[5/6] PCI: Add PCIE_LNKCAP2_SLS2SPEED macro
diff mbox series

Message ID 1579079063-5668-6-git-send-email-yangyicong@hisilicon.com
State New
Headers show
Series
  • Improve link speed presentation process
Related show

Commit Message

Yicong Yang Jan. 15, 2020, 9:04 a.m. UTC
Add PCIE_LNKCAP2_SLS2SPEED macro for transforming raw link cap 2
value to link speed. Use it in pcie_get_speed_cap() to reduce
redundancy. We'll not touch the functions when new link
speed comes.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
 drivers/pci/pci.c | 17 ++++-------------
 drivers/pci/pci.h |  9 +++++++++
 2 files changed, 13 insertions(+), 13 deletions(-)

Comments

Bjorn Helgaas Feb. 5, 2020, 6:54 p.m. UTC | #1
On Wed, Jan 15, 2020 at 05:04:22PM +0800, Yicong Yang wrote:
> Add PCIE_LNKCAP2_SLS2SPEED macro for transforming raw link cap 2
> value to link speed. Use it in pcie_get_speed_cap() to reduce
> redundancy. We'll not touch the functions when new link
> speed comes.

The patch seems OK to me, but I don't see where it reduces redundancy.
There was one copy of "lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB" before,
and there's one copy after.  It's just moved from pci.c to pci.h.
Or am I missing something?

> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> ---
>  drivers/pci/pci.c | 17 ++++-------------
>  drivers/pci/pci.h |  9 +++++++++
>  2 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index dce32ce..2ef4030 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5780,19 +5780,10 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
>  	 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
>  	 */
>  	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
> -	if (lnkcap2) { /* PCIe r3.0-compliant */
> -		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
> -			return PCIE_SPEED_32_0GT;
> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
> -			return PCIE_SPEED_16_0GT;
> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
> -			return PCIE_SPEED_8_0GT;
> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
> -			return PCIE_SPEED_5_0GT;
> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
> -			return PCIE_SPEED_2_5GT;
> -		return PCI_SPEED_UNKNOWN;
> -	}
> +
> +	/* PCIe r3.0-compliant */
> +	if (lnkcap2)
> +		return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
>  
>  	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
>  	if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 5e1f810..3d988e9 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -290,6 +290,15 @@ void pci_disable_bridge_window(struct pci_dev *dev);
>  struct pci_bus *pci_bus_get(struct pci_bus *bus);
>  void pci_bus_put(struct pci_bus *bus);
>  
> +/* PCIe link information from Link Capabilities 2 */
> +#define PCIE_LNKCAP2_SLS2SPEED(lnkcap2) \
> +	((lnkcap2) & PCI_EXP_LNKCAP2_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
> +	 PCI_SPEED_UNKNOWN)
> +
>  /* PCIe link information */
>  #define PCI_SPEED2STR(speed) \
>  	((speed) == PCI_SPEED_UNKNOWN ? "Unknown speed" : \
> -- 
> 2.8.1
>
Yicong Yang Feb. 6, 2020, 1:53 a.m. UTC | #2
On 2020/2/6 2:54, Bjorn Helgaas wrote:
> On Wed, Jan 15, 2020 at 05:04:22PM +0800, Yicong Yang wrote:
>> Add PCIE_LNKCAP2_SLS2SPEED macro for transforming raw link cap 2
>> value to link speed. Use it in pcie_get_speed_cap() to reduce
>> redundancy. We'll not touch the functions when new link
>> speed comes.
> The patch seems OK to me, but I don't see where it reduces redundancy.
> There was one copy of "lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB" before,
> and there's one copy after.  It's just moved from pci.c to pci.h.
> Or am I missing something?

Seems I used improper description here. I'll correct it in next version.

Thanks,
Yang


>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
>> ---
>>  drivers/pci/pci.c | 17 ++++-------------
>>  drivers/pci/pci.h |  9 +++++++++
>>  2 files changed, 13 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index dce32ce..2ef4030 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -5780,19 +5780,10 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
>>  	 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
>>  	 */
>>  	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
>> -	if (lnkcap2) { /* PCIe r3.0-compliant */
>> -		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
>> -			return PCIE_SPEED_32_0GT;
>> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
>> -			return PCIE_SPEED_16_0GT;
>> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
>> -			return PCIE_SPEED_8_0GT;
>> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
>> -			return PCIE_SPEED_5_0GT;
>> -		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
>> -			return PCIE_SPEED_2_5GT;
>> -		return PCI_SPEED_UNKNOWN;
>> -	}
>> +
>> +	/* PCIe r3.0-compliant */
>> +	if (lnkcap2)
>> +		return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
>>  
>>  	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
>>  	if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>> index 5e1f810..3d988e9 100644
>> --- a/drivers/pci/pci.h
>> +++ b/drivers/pci/pci.h
>> @@ -290,6 +290,15 @@ void pci_disable_bridge_window(struct pci_dev *dev);
>>  struct pci_bus *pci_bus_get(struct pci_bus *bus);
>>  void pci_bus_put(struct pci_bus *bus);
>>  
>> +/* PCIe link information from Link Capabilities 2 */
>> +#define PCIE_LNKCAP2_SLS2SPEED(lnkcap2) \
>> +	((lnkcap2) & PCI_EXP_LNKCAP2_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
>> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
>> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
>> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
>> +	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
>> +	 PCI_SPEED_UNKNOWN)
>> +
>>  /* PCIe link information */
>>  #define PCI_SPEED2STR(speed) \
>>  	((speed) == PCI_SPEED_UNKNOWN ? "Unknown speed" : \
>> -- 
>> 2.8.1
>>
> .
>

Patch
diff mbox series

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index dce32ce..2ef4030 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5780,19 +5780,10 @@  enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
 	 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
 	 */
 	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
-	if (lnkcap2) { /* PCIe r3.0-compliant */
-		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
-			return PCIE_SPEED_32_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
-			return PCIE_SPEED_16_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
-			return PCIE_SPEED_8_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
-			return PCIE_SPEED_5_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
-			return PCIE_SPEED_2_5GT;
-		return PCI_SPEED_UNKNOWN;
-	}
+
+	/* PCIe r3.0-compliant */
+	if (lnkcap2)
+		return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
 
 	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
 	if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5e1f810..3d988e9 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -290,6 +290,15 @@  void pci_disable_bridge_window(struct pci_dev *dev);
 struct pci_bus *pci_bus_get(struct pci_bus *bus);
 void pci_bus_put(struct pci_bus *bus);
 
+/* PCIe link information from Link Capabilities 2 */
+#define PCIE_LNKCAP2_SLS2SPEED(lnkcap2) \
+	((lnkcap2) & PCI_EXP_LNKCAP2_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
+	 PCI_SPEED_UNKNOWN)
+
 /* PCIe link information */
 #define PCI_SPEED2STR(speed) \
 	((speed) == PCI_SPEED_UNKNOWN ? "Unknown speed" : \