diff mbox series

[V3,1/6] PCI: Use cached Device Capabilities Register

Message ID 20210512143737.42352-2-liudongdong3@huawei.com
State New
Headers show
Series PCI: Enable 10-Bit tag support for PCIe devices | expand

Commit Message

Dongdong Liu May 12, 2021, 2:37 p.m. UTC 
It will make sense to store the pcie_devcap value in the pci_dev
structure instead of reading Device Capabilities Register multiple
times. The fisrt place to use pcie_devcap is in set_pcie_port_type(),
get the pcie_devcap value here, then use cached pcie_devcap in the
needed place.

Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
---
 drivers/media/pci/cobalt/cobalt-driver.c |  4 ++--
 drivers/pci/pci.c                        |  5 +----
 drivers/pci/pcie/aspm.c                  | 11 ++++-------
 drivers/pci/probe.c                      | 11 +++--------
 drivers/pci/quirks.c                     |  3 +--
 include/linux/pci.h                      |  1 +
 6 files changed, 12 insertions(+), 23 deletions(-)

--
2.7.4

Comments

Hans Verkuil May 26, 2021, 10:46 a.m. UTC | #1 
On 12/05/2021 16:37, Dongdong Liu wrote:
> It will make sense to store the pcie_devcap value in the pci_dev
> structure instead of reading Device Capabilities Register multiple
> times. The fisrt place to use pcie_devcap is in set_pcie_port_type(),
> get the pcie_devcap value here, then use cached pcie_devcap in the
> needed place.
> 
> Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
> ---
>  drivers/media/pci/cobalt/cobalt-driver.c |  4 ++--

For the cobalt driver:

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Regards,

	Hans

>  drivers/pci/pci.c                        |  5 +----
>  drivers/pci/pcie/aspm.c                  | 11 ++++-------
>  drivers/pci/probe.c                      | 11 +++--------
>  drivers/pci/quirks.c                     |  3 +--
>  include/linux/pci.h                      |  1 +
>  6 files changed, 12 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c
> index 839503e..04e735f 100644
> --- a/drivers/media/pci/cobalt/cobalt-driver.c
> +++ b/drivers/media/pci/cobalt/cobalt-driver.c
> @@ -193,11 +193,11 @@ void cobalt_pcie_status_show(struct cobalt *cobalt)
>  		return;
> 
>  	/* Device */
> -	pcie_capability_read_dword(pci_dev, PCI_EXP_DEVCAP, &capa);
>  	pcie_capability_read_word(pci_dev, PCI_EXP_DEVCTL, &ctrl);
>  	pcie_capability_read_word(pci_dev, PCI_EXP_DEVSTA, &stat);
>  	cobalt_info("PCIe device capability 0x%08x: Max payload %d\n",
> -		    capa, get_payload_size(capa & PCI_EXP_DEVCAP_PAYLOAD));
> +		    capa,
> +		    get_payload_size(pci_dev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD));
>  	cobalt_info("PCIe device control 0x%04x: Max payload %d. Max read request %d\n",
>  		    ctrl,
>  		    get_payload_size((ctrl & PCI_EXP_DEVCTL_PAYLOAD) >> 5),
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index b717680..68ccd77 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4620,13 +4620,10 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
>   */
>  bool pcie_has_flr(struct pci_dev *dev)
>  {
> -	u32 cap;
> -
>  	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
>  		return false;
> 
> -	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
> -	return cap & PCI_EXP_DEVCAP_FLR;
> +	return dev->pcie_devcap & PCI_EXP_DEVCAP_FLR;
>  }
>  EXPORT_SYMBOL_GPL(pcie_has_flr);
> 
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index ac0557a..d637564 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -660,7 +660,7 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
> 
>  	/* Get and check endpoint acceptable latencies */
>  	list_for_each_entry(child, &linkbus->devices, bus_list) {
> -		u32 reg32, encoding;
> +		u32 encoding;
>  		struct aspm_latency *acceptable =
>  			&link->acceptable[PCI_FUNC(child->devfn)];
> 
> @@ -668,12 +668,11 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
>  		    pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END)
>  			continue;
> 
> -		pcie_capability_read_dword(child, PCI_EXP_DEVCAP, &reg32);
>  		/* Calculate endpoint L0s acceptable latency */
> -		encoding = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
> +		encoding = (child->pcie_devcap & PCI_EXP_DEVCAP_L0S) >> 6;
>  		acceptable->l0s = calc_l0s_acceptable(encoding);
>  		/* Calculate endpoint L1 acceptable latency */
> -		encoding = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
> +		encoding = (child->pcie_devcap & PCI_EXP_DEVCAP_L1) >> 9;
>  		acceptable->l1 = calc_l1_acceptable(encoding);
> 
>  		pcie_aspm_check_latency(child);
> @@ -808,7 +807,6 @@ static void free_link_state(struct pcie_link_state *link)
>  static int pcie_aspm_sanity_check(struct pci_dev *pdev)
>  {
>  	struct pci_dev *child;
> -	u32 reg32;
> 
>  	/*
>  	 * Some functions in a slot might not all be PCIe functions,
> @@ -831,8 +829,7 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
>  		 * Disable ASPM for pre-1.1 PCIe device, we follow MS to use
>  		 * RBER bit to determine if a function is 1.1 version device
>  		 */
> -		pcie_capability_read_dword(child, PCI_EXP_DEVCAP, &reg32);
> -		if (!(reg32 & PCI_EXP_DEVCAP_RBER) && !aspm_force) {
> +		if (!(child->pcie_devcap & PCI_EXP_DEVCAP_RBER) && !aspm_force) {
>  			pci_info(child, "disabling ASPM on pre-1.1 PCIe device.  You can enable it with 'pcie_aspm=force'\n");
>  			return -EINVAL;
>  		}
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 3a62d09..7963ab2 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1497,8 +1497,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
>  	pdev->pcie_cap = pos;
>  	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
>  	pdev->pcie_flags_reg = reg16;
> -	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
> -	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
> +	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->pcie_devcap);
> +	pdev->pcie_mpss = pdev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD;
> 
>  	parent = pci_upstream_bridge(pdev);
>  	if (!parent)
> @@ -2008,18 +2008,13 @@ static void pci_configure_mps(struct pci_dev *dev)
>  int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
>  {
>  	struct pci_host_bridge *host;
> -	u32 cap;
>  	u16 ctl;
>  	int ret;
> 
>  	if (!pci_is_pcie(dev))
>  		return 0;
> 
> -	ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
> -	if (ret)
> -		return 0;
> -
> -	if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
> +	if (!(dev->pcie_devcap & PCI_EXP_DEVCAP_EXT_TAG))
>  		return 0;
> 
>  	ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index dcb229d..b89b438 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5073,8 +5073,7 @@ static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
>  		pdev->pcie_cap = pos;
>  		pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
>  		pdev->pcie_flags_reg = reg16;
> -		pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
> -		pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
> +		pdev->pcie_mpss = pdev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD;
> 
>  		pdev->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
>  		if (pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &status) !=
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index c20211e..555a3ac 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -340,6 +340,7 @@ struct pci_dev {
>  	u8		rom_base_reg;	/* Config register controlling ROM */
>  	u8		pin;		/* Interrupt pin this device uses */
>  	u16		pcie_flags_reg;	/* Cached PCIe Capabilities Register */
> +	u32		pcie_devcap;	/* Cached Device Capabilities Register */
>  	unsigned long	*dma_alias_mask;/* Mask of enabled devfn aliases */
> 
>  	struct pci_driver *driver;	/* Driver bound to this device */
> --
> 2.7.4
>
diff mbox series

Patch

diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c
index 839503e..04e735f 100644
--- a/drivers/media/pci/cobalt/cobalt-driver.c
+++ b/drivers/media/pci/cobalt/cobalt-driver.c
@@ -193,11 +193,11 @@  void cobalt_pcie_status_show(struct cobalt *cobalt)
 		return;

 	/* Device */
-	pcie_capability_read_dword(pci_dev, PCI_EXP_DEVCAP, &capa);
 	pcie_capability_read_word(pci_dev, PCI_EXP_DEVCTL, &ctrl);
 	pcie_capability_read_word(pci_dev, PCI_EXP_DEVSTA, &stat);
 	cobalt_info("PCIe device capability 0x%08x: Max payload %d\n",
-		    capa, get_payload_size(capa & PCI_EXP_DEVCAP_PAYLOAD));
+		    capa,
+		    get_payload_size(pci_dev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD));
 	cobalt_info("PCIe device control 0x%04x: Max payload %d. Max read request %d\n",
 		    ctrl,
 		    get_payload_size((ctrl & PCI_EXP_DEVCTL_PAYLOAD) >> 5),
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b717680..68ccd77 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4620,13 +4620,10 @@  EXPORT_SYMBOL(pci_wait_for_pending_transaction);
  */
 bool pcie_has_flr(struct pci_dev *dev)
 {
-	u32 cap;
-
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return false;

-	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
-	return cap & PCI_EXP_DEVCAP_FLR;
+	return dev->pcie_devcap & PCI_EXP_DEVCAP_FLR;
 }
 EXPORT_SYMBOL_GPL(pcie_has_flr);

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index ac0557a..d637564 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -660,7 +660,7 @@  static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)

 	/* Get and check endpoint acceptable latencies */
 	list_for_each_entry(child, &linkbus->devices, bus_list) {
-		u32 reg32, encoding;
+		u32 encoding;
 		struct aspm_latency *acceptable =
 			&link->acceptable[PCI_FUNC(child->devfn)];

@@ -668,12 +668,11 @@  static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
 		    pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END)
 			continue;

-		pcie_capability_read_dword(child, PCI_EXP_DEVCAP, &reg32);
 		/* Calculate endpoint L0s acceptable latency */
-		encoding = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
+		encoding = (child->pcie_devcap & PCI_EXP_DEVCAP_L0S) >> 6;
 		acceptable->l0s = calc_l0s_acceptable(encoding);
 		/* Calculate endpoint L1 acceptable latency */
-		encoding = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
+		encoding = (child->pcie_devcap & PCI_EXP_DEVCAP_L1) >> 9;
 		acceptable->l1 = calc_l1_acceptable(encoding);

 		pcie_aspm_check_latency(child);
@@ -808,7 +807,6 @@  static void free_link_state(struct pcie_link_state *link)
 static int pcie_aspm_sanity_check(struct pci_dev *pdev)
 {
 	struct pci_dev *child;
-	u32 reg32;

 	/*
 	 * Some functions in a slot might not all be PCIe functions,
@@ -831,8 +829,7 @@  static int pcie_aspm_sanity_check(struct pci_dev *pdev)
 		 * Disable ASPM for pre-1.1 PCIe device, we follow MS to use
 		 * RBER bit to determine if a function is 1.1 version device
 		 */
-		pcie_capability_read_dword(child, PCI_EXP_DEVCAP, &reg32);
-		if (!(reg32 & PCI_EXP_DEVCAP_RBER) && !aspm_force) {
+		if (!(child->pcie_devcap & PCI_EXP_DEVCAP_RBER) && !aspm_force) {
 			pci_info(child, "disabling ASPM on pre-1.1 PCIe device.  You can enable it with 'pcie_aspm=force'\n");
 			return -EINVAL;
 		}
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3a62d09..7963ab2 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1497,8 +1497,8 @@  void set_pcie_port_type(struct pci_dev *pdev)
 	pdev->pcie_cap = pos;
 	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
 	pdev->pcie_flags_reg = reg16;
-	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
-	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
+	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->pcie_devcap);
+	pdev->pcie_mpss = pdev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD;

 	parent = pci_upstream_bridge(pdev);
 	if (!parent)
@@ -2008,18 +2008,13 @@  static void pci_configure_mps(struct pci_dev *dev)
 int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
 {
 	struct pci_host_bridge *host;
-	u32 cap;
 	u16 ctl;
 	int ret;

 	if (!pci_is_pcie(dev))
 		return 0;

-	ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
-	if (ret)
-		return 0;
-
-	if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
+	if (!(dev->pcie_devcap & PCI_EXP_DEVCAP_EXT_TAG))
 		return 0;

 	ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index dcb229d..b89b438 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5073,8 +5073,7 @@  static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
 		pdev->pcie_cap = pos;
 		pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
 		pdev->pcie_flags_reg = reg16;
-		pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
-		pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
+		pdev->pcie_mpss = pdev->pcie_devcap & PCI_EXP_DEVCAP_PAYLOAD;

 		pdev->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
 		if (pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &status) !=
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c20211e..555a3ac 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -340,6 +340,7 @@  struct pci_dev {
 	u8		rom_base_reg;	/* Config register controlling ROM */
 	u8		pin;		/* Interrupt pin this device uses */
 	u16		pcie_flags_reg;	/* Cached PCIe Capabilities Register */
+	u32		pcie_devcap;	/* Cached Device Capabilities Register */
 	unsigned long	*dma_alias_mask;/* Mask of enabled devfn aliases */

 	struct pci_driver *driver;	/* Driver bound to this device */