[PATCH v4 0/5] MIPS: Loongson64: Process ISA Node in DeviceTree

[PATCH v4 0/5] MIPS: Loongson64: Process ISA Node in DeviceTree

[Jiaxun Yang]

Hi,

This series convert reservation of Loongson64 Logic PIO into DeviceTree based
method.

It can be used to replace Huacai's
"MIPS: Loongson64: Reserve legacy MMIO space according to bridge type".

Thanks.

v2:
  - Address Rob and Huacai's review comments.
v3:
  - Address Rob, Thomas's review comments.
v4:
  - Fix typo & grammar issue according to Xuerui's suggestion.

Jiaxun Yang (5):
  of_address: Add bus type match for pci ranges parser
  MIPS: Loongson64: Process ISA Node in DeviceTree
  MIPS: Loongson64: Enlarge IO_SPACE_LIMIT
  MIPS: Loongson64: DTS: Fix ISA and PCI I/O ranges for RS780E PCH
  MIPS: Loongson64: Add ISA node for LS7A PCH

 arch/mips/boot/dts/loongson/ls7a-pch.dtsi     |  7 ++
 arch/mips/boot/dts/loongson/rs780e-pch.dtsi   |  4 +-
 arch/mips/include/asm/io.h                    |  2 -
 arch/mips/include/asm/mach-generic/spaces.h   |  4 +
 .../mips/include/asm/mach-loongson64/spaces.h |  3 +-
 arch/mips/loongson64/init.c                   | 87 +++++++++++++------
 drivers/of/address.c                          | 29 ++++---
 include/linux/of_address.h                    |  4 +
 8 files changed, 97 insertions(+), 43 deletions(-)

-- 
2.28.0.rc1

[PATCH v4 1/5] of_address: Add bus type match for pci ranges parser

[Jiaxun Yang]

So the parser can be used to parse range property of ISA bus.

As they're all using PCI-like method of range property, there is no need
start a new parser.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Rob Herring <robh@kernel.org>

--
v2: Drop useless check, fix some na for bus_addr
	add define of of_range_parser_init according to
	Rob's suggestion.
v3: Abstract out has_flags. simplify define.
---
 drivers/of/address.c       | 29 +++++++++++++++++------------
 include/linux/of_address.h |  4 ++++
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 8eea3f6e29a4..813936d419ad 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -49,6 +49,7 @@ struct of_bus {
 	u64		(*map)(__be32 *addr, const __be32 *range,
 				int na, int ns, int pna);
 	int		(*translate)(__be32 *addr, u64 offset, int na);
+	bool	has_flags;
 	unsigned int	(*get_flags)(const __be32 *addr);
 };
 
@@ -364,6 +365,7 @@ static struct of_bus of_busses[] = {
 		.count_cells = of_bus_pci_count_cells,
 		.map = of_bus_pci_map,
 		.translate = of_bus_pci_translate,
+		.has_flags = true,
 		.get_flags = of_bus_pci_get_flags,
 	},
 #endif /* CONFIG_PCI */
@@ -375,6 +377,7 @@ static struct of_bus of_busses[] = {
 		.count_cells = of_bus_isa_count_cells,
 		.map = of_bus_isa_map,
 		.translate = of_bus_isa_translate,
+		.has_flags = true,
 		.get_flags = of_bus_isa_get_flags,
 	},
 	/* Default */
@@ -698,9 +701,10 @@ static int parser_init(struct of_pci_range_parser *parser,
 
 	parser->node = node;
 	parser->pna = of_n_addr_cells(node);
-	parser->na = of_bus_n_addr_cells(node);
-	parser->ns = of_bus_n_size_cells(node);
 	parser->dma = !strcmp(name, "dma-ranges");
+	parser->bus = of_match_bus(node);
+
+	parser->bus->count_cells(parser->node, &parser->na, &parser->ns);
 
 	parser->range = of_get_property(node, name, &rlen);
 	if (parser->range == NULL)
@@ -732,6 +736,7 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
 	int na = parser->na;
 	int ns = parser->ns;
 	int np = parser->pna + na + ns;
+	int busflag_na = 0;
 
 	if (!range)
 		return NULL;
@@ -739,12 +744,13 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
 	if (!parser->range || parser->range + np > parser->end)
 		return NULL;
 
-	if (parser->na == 3)
-		range->flags = of_bus_pci_get_flags(parser->range);
-	else
-		range->flags = 0;
+	range->flags = parser->bus->get_flags(parser->range);
+
+	/* A extra cell for resource flags */
+	if (parser->bus->has_flags)
+		busflag_na = 1;
 
-	range->pci_addr = of_read_number(parser->range, na);
+	range->bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
 
 	if (parser->dma)
 		range->cpu_addr = of_translate_dma_address(parser->node,
@@ -759,11 +765,10 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
 	/* Now consume following elements while they are contiguous */
 	while (parser->range + np <= parser->end) {
 		u32 flags = 0;
-		u64 pci_addr, cpu_addr, size;
+		u64 bus_addr, cpu_addr, size;
 
-		if (parser->na == 3)
-			flags = of_bus_pci_get_flags(parser->range);
-		pci_addr = of_read_number(parser->range, na);
+		flags = parser->bus->get_flags(parser->range);
+		bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
 		if (parser->dma)
 			cpu_addr = of_translate_dma_address(parser->node,
 					parser->range + na);
@@ -774,7 +779,7 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
 
 		if (flags != range->flags)
 			break;
-		if (pci_addr != range->pci_addr + range->size ||
+		if (bus_addr != range->bus_addr + range->size ||
 		    cpu_addr != range->cpu_addr + range->size)
 			break;
 
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 763022ed3456..88bc943405cd 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -6,8 +6,11 @@
 #include <linux/of.h>
 #include <linux/io.h>
 
+struct of_bus;
+
 struct of_pci_range_parser {
 	struct device_node *node;
+	struct of_bus *bus;
 	const __be32 *range;
 	const __be32 *end;
 	int na;
@@ -119,6 +122,7 @@ static inline void __iomem *of_iomap(struct device_node *device, int index)
 	return NULL;
 }
 #endif
+#define of_range_parser_init of_pci_range_parser_init
 
 #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)
 extern const __be32 *of_get_pci_address(struct device_node *dev, int bar_no,
-- 
2.28.0.rc1

[PATCH v4 2/5] MIPS: Loongson64: Process ISA Node in DeviceTree

[Jiaxun Yang]

Previously, we're hardcoding reserved ISA I/O Space in, now
we're processing it I/O via DeviceTree directly.
The ranges property if ISA node is used to determine the size and address
of reserved I/O space.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
--
v2: Use range_parser instead of pci_range_parser
v4: Fix typos & grammar problem thanks to Xuerui.
---
 arch/mips/loongson64/init.c | 87 ++++++++++++++++++++++++++-----------
 1 file changed, 62 insertions(+), 25 deletions(-)

diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
index 59ddadace83f..8ba22c30f312 100644
--- a/arch/mips/loongson64/init.c
+++ b/arch/mips/loongson64/init.c
@@ -7,6 +7,8 @@
 #include <linux/irqchip.h>
 #include <linux/logic_pio.h>
 #include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <asm/bootinfo.h>
 #include <asm/traps.h>
 #include <asm/smp-ops.h>
@@ -63,41 +65,76 @@ void __init prom_free_prom_memory(void)
 {
 }
 
-static __init void reserve_pio_range(void)
+static int __init add_legacy_isa_io(struct fwnode_handle *fwnode, resource_size_t hw_start,
+				    resource_size_t size)
 {
+	int ret = 0;
 	struct logic_pio_hwaddr *range;
+	unsigned long vaddr;
 
 	range = kzalloc(sizeof(*range), GFP_ATOMIC);
 	if (!range)
-		return;
+		return -ENOMEM;
 
-	range->fwnode = &of_root->fwnode;
-	range->size = MMIO_LOWER_RESERVED;
-	range->hw_start = LOONGSON_PCIIO_BASE;
+	range->fwnode = fwnode;
+	range->size = size;
+	range->hw_start = hw_start;
 	range->flags = LOGIC_PIO_CPU_MMIO;
 
-	if (logic_pio_register_range(range)) {
-		pr_err("Failed to reserve PIO range for legacy ISA\n");
-		goto free_range;
+	ret = logic_pio_register_range(range);
+	if (ret) {
+		kfree(range);
+		return ret;
+	}
+
+	/* Legacy ISA must placed at the start of PCI_IOBASE */
+	if (range->io_start != 0) {
+		logic_pio_unregister_range(range);
+		kfree(range);
+		return -EINVAL;
 	}
 
-	if (WARN(range->io_start != 0,
-			"Reserved PIO range does not start from 0\n"))
-		goto unregister;
-
-	/*
-	 * i8259 would access I/O space, so mapping must be done here.
-	 * Please remove it when all drivers can be managed by logic_pio.
-	 */
-	ioremap_page_range(PCI_IOBASE, PCI_IOBASE + MMIO_LOWER_RESERVED,
-				LOONGSON_PCIIO_BASE,
-				pgprot_device(PAGE_KERNEL));
-
-	return;
-unregister:
-	logic_pio_unregister_range(range);
-free_range:
-	kfree(range);
+	vaddr = PCI_IOBASE + range->io_start;
+
+	ioremap_page_range(vaddr, vaddr + size, hw_start, pgprot_device(PAGE_KERNEL));
+
+	return 0;
+}
+
+static __init void reserve_pio_range(void)
+{
+	struct device_node *np;
+
+	for_each_node_by_name(np, "isa") {
+		struct of_range range;
+		struct of_range_parser parser;
+
+		pr_info("ISA Bridge: %pOF\n", np);
+
+		if (of_range_parser_init(&parser, np)) {
+			pr_info("Failed to parse resources.\n");
+			break;
+		}
+
+		for_each_of_range(&parser, &range) {
+			switch (range.flags & IORESOURCE_TYPE_BITS) {
+			case IORESOURCE_IO:
+				pr_info(" IO 0x%016llx..0x%016llx  ->  0x%016llx\n",
+					range.cpu_addr,
+					range.cpu_addr + range.size - 1,
+					range.bus_addr);
+				if (add_legacy_isa_io(&np->fwnode, range.cpu_addr, range.size))
+					pr_warn("Failed to reserve legacy IO in Logic PIO\n");
+				break;
+			case IORESOURCE_MEM:
+				pr_info(" MEM 0x%016llx..0x%016llx  ->  0x%016llx\n",
+					range.cpu_addr,
+					range.cpu_addr + range.size - 1,
+					range.bus_addr);
+				break;
+			}
+		}
+	}
 }
 
 void __init arch_init_irq(void)
-- 
2.28.0.rc1

[PATCH v4 3/5] MIPS: Loongson64: Enlarge IO_SPACE_LIMIT

[Jiaxun Yang]

It can be very big on LS7A PCH systems.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
--
v3: Move IO_SPACE_LIMIT to spaces.h
---
 arch/mips/include/asm/io.h                     | 2 --
 arch/mips/include/asm/mach-generic/spaces.h    | 4 ++++
 arch/mips/include/asm/mach-loongson64/spaces.h | 3 +--
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 346fffd9e972..8ca53f17c7c2 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -51,8 +51,6 @@
 
 /* ioswab[bwlq], __mem_ioswab[bwlq] are defined in mangle-port.h */
 
-#define IO_SPACE_LIMIT 0xffff
-
 /*
  * On MIPS I/O ports are memory mapped, so we access them using normal
  * load/store instructions. mips_io_port_base is the virtual address to
diff --git a/arch/mips/include/asm/mach-generic/spaces.h b/arch/mips/include/asm/mach-generic/spaces.h
index ee5ebe98f6cf..c3ac06a6acd2 100644
--- a/arch/mips/include/asm/mach-generic/spaces.h
+++ b/arch/mips/include/asm/mach-generic/spaces.h
@@ -14,6 +14,10 @@
 
 #include <asm/mipsregs.h>
 
+#ifndef IO_SPACE_LIMIT
+#define IO_SPACE_LIMIT 0xffff
+#endif
+
 /*
  * This gives the physical RAM offset.
  */
diff --git a/arch/mips/include/asm/mach-loongson64/spaces.h b/arch/mips/include/asm/mach-loongson64/spaces.h
index 3de0ac9d8829..ce04e998a37b 100644
--- a/arch/mips/include/asm/mach-loongson64/spaces.h
+++ b/arch/mips/include/asm/mach-loongson64/spaces.h
@@ -11,8 +11,7 @@
 #define PCI_IOSIZE	SZ_16M
 #define MAP_BASE	(PCI_IOBASE + PCI_IOSIZE)
 
-/* Reserved at the start of PCI_IOBASE for legacy drivers */
-#define MMIO_LOWER_RESERVED	0x10000
+#define IO_SPACE_LIMIT  (PCI_IOSIZE - 1)
 
 #include <asm/mach-generic/spaces.h>
 #endif
-- 
2.28.0.rc1

[PATCH v4 4/5] MIPS: Loongson64: DTS: Fix ISA and PCI I/O ranges for RS780E PCH

[Jiaxun Yang]

Ranges should express the actual physical address on bus.
Also enlarge the PCI I/O size to the actual hardware limit.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/boot/dts/loongson/rs780e-pch.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/boot/dts/loongson/rs780e-pch.dtsi b/arch/mips/boot/dts/loongson/rs780e-pch.dtsi
index d4c803d74036..871c866e0423 100644
--- a/arch/mips/boot/dts/loongson/rs780e-pch.dtsi
+++ b/arch/mips/boot/dts/loongson/rs780e-pch.dtsi
@@ -17,7 +17,7 @@ pci@1a000000 {
 
 			reg = <0 0x1a000000 0 0x02000000>;
 
-			ranges = <0x01000000 0 0x00004000 0 0x18004000 0 0x00008000>,
+			ranges = <0x01000000 0 0x00004000 0 0x18004000 0 0x0000c000>,
 				 <0x02000000 0 0x40000000 0 0x40000000 0 0x40000000>;
 		};
 
@@ -25,7 +25,7 @@ isa {
 			compatible = "isa";
 			#address-cells = <2>;
 			#size-cells = <1>;
-			ranges = <1 0 0 0 0x4000>;
+			ranges = <1 0 0 0x18000000 0x4000>;
 
 			rtc0: rtc@70 {
 				compatible = "motorola,mc146818";
-- 
2.28.0.rc1

[PATCH v4 5/5] MIPS: Loongson64: Add ISA node for LS7A PCH

[Jiaxun Yang]

Although currently we're not enabling any ISA device in devicetree,
but this node is required to express the ranges of address reserved
for ISA.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/boot/dts/loongson/ls7a-pch.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
index 1c286bb8c703..e574a062dfae 100644
--- a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
+++ b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
@@ -367,5 +367,12 @@ pci_bridge@14,0 {
 				interrupt-map = <0 0 0 0 &pic 39 IRQ_TYPE_LEVEL_HIGH>;
 			};
 		};
+
+		isa {
+			compatible = "isa";
+			#address-cells = <2>;
+			#size-cells = <1>;
+			ranges = <1 0 0 0x18000000 0x20000>;
+		};
 	};
 };
-- 
2.28.0.rc1

Re: [PATCH v4 0/5] MIPS: Loongson64: Process ISA Node in DeviceTree

[Thomas Bogendoerfer]

On Tue, Jul 28, 2020 at 11:36:54PM +0800, Jiaxun Yang wrote:
> Hi,
> 
> This series convert reservation of Loongson64 Logic PIO into DeviceTree based
> method.
> 
> It can be used to replace Huacai's
> "MIPS: Loongson64: Reserve legacy MMIO space according to bridge type".
> 
> Thanks.
> 
> v2:
>   - Address Rob and Huacai's review comments.
> v3:
>   - Address Rob, Thomas's review comments.
> v4:
>   - Fix typo & grammar issue according to Xuerui's suggestion.
> 
> Jiaxun Yang (5):
>   of_address: Add bus type match for pci ranges parser
>   MIPS: Loongson64: Process ISA Node in DeviceTree
>   MIPS: Loongson64: Enlarge IO_SPACE_LIMIT
>   MIPS: Loongson64: DTS: Fix ISA and PCI I/O ranges for RS780E PCH
>   MIPS: Loongson64: Add ISA node for LS7A PCH
> 
>  arch/mips/boot/dts/loongson/ls7a-pch.dtsi     |  7 ++
>  arch/mips/boot/dts/loongson/rs780e-pch.dtsi   |  4 +-
>  arch/mips/include/asm/io.h                    |  2 -
>  arch/mips/include/asm/mach-generic/spaces.h   |  4 +
>  .../mips/include/asm/mach-loongson64/spaces.h |  3 +-
>  arch/mips/loongson64/init.c                   | 87 +++++++++++++------
>  drivers/of/address.c                          | 29 ++++---
>  include/linux/of_address.h                    |  4 +
>  8 files changed, 97 insertions(+), 43 deletions(-)

series applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v4 0/5] MIPS: Loongson64: Process ISA Node in DeviceTree

[Jiaxun Yang]

在 2020/7/29 4:52, Thomas Bogendoerfer 写道:
> On Tue, Jul 28, 2020 at 11:36:54PM +0800, Jiaxun Yang wrote:
>> Hi,
>>
>> This series convert reservation of Loongson64 Logic PIO into DeviceTree based
>> method.
>>
>> It can be used to replace Huacai's
>> "MIPS: Loongson64: Reserve legacy MMIO space according to bridge type".
>>
>> Thanks.
>>
>> v2:
>>    - Address Rob and Huacai's review comments.
>> v3:
>>    - Address Rob, Thomas's review comments.
>> v4:
>>    - Fix typo & grammar issue according to Xuerui's suggestion.
>>
>> Jiaxun Yang (5):
>>    of_address: Add bus type match for pci ranges parser
>>    MIPS: Loongson64: Process ISA Node in DeviceTree
>>    MIPS: Loongson64: Enlarge IO_SPACE_LIMIT
>>    MIPS: Loongson64: DTS: Fix ISA and PCI I/O ranges for RS780E PCH
>>    MIPS: Loongson64: Add ISA node for LS7A PCH
>>
>>   arch/mips/boot/dts/loongson/ls7a-pch.dtsi     |  7 ++
>>   arch/mips/boot/dts/loongson/rs780e-pch.dtsi   |  4 +-
>>   arch/mips/include/asm/io.h                    |  2 -
>>   arch/mips/include/asm/mach-generic/spaces.h   |  4 +
>>   .../mips/include/asm/mach-loongson64/spaces.h |  3 +-
>>   arch/mips/loongson64/init.c                   | 87 +++++++++++++------
>>   drivers/of/address.c                          | 29 ++++---
>>   include/linux/of_address.h                    |  4 +
>>   8 files changed, 97 insertions(+), 43 deletions(-)
> series applied to mips-next.

+ Xuerui & Bibo,

This series should fix the issue that RTC on RS780E chipset failed
to be probed, please kindly test latest mips-next.

Thanks!

- Jiaxun

>
> Thomas.
>

Re: [PATCH v4 1/5] of_address: Add bus type match for pci ranges parser

[Marc Zyngier]

Hi all,

On 2020-07-28 16:36, Jiaxun Yang wrote:
> So the parser can be used to parse range property of ISA bus.
> 
> As they're all using PCI-like method of range property, there is no 
> need
> start a new parser.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> Reviewed-by: Rob Herring <robh@kernel.org>

This patch, although it looks correct, breaks the RK3399-based
systems, as they miss the (now required) 'device_type = "pci";'
property.

We can fix the in-tree DT, but that's not really an option
if someone relies on the DT being provided by the firmware
(I for one definitely do).

I came up with the following hack, which solves the issue for
me. Definitely not my finest hour, but I really need this box
to keep going. I will post a patch fixing the DT separately.

Thanks,

         M.

 From ceef5fd9c4d2005eb577505c68868ebe527c098f Mon Sep 17 00:00:00 2001
 From: Marc Zyngier <maz@kernel.org>
Date: Fri, 14 Aug 2020 19:10:12 +0100
Subject: [PATCH] of: address: Workaround broken DTs missing the 
'device_type =
  "pci"' property

Recent changes to the PCI bus parsing made it mandatory for
device trees nodes describing a PCI controller to have the
'device_type = "pci"' property for the node to be matched.

Although this is compliant with the specification, it breaks
existing device-trees that have been working fine for years
(the Rockchip rk3399-based systems being a prime example of
such breakage).

In order to paper over the blunder, let's also match nodes
that have the "linux,pci-domain" property, as they are
pretty likely to be PCI nodes. This fixes the issue for
systems such as the above platforms.

Fixes: 2f96593ecc37 ("of_address: Add bus type match for pci ranges 
parser")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
  drivers/of/address.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 590493e04b01..712e03781a2a 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -134,9 +134,12 @@ static int of_bus_pci_match(struct device_node *np)
   	 * "pciex" is PCI Express
  	 * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
  	 * "ht" is hypertransport
+	 * "linux,pci-domain" is a workaround for broken device trees
+	 * lacking the required "device_type" property.
  	 */
  	return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
-		of_node_is_type(np, "vci") || of_node_is_type(np, "ht");
+		of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
+		of_find_property(np, "linux,pci-domain", NULL);
  }

  static void of_bus_pci_count_cells(struct device_node *np,
-- 
2.27.0


-- 
Jazz is not dead. It just smells funny...

Re: [PATCH v4 1/5] of_address: Add bus type match for pci ranges parser

[Rob Herring]

On Fri, Aug 14, 2020 at 12:21 PM Marc Zyngier <maz@kernel.org> wrote:
>
> Hi all,
>
> On 2020-07-28 16:36, Jiaxun Yang wrote:
> > So the parser can be used to parse range property of ISA bus.
> >
> > As they're all using PCI-like method of range property, there is no
> > need
> > start a new parser.
> >
> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> > Reviewed-by: Rob Herring <robh@kernel.org>
>
> This patch, although it looks correct, breaks the RK3399-based
> systems, as they miss the (now required) 'device_type = "pci";'
> property.

Required since 1990 something...

> We can fix the in-tree DT, but that's not really an option
> if someone relies on the DT being provided by the firmware
> (I for one definitely do).

Perhaps time to pay attention to schema errors:

arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dt.yaml:
pcie@f8000000: 'device_type' is a required property

(I thought dtc would also catch this, but there we look for
device_type and then do PCI checks like node name. I guess we needed
to check for either device_type or the node name...)

> I came up with the following hack, which solves the issue for
> me. Definitely not my finest hour, but I really need this box
> to keep going. I will post a patch fixing the DT separately.
>
> Thanks,
>
>          M.
>
>  From ceef5fd9c4d2005eb577505c68868ebe527c098f Mon Sep 17 00:00:00 2001
>  From: Marc Zyngier <maz@kernel.org>
> Date: Fri, 14 Aug 2020 19:10:12 +0100
> Subject: [PATCH] of: address: Workaround broken DTs missing the
> 'device_type =
>   "pci"' property
>
> Recent changes to the PCI bus parsing made it mandatory for
> device trees nodes describing a PCI controller to have the
> 'device_type = "pci"' property for the node to be matched.
>
> Although this is compliant with the specification, it breaks
> existing device-trees that have been working fine for years
> (the Rockchip rk3399-based systems being a prime example of
> such breakage).
>
> In order to paper over the blunder, let's also match nodes
> that have the "linux,pci-domain" property, as they are
> pretty likely to be PCI nodes. This fixes the issue for
> systems such as the above platforms.
>
> Fixes: 2f96593ecc37 ("of_address: Add bus type match for pci ranges
> parser")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>   drivers/of/address.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 590493e04b01..712e03781a2a 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -134,9 +134,12 @@ static int of_bus_pci_match(struct device_node *np)
>          * "pciex" is PCI Express
>          * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
>          * "ht" is hypertransport
> +        * "linux,pci-domain" is a workaround for broken device trees
> +        * lacking the required "device_type" property.

I would suggest looking for 'pci' or 'pcie' node name instead.

You should remove linux,pci-domain from rk3399 as it is pointless when
there's a single PCI host bridge.

The other option is fixup the live tree with of_add_property() in the
Rockchip PCI driver. Less likely to impact anyone else.

>          */
>         return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
> -               of_node_is_type(np, "vci") || of_node_is_type(np, "ht");
> +               of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
> +               of_find_property(np, "linux,pci-domain", NULL);
>   }
>
>   static void of_bus_pci_count_cells(struct device_node *np,
> --
> 2.27.0
>
>
> --
> Jazz is not dead. It just smells funny...

Re: [PATCH v4 1/5] of_address: Add bus type match for pci ranges parser

[Marc Zyngier]

On 2020-08-14 23:51, Rob Herring wrote:
> On Fri, Aug 14, 2020 at 12:21 PM Marc Zyngier <maz@kernel.org> wrote:
>> 
>> Hi all,
>> 
>> On 2020-07-28 16:36, Jiaxun Yang wrote:
>> > So the parser can be used to parse range property of ISA bus.
>> >
>> > As they're all using PCI-like method of range property, there is no
>> > need
>> > start a new parser.
>> >
>> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> > Reviewed-by: Rob Herring <robh@kernel.org>
>> 
>> This patch, although it looks correct, breaks the RK3399-based
>> systems, as they miss the (now required) 'device_type = "pci";'
>> property.
> 
> Required since 1990 something...

And yet... The fact that it has been broken from day-1 (3.5 years
ago) shows how good we are at enforcing those requirements.

> 
>> We can fix the in-tree DT, but that's not really an option
>> if someone relies on the DT being provided by the firmware
>> (I for one definitely do).
> 
> Perhaps time to pay attention to schema errors:
> 
> arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dt.yaml:
> pcie@f8000000: 'device_type' is a required property

As long as this isn't part of the normal build flow, these errors
will get ignored. I don't even know how to trigger this validation,
TBH.

> (I thought dtc would also catch this, but there we look for
> device_type and then do PCI checks like node name. I guess we needed
> to check for either device_type or the node name...)

That would be much better. At least this *does* run at build time.

> 
>> I came up with the following hack, which solves the issue for
>> me. Definitely not my finest hour, but I really need this box
>> to keep going. I will post a patch fixing the DT separately.
>> 
>> Thanks,
>> 
>>          M.
>> 
>>  From ceef5fd9c4d2005eb577505c68868ebe527c098f Mon Sep 17 00:00:00 
>> 2001
>>  From: Marc Zyngier <maz@kernel.org>
>> Date: Fri, 14 Aug 2020 19:10:12 +0100
>> Subject: [PATCH] of: address: Workaround broken DTs missing the
>> 'device_type =
>>   "pci"' property
>> 
>> Recent changes to the PCI bus parsing made it mandatory for
>> device trees nodes describing a PCI controller to have the
>> 'device_type = "pci"' property for the node to be matched.
>> 
>> Although this is compliant with the specification, it breaks
>> existing device-trees that have been working fine for years
>> (the Rockchip rk3399-based systems being a prime example of
>> such breakage).
>> 
>> In order to paper over the blunder, let's also match nodes
>> that have the "linux,pci-domain" property, as they are
>> pretty likely to be PCI nodes. This fixes the issue for
>> systems such as the above platforms.
>> 
>> Fixes: 2f96593ecc37 ("of_address: Add bus type match for pci ranges
>> parser")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>>   drivers/of/address.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/of/address.c b/drivers/of/address.c
>> index 590493e04b01..712e03781a2a 100644
>> --- a/drivers/of/address.c
>> +++ b/drivers/of/address.c
>> @@ -134,9 +134,12 @@ static int of_bus_pci_match(struct device_node 
>> *np)
>>          * "pciex" is PCI Express
>>          * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
>>          * "ht" is hypertransport
>> +        * "linux,pci-domain" is a workaround for broken device trees
>> +        * lacking the required "device_type" property.
> 
> I would suggest looking for 'pci' or 'pcie' node name instead.
> 
> You should remove linux,pci-domain from rk3399 as it is pointless when
> there's a single PCI host bridge.

Indeed. I was clutching at straws here.

> 
> The other option is fixup the live tree with of_add_property() in the
> Rockchip PCI driver. Less likely to impact anyone else.

That's actually a much better solution, thanks for pointing this out.
At least I can shout about broken DTs while fixing it up, and the
new fix is fairly neat.

I'll post new patches shortly.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...