[V4,06/16] PCI: dwc: Add ext config space capability search API
diff mbox series

Message ID 20190423082730.370-7-vidyas@nvidia.com
State New
Headers show
Series
  • Add Tegra194 PCIe support
Related show

Commit Message

Vidya Sagar April 23, 2019, 8:27 a.m. UTC
Add extended configuration space capability search API using struct dw_pcie *
pointer

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Changes from [v3]:
* None

Changes from [v2]:
* None

Changes from [v1]:
* This is a new patch in v2 series

 drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h |  1 +
 2 files changed, 42 insertions(+)

Comments

Bjorn Helgaas April 23, 2019, 8:35 p.m. UTC | #1
On Tue, Apr 23, 2019 at 01:57:20PM +0530, Vidya Sagar wrote:
> Add extended configuration space capability search API using struct dw_pcie *
> pointer
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
> ---
> Changes from [v3]:
> * None
> 
> Changes from [v2]:
> * None
> 
> Changes from [v1]:
> * This is a new patch in v2 series
> 
>  drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++
>  drivers/pci/controller/dwc/pcie-designware.h |  1 +
>  2 files changed, 42 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 6a98135244d6..ecf5fe8842f6 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
>  	return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
>  }
>  

Please make sure there's a comment here about why
pci_find_ext_capability() can't be used (a comment covering both this
and pci_find_capability() is fine, if the reason is the same).

> +static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start,
> +					    int cap)
> +{
> +	u32 header;
> +	int ttl;
> +	int pos = PCI_CFG_SPACE_SIZE;
> +
> +	/* minimum 8 bytes per capability */
> +	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
> +
> +	if (start)
> +		pos = start;
> +
> +	header = dw_pcie_readl_dbi(pci, pos);
> +	/*
> +	 * If we have no capabilities, this is indicated by cap ID,
> +	 * cap version and next pointer all being 0.
> +	 */
> +	if (header == 0)
> +		return 0;
> +
> +	while (ttl-- > 0) {
> +		if (PCI_EXT_CAP_ID(header) == cap && pos != start)
> +			return pos;
> +
> +		pos = PCI_EXT_CAP_NEXT(header);
> +		if (pos < PCI_CFG_SPACE_SIZE)
> +			break;
> +
> +		header = dw_pcie_readl_dbi(pci, pos);
> +	}
> +
> +	return 0;
> +}
> +
> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap)
> +{
> +	return dw_pcie_find_next_ext_capability(pci, 0, cap);
> +}
> +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability);
> +
>  int dw_pcie_read(void __iomem *addr, int size, u32 *val)
>  {
>  	if (!IS_ALIGNED((uintptr_t)addr, size)) {
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 35160b4ce929..67307842e003 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -249,6 +249,7 @@ struct dw_pcie {
>  		container_of((endpoint), struct dw_pcie, ep)
>  
>  u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap);
>  
>  int dw_pcie_read(void __iomem *addr, int size, u32 *val);
>  int dw_pcie_write(void __iomem *addr, int size, u32 val);
> -- 
> 2.17.1
>
Vidya Sagar April 24, 2019, 3:12 a.m. UTC | #2
On 4/24/2019 2:05 AM, Bjorn Helgaas wrote:
> On Tue, Apr 23, 2019 at 01:57:20PM +0530, Vidya Sagar wrote:
>> Add extended configuration space capability search API using struct dw_pcie *
>> pointer
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>> ---
>> Changes from [v3]:
>> * None
>>
>> Changes from [v2]:
>> * None
>>
>> Changes from [v1]:
>> * This is a new patch in v2 series
>>
>>   drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++
>>   drivers/pci/controller/dwc/pcie-designware.h |  1 +
>>   2 files changed, 42 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
>> index 6a98135244d6..ecf5fe8842f6 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware.c
>> @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
>>   	return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
>>   }
>>   
> 
> Please make sure there's a comment here about why
> pci_find_ext_capability() can't be used (a comment covering both this
> and pci_find_capability() is fine, if the reason is the same).
Reason is same that standard pci_find_ext_capability() uses 'struct pci_dev *dev' pointer
and can only be used post enumeration whereas APIs being added here use 'struct dw_pcie *pci'
and can be used before link up also.
I'll add a comment in the other patch where I'm moving these APIs from pcie-designware-ep.c file
to pcie-designware.c file.

> 
>> +static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start,
>> +					    int cap)
>> +{
>> +	u32 header;
>> +	int ttl;
>> +	int pos = PCI_CFG_SPACE_SIZE;
>> +
>> +	/* minimum 8 bytes per capability */
>> +	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
>> +
>> +	if (start)
>> +		pos = start;
>> +
>> +	header = dw_pcie_readl_dbi(pci, pos);
>> +	/*
>> +	 * If we have no capabilities, this is indicated by cap ID,
>> +	 * cap version and next pointer all being 0.
>> +	 */
>> +	if (header == 0)
>> +		return 0;
>> +
>> +	while (ttl-- > 0) {
>> +		if (PCI_EXT_CAP_ID(header) == cap && pos != start)
>> +			return pos;
>> +
>> +		pos = PCI_EXT_CAP_NEXT(header);
>> +		if (pos < PCI_CFG_SPACE_SIZE)
>> +			break;
>> +
>> +		header = dw_pcie_readl_dbi(pci, pos);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap)
>> +{
>> +	return dw_pcie_find_next_ext_capability(pci, 0, cap);
>> +}
>> +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability);
>> +
>>   int dw_pcie_read(void __iomem *addr, int size, u32 *val)
>>   {
>>   	if (!IS_ALIGNED((uintptr_t)addr, size)) {
>> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
>> index 35160b4ce929..67307842e003 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware.h
>> +++ b/drivers/pci/controller/dwc/pcie-designware.h
>> @@ -249,6 +249,7 @@ struct dw_pcie {
>>   		container_of((endpoint), struct dw_pcie, ep)
>>   
>>   u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
>> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap);
>>   
>>   int dw_pcie_read(void __iomem *addr, int size, u32 *val);
>>   int dw_pcie_write(void __iomem *addr, int size, u32 val);
>> -- 
>> 2.17.1
>>

Patch
diff mbox series

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 6a98135244d6..ecf5fe8842f6 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -53,6 +53,47 @@  u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
 	return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
 }
 
+static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start,
+					    int cap)
+{
+	u32 header;
+	int ttl;
+	int pos = PCI_CFG_SPACE_SIZE;
+
+	/* minimum 8 bytes per capability */
+	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
+
+	if (start)
+		pos = start;
+
+	header = dw_pcie_readl_dbi(pci, pos);
+	/*
+	 * If we have no capabilities, this is indicated by cap ID,
+	 * cap version and next pointer all being 0.
+	 */
+	if (header == 0)
+		return 0;
+
+	while (ttl-- > 0) {
+		if (PCI_EXT_CAP_ID(header) == cap && pos != start)
+			return pos;
+
+		pos = PCI_EXT_CAP_NEXT(header);
+		if (pos < PCI_CFG_SPACE_SIZE)
+			break;
+
+		header = dw_pcie_readl_dbi(pci, pos);
+	}
+
+	return 0;
+}
+
+int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap)
+{
+	return dw_pcie_find_next_ext_capability(pci, 0, cap);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability);
+
 int dw_pcie_read(void __iomem *addr, int size, u32 *val)
 {
 	if (!IS_ALIGNED((uintptr_t)addr, size)) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 35160b4ce929..67307842e003 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -249,6 +249,7 @@  struct dw_pcie {
 		container_of((endpoint), struct dw_pcie, ep)
 
 u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
+int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap);
 
 int dw_pcie_read(void __iomem *addr, int size, u32 *val);
 int dw_pcie_write(void __iomem *addr, int size, u32 val);