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PCI: xgene: Revert "PCI: xgene: Use inbound resources for setup"

PATCH Superseded Marc Zyngier 4 participants 5 messages Mar 14, 2022 – Mar 21, 2022

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#0 lore raw

PATCH 1/1 PCI: xgene: Revert "PCI: xgene: Use inbound resources for setup"

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup") killed PCIe on my XGene-1 box (a Mustang board). The machine itself is still alive, but half of its storage (over NVMe) is gone, and the NVMe driver just times out.

Note that this machine boots with a device tree provided by the UEFI firmware (2016 vintage), which could well be non conformant with the spec, hence the breakage.

With the patch reverted, the box boots 5.17-rc8 with flying colors.

Cc Rob Herring <[email protected]>
Cc Toan Le <[email protected]>
Cc Lorenzo Pieralisi <[email protected]>
Cc Krzysztof Wilczyński <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Stéphane Graber <[email protected]>
Cc dann frazier <[email protected]>
Cc Thorsten Leemhuis <[email protected]>
---
 drivers/pci/controller/pci-xgene.c | 33 ++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 11 deletions(-)
drivers/pci/controller/pci-xgene.c +22 -11
index 0d5acbfc7143..aa41ceaf031f 100644
@@ -479,28 +479,27 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
 }
 
 static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
-				    struct resource_entry *entry,
-				    u8 *ib_reg_mask)
+				    struct of_pci_range *range, u8 *ib_reg_mask)
 {
 	void __iomem *cfg_base = port->cfg_base;
 	struct device *dev = port->dev;
 	void __iomem *bar_addr;
 	u32 pim_reg;
-	u64 cpu_addr = entry->res->start;
-	u64 pci_addr = cpu_addr - entry->offset;
-	u64 size = resource_size(entry->res);
+	u64 cpu_addr = range->cpu_addr;
+	u64 pci_addr = range->pci_addr;
+	u64 size = range->size;
 	u64 mask = ~(size - 1) | EN_REG;
 	u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
 	u32 bar_low;
 	int region;
 
-	region = xgene_pcie_select_ib_reg(ib_reg_mask, size);
+	region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
 	if (region < 0) {
 		dev_warn(dev, "invalid pcie dma-range config\n");
 		return;
 	}
 
-	if (entry->res->flags & IORESOURCE_PREFETCH)
+	if (range->flags & IORESOURCE_PREFETCH)
 		flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
 
 	bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
@@ -531,13 +530,25 @@ static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
 
 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie *port)
 {
-	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
-	struct resource_entry *entry;
+	struct device_node *np = port->node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device *dev = port->dev;
 	u8 ib_reg_mask = 0;
 
-	resource_list_for_each_entry(entry, &bridge->dma_ranges)
-		xgene_pcie_setup_ib_reg(port, entry, &ib_reg_mask);
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		dev_err(dev, "missing dma-ranges property\n");
+		return -EINVAL;
+	}
+
+	/* Get the dma-ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		u64 end = range.cpu_addr + range.size - 1;
 
+		dev_dbg(dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
+			range.flags, range.cpu_addr, end, range.pci_addr);
+		xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
+	}
 	return 0;
 }
 
Signature · 1 line
2.34.1
#1 lore raw
Quoted 11 lines · Marc Zyngier

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup") killed PCIe on my XGene-1 box (a Mustang board). The machine itself is still alive, but half of its storage (over NVMe) is gone, and the NVMe driver just times out.

Note that this machine boots with a device tree provided by the UEFI firmware (2016 vintage), which could well be non conformant with the spec, hence the breakage.

With the patch reverted, the box boots 5.17-rc8 with flying colors.

Quoted 9 lines
Cc Rob Herring <[email protected]>
Cc Toan Le <[email protected]>
Cc Lorenzo Pieralisi <[email protected]>
Cc Krzysztof Wilczyński <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Stéphane Graber <[email protected]>
Cc dann frazier <[email protected]>
Cc Thorsten Leemhuis <[email protected]>

Feel free to drop me there. But could you please instead add a 'Link:' tag pointing to the report for anyone wanting to look into the backstory in the future, as explained in 'Documentation/process/submitting-patches.rst' and 'Documentation/process/5.Posting.rst'? E.g. like this:

"Link: https://lore.kernel.org/r/Yf2wTLjmcRj%[email protected]/"

FWIW, I care for another reason: I'm tracking this regression with regzbot, my regression tracking bot. Proper "Link:" tags allow the bot to connect regression reports with fixes being posted or applied to resolve the regression -- which makes regression tracking a whole lot easier.

While at it, let me tell regzbot about this thread:
#regzbot ^backmonitor:
https://lore.kernel.org/r/Yf2wTLjmcRj%[email protected]/

Quoted 1 line

Typo, missing a "<"

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them and lack knowledge about most of the areas they concern. I thus unfortunately will sometimes get things wrong or miss something important. I hope that's not the case here; if you think it is, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.

Signature · 25 lines
Additional information about regzbot:

If you want to know more about regzbot, check out its web-interface, the
getting start guide, and the references documentation:

https://linux-regtracking.leemhuis.info/regzbot/
https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md
https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md

The last two documents will explain how you can interact with regzbot
yourself if your want to.

Hint for reporters: when reporting a regression it's in your interest to
CC the regression list and tell regzbot about the issue, as that ensures
the regression makes it onto the radar of the Linux kernel's regression
tracker -- that's in your interest, as it ensures your report won't fall
through the cracks unnoticed.

Hint for developers: you normally don't need to care about regzbot once
it's involved. Fix the issue as you normally would, just remember to
include 'Link:' tag in the patch descriptions pointing to all reports
about the issue. This has been expected from developers even before
regzbot showed up for reasons explained in
'Documentation/process/submitting-patches.rst' and
'Documentation/process/5.Posting.rst'.
#2 lore raw
In reply to Marc Zyngier

[removed CC stable]

Quoted 21 lines · Marc Zyngier

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup") killed PCIe on my XGene-1 box (a Mustang board). The machine itself is still alive, but half of its storage (over NVMe) is gone, and the NVMe driver just times out.

Note that this machine boots with a device tree provided by the UEFI firmware (2016 vintage), which could well be non conformant with the spec, hence the breakage.

With the patch reverted, the box boots 5.17-rc8 with flying colors.

Cc Rob Herring <[email protected]>
Cc Toan Le <[email protected]>
Cc Lorenzo Pieralisi <[email protected]>
Cc Krzysztof Wilczyński <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Stéphane Graber <[email protected]>
Cc dann frazier <[email protected]>
Cc Thorsten Leemhuis <[email protected]>
Quoted 3 lines
---
 drivers/pci/controller/pci-xgene.c | 33 ++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 11 deletions(-)

Dann, Rob,

does this fix the regression debated here:

https://lore.kernel.org/all/[email protected]

It is unclear in that thread what the conclusion reached was.

Thanks,
Lorenzo

Quoted 72 lines
drivers/pci/controller/pci-xgene.c +22 -11
index 0d5acbfc7143..aa41ceaf031f 100644
@@ -479,28 +479,27 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
 }
 
 static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
-				    struct resource_entry *entry,
-				    u8 *ib_reg_mask)
+				    struct of_pci_range *range, u8 *ib_reg_mask)
 {
 	void __iomem *cfg_base = port->cfg_base;
 	struct device *dev = port->dev;
 	void __iomem *bar_addr;
 	u32 pim_reg;
-	u64 cpu_addr = entry->res->start;
-	u64 pci_addr = cpu_addr - entry->offset;
-	u64 size = resource_size(entry->res);
+	u64 cpu_addr = range->cpu_addr;
+	u64 pci_addr = range->pci_addr;
+	u64 size = range->size;
 	u64 mask = ~(size - 1) | EN_REG;
 	u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
 	u32 bar_low;
 	int region;
 
-	region = xgene_pcie_select_ib_reg(ib_reg_mask, size);
+	region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
 	if (region < 0) {
 		dev_warn(dev, "invalid pcie dma-range config\n");
 		return;
 	}
 
-	if (entry->res->flags & IORESOURCE_PREFETCH)
+	if (range->flags & IORESOURCE_PREFETCH)
 		flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
 
 	bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
@@ -531,13 +530,25 @@ static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
 
 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie *port)
 {
-	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
-	struct resource_entry *entry;
+	struct device_node *np = port->node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device *dev = port->dev;
 	u8 ib_reg_mask = 0;
 
-	resource_list_for_each_entry(entry, &bridge->dma_ranges)
-		xgene_pcie_setup_ib_reg(port, entry, &ib_reg_mask);
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		dev_err(dev, "missing dma-ranges property\n");
+		return -EINVAL;
+	}
+
+	/* Get the dma-ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		u64 end = range.cpu_addr + range.size - 1;
 
+		dev_dbg(dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
+			range.flags, range.cpu_addr, end, range.pci_addr);
+		xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
+	}
 	return 0;
 }
 
Signature · 1 line
2.34.1
#3 lore raw
Quoted 28 lines · Lorenzo Pieralisi

[removed CC stable]

Quoted 21 lines · Marc Zyngier

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup") killed PCIe on my XGene-1 box (a Mustang board). The machine itself is still alive, but half of its storage (over NVMe) is gone, and the NVMe driver just times out.

Note that this machine boots with a device tree provided by the UEFI firmware (2016 vintage), which could well be non conformant with the spec, hence the breakage.

With the patch reverted, the box boots 5.17-rc8 with flying colors.

Cc Rob Herring <[email protected]>
Cc Toan Le <[email protected]>
Cc Lorenzo Pieralisi <[email protected]>
Cc Krzysztof Wilczyński <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Stéphane Graber <[email protected]>
Cc dann frazier <[email protected]>
Cc Thorsten Leemhuis <[email protected]>
Quoted 3 lines
---
 drivers/pci/controller/pci-xgene.c | 33 ++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 11 deletions(-)
Quoted 7 lines

Dann, Rob,

does this fix the regression debated here:

https://lore.kernel.org/all/[email protected]

It is unclear in that thread what the conclusion reached was.

Thanks for checking in Lorenzo! Reverting that patch is required but not sufficient to get our m400s working. In addition, we'd also need to revert commit c7a75d07827a ("PCI: xgene: Fix IB window setup").

I believe if we revert both then it should return us to a state where Marc's Mustang, Stéphane's Merlins and our m400s all work again.

-dann

Quoted 72 lines

Thanks,
Lorenzo

Quoted 69 lines
drivers/pci/controller/pci-xgene.c +22 -11
index 0d5acbfc7143..aa41ceaf031f 100644
@@ -479,28 +479,27 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
 }
 
 static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
-				    struct resource_entry *entry,
-				    u8 *ib_reg_mask)
+				    struct of_pci_range *range, u8 *ib_reg_mask)
 {
 	void __iomem *cfg_base = port->cfg_base;
 	struct device *dev = port->dev;
 	void __iomem *bar_addr;
 	u32 pim_reg;
-	u64 cpu_addr = entry->res->start;
-	u64 pci_addr = cpu_addr - entry->offset;
-	u64 size = resource_size(entry->res);
+	u64 cpu_addr = range->cpu_addr;
+	u64 pci_addr = range->pci_addr;
+	u64 size = range->size;
 	u64 mask = ~(size - 1) | EN_REG;
 	u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
 	u32 bar_low;
 	int region;
 
-	region = xgene_pcie_select_ib_reg(ib_reg_mask, size);
+	region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
 	if (region < 0) {
 		dev_warn(dev, "invalid pcie dma-range config\n");
 		return;
 	}
 
-	if (entry->res->flags & IORESOURCE_PREFETCH)
+	if (range->flags & IORESOURCE_PREFETCH)
 		flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
 
 	bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
@@ -531,13 +530,25 @@ static void xgene_pcie_setup_ib_reg(struct xgene_pcie *port,
 
 static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie *port)
 {
-	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(port);
-	struct resource_entry *entry;
+	struct device_node *np = port->node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device *dev = port->dev;
 	u8 ib_reg_mask = 0;
 
-	resource_list_for_each_entry(entry, &bridge->dma_ranges)
-		xgene_pcie_setup_ib_reg(port, entry, &ib_reg_mask);
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		dev_err(dev, "missing dma-ranges property\n");
+		return -EINVAL;
+	}
+
+	/* Get the dma-ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		u64 end = range.cpu_addr + range.size - 1;
 
+		dev_dbg(dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
+			range.flags, range.cpu_addr, end, range.pci_addr);
+		xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
+	}
 	return 0;
 }
 
#4 lore raw
Quoted 36 lines · dann frazier
Quoted 34 lines · Lorenzo Pieralisi

[removed CC stable]

Quoted 21 lines · Marc Zyngier

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup") killed PCIe on my XGene-1 box (a Mustang board). The machine itself is still alive, but half of its storage (over NVMe) is gone, and the NVMe driver just times out.

Note that this machine boots with a device tree provided by the UEFI firmware (2016 vintage), which could well be non conformant with the spec, hence the breakage.

With the patch reverted, the box boots 5.17-rc8 with flying colors.

Cc Rob Herring <[email protected]>
Cc Toan Le <[email protected]>
Cc Lorenzo Pieralisi <[email protected]>
Cc Krzysztof Wilczyński <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Stéphane Graber <[email protected]>
Cc dann frazier <[email protected]>
Cc Thorsten Leemhuis <[email protected]>
Quoted 3 lines
---
 drivers/pci/controller/pci-xgene.c | 33 ++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 11 deletions(-)

Dann, Rob,

does this fix the regression debated here:

https://lore.kernel.org/all/[email protected]

Quoted 8 lines
Quoted 1 line

It is unclear in that thread what the conclusion reached was.

Thanks for checking in Lorenzo! Reverting that patch is required but not sufficient to get our m400s working. In addition, we'd also need to revert commit c7a75d07827a ("PCI: xgene: Fix IB window setup").

I believe if we revert both then it should return us to a state where Marc's Mustang, Stéphane's Merlins and our m400s all work again.

Right. I'll post a series reverting both patches, which hopefully Lorenzo and Bjorn can merge shortly.

Thanks,

	M.
Signature · 1 line
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