[v4,2/7] PCI: Add ACS quirk for Amazon Annapurna Labs root ports
diff mbox series

Message ID 20190821153545.17635-3-jonnyc@amazon.com
State Accepted
Delegated to: Lorenzo Pieralisi
Headers show
Series
  • Amazon's Annapurna Labs DT-based PCIe host controller driver
Related show

Commit Message

Jonathan Chocron Aug. 21, 2019, 3:35 p.m. UTC
From: Ali Saidi <alisaidi@amazon.com>

The Amazon's Annapurna Labs root ports don't advertise an ACS
capability, but they don't allow peer-to-peer transactions and do
validate bus numbers through the SMMU. Additionally, it's not possible
for one RP to pass traffic to another RP.

Signed-off-by: Ali Saidi <alisaidi@amazon.com>
Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
 drivers/pci/quirks.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Andrew Murray Aug. 22, 2019, 8:31 a.m. UTC | #1
On Wed, Aug 21, 2019 at 06:35:42PM +0300, Jonathan Chocron wrote:
> From: Ali Saidi <alisaidi@amazon.com>
> 
> The Amazon's Annapurna Labs root ports don't advertise an ACS
> capability, but they don't allow peer-to-peer transactions and do
> validate bus numbers through the SMMU. Additionally, it's not possible
> for one RP to pass traffic to another RP.
> 
> Signed-off-by: Ali Saidi <alisaidi@amazon.com>
> Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
> Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
>  drivers/pci/quirks.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 208aacf39329..23672680dba7 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -4366,6 +4366,23 @@ static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
>  	return ret;
>  }
>  
> +static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
> +{
> +	/*
> +	 * Amazon's Annapurna Labs root ports don't include an ACS capability,
> +	 * but do include ACS-like functionality. The hardware doesn't support
> +	 * peer-to-peer transactions via the root port and each has a unique
> +	 * segment number.
> +	 * Additionally, the root ports cannot send traffic to each other.

Nit: I'd probably put a new line between the above two lines, or start the
'Additionally' sentence on the first line. But either way...

Reviewed-by: Andrew Murray <andrew.murray@arm.com>


> +	 */
> +	acs_flags &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF);
> +
> +	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
> +		return -ENOTTY;
> +
> +	return acs_flags ? 0 : 1;
> +}
> +
>  /*
>   * Sunrise Point PCH root ports implement ACS, but unfortunately as shown in
>   * the datasheet (Intel 100 Series Chipset Family PCH Datasheet, Vol. 2,
> @@ -4559,6 +4576,8 @@ static const struct pci_dev_acs_enabled {
>  	{ PCI_VENDOR_ID_AMPERE, 0xE00A, pci_quirk_xgene_acs },
>  	{ PCI_VENDOR_ID_AMPERE, 0xE00B, pci_quirk_xgene_acs },
>  	{ PCI_VENDOR_ID_AMPERE, 0xE00C, pci_quirk_xgene_acs },
> +	/* Amazon Annapurna Labs */
> +	{ PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, pci_quirk_al_acs },
>  	{ 0 }
>  };
>  
> -- 
> 2.17.1
>
Jonathan Chocron Sept. 4, 2019, 1:33 p.m. UTC | #2
On Thu, 2019-08-22 at 09:31 +0100, Andrew Murray wrote:
> On Wed, Aug 21, 2019 at 06:35:42PM +0300, Jonathan Chocron wrote:
> > From: Ali Saidi <alisaidi@amazon.com>
> > 
> > The Amazon's Annapurna Labs root ports don't advertise an ACS
> > capability, but they don't allow peer-to-peer transactions and do
> > validate bus numbers through the SMMU. Additionally, it's not
> > possible
> > for one RP to pass traffic to another RP.
> > 
> > Signed-off-by: Ali Saidi <alisaidi@amazon.com>
> > Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
> > Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> > ---
> >  drivers/pci/quirks.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> > 
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index 208aacf39329..23672680dba7 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -4366,6 +4366,23 @@ static int pci_quirk_qcom_rp_acs(struct
> > pci_dev *dev, u16 acs_flags)
> >  	return ret;
> >  }
> >  
> > +static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
> > +{
> > +	/*
> > +	 * Amazon's Annapurna Labs root ports don't include an ACS
> > capability,
> > +	 * but do include ACS-like functionality. The hardware doesn't
> > support
> > +	 * peer-to-peer transactions via the root port and each has a
> > unique
> > +	 * segment number.
> > +	 * Additionally, the root ports cannot send traffic to each
> > other.
> 
> Nit: I'd probably put a new line between the above two lines, or
> start the
> 'Additionally' sentence on the first line. But either way...
> 
Added a newline.

> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> 
> 
> > +	 */
> > +	acs_flags &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV |
> > PCI_ACS_UF);
> > +
> > +	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
> > +		return -ENOTTY;
> > +
> > +	return acs_flags ? 0 : 1;
> > +}
> > +
> >  /*
> >   * Sunrise Point PCH root ports implement ACS, but unfortunately
> > as shown in
> >   * the datasheet (Intel 100 Series Chipset Family PCH Datasheet,
> > Vol. 2,
> > @@ -4559,6 +4576,8 @@ static const struct pci_dev_acs_enabled {
> >  	{ PCI_VENDOR_ID_AMPERE, 0xE00A, pci_quirk_xgene_acs },
> >  	{ PCI_VENDOR_ID_AMPERE, 0xE00B, pci_quirk_xgene_acs },
> >  	{ PCI_VENDOR_ID_AMPERE, 0xE00C, pci_quirk_xgene_acs },
> > +	/* Amazon Annapurna Labs */
> > +	{ PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, pci_quirk_al_acs
> > },
> >  	{ 0 }
> >  };
> >  
> > -- 
> > 2.17.1
> >

Patch
diff mbox series

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 208aacf39329..23672680dba7 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4366,6 +4366,23 @@  static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
 	return ret;
 }
 
+static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
+{
+	/*
+	 * Amazon's Annapurna Labs root ports don't include an ACS capability,
+	 * but do include ACS-like functionality. The hardware doesn't support
+	 * peer-to-peer transactions via the root port and each has a unique
+	 * segment number.
+	 * Additionally, the root ports cannot send traffic to each other.
+	 */
+	acs_flags &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF);
+
+	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
+		return -ENOTTY;
+
+	return acs_flags ? 0 : 1;
+}
+
 /*
  * Sunrise Point PCH root ports implement ACS, but unfortunately as shown in
  * the datasheet (Intel 100 Series Chipset Family PCH Datasheet, Vol. 2,
@@ -4559,6 +4576,8 @@  static const struct pci_dev_acs_enabled {
 	{ PCI_VENDOR_ID_AMPERE, 0xE00A, pci_quirk_xgene_acs },
 	{ PCI_VENDOR_ID_AMPERE, 0xE00B, pci_quirk_xgene_acs },
 	{ PCI_VENDOR_ID_AMPERE, 0xE00C, pci_quirk_xgene_acs },
+	/* Amazon Annapurna Labs */
+	{ PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, pci_quirk_al_acs },
 	{ 0 }
 };