Subject: Re: [PATCH 3/8] powerpc/powernv: Export functions to retrieve slot status

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 26 Nov 2014 10:00:33 +1100

On Tue, 2014-11-25 at 09:49 +1100, Gavin Shan wrote:
> The patch exports two functions, which base on corresponding OPAL
> APIs to retrieve PCI slot status:
> 
>    pnv_pci_get_power_status()     opal_pci_get_power_status()
>    pnv_pci_get_presence_status()  opal_pci_get_presence_status()
> 
> Signed-off-by: Gavin Shan <[email-masked]>
> ---
>  arch/powerpc/include/asm/opal.h                |  6 +++-
>  arch/powerpc/include/asm/pnv-pci.h             |  3 ++
>  arch/powerpc/platforms/powernv/eeh-ioda.c      | 34 ++---------------------
>  arch/powerpc/platforms/powernv/opal-wrappers.S |  2 ++
>  arch/powerpc/platforms/powernv/pci.c           | 38 ++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/pci.h           |  1 +
>  6 files changed, 51 insertions(+), 33 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index b59811f..b75be1c 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -153,6 +153,8 @@ struct opal_sg_list {
>  #define OPAL_HANDLE_HMI				98
>  #define OPAL_REGISTER_DUMP_REGION		101
>  #define OPAL_UNREGISTER_DUMP_REGION		102
> +#define OPAL_PCI_GET_POWER_STATUS		110
> +#define OPAL_PCI_GET_PRESENCE_STATUS		111
>  
>  #ifndef __ASSEMBLY__
>  
> @@ -905,7 +907,7 @@ int64_t opal_get_epow_status(__be64 *status);
>  int64_t opal_set_system_attention_led(uint8_t led_action);
>  int64_t opal_pci_next_error(uint64_t phb_id, __be64 *first_frozen_pe,
>  			    __be16 *pci_error_type, __be16 *severity);
> -int64_t opal_pci_poll(uint64_t id);
> +int64_t opal_pci_poll(uint64_t id, uint8_t *val);
>  int64_t opal_return_cpu(void);
>  int64_t opal_check_token(uint64_t token);
>  int64_t opal_reinit_cpus(uint64_t flags);
> @@ -946,6 +948,8 @@ int64_t opal_handle_hmi(void);
>  int64_t opal_register_dump_region(uint32_t id, uint64_t start, uint64_t end);
>  int64_t opal_unregister_dump_region(uint32_t id);
>  int64_t opal_pci_set_phb_cxl_mode(uint64_t phb_id, uint64_t mode, uint64_t pe_number);
> +int64_t opal_pci_get_power_status(uint64_t id, uint8_t *status);
> +int64_t opal_pci_get_presence_status(uint64_t id, uint8_t *status);
>  
>  /* Internal functions */
>  extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
> diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h
> index f09a22f..527d97a 100644
> --- a/arch/powerpc/include/asm/pnv-pci.h
> +++ b/arch/powerpc/include/asm/pnv-pci.h
> @@ -13,6 +13,9 @@
>  #include <linux/pci.h>
>  #include <misc/cxl.h>
>  
> +extern int pnv_pci_get_power_status(unsigned int index, unsigned char *status);
> +extern int pnv_pci_get_presence_status(unsigned int index, unsigned char *status);
> +
>  int pnv_phb_to_cxl(struct pci_dev *dev);
>  int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
>  			   unsigned int virq);
> diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
> index 4bf2fb5..fb66c74 100644
> --- a/arch/powerpc/platforms/powernv/eeh-ioda.c
> +++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
> @@ -490,24 +490,6 @@ static int ioda_eeh_get_state(struct eeh_pe *pe)
>  	return ioda_eeh_get_pe_state(pe);
>  }
>  
> -static s64 ioda_eeh_phb_poll(uint64_t id)
> -{
> -	s64 rc = OPAL_HARDWARE;
> -
> -	while (1) {
> -		rc = opal_pci_poll(id);
> -		if (rc <= 0)
> -			break;
> -
> -		if (system_state < SYSTEM_RUNNING)
> -			udelay(1000 * rc);
> -		else
> -			msleep(rc);
> -	}
> -
> -	return rc;
> -}
> -
>  int ioda_eeh_phb_reset(struct pci_controller *hose, int option)
>  {
>  	struct pnv_phb *phb = hose->private_data;
> @@ -542,13 +524,7 @@ int ioda_eeh_phb_reset(struct pci_controller *hose, int option)
>  	 * need the PCI bus settlement delay.
>  	 */
>  	rc = opal_pci_reset(phb->opal_id, reset_scope);
> -	if (rc > 0)
> -		rc = ioda_eeh_phb_poll(phb->opal_id);
> -
> -	if (rc != OPAL_SUCCESS)
> -		return -EIO;
> -
> -	return 0;
> +	return pnv_pci_poll(phb->opal_id, rc, NULL);
>  }

Patch does too mutch, the factoring out of pnv_pci_poll should be a
separate patch.

>  static int __ioda_eeh_bridge_reset(struct pci_dev *dev, int option)
> @@ -641,13 +617,7 @@ static int ioda_eeh_bridge_reset(struct pci_dev *dev, int option)
>  	phb = hose->private_data;
>  	id |= ((phb->opal_id << 16) | (dev->bus->number << 8) | (dev->devfn));
>  	rc = opal_pci_reset(id, reset_scope);
> -	if (rc > 0)
> -		rc = ioda_eeh_phb_poll(id);
> -
> -	if (rc != OPAL_SUCCESS)
> -		return -EIO;
> -
> -	return 0;
> +	return pnv_pci_poll(id, rc, NULL);
>  }
>  
>  static int pnv_pci_dev_reset_type(struct pci_dev *pdev, void *data)
> diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
> index b6474a1..b2c15ff 100644
> --- a/arch/powerpc/platforms/powernv/opal-wrappers.S
> +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
> @@ -249,3 +249,5 @@ OPAL_CALL(opal_handle_hmi,			OPAL_HANDLE_HMI);
>  OPAL_CALL(opal_register_dump_region,		OPAL_REGISTER_DUMP_REGION);
>  OPAL_CALL(opal_unregister_dump_region,		OPAL_UNREGISTER_DUMP_REGION);
>  OPAL_CALL(opal_pci_set_phb_cxl_mode,		OPAL_PCI_SET_PHB_CXL_MODE);
> +OPAL_CALL(opal_pci_get_power_status,		OPAL_PCI_GET_POWER_STATUS);
> +OPAL_CALL(opal_pci_get_presence_status,		OPAL_PCI_GET_PRESENCE_STATUS);
> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> index b2187d0..f5bae4f 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -45,6 +45,44 @@
>  #define cfg_dbg(fmt...)	do { } while(0)
>  //#define cfg_dbg(fmt...)	printk(fmt)
>  
> +int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *pval)
> +{
> +	while (rval > 0) {
> +		rval = opal_pci_poll(id, pval);
> +		if (rval <= 0)
> +			break;
> +
> +		if (system_state < SYSTEM_RUNNING)
> +			udelay(1000 * rval);
> +		else
> +			msleep(rval);
> +	}
> +
> +	return rval ? -EIO : 0;
> +}

Do we need the udelay case still nowadays ? When do we call this early
enough that msleep won't work ?

> +int pnv_pci_get_power_status(unsigned int index, unsigned char *status)
> +{
> +	uint64_t id = (0x1ul << 63);
> +	long rc;
> +
> +	id |= index;
> +	rc = opal_pci_get_power_status(id, status);
> +	return pnv_pci_poll(id, rc, status);
> +}
> +EXPORT_SYMBOL_GPL(pnv_pci_get_power_status);
> +
> +int pnv_pci_get_presence_status(unsigned int index, unsigned char *status)
> +{
> +	uint64_t id = (0x1ul << 63);
> +	long rc;
> +
> +	id |= index;
> +	rc = opal_pci_get_presence_status(id, status);
> +	return pnv_pci_poll(id, rc, status);
> +}
> +EXPORT_SYMBOL_GPL(pnv_pci_get_presence_status);
> +
>  #ifdef CONFIG_PCI_MSI
>  static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
>  {
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 6c02ff8..396fe02 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -217,6 +217,7 @@ extern struct pci_ops pnv_pci_ops;
>  extern struct pnv_eeh_ops ioda_eeh_ops;
>  #endif
>  
> +int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *pval);
>  void pnv_pci_dump_phb_diag_data(struct pci_controller *hose,
>  				unsigned char *log_buff);
>  int pnv_pci_cfg_read(struct device_node *dn,