diff mbox series

[2/3] PCI: dwc: Add ECAM support with iATU configuration

Message ID 20241117-ecam-v1-2-6059faf38d07@quicinc.com
State New
Headers show
Series PCI: dwc: Add ECAM support with iATU configuration | expand

Commit Message

Krishna Chaitanya Chundru Nov. 16, 2024, 10 p.m. UTC
The current implementation requires iATU for every configuration
space access which increases latency & cpu utilization.

Configuring iATU in config shift mode enables ECAM feature to access the
config space, which avoids iATU configuration for every config access.

Add "ctrl2" into struct dw_pcie_ob_atu_cfg  to enable config shift mode.

As DBI comes under config space, this avoids remapping of DBI space
separately. Instead, it uses the mapped config space address returned from
ECAM initialization. Change the order of dw_pcie_get_resources() execution
to acheive this.

Introduce new ecam_init() function op for the clients to configure after
ecam window creation has been done.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 114 ++++++++++++++++++----
 drivers/pci/controller/dwc/pcie-designware.c      |   2 +-
 drivers/pci/controller/dwc/pcie-designware.h      |   6 ++
 3 files changed, 102 insertions(+), 20 deletions(-)

Comments

kernel test robot Nov. 21, 2024, 12:55 p.m. UTC | #1
Hi Krishna,

kernel test robot noticed the following build errors:

[auto build test ERROR on 2f87d0916ce0d2925cedbc9e8f5d6291ba2ac7b2]

url:    https://github.com/intel-lab-lkp/linux/commits/Krishna-chaitanya-chundru/arm64-dts-qcom-sc7280-Increase-config-size-to-256MB-for-ECAM-feature/20241121-095614
base:   2f87d0916ce0d2925cedbc9e8f5d6291ba2ac7b2
patch link:    https://lore.kernel.org/r/20241117-ecam-v1-2-6059faf38d07%40quicinc.com
patch subject: [PATCH 2/3] PCI: dwc: Add ECAM support with iATU configuration
config: i386-buildonly-randconfig-005-20241121 (https://download.01.org/0day-ci/archive/20241121/202411212032.CbThzjSv-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241121/202411212032.CbThzjSv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411212032.CbThzjSv-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: pci_generic_ecam_ops
   >>> referenced by pcie-designware-host.c
   >>>               drivers/pci/controller/dwc/pcie-designware-host.o:(dw_pcie_host_init) in archive vmlinux.a
   >>> referenced by pcie-designware-host.c
   >>>               drivers/pci/controller/dwc/pcie-designware-host.o:(dw_pcie_host_init) in archive vmlinux.a
--
>> ld.lld: error: undefined symbol: pci_ecam_create
   >>> referenced by pcie-designware-host.c
   >>>               drivers/pci/controller/dwc/pcie-designware-host.o:(dw_pcie_host_init) in archive vmlinux.a
--
>> ld.lld: error: undefined symbol: pci_ecam_free
   >>> referenced by pcie-designware-host.c
   >>>               drivers/pci/controller/dwc/pcie-designware-host.o:(dw_pcie_host_init) in archive vmlinux.a
   >>> referenced by pcie-designware-host.c
   >>>               drivers/pci/controller/dwc/pcie-designware-host.o:(dw_pcie_host_deinit) in archive vmlinux.a
kernel test robot Nov. 21, 2024, 9:43 p.m. UTC | #2
Hi Krishna,

kernel test robot noticed the following build errors:

[auto build test ERROR on 2f87d0916ce0d2925cedbc9e8f5d6291ba2ac7b2]

url:    https://github.com/intel-lab-lkp/linux/commits/Krishna-chaitanya-chundru/arm64-dts-qcom-sc7280-Increase-config-size-to-256MB-for-ECAM-feature/20241121-095614
base:   2f87d0916ce0d2925cedbc9e8f5d6291ba2ac7b2
patch link:    https://lore.kernel.org/r/20241117-ecam-v1-2-6059faf38d07%40quicinc.com
patch subject: [PATCH 2/3] PCI: dwc: Add ECAM support with iATU configuration
config: alpha-randconfig-r064-20241121 (https://download.01.org/0day-ci/archive/20241122/202411220541.dAciinyb-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241122/202411220541.dAciinyb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411220541.dAciinyb-lkp@intel.com/

All errors (new ones prefixed by >>):

   alpha-linux-ld: drivers/pci/controller/dwc/pcie-designware-host.o: in function `dw_pcie_host_deinit':
>> (.text+0x17a4): undefined reference to `pci_ecam_free'
>> alpha-linux-ld: (.text+0x17a8): undefined reference to `pci_ecam_free'
   alpha-linux-ld: drivers/pci/controller/dwc/pcie-designware-host.o: in function `dw_pcie_host_init':
>> (.text+0x21e4): undefined reference to `pci_generic_ecam_ops'
>> alpha-linux-ld: (.text+0x21e8): undefined reference to `pci_ecam_create'
   alpha-linux-ld: (.text+0x21f0): undefined reference to `pci_ecam_create'
>> alpha-linux-ld: (.text+0x2240): undefined reference to `pci_generic_ecam_ops'
   alpha-linux-ld: (.text+0x2834): undefined reference to `pci_ecam_free'
   alpha-linux-ld: (.text+0x2838): undefined reference to `pci_ecam_free'
Manivannan Sadhasivam Dec. 2, 2024, 4:42 p.m. UTC | #3
On Sun, Nov 17, 2024 at 03:30:19AM +0530, Krishna chaitanya chundru wrote:
> The current implementation requires iATU for every configuration
> space access which increases latency & cpu utilization.
> 
> Configuring iATU in config shift mode enables ECAM feature to access the

Can you please elaborate 'config shift mode'? Quote relevant section in DWC
databook for reference.

> config space, which avoids iATU configuration for every config access.
> 
> Add "ctrl2" into struct dw_pcie_ob_atu_cfg  to enable config shift mode.
> 
> As DBI comes under config space, this avoids remapping of DBI space
> separately. Instead, it uses the mapped config space address returned from
> ECAM initialization. Change the order of dw_pcie_get_resources() execution
> to acheive this.
> 
> Introduce new ecam_init() function op for the clients to configure after

We use 'DWC glue drivers' to refer the 'clients' of this driver.

> ecam window creation has been done.
> 

Use 'ECAM' everywhere.

> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 114 ++++++++++++++++++----
>  drivers/pci/controller/dwc/pcie-designware.c      |   2 +-
>  drivers/pci/controller/dwc/pcie-designware.h      |   6 ++
>  3 files changed, 102 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 3e41865c7290..e98cc841a2a9 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -418,6 +418,62 @@ static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp)
>  	}
>  }
>  
> +static int dw_pcie_config_ecam_iatu(struct dw_pcie_rp *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct dw_pcie_ob_atu_cfg atu = {0};
> +	struct resource_entry *bus;
> +	int ret, bus_range_max;
> +
> +	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
> +
> +	/*
> +	 * Bus 1 config space needs type 0 atu configuration
> +	 * Remaining buses need type 1 atu configuration
> +	 */
> +	atu.index = 0;
> +	atu.type = PCIE_ATU_TYPE_CFG0;
> +	atu.cpu_addr = pp->cfg0_base + SZ_1M;

You didn't mention what occupies the first 1MB.

> +	atu.size = SZ_1M;
> +	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
> +	ret = dw_pcie_prog_outbound_atu(pci, &atu);
> +	if (ret)
> +		return ret;
> +
> +	bus_range_max = bus->res->end - bus->res->start + 1;

resource_size(bus->res)

> +
> +	/* Configure for bus 2 - bus_range_max in type 1 */
> +	atu.index = 1;
> +	atu.type = PCIE_ATU_TYPE_CFG1;
> +	atu.cpu_addr = pp->cfg0_base + SZ_2M;
> +	atu.size = (SZ_1M * (bus_range_max - 2));
> +	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
> +	return dw_pcie_prog_outbound_atu(pci, &atu);
> +}
> +
> +static int dw_pcie_create_ecam_window(struct dw_pcie_rp *pp, struct resource *res)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct device *dev = pci->dev;
> +	struct resource_entry *bus;
> +
> +	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
> +	if (!bus)
> +		return -ENODEV;
> +
> +	pp->cfg = pci_ecam_create(dev, res, bus->res, &pci_generic_ecam_ops);
> +	if (IS_ERR(pp->cfg))
> +		return PTR_ERR(pp->cfg);
> +
> +	pci->dbi_base = pp->cfg->win;
> +	pci->dbi_phys_addr = res->start;
> +
> +	if (pp->ops->ecam_init)
> +		pp->ops->ecam_init(pci, pp->cfg);
> +
> +	return 0;
> +}
> +
>  int dw_pcie_host_init(struct dw_pcie_rp *pp)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -431,19 +487,8 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
>  
>  	raw_spin_lock_init(&pp->lock);
>  
> -	ret = dw_pcie_get_resources(pci);
> -	if (ret)
> -		return ret;
> -
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
> -	if (res) {
> -		pp->cfg0_size = resource_size(res);
> -		pp->cfg0_base = res->start;
> -
> -		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
> -		if (IS_ERR(pp->va_cfg0_base))
> -			return PTR_ERR(pp->va_cfg0_base);
> -	} else {
> +	if (!res) {
>  		dev_err(dev, "Missing *config* reg space\n");
>  		return -ENODEV;
>  	}
> @@ -454,6 +499,30 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
>  
>  	pp->bridge = bridge;
>  
> +	pp->cfg0_size = resource_size(res);
> +	pp->cfg0_base = res->start;
> +
> +	if (!pp->enable_ecam) {

Why can't you just use the ECAM mode when there is enough memory defined in DT?
Using this flag slightly defeats the purpose of the ECAM mode.

> +		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
> +		if (IS_ERR(pp->va_cfg0_base))
> +			return PTR_ERR(pp->va_cfg0_base);
> +
> +		/* Set default bus ops */
> +		bridge->ops = &dw_pcie_ops;
> +		bridge->child_ops = &dw_child_pcie_ops;
> +		bridge->sysdata = pp;
> +	} else {
> +		ret = dw_pcie_create_ecam_window(pp, res);
> +		if (ret)
> +			return ret;
> +		bridge->ops = (struct pci_ops *)&pci_generic_ecam_ops.pci_ops;
> +		pp->bridge->sysdata = pp->cfg;

'bridge->sysdata = pp->cfg'?

- Mani
Krishna Chaitanya Chundru Dec. 4, 2024, 2:02 a.m. UTC | #4
On 12/2/2024 10:12 PM, Manivannan Sadhasivam wrote:
> On Sun, Nov 17, 2024 at 03:30:19AM +0530, Krishna chaitanya chundru wrote:
>> The current implementation requires iATU for every configuration
>> space access which increases latency & cpu utilization.
>>
>> Configuring iATU in config shift mode enables ECAM feature to access the
> 
> Can you please elaborate 'config shift mode'? Quote relevant section in DWC
> databook for reference.
> 
>> config space, which avoids iATU configuration for every config access.
>>
>> Add "ctrl2" into struct dw_pcie_ob_atu_cfg  to enable config shift mode.
>>
>> As DBI comes under config space, this avoids remapping of DBI space
>> separately. Instead, it uses the mapped config space address returned from
>> ECAM initialization. Change the order of dw_pcie_get_resources() execution
>> to acheive this.
>>
>> Introduce new ecam_init() function op for the clients to configure after
> 
> We use 'DWC glue drivers' to refer the 'clients' of this driver.
> 
>> ecam window creation has been done.
>>
> 
> Use 'ECAM' everywhere.
> 
>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>> ---
>>   drivers/pci/controller/dwc/pcie-designware-host.c | 114 ++++++++++++++++++----
>>   drivers/pci/controller/dwc/pcie-designware.c      |   2 +-
>>   drivers/pci/controller/dwc/pcie-designware.h      |   6 ++
>>   3 files changed, 102 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
>> index 3e41865c7290..e98cc841a2a9 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
>> @@ -418,6 +418,62 @@ static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp)
>>   	}
>>   }
>>   
>> +static int dw_pcie_config_ecam_iatu(struct dw_pcie_rp *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct dw_pcie_ob_atu_cfg atu = {0};
>> +	struct resource_entry *bus;
>> +	int ret, bus_range_max;
>> +
>> +	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
>> +
>> +	/*
>> +	 * Bus 1 config space needs type 0 atu configuration
>> +	 * Remaining buses need type 1 atu configuration
>> +	 */
>> +	atu.index = 0;
>> +	atu.type = PCIE_ATU_TYPE_CFG0;
>> +	atu.cpu_addr = pp->cfg0_base + SZ_1M;
> 
> You didn't mention what occupies the first 1MB.
> 
>> +	atu.size = SZ_1M;
>> +	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
>> +	ret = dw_pcie_prog_outbound_atu(pci, &atu);
>> +	if (ret)
>> +		return ret;
>> +
>> +	bus_range_max = bus->res->end - bus->res->start + 1;
> 
> resource_size(bus->res)
> 
>> +
>> +	/* Configure for bus 2 - bus_range_max in type 1 */
>> +	atu.index = 1;
>> +	atu.type = PCIE_ATU_TYPE_CFG1;
>> +	atu.cpu_addr = pp->cfg0_base + SZ_2M;
>> +	atu.size = (SZ_1M * (bus_range_max - 2));
>> +	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
>> +	return dw_pcie_prog_outbound_atu(pci, &atu);
>> +}
>> +
>> +static int dw_pcie_create_ecam_window(struct dw_pcie_rp *pp, struct resource *res)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct device *dev = pci->dev;
>> +	struct resource_entry *bus;
>> +
>> +	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
>> +	if (!bus)
>> +		return -ENODEV;
>> +
>> +	pp->cfg = pci_ecam_create(dev, res, bus->res, &pci_generic_ecam_ops);
>> +	if (IS_ERR(pp->cfg))
>> +		return PTR_ERR(pp->cfg);
>> +
>> +	pci->dbi_base = pp->cfg->win;
>> +	pci->dbi_phys_addr = res->start;
>> +
>> +	if (pp->ops->ecam_init)
>> +		pp->ops->ecam_init(pci, pp->cfg);
>> +
>> +	return 0;
>> +}
>> +
>>   int dw_pcie_host_init(struct dw_pcie_rp *pp)
>>   {
>>   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> @@ -431,19 +487,8 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
>>   
>>   	raw_spin_lock_init(&pp->lock);
>>   
>> -	ret = dw_pcie_get_resources(pci);
>> -	if (ret)
>> -		return ret;
>> -
>>   	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
>> -	if (res) {
>> -		pp->cfg0_size = resource_size(res);
>> -		pp->cfg0_base = res->start;
>> -
>> -		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
>> -		if (IS_ERR(pp->va_cfg0_base))
>> -			return PTR_ERR(pp->va_cfg0_base);
>> -	} else {
>> +	if (!res) {
>>   		dev_err(dev, "Missing *config* reg space\n");
>>   		return -ENODEV;
>>   	}
>> @@ -454,6 +499,30 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
>>   
>>   	pp->bridge = bridge;
>>   
>> +	pp->cfg0_size = resource_size(res);
>> +	pp->cfg0_base = res->start;
>> +
>> +	if (!pp->enable_ecam) {
> 
> Why can't you just use the ECAM mode when there is enough memory defined in DT?
> Using this flag slightly defeats the purpose of the ECAM mode.
> 
>> +		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
>> +		if (IS_ERR(pp->va_cfg0_base))
>> +			return PTR_ERR(pp->va_cfg0_base);
>> +
>> +		/* Set default bus ops */
>> +		bridge->ops = &dw_pcie_ops;
>> +		bridge->child_ops = &dw_child_pcie_ops;
>> +		bridge->sysdata = pp;
>> +	} else {
>> +		ret = dw_pcie_create_ecam_window(pp, res);
>> +		if (ret)
>> +			return ret;
>> +		bridge->ops = (struct pci_ops *)&pci_generic_ecam_ops.pci_ops;
>> +		pp->bridge->sysdata = pp->cfg;
> 
> 'bridge->sysdata = pp->cfg'?
>
as we are using pci_generic_ecam_ops.pci_ops for config reads & writes
it expects cfg space as sysdata[1].

[1] https://elixir.bootlin.com/linux/v6.12.1/source/drivers/pci/ecam.c#L170

- Krishna Chaitanya.

> - Mani
>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 3e41865c7290..e98cc841a2a9 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -418,6 +418,62 @@  static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp)
 	}
 }
 
+static int dw_pcie_config_ecam_iatu(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct dw_pcie_ob_atu_cfg atu = {0};
+	struct resource_entry *bus;
+	int ret, bus_range_max;
+
+	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
+
+	/*
+	 * Bus 1 config space needs type 0 atu configuration
+	 * Remaining buses need type 1 atu configuration
+	 */
+	atu.index = 0;
+	atu.type = PCIE_ATU_TYPE_CFG0;
+	atu.cpu_addr = pp->cfg0_base + SZ_1M;
+	atu.size = SZ_1M;
+	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
+	ret = dw_pcie_prog_outbound_atu(pci, &atu);
+	if (ret)
+		return ret;
+
+	bus_range_max = bus->res->end - bus->res->start + 1;
+
+	/* Configure for bus 2 - bus_range_max in type 1 */
+	atu.index = 1;
+	atu.type = PCIE_ATU_TYPE_CFG1;
+	atu.cpu_addr = pp->cfg0_base + SZ_2M;
+	atu.size = (SZ_1M * (bus_range_max - 2));
+	atu.ctrl2 = PCIE_ATU_CFG_SHIFT_MODE_ENABLE;
+	return dw_pcie_prog_outbound_atu(pci, &atu);
+}
+
+static int dw_pcie_create_ecam_window(struct dw_pcie_rp *pp, struct resource *res)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct device *dev = pci->dev;
+	struct resource_entry *bus;
+
+	bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS);
+	if (!bus)
+		return -ENODEV;
+
+	pp->cfg = pci_ecam_create(dev, res, bus->res, &pci_generic_ecam_ops);
+	if (IS_ERR(pp->cfg))
+		return PTR_ERR(pp->cfg);
+
+	pci->dbi_base = pp->cfg->win;
+	pci->dbi_phys_addr = res->start;
+
+	if (pp->ops->ecam_init)
+		pp->ops->ecam_init(pci, pp->cfg);
+
+	return 0;
+}
+
 int dw_pcie_host_init(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -431,19 +487,8 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	raw_spin_lock_init(&pp->lock);
 
-	ret = dw_pcie_get_resources(pci);
-	if (ret)
-		return ret;
-
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
-	if (res) {
-		pp->cfg0_size = resource_size(res);
-		pp->cfg0_base = res->start;
-
-		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
-		if (IS_ERR(pp->va_cfg0_base))
-			return PTR_ERR(pp->va_cfg0_base);
-	} else {
+	if (!res) {
 		dev_err(dev, "Missing *config* reg space\n");
 		return -ENODEV;
 	}
@@ -454,6 +499,30 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	pp->bridge = bridge;
 
+	pp->cfg0_size = resource_size(res);
+	pp->cfg0_base = res->start;
+
+	if (!pp->enable_ecam) {
+		pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res);
+		if (IS_ERR(pp->va_cfg0_base))
+			return PTR_ERR(pp->va_cfg0_base);
+
+		/* Set default bus ops */
+		bridge->ops = &dw_pcie_ops;
+		bridge->child_ops = &dw_child_pcie_ops;
+		bridge->sysdata = pp;
+	} else {
+		ret = dw_pcie_create_ecam_window(pp, res);
+		if (ret)
+			return ret;
+		bridge->ops = (struct pci_ops *)&pci_generic_ecam_ops.pci_ops;
+		pp->bridge->sysdata = pp->cfg;
+	}
+
+	ret = dw_pcie_get_resources(pci);
+	if (ret)
+		goto err_free_ecam;
+
 	/* Get the I/O range from DT */
 	win = resource_list_first_type(&bridge->windows, IORESOURCE_IO);
 	if (win) {
@@ -462,14 +531,10 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 		pp->io_base = pci_pio_to_address(win->res->start);
 	}
 
-	/* Set default bus ops */
-	bridge->ops = &dw_pcie_ops;
-	bridge->child_ops = &dw_child_pcie_ops;
-
 	if (pp->ops->init) {
 		ret = pp->ops->init(pp);
 		if (ret)
-			return ret;
+			goto err_free_ecam;
 	}
 
 	if (pci_msi_enabled()) {
@@ -504,6 +569,12 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	dw_pcie_iatu_detect(pci);
 
+	if (pp->enable_ecam) {
+		ret = dw_pcie_config_ecam_iatu(pp);
+		if (ret)
+			goto err_free_msi;
+	}
+
 	/*
 	 * Allocate the resource for MSG TLP before programming the iATU
 	 * outbound window in dw_pcie_setup_rc(). Since the allocation depends
@@ -533,8 +604,6 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 	/* Ignore errors, the link may come up later */
 	dw_pcie_wait_for_link(pci);
 
-	bridge->sysdata = pp;
-
 	ret = pci_host_probe(bridge);
 	if (ret)
 		goto err_stop_link;
@@ -558,6 +627,10 @@  int dw_pcie_host_init(struct dw_pcie_rp *pp)
 	if (pp->ops->deinit)
 		pp->ops->deinit(pp);
 
+err_free_ecam:
+	if (pp->cfg)
+		pci_ecam_free(pp->cfg);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dw_pcie_host_init);
@@ -578,6 +651,9 @@  void dw_pcie_host_deinit(struct dw_pcie_rp *pp)
 
 	if (pp->ops->deinit)
 		pp->ops->deinit(pp);
+
+	if (pp->cfg)
+		pci_ecam_free(pp->cfg);
 }
 EXPORT_SYMBOL_GPL(dw_pcie_host_deinit);
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 6d6cbc8b5b2c..63d36676f858 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -509,7 +509,7 @@  int dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
 		val = dw_pcie_enable_ecrc(val);
 	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL1, val);
 
-	val = PCIE_ATU_ENABLE;
+	val = PCIE_ATU_ENABLE | atu->ctrl2;
 	if (atu->type == PCIE_ATU_TYPE_MSG) {
 		/* The data-less messages only for now */
 		val |= PCIE_ATU_INHIBIT_PAYLOAD | atu->code;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 347ab74ac35a..33afa91b402c 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -20,6 +20,7 @@ 
 #include <linux/irq.h>
 #include <linux/msi.h>
 #include <linux/pci.h>
+#include <linux/pci-ecam.h>
 #include <linux/reset.h>
 
 #include <linux/pci-epc.h>
@@ -171,6 +172,7 @@ 
 #define PCIE_ATU_REGION_CTRL2		0x004
 #define PCIE_ATU_ENABLE			BIT(31)
 #define PCIE_ATU_BAR_MODE_ENABLE	BIT(30)
+#define PCIE_ATU_CFG_SHIFT_MODE_ENABLE	BIT(28)
 #define PCIE_ATU_INHIBIT_PAYLOAD	BIT(22)
 #define PCIE_ATU_FUNC_NUM_MATCH_EN      BIT(19)
 #define PCIE_ATU_LOWER_BASE		0x008
@@ -342,6 +344,7 @@  struct dw_pcie_ob_atu_cfg {
 	u8 func_no;
 	u8 code;
 	u8 routing;
+	u32 ctrl2;
 	u64 cpu_addr;
 	u64 pci_addr;
 	u64 size;
@@ -353,6 +356,7 @@  struct dw_pcie_host_ops {
 	void (*post_init)(struct dw_pcie_rp *pp);
 	int (*msi_init)(struct dw_pcie_rp *pp);
 	void (*pme_turn_off)(struct dw_pcie_rp *pp);
+	int (*ecam_init)(struct dw_pcie *pcie, struct pci_config_window *cfg);
 };
 
 struct dw_pcie_rp {
@@ -379,6 +383,8 @@  struct dw_pcie_rp {
 	bool			use_atu_msg;
 	int			msg_atu_index;
 	struct resource		*msg_res;
+	bool			enable_ecam;
+	struct pci_config_window *cfg;
 };
 
 struct dw_pcie_ep_ops {