash_dump.h>
 #include <linux/hugetlb.h>
+#include <linux/acpi_iort.h>
 
 #include <asm/boot.h>
 #include <asm/fixmap.h>
@@ -186,11 +187,13 @@ static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
 static void __init zone_sizes_init(unsigned long min, unsigned long max)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
+	unsigned int __maybe_unused acpi_zone_dma_bits;
 	unsigned int __maybe_unused dt_zone_dma_bits;
 
 #ifdef CONFIG_ZONE_DMA
+	acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address());
 	dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL));
-	zone_dma_bits = min(32U, dt_zone_dma_bits);
+	zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits);
 	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 94f34109695c..2494138a6905 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1730,3 +1730,58 @@ void __init acpi_iort_init(void)
 
 	iort_init_platform_devices();
 }
+
+#ifdef CONFIG_ZONE_DMA
+/*
+ * Extract the highest CPU physical address accessible to all DMA masters in
+ * the system. PHYS_ADDR_MAX is returned when no constrained device is found.
+ */
+phys_addr_t __init acpi_iort_dma_get_max_cpu_address(void)
+{
+	phys_addr_t limit = PHYS_ADDR_MAX;
+	struct acpi_iort_node *node, *end;
+	struct acpi_table_iort *iort;
+	acpi_status status;
+	int i;
+
+	if (acpi_disabled)
+		return limit;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0,
+				(struct acpi_table_header **)&iort);
+	if (ACPI_FAILURE(status))
+		return limit;
+
+	node = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->node_offset);
+	end = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->header.length);
+
+	for (i = 0; i < iort->node_count; i++) {
+		if (node >= end)
+			break;
+
+		switch (node->type) {
+			struct acpi_iort_named_component *ncomp;
+			struct acpi_iort_root_complex *rc;
+			phys_addr_t local_limit;
+
+		case ACPI_IORT_NODE_NAMED_COMPONENT:
+			ncomp = (struct acpi_iort_named_component *)node->node_data;
+			local_limit = DMA_BIT_MASK(ncomp->memory_address_limit);
+			limit = min_not_zero(limit, local_limit);
+			break;
+
+		case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
+			if (node->revision < 1)
+				break;
+
+			rc = (struct acpi_iort_root_complex *)node->node_data;
+			local_limit = DMA_BIT_MASK(rc->memory_address_limit);
+			limit = min_not_zero(limit, local_limit);
+			break;
+		}
+		node = ACPI_ADD_PTR(struct acpi_iort_node, node, node->length);
+	}
+	acpi_put_table(&iort->header);
+	return limit;
+}
+#endif
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 20a32120bb88..1a12baa58e40 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -38,6 +38,7 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size);
 const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
 						const u32 *id_in);
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
+phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
 #else
 static inline void acpi_iort_init(void) { }
 static inline u32 iort_msi_map_id(struct device *dev, u32 id)
@@ -55,6 +56,9 @@ static inline const struct iommu_ops *iort_iommu_configure_id(
 static inline
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
+
+static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void)
+{ return PHYS_ADDR_MAX; }
 #endif
 
 #endif /* __ACPI_IORT_H__ */
-- 
2.25.1

Patch "arm64: mm: Set ZONE_DMA size based on early IORT scan" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: mm: Set ZONE_DMA size based on early IORT scan

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:18 +0800
Subject: arm64: mm: Set ZONE_DMA size based on early IORT scan
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Jeremy Linton <jeremy.linton@arm.com>, Christoph Hellwig <hch@lst.de>, Robin Murphy <robin.murphy@arm.com>
Message-ID: <20210303073319.2215839-7-jingxiangfeng@huawei.com>

From: Ard Biesheuvel <ardb@kernel.org>

commit 2b8652936f0ca9ca2e6c984ae76c7bfcda1b3f22 upstream

We recently introduced a 1 GB sized ZONE_DMA to cater for platforms
incorporating masters that can address less than 32 bits of DMA, in
particular the Raspberry Pi 4, which has 4 or 8 GB of DRAM, but has
peripherals that can only address up to 1 GB (and its PCIe host
bridge can only access the bottom 3 GB)

Instructing the DMA layer about these limitations is straight-forward,
even though we had to fix some issues regarding memory limits set in
the IORT for named components, and regarding the handling of ACPI _DMA
methods. However, the DMA layer also needs to be able to allocate
memory that is guaranteed to meet those DMA constraints, for bounce
buffering as well as allocating the backing for consistent mappings.

This is why the 1 GB ZONE_DMA was introduced recently. Unfortunately,
it turns out the having a 1 GB ZONE_DMA as well as a ZONE_DMA32 causes
problems with kdump, and potentially in other places where allocations
cannot cross zone boundaries. Therefore, we should avoid having two
separate DMA zones when possible.

So let's do an early scan of the IORT, and only create the ZONE_DMA
if we encounter any devices that need it. This puts the burden on
the firmware to describe such limitations in the IORT, which may be
redundant (and less precise) if _DMA methods are also being provided.
However, it should be noted that this situation is highly unusual for
arm64 ACPI machines. Also, the DMA subsystem still gives precedence to
the _DMA method if implemented, and so we will not lose the ability to
perform streaming DMA outside the ZONE_DMA if the _DMA method permits
it.

[nsaenz: unified implementation with DT's counterpart]

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-7-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/mm/init.c      |    5 +++-
 drivers/acpi/arm64/iort.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi_iort.h |    4 +++
 3 files changed, 63 insertions(+), 1 deletion(-)

--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -29,6 +29,7 @@
 #include <linux/kexec.h>
 #include <linux/crash_dump.h>
 #include <linux/hugetlb.h>
+#include <linux/acpi_iort.h>
 
 #include <asm/boot.h>
 #include <asm/fixmap.h>
@@ -186,11 +187,13 @@ static phys_addr_t __init max_zone_phys(
 static void __init zone_sizes_init(unsigned long min, unsigned long max)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
+	unsigned int __maybe_unused acpi_zone_dma_bits;
 	unsigned int __maybe_unused dt_zone_dma_bits;
 
 #ifdef CONFIG_ZONE_DMA
+	acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address());
 	dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL));
-	zone_dma_bits = min(32U, dt_zone_dma_bits);
+	zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits);
 	arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
 #endif
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1730,3 +1730,58 @@ void __init acpi_iort_init(void)
 
 	iort_init_platform_devices();
 }
+
+#ifdef CONFIG_ZONE_DMA
+/*
+ * Extract the highest CPU physical address accessible to all DMA masters in
+ * the system. PHYS_ADDR_MAX is returned when no constrained device is found.
+ */
+phys_addr_t __init acpi_iort_dma_get_max_cpu_address(void)
+{
+	phys_addr_t limit = PHYS_ADDR_MAX;
+	struct acpi_iort_node *node, *end;
+	struct acpi_table_iort *iort;
+	acpi_status status;
+	int i;
+
+	if (acpi_disabled)
+		return limit;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0,
+				(struct acpi_table_header **)&iort);
+	if (ACPI_FAILURE(status))
+		return limit;
+
+	node = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->node_offset);
+	end = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->header.length);
+
+	for (i = 0; i < iort->node_count; i++) {
+		if (node >= end)
+			break;
+
+		switch (node->type) {
+			struct acpi_iort_named_component *ncomp;
+			struct acpi_iort_root_complex *rc;
+			phys_addr_t local_limit;
+
+		case ACPI_IORT_NODE_NAMED_COMPONENT:
+			ncomp = (struct acpi_iort_named_component *)node->node_data;
+			local_limit = DMA_BIT_MASK(ncomp->memory_address_limit);
+			limit = min_not_zero(limit, local_limit);
+			break;
+
+		case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
+			if (node->revision < 1)
+				break;
+
+			rc = (struct acpi_iort_root_complex *)node->node_data;
+			local_limit = DMA_BIT_MASK(rc->memory_address_limit);
+			limit = min_not_zero(limit, local_limit);
+			break;
+		}
+		node = ACPI_ADD_PTR(struct acpi_iort_node, node, node->length);
+	}
+	acpi_put_table(&iort->header);
+	return limit;
+}
+#endif
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -38,6 +38,7 @@ void iort_dma_setup(struct device *dev,
 const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
 						const u32 *id_in);
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
+phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
 #else
 static inline void acpi_iort_init(void) { }
 static inline u32 iort_msi_map_id(struct device *dev, u32 id)
@@ -55,6 +56,9 @@ static inline const struct iommu_ops *io
 static inline
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
+
+static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void)
+{ return PHYS_ADDR_MAX; }
 #endif
 
 #endif /* __ACPI_IORT_H__ */


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

[PATCH stable v5.10 7/7] mm: Remove examples from enum zone_type comment

[Jing Xiangfeng]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 04435217f96869ac3a8f055ff68c5237a60bcd7e upstream

We can't really list every setup in common code. On top of that they are
unlikely to stay true for long as things change in the arch trees
independently of this comment.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20201119175400.9995-8-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
---
 include/linux/mmzone.h | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index fb3bf696c05e..9d0c454d23cd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -354,26 +354,6 @@ enum zone_type {
 	 * 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.
-	 *
-	 *  - 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,
-- 
2.25.1

Patch "mm: Remove examples from enum zone_type comment" has been added to the 5.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm: Remove examples from enum zone_type comment

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mm-remove-examples-from-enum-zone_type-comment.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Sun Mar  7 04:22:37 PM CET 2021
From: Jing Xiangfeng <jingxiangfeng@huawei.com>
Date: Wed, 3 Mar 2021 15:33:19 +0800
Subject: mm: Remove examples from enum zone_type comment
To: <gregkh@linuxfoundation.org>, <catalin.marinas@arm.com>, <will@kernel.org>, <akpm@linux-foundation.org>, <nsaenzjulienne@suse.de>, <paul.walmsley@sifive.com>, <palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <rppt@kernel.org>, <lorenzo.pieralisi@arm.com>, <guohanjun@huawei.com>, <sudeep.holla@arm.com>, <rjw@rjwysocki.net>, <lenb@kernel.org>, <song.bao.hua@hisilicon.com>, <ardb@kernel.org>, <anshuman.khandual@arm.com>, <bhelgaas@google.com>, <guro@fb.com>, <robh+dt@kernel.org>
Cc: <stable@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <frowand.list@gmail.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>, <linux-riscv@lists.infradead.org>, <jingxiangfeng@huawei.com>, <wangkefeng.wang@huawei.com>, Christoph Hellwig <hch@lst.de>
Message-ID: <20210303073319.2215839-8-jingxiangfeng@huawei.com>

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

commit 04435217f96869ac3a8f055ff68c5237a60bcd7e upstream

We can't really list every setup in common code. On top of that they are
unlikely to stay true for long as things change in the arch trees
independently of this comment.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20201119175400.9995-8-nsaenzjulienne@suse.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/mmzone.h |   20 --------------------
 1 file changed, 20 deletions(-)

--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -354,26 +354,6 @@ enum zone_type {
 	 * 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.
-	 *
-	 *  - 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,


Patches currently in stable-queue which might be from jingxiangfeng@huawei.com are

queue-5.10/of-unittest-add-test-for-of_dma_get_max_cpu_address.patch
queue-5.10/mm-remove-examples-from-enum-zone_type-comment.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-devicetree-s-dma-ranges.patch
queue-5.10/of-address-introduce-of_dma_get_max_cpu_address.patch
queue-5.10/arm64-mm-move-zone_dma_bits-initialization-into-zone_sizes_init.patch
queue-5.10/arm64-mm-set-zone_dma-size-based-on-early-iort-scan.patch
queue-5.10/arm64-mm-move-reserve_crashkernel-into-mem_init.patch

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> Using two distinct DMA zones turned out to be problematic. Here's an
> attempt go back to a saner default.

What problem does this solve?  How does this fit into the stable kernel
rules?

thanks,

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Nicolas Saenz Julienne]

[-- Attachment #1: Type: text/plain, Size: 924 bytes --]

Hi Greg.

On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > Using two distinct DMA zones turned out to be problematic. Here's an
> > attempt go back to a saner default.
> 
> What problem does this solve?  How does this fit into the stable kernel
> rules?

We changed the way we setup memory zones in arm64 in order to cater for
Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
memory that crosses zone boundaries, this broke crashkernel allocations on big
machines. This series fixes all this by parsing the HW description and checking
for DMA constrained buses. When not found, the unnecessary zone creation is
skipped.

That said, I have no clue whether this falls or not into the stable kernel
rules.

Regards,
Nicolas


[-- Attachment #2: This is a digitally signed message part --]
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Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
> Hi Greg.
> 
> On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > > Using two distinct DMA zones turned out to be problematic. Here's an
> > > attempt go back to a saner default.
> > 
> > What problem does this solve?  How does this fit into the stable kernel
> > rules?
> 
> We changed the way we setup memory zones in arm64 in order to cater for
> Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
> and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
> memory that crosses zone boundaries, this broke crashkernel allocations on big
> machines. This series fixes all this by parsing the HW description and checking
> for DMA constrained buses. When not found, the unnecessary zone creation is
> skipped.

What kernel/commit caused this "breakage"?

thanks,

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Nicolas Saenz Julienne]

[-- Attachment #1: Type: text/plain, Size: 1138 bytes --]

On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
> On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
> > Hi Greg.
> > 
> > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > > > Using two distinct DMA zones turned out to be problematic. Here's an
> > > > attempt go back to a saner default.
> > > 
> > > What problem does this solve?  How does this fit into the stable kernel
> > > rules?
> > 
> > We changed the way we setup memory zones in arm64 in order to cater for
> > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
> > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
> > memory that crosses zone boundaries, this broke crashkernel allocations on big
> > machines. This series fixes all this by parsing the HW description and checking
> > for DMA constrained buses. When not found, the unnecessary zone creation is
> > skipped.
> 
> What kernel/commit caused this "breakage"?

1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32

Regards,
Nicolas


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
> On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
> > On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
> > > Hi Greg.
> > > 
> > > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> > > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > > > > Using two distinct DMA zones turned out to be problematic. Here's an
> > > > > attempt go back to a saner default.
> > > > 
> > > > What problem does this solve?  How does this fit into the stable kernel
> > > > rules?
> > > 
> > > We changed the way we setup memory zones in arm64 in order to cater for
> > > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
> > > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
> > > memory that crosses zone boundaries, this broke crashkernel allocations on big
> > > machines. This series fixes all this by parsing the HW description and checking
> > > for DMA constrained buses. When not found, the unnecessary zone creation is
> > > skipped.
> > 
> > What kernel/commit caused this "breakage"?
> 
> 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32

Thanks for the info, all now queued up.

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Jing Xiangfeng]

On 2021/3/7 23:24, Greg KH wrote:
> On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
>> On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
>>> On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
>>>> Hi Greg.
>>>>
>>>> On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
>>>>> On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
>>>>>> Using two distinct DMA zones turned out to be problematic. Here's an
>>>>>> attempt go back to a saner default.
>>>>> What problem does this solve?  How does this fit into the stable kernel
>>>>> rules?
>>>> We changed the way we setup memory zones in arm64 in order to cater for
>>>> Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
>>>> and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
>>>> memory that crosses zone boundaries, this broke crashkernel allocations on big
>>>> machines. This series fixes all this by parsing the HW description and checking
>>>> for DMA constrained buses. When not found, the unnecessary zone creation is
>>>> skipped.
>>> What kernel/commit caused this "breakage"?
>> 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32
> Thanks for the info, all now queued up.
There is a fix in 5.11. Please consider applying the following commit to 
5.10.y:

aed5041ef9a3 of: unittest: Fix build on architectures without 
CONFIG_OF_ADDRES

Thanks

>
> greg k-h
> .
>

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote:
> 
> 
> On 2021/3/7 23:24, Greg KH wrote:
> > On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
> > > On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
> > > > On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
> > > > > Hi Greg.
> > > > > 
> > > > > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> > > > > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > > > > > > Using two distinct DMA zones turned out to be problematic. Here's an
> > > > > > > attempt go back to a saner default.
> > > > > > What problem does this solve?  How does this fit into the stable kernel
> > > > > > rules?
> > > > > We changed the way we setup memory zones in arm64 in order to cater for
> > > > > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
> > > > > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
> > > > > memory that crosses zone boundaries, this broke crashkernel allocations on big
> > > > > machines. This series fixes all this by parsing the HW description and checking
> > > > > for DMA constrained buses. When not found, the unnecessary zone creation is
> > > > > skipped.
> > > > What kernel/commit caused this "breakage"?
> > > 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32
> > Thanks for the info, all now queued up.
> There is a fix in 5.11. Please consider applying the following commit to
> 5.10.y:
> 
> aed5041ef9a3 of: unittest: Fix build on architectures without
> CONFIG_OF_ADDRES

Thanks, now queued up.

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Kefeng Wang]

On 2021/3/8 17:58, Greg KH wrote:
> On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote:
>>
>>
>> On 2021/3/7 23:24, Greg KH wrote:
>>> On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
>>>> On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
>>>>> On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
>>>>>> Hi Greg.
>>>>>>
>>>>>> On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
>>>>>>> On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
>>>>>>>> Using two distinct DMA zones turned out to be problematic. Here's an
>>>>>>>> attempt go back to a saner default.
>>>>>>> What problem does this solve?  How does this fit into the stable kernel
>>>>>>> rules?
>>>>>> We changed the way we setup memory zones in arm64 in order to cater for
>>>>>> Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
>>>>>> and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
>>>>>> memory that crosses zone boundaries, this broke crashkernel allocations on big
>>>>>> machines. This series fixes all this by parsing the HW description and checking
>>>>>> for DMA constrained buses. When not found, the unnecessary zone creation is
>>>>>> skipped.
>>>>> What kernel/commit caused this "breakage"?
>>>> 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32
>>> Thanks for the info, all now queued up.
>> There is a fix in 5.11. Please consider applying the following commit to
>> 5.10.y:
>>
>> aed5041ef9a3 of: unittest: Fix build on architectures without
>> CONFIG_OF_ADDRES
> 
> Thanks, now queued up.

Hi Grep, another commit d78050ee3544 "arm64: Remove 
arm64_dma32_phys_limit and its uses" should be involved, thanks.

"Prior to this patch, disabling CONFIG_ZONE_DMA32 leads to CMA
allocation from the whole RAM as arm64_dma32_phys_limit becomes
PHYS_MASK+1." from Catalin, see more from the link
https://www.spinics.net/lists/arm-kernel/msg867356.html
> 
> greg k-h
> .
> 

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Tue, May 11, 2021 at 08:35:47PM +0800, Kefeng Wang wrote:
> 
> 
> On 2021/3/8 17:58, Greg KH wrote:
> > On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote:
> > > 
> > > 
> > > On 2021/3/7 23:24, Greg KH wrote:
> > > > On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
> > > > > On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
> > > > > > On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote:
> > > > > > > Hi Greg.
> > > > > > > 
> > > > > > > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
> > > > > > > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
> > > > > > > > > Using two distinct DMA zones turned out to be problematic. Here's an
> > > > > > > > > attempt go back to a saner default.
> > > > > > > > What problem does this solve?  How does this fit into the stable kernel
> > > > > > > > rules?
> > > > > > > We changed the way we setup memory zones in arm64 in order to cater for
> > > > > > > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory
> > > > > > > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate
> > > > > > > memory that crosses zone boundaries, this broke crashkernel allocations on big
> > > > > > > machines. This series fixes all this by parsing the HW description and checking
> > > > > > > for DMA constrained buses. When not found, the unnecessary zone creation is
> > > > > > > skipped.
> > > > > > What kernel/commit caused this "breakage"?
> > > > > 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32
> > > > Thanks for the info, all now queued up.
> > > There is a fix in 5.11. Please consider applying the following commit to
> > > 5.10.y:
> > > 
> > > aed5041ef9a3 of: unittest: Fix build on architectures without
> > > CONFIG_OF_ADDRES
> > 
> > Thanks, now queued up.
> 
> Hi Grep, another commit d78050ee3544 "arm64: Remove arm64_dma32_phys_limit
> and its uses" should be involved, thanks.
> 
> "Prior to this patch, disabling CONFIG_ZONE_DMA32 leads to CMA
> allocation from the whole RAM as arm64_dma32_phys_limit becomes
> PHYS_MASK+1." from Catalin, see more from the link
> https://www.spinics.net/lists/arm-kernel/msg867356.html

Ok, now queued up.

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Kefeng Wang]

Hi Greg,

There are two more patches about the ZONE_DMA[32] changes, especially 
the second one, both them need be backported, thanks.

791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys() 
calculation
2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation 
is required



On 2021/5/11 20:35, Kefeng Wang wrote:
> 
> 
> On 2021/3/8 17:58, Greg KH wrote:
>> On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote:
>>>
>>>
>>> On 2021/3/7 23:24, Greg KH wrote:
>>>> On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote:
>>>>> On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote:
>>>>>> On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne 
>>>>>> wrote:
>>>>>>> Hi Greg.
>>>>>>>
>>>>>>> On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote:
>>>>>>>> On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote:
>>>>>>>>> Using two distinct DMA zones turned out to be problematic. 
>>>>>>>>> Here's an
>>>>>>>>> attempt go back to a saner default.
>>>>>>>> What problem does this solve?  How does this fit into the stable 
>>>>>>>> kernel
>>>>>>>> rules?
>>>>>>> We changed the way we setup memory zones in arm64 in order to 
>>>>>>> cater for
>>>>>>> Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 
>>>>>>> 1GB of memory
>>>>>>> and ZONE_DMA32 the rest of the 32bit address space. Since you 
>>>>>>> can't allocate
>>>>>>> memory that crosses zone boundaries, this broke crashkernel 
>>>>>>> allocations on big
>>>>>>> machines. This series fixes all this by parsing the HW 
>>>>>>> description and checking
>>>>>>> for DMA constrained buses. When not found, the unnecessary zone 
>>>>>>> creation is
>>>>>>> skipped.
>>>>>> What kernel/commit caused this "breakage"?
>>>>> 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32
>>>> Thanks for the info, all now queued up.
>>> There is a fix in 5.11. Please consider applying the following commit to
>>> 5.10.y:
>>>
>>> aed5041ef9a3 of: unittest: Fix build on architectures without
>>> CONFIG_OF_ADDRES
>>
>> Thanks, now queued up.
> 
> Hi Grep, another commit d78050ee3544 "arm64: Remove 
> arm64_dma32_phys_limit and its uses" should be involved, thanks.
> 
> "Prior to this patch, disabling CONFIG_ZONE_DMA32 leads to CMA
> allocation from the whole RAM as arm64_dma32_phys_limit becomes
> PHYS_MASK+1." from Catalin, see more from the link
> https://www.spinics.net/lists/arm-kernel/msg867356.html
>>
>> greg k-h
>> .
>>

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Wed, Jun 23, 2021 at 02:59:59PM +0800, Kefeng Wang wrote:
> Hi Greg,
> 
> There are two more patches about the ZONE_DMA[32] changes,

What ZONE_DMA changes?

> especially the
> second one, both them need be backported, thanks.

Backported to where?

> 791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys()
> calculation
> 2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is
> required

Have you tried these patches?  Where do they need to be applied to?

confused,

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Kefeng Wang]

On 2021/6/23 15:12, Greg KH wrote:
> On Wed, Jun 23, 2021 at 02:59:59PM +0800, Kefeng Wang wrote:
>> Hi Greg,
>>
>> There are two more patches about the ZONE_DMA[32] changes,
> 
> What ZONE_DMA changes?

See the subject, [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide 
ZONE_DMA, We asked the ARM64 ZONE_DMA change backport before, link[1]
> 
>> especially the
>> second one, both them need be backported, thanks.
> 
> Backported to where?

stable 5.10

> 
>> 791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys()
>> calculation
>> 2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is
>> required
> 
> Have you tried these patches?  Where do they need to be applied to?

Yes, we tested it, without them, especially the second one, we will
meet crash when using kexec boot, also there is discussion in [2]
and [3] from Catalin.


> 
> confused,
> 
Sorry about this, should add more information, thanks.

[1] 
https://lore.kernel.org/linux-riscv/20210303073319.2215839-1-jingxiangfeng@huawei.com/
[2] 
https://lore.kernel.org/linux-devicetree/e60d643e-4879-3fc3-737d-2c145332a6d7@arm.com/
[3] 
https://lore.kernel.org/linux-arm-kernel/20201119175556.18681-1-catalin.marinas@arm.com/
> greg k-h
> .
> 

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Wed, Jun 23, 2021 at 03:25:10PM +0800, Kefeng Wang wrote:
> 
> 
> On 2021/6/23 15:12, Greg KH wrote:
> > On Wed, Jun 23, 2021 at 02:59:59PM +0800, Kefeng Wang wrote:
> > > Hi Greg,
> > > 
> > > There are two more patches about the ZONE_DMA[32] changes,
> > 
> > What ZONE_DMA changes?
> 
> See the subject, [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide
> ZONE_DMA, We asked the ARM64 ZONE_DMA change backport before, link[1]

The subject doesn't help much, sorry, what commit does this refer to?
What happened to it?  Was it accepted or rejected?

> > > especially the
> > > second one, both them need be backported, thanks.
> > 
> > Backported to where?
> 
> stable 5.10

Why?

> > > 791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys()
> > > calculation
> > > 2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is
> > > required
> > 
> > Have you tried these patches?  Where do they need to be applied to?
> 
> Yes, we tested it, without them, especially the second one, we will
> meet crash when using kexec boot, also there is discussion in [2]
> and [3] from Catalin.

These [] do not seem to be links :(

thanks,

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Kefeng Wang]

On 2021/6/23 15:34, Greg KH wrote:
> On Wed, Jun 23, 2021 at 03:25:10PM +0800, Kefeng Wang wrote:
>>
>>
>> On 2021/6/23 15:12, Greg KH wrote:
>>> On Wed, Jun 23, 2021 at 02:59:59PM +0800, Kefeng Wang wrote:
>>>> Hi Greg,
>>>>
>>>> There are two more patches about the ZONE_DMA[32] changes,
>>>
>>> What ZONE_DMA changes?
>>
>> See the subject, [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide
>> ZONE_DMA, We asked the ARM64 ZONE_DMA change backport before, link[1]

Let's inline the link:
https://lore.kernel.org/lkml/20210303073319.2215839-1-jingxiangfeng@huawei.com/

The following 7 patches(we asked from link) has merged into lts5.10(tag: 
v5.10.22)

   4d7ed9a49b0c mm: Remove examples from enum zone_type comment
   8eaef922e938 arm64: mm: Set ZONE_DMA size based on early IORT scan
   35ec3d09ff6a arm64: mm: Set ZONE_DMA size based on devicetree's 
dma-ranges
   a9861e7fa4f8 of: unittest: Add test for of_dma_get_max_cpu_address()
   18bf6e998d08 of/address: Introduce of_dma_get_max_cpu_address()
   3fbe62ffbb54 arm64: mm: Move zone_dma_bits initialization into 
zone_sizes_init()
   407b173adfac arm64: mm: Move reserve_crashkernel() into mem_init()

but the patch "arm64: mm: Move reserve_crashkernel() into mem_init()"
has some issue, see the following discussion from Catalin,

https://lore.kernel.org/linux-devicetree/e60d643e-4879-3fc3-737d-2c145332a6d7@arm.com/
https://lore.kernel.org/linux-arm-kernel/20201119175556.18681-1-catalin.marinas@arm.com/

and yes, we met crash in lts5.10 when kexec boot due to "arm64: mm: Move 
reserve_crashkernel() into mem_init()" too, which could be fixed by
commit 2687275a5843 "arm64: Force NO_BLOCK_MAPPINGS if crashkernel 
reservation is required", and the commit 791ab8b2e3db "arm64: Ignore any 
DMA offsets in the max_zone_phys() calculation" also about DMA set,
So I only asked the two patches(both in v5.11) related ARM64 ZONE_DMA 
changes backported into lts5.10.

> 
> The subject doesn't help much, sorry, what commit does this refer to?
> What happened to it?  Was it accepted or rejected?
> 
>>>> especially the
>>>> second one, both them need be backported, thanks.
>>>
>>> Backported to where?
>>
>> stable 5.10
> 
> Why?

> 
>>>> 791ab8b2e3db - arm64: Ignore any DMA offsets in the max_zone_phys()
>>>> calculation
>>>> 2687275a5843 - arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is
>>>> required
>>>
>>> Have you tried these patches?  Where do they need to be applied to?
>>
>> Yes, we tested it, without them, especially the second one, we will
>> meet crash when using kexec boot, also there is discussion in [2]
>> and [3] from Catalin.
> 
> These [] do not seem to be links :(
I could see the links is in the end, see 
https://lore.kernel.org/lkml/e47df0fd-0ddd-408b-2972-1b6d0a786f00@huawei.com/

> 
> thanks,
> 
> greg k-h
> .
> 

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Greg KH]

On Wed, Jun 23, 2021 at 04:01:10PM +0800, Kefeng Wang wrote:
> 
> 
> On 2021/6/23 15:34, Greg KH wrote:
> > On Wed, Jun 23, 2021 at 03:25:10PM +0800, Kefeng Wang wrote:
> > > 
> > > 
> > > On 2021/6/23 15:12, Greg KH wrote:
> > > > On Wed, Jun 23, 2021 at 02:59:59PM +0800, Kefeng Wang wrote:
> > > > > Hi Greg,
> > > > > 
> > > > > There are two more patches about the ZONE_DMA[32] changes,
> > > > 
> > > > What ZONE_DMA changes?
> > > 
> > > See the subject, [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide
> > > ZONE_DMA, We asked the ARM64 ZONE_DMA change backport before, link[1]
> 
> Let's inline the link:
> https://lore.kernel.org/lkml/20210303073319.2215839-1-jingxiangfeng@huawei.com/
> 
> The following 7 patches(we asked from link) has merged into lts5.10(tag:
> v5.10.22)
> 
>   4d7ed9a49b0c mm: Remove examples from enum zone_type comment
>   8eaef922e938 arm64: mm: Set ZONE_DMA size based on early IORT scan
>   35ec3d09ff6a arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges
>   a9861e7fa4f8 of: unittest: Add test for of_dma_get_max_cpu_address()
>   18bf6e998d08 of/address: Introduce of_dma_get_max_cpu_address()
>   3fbe62ffbb54 arm64: mm: Move zone_dma_bits initialization into
> zone_sizes_init()
>   407b173adfac arm64: mm: Move reserve_crashkernel() into mem_init()
> 
> but the patch "arm64: mm: Move reserve_crashkernel() into mem_init()"
> has some issue, see the following discussion from Catalin,
> 
> https://lore.kernel.org/linux-devicetree/e60d643e-4879-3fc3-737d-2c145332a6d7@arm.com/
> https://lore.kernel.org/linux-arm-kernel/20201119175556.18681-1-catalin.marinas@arm.com/
> 
> and yes, we met crash in lts5.10 when kexec boot due to "arm64: mm: Move
> reserve_crashkernel() into mem_init()" too, which could be fixed by
> commit 2687275a5843 "arm64: Force NO_BLOCK_MAPPINGS if crashkernel
> reservation is required", and the commit 791ab8b2e3db "arm64: Ignore any DMA
> offsets in the max_zone_phys() calculation" also about DMA set,
> So I only asked the two patches(both in v5.11) related ARM64 ZONE_DMA
> changes backported into lts5.10.

Thanks, all now queued up.

greg k-h

Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA

[Kefeng Wang]

On 2021/6/25 18:19, Greg KH wrote:
> On Wed, Jun 23, 2021 at 04:01:10PM +0800, Kefeng Wang wrote:
>>
>> Let's inline the link:
>> https://lore.kernel.org/lkml/20210303073319.2215839-1-jingxiangfeng@huawei.com/
>>
>> The following 7 patches(we asked from link) has merged into lts5.10(tag:
>> v5.10.22)
>>
>>    4d7ed9a49b0c mm: Remove examples from enum zone_type comment
>>    8eaef922e938 arm64: mm: Set ZONE_DMA size based on early IORT scan
>>    35ec3d09ff6a arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges
>>    a9861e7fa4f8 of: unittest: Add test for of_dma_get_max_cpu_address()
>>    18bf6e998d08 of/address: Introduce of_dma_get_max_cpu_address()
>>    3fbe62ffbb54 arm64: mm: Move zone_dma_bits initialization into
>> zone_sizes_init()
>>    407b173adfac arm64: mm: Move reserve_crashkernel() into mem_init()
>>
>> but the patch "arm64: mm: Move reserve_crashkernel() into mem_init()"
>> has some issue, see the following discussion from Catalin,
>>
>> https://lore.kernel.org/linux-devicetree/e60d643e-4879-3fc3-737d-2c145332a6d7@arm.com/
>> https://lore.kernel.org/linux-arm-kernel/20201119175556.18681-1-catalin.marinas@arm.com/
>>
>> and yes, we met crash in lts5.10 when kexec boot due to "arm64: mm: Move
>> reserve_crashkernel() into mem_init()" too, which could be fixed by
>> commit 2687275a5843 "arm64: Force NO_BLOCK_MAPPINGS if crashkernel
>> reservation is required", and the commit 791ab8b2e3db "arm64: Ignore any DMA
>> offsets in the max_zone_phys() calculation" also about DMA set,
>> So I only asked the two patches(both in v5.11) related ARM64 ZONE_DMA
>> changes backported into lts5.10.
> Thanks, all now queued up.
Thank you again ;)
> greg k-h
> .
>