[PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

The resource management improve for PCI on x86 broke booting of Intel MID
platforms. It seems that the current code removes all available resources
from the list and none of the PCI device may be initialized. Restore the
old behaviour by force disabling the e820 usage for the resource allocation.

Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 arch/x86/include/asm/pci_x86.h | 1 +
 arch/x86/pci/acpi.c            | 2 +-
 arch/x86/pci/intel_mid_pci.c   | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index f52a886d35cf..503f83fbc686 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -126,6 +126,7 @@ extern const struct pci_raw_ops *raw_pci_ext_ops;
 extern const struct pci_raw_ops pci_mmcfg;
 extern const struct pci_raw_ops pci_direct_conf1;
 extern bool port_cf9_safe;
+extern bool pci_use_e820;
 
 /* arch_initcall level */
 #ifdef CONFIG_PCI_DIRECT
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index a4f43054bc79..ac2f220d50fc 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -20,7 +20,7 @@ struct pci_root_info {
 #endif
 };
 
-static bool pci_use_e820 = true;
+bool pci_use_e820 = true;
 static bool pci_use_crs = true;
 static bool pci_ignore_seg;
 
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index 8edd62206604..7869b86bff04 100644
--- a/arch/x86/pci/intel_mid_pci.c
+++ b/arch/x86/pci/intel_mid_pci.c
@@ -313,6 +313,7 @@ int __init intel_mid_pci_init(void)
 	pcibios_enable_irq = intel_mid_pci_irq_enable;
 	pcibios_disable_irq = intel_mid_pci_irq_disable;
 	pci_root_ops = intel_mid_pci_ops;
+	pci_use_e820 = false;
 	pci_soc_mode = 1;
 	/* Continue with standard init */
 	acpi_noirq_set();
-- 
2.35.1

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Hans de Goede]

Hi,

On 6/13/22 22:16, Andy Shevchenko wrote:
> The resource management improve for PCI on x86 broke booting of Intel MID
> platforms. It seems that the current code removes all available resources
> from the list and none of the PCI device may be initialized. Restore the
> old behaviour by force disabling the e820 usage for the resource allocation.
> 
> Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Andy, thank you for the patch. Commit 4c5e242d3e93 has also been causing
issues for other platforms, so I've submitted a revert of it here:

https://lore.kernel.org/linux-pci/20220612144325.85366-1-hdegoede@redhat.com/T/#u

can you please give the revert a try, and confirm that that fixes
the Intel MID platform issue too ?

Regards,

Hans



> ---
>  arch/x86/include/asm/pci_x86.h | 1 +
>  arch/x86/pci/acpi.c            | 2 +-
>  arch/x86/pci/intel_mid_pci.c   | 1 +
>  3 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index f52a886d35cf..503f83fbc686 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -126,6 +126,7 @@ extern const struct pci_raw_ops *raw_pci_ext_ops;
>  extern const struct pci_raw_ops pci_mmcfg;
>  extern const struct pci_raw_ops pci_direct_conf1;
>  extern bool port_cf9_safe;
> +extern bool pci_use_e820;
>  
>  /* arch_initcall level */
>  #ifdef CONFIG_PCI_DIRECT
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index a4f43054bc79..ac2f220d50fc 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -20,7 +20,7 @@ struct pci_root_info {
>  #endif
>  };
>  
> -static bool pci_use_e820 = true;
> +bool pci_use_e820 = true;
>  static bool pci_use_crs = true;
>  static bool pci_ignore_seg;
>  
> diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
> index 8edd62206604..7869b86bff04 100644
> --- a/arch/x86/pci/intel_mid_pci.c
> +++ b/arch/x86/pci/intel_mid_pci.c
> @@ -313,6 +313,7 @@ int __init intel_mid_pci_init(void)
>  	pcibios_enable_irq = intel_mid_pci_irq_enable;
>  	pcibios_disable_irq = intel_mid_pci_irq_disable;
>  	pci_root_ops = intel_mid_pci_ops;
> +	pci_use_e820 = false;
>  	pci_soc_mode = 1;
>  	/* Continue with standard init */
>  	acpi_noirq_set();

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

On Mon, Jun 13, 2022 at 10:31:39PM +0200, Hans de Goede wrote:
> On 6/13/22 22:16, Andy Shevchenko wrote:
> > The resource management improve for PCI on x86 broke booting of Intel MID
> > platforms. It seems that the current code removes all available resources
> > from the list and none of the PCI device may be initialized. Restore the
> > old behaviour by force disabling the e820 usage for the resource allocation.
> > 
> > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Andy, thank you for the patch. Commit 4c5e242d3e93 has also been causing
> issues for other platforms, so I've submitted a revert of it here:
> 
> https://lore.kernel.org/linux-pci/20220612144325.85366-1-hdegoede@redhat.com/T/#u
> 
> can you please give the revert a try, and confirm that that fixes
> the Intel MID platform issue too ?

Nope, it doesn't fix. The problem is in flags checking as far as I can see.
My patch is needed either we have yours or not.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

On Tue, Jun 14, 2022 at 03:30:08PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 13, 2022 at 10:31:39PM +0200, Hans de Goede wrote:
> > On 6/13/22 22:16, Andy Shevchenko wrote:
> > > The resource management improve for PCI on x86 broke booting of Intel MID
> > > platforms. It seems that the current code removes all available resources
> > > from the list and none of the PCI device may be initialized. Restore the
> > > old behaviour by force disabling the e820 usage for the resource allocation.
> > > 
> > > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > 
> > Andy, thank you for the patch. Commit 4c5e242d3e93 has also been causing
> > issues for other platforms, so I've submitted a revert of it here:
> > 
> > https://lore.kernel.org/linux-pci/20220612144325.85366-1-hdegoede@redhat.com/T/#u
> > 
> > can you please give the revert a try, and confirm that that fixes
> > the Intel MID platform issue too ?
> 
> Nope, it doesn't fix. The problem is in flags checking as far as I can see.
> My patch is needed either we have yours or not.

Hold on, it seems I have tried to build something that is not what I develop.
Lemme retest.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

On Tue, Jun 14, 2022 at 03:50:09PM +0300, Andy Shevchenko wrote:
> On Tue, Jun 14, 2022 at 03:30:08PM +0300, Andy Shevchenko wrote:
> > On Mon, Jun 13, 2022 at 10:31:39PM +0200, Hans de Goede wrote:
> > > On 6/13/22 22:16, Andy Shevchenko wrote:
> > > > The resource management improve for PCI on x86 broke booting of Intel MID
> > > > platforms. It seems that the current code removes all available resources
> > > > from the list and none of the PCI device may be initialized. Restore the
> > > > old behaviour by force disabling the e820 usage for the resource allocation.
> > > > 
> > > > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > > > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > 
> > > Andy, thank you for the patch. Commit 4c5e242d3e93 has also been causing
> > > issues for other platforms, so I've submitted a revert of it here:
> > > 
> > > https://lore.kernel.org/linux-pci/20220612144325.85366-1-hdegoede@redhat.com/T/#u
> > > 
> > > can you please give the revert a try, and confirm that that fixes
> > > the Intel MID platform issue too ?
> > 
> > Nope, it doesn't fix. The problem is in flags checking as far as I can see.
> > My patch is needed either we have yours or not.
> 
> Hold on, it seems I have tried to build something that is not what I develop.
> Lemme retest.

Yes, I have tested something weird. Now it works, but I will triple check and
give my tag to your patch later on.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Bjorn Helgaas]

On Mon, Jun 13, 2022 at 11:16:41PM +0300, Andy Shevchenko wrote:
> The resource management improve for PCI on x86 broke booting of Intel MID
> platforms. It seems that the current code removes all available resources
> from the list and none of the PCI device may be initialized. Restore the
> old behaviour by force disabling the e820 usage for the resource allocation.
> 
> Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Yeah, I blew it with 4c5e242d3e93.  Can you provide more details on
how the MID platforms broke?  Since you set "pci_use_e820 = false" for
MID below, I assume MID doesn't depend on the e820 clipping and thus
should not break if we turn off clipping by default in 2023 as in
0ae084d5a674 ("x86/PCI: Disable E820 reserved region clipping starting
in 2023").  But it'd be nice to see the dmesg log and make sure.

> ---
>  arch/x86/include/asm/pci_x86.h | 1 +
>  arch/x86/pci/acpi.c            | 2 +-
>  arch/x86/pci/intel_mid_pci.c   | 1 +
>  3 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
> index f52a886d35cf..503f83fbc686 100644
> --- a/arch/x86/include/asm/pci_x86.h
> +++ b/arch/x86/include/asm/pci_x86.h
> @@ -126,6 +126,7 @@ extern const struct pci_raw_ops *raw_pci_ext_ops;
>  extern const struct pci_raw_ops pci_mmcfg;
>  extern const struct pci_raw_ops pci_direct_conf1;
>  extern bool port_cf9_safe;
> +extern bool pci_use_e820;
>  
>  /* arch_initcall level */
>  #ifdef CONFIG_PCI_DIRECT
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index a4f43054bc79..ac2f220d50fc 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -20,7 +20,7 @@ struct pci_root_info {
>  #endif
>  };
>  
> -static bool pci_use_e820 = true;
> +bool pci_use_e820 = true;
>  static bool pci_use_crs = true;
>  static bool pci_ignore_seg;
>  
> diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
> index 8edd62206604..7869b86bff04 100644
> --- a/arch/x86/pci/intel_mid_pci.c
> +++ b/arch/x86/pci/intel_mid_pci.c
> @@ -313,6 +313,7 @@ int __init intel_mid_pci_init(void)
>  	pcibios_enable_irq = intel_mid_pci_irq_enable;
>  	pcibios_disable_irq = intel_mid_pci_irq_disable;
>  	pci_root_ops = intel_mid_pci_ops;
> +	pci_use_e820 = false;
>  	pci_soc_mode = 1;
>  	/* Continue with standard init */
>  	acpi_noirq_set();
> -- 
> 2.35.1
> 

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

On Mon, Jun 13, 2022 at 05:35:20PM -0500, Bjorn Helgaas wrote:
> On Mon, Jun 13, 2022 at 11:16:41PM +0300, Andy Shevchenko wrote:
> > The resource management improve for PCI on x86 broke booting of Intel MID
> > platforms. It seems that the current code removes all available resources
> > from the list and none of the PCI device may be initialized. Restore the
> > old behaviour by force disabling the e820 usage for the resource allocation.
> > 
> > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Yeah, I blew it with 4c5e242d3e93.  Can you provide more details on
> how the MID platforms broke?

It's not so easy. The breakage seems affects the console driver and earlycon
doesn't work. erlyprintk doesn't support 32-bit MMIO addresses (again,
addresses, not data size). That said, there is nothing to show at all.

What I did, I have bisected to your patch, commented out the call and instead
added a printk() to see what it does, and it basically removed all resources
listed in _CRS.

> Since you set "pci_use_e820 = false" for
> MID below, I assume MID doesn't depend on the e820 clipping and thus
> should not break if we turn off clipping by default in 2023 as in
> 0ae084d5a674 ("x86/PCI: Disable E820 reserved region clipping starting
> in 2023").

> But it'd be nice to see the dmesg log and make sure.

Nothing to provide (see above why), sorry.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Bjorn Helgaas]

On Tue, Jun 14, 2022 at 02:55:42PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 13, 2022 at 05:35:20PM -0500, Bjorn Helgaas wrote:
> > On Mon, Jun 13, 2022 at 11:16:41PM +0300, Andy Shevchenko wrote:
> > > The resource management improve for PCI on x86 broke booting of Intel MID
> > > platforms. It seems that the current code removes all available resources
> > > from the list and none of the PCI device may be initialized. Restore the
> > > old behaviour by force disabling the e820 usage for the resource allocation.
> > > 
> > > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > 
> > Yeah, I blew it with 4c5e242d3e93.  Can you provide more details on
> > how the MID platforms broke?
> 
> It's not so easy. The breakage seems affects the console driver and earlycon
> doesn't work. erlyprintk doesn't support 32-bit MMIO addresses (again,
> addresses, not data size). That said, there is nothing to show at all.
> 
> What I did, I have bisected to your patch, commented out the call and instead
> added a printk() to see what it does, and it basically removed all resources
> listed in _CRS.
> 
> > Since you set "pci_use_e820 = false" for
> > MID below, I assume MID doesn't depend on the e820 clipping and thus
> > should not break if we turn off clipping by default in 2023 as in
> > 0ae084d5a674 ("x86/PCI: Disable E820 reserved region clipping starting
> > in 2023").
> 
> > But it'd be nice to see the dmesg log and make sure.
> 
> Nothing to provide (see above why), sorry.

A dmesg log with a working kernel, especially from one with Hans'
revert, which might have a little more logging about clipping, might
have enough info to help figure this out.

Bjorn

Re: [PATCH v1 1/1] x86/PCI: Disable e820 usage for the resource allocation

[Andy Shevchenko]

On Tue, Jun 14, 2022 at 5:26 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Tue, Jun 14, 2022 at 02:55:42PM +0300, Andy Shevchenko wrote:
> > On Mon, Jun 13, 2022 at 05:35:20PM -0500, Bjorn Helgaas wrote:
> > > On Mon, Jun 13, 2022 at 11:16:41PM +0300, Andy Shevchenko wrote:
> > > > The resource management improve for PCI on x86 broke booting of Intel MID
> > > > platforms. It seems that the current code removes all available resources
> > > > from the list and none of the PCI device may be initialized. Restore the
> > > > old behaviour by force disabling the e820 usage for the resource allocation.
> > > >
> > > > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions")
> > > > Depends-on: fa6dae5d8208 ("x86/PCI: Add kernel cmdline options to use/ignore E820 reserved regions")
> > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > >
> > > Yeah, I blew it with 4c5e242d3e93.  Can you provide more details on
> > > how the MID platforms broke?
> >
> > It's not so easy. The breakage seems affects the console driver and earlycon
> > doesn't work. erlyprintk doesn't support 32-bit MMIO addresses (again,
> > addresses, not data size). That said, there is nothing to show at all.
> >
> > What I did, I have bisected to your patch, commented out the call and instead
> > added a printk() to see what it does, and it basically removed all resources
> > listed in _CRS.
> >
> > > Since you set "pci_use_e820 = false" for
> > > MID below, I assume MID doesn't depend on the e820 clipping and thus
> > > should not break if we turn off clipping by default in 2023 as in
> > > 0ae084d5a674 ("x86/PCI: Disable E820 reserved region clipping starting
> > > in 2023").
> >
> > > But it'd be nice to see the dmesg log and make sure.
> >
> > Nothing to provide (see above why), sorry.
>
> A dmesg log with a working kernel, especially from one with Hans'
> revert, which might have a little more logging about clipping, might
> have enough info to help figure this out.

https://paste.debian.net/1244105/

(It has a lot of unrelated debug thingy, sorry I didn't cut that out)

-- 
With Best Regards,
Andy Shevchenko