[Skiboot] [PATCH 2/2] npu2: Implement FLR

[Alexey Kardashevskiy]

On 10/08/17 04:29, Reza Arbab wrote:
> Add basic handling of FLR (function level reset) by porting the changes
> from commit b74841db759d ("npu: Implement FLR") to npu2.
> 
> The only difference for npu2 is that we track the reset state explicitly
> with a link flag instead of inferring it from
> dev->procedure_{status,number,step,data}.

Sounds like a reasonable thing to do for NPU too.


> Signed-off-by: Reza Arbab <arbab at linux.vnet.ibm.com>
> Cc: Alexey Kardashevskiy <aik at ozlabs.ru>


Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>


Also, please, when you post a patchset, cc: everyone in every patch, I had
to dig for 1/2. Thanks.


> ---
>  hw/npu2-hw-procedures.c |  5 +++++
>  hw/npu2.c               | 29 ++++++++++++++++++++++++++++-
>  include/npu2.h          |  1 +
>  3 files changed, 34 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/npu2-hw-procedures.c b/hw/npu2-hw-procedures.c
> index 71af3e7..1a990f2 100644
> --- a/hw/npu2-hw-procedures.c
> +++ b/hw/npu2-hw-procedures.c
> @@ -719,3 +719,8 @@ int64_t npu2_dev_procedure(void *dev, struct pci_cfg_reg_filter *pcrf,
>  
>  	return npu_dev_procedure_read(ndev, offset - pcrf->start, len, data);
>  }
> +
> +void npu2_dev_procedure_reset(struct npu2_dev *dev)
> +{
> +	npu2_clear_link_flag(dev, NPU2_DEV_DL_RESET);
> +}
> diff --git a/hw/npu2.c b/hw/npu2.c
> index 807c78d..87f52e2 100644
> --- a/hw/npu2.c
> +++ b/hw/npu2.c
> @@ -405,6 +405,29 @@ static int64_t npu2_dev_cfg_bar(void *dev, struct pci_cfg_reg_filter *pcrf,
>  	return npu2_cfg_read_bar(ndev, pcrf, offset, len, data);
>  }
>  
> +static int64_t npu2_dev_cfg_exp_devcap(void *dev,
> +		struct pci_cfg_reg_filter *pcrf __unused,
> +		uint32_t offset, uint32_t size,
> +		uint32_t *data, bool write)
> +{
> +	struct pci_virt_device *pvd = dev;
> +	struct npu2_dev *ndev = pvd->data;
> +
> +	assert(write);
> +
> +	if ((size != 2) || (offset & 1)) {
> +		/* Short config writes are not supported */
> +		prlog(PR_ERR, "NPU%d: Unsupported write to pcie control register\n",
> +		      ndev->phb->opal_id);
> +		return OPAL_PARAMETER;
> +	}
> +
> +	if (*data & PCICAP_EXP_DEVCTL_FUNC_RESET)
> +		npu2_dev_procedure_reset(ndev);
> +
> +	return OPAL_PARTIAL;
> +}
> +
>  #define NPU2_CFG_READ(size, type)					\
>  static int64_t npu2_cfg_read##size(struct phb *phb, uint32_t bdfn,	\
>  				   uint32_t offset, type *data)		\
> @@ -1336,7 +1359,7 @@ static uint32_t npu2_populate_pcie_cap(struct npu2_dev *dev,
>  
>  	/* 0x04 - Device capability
>  	 *
> -	 * We should support FLR. Oterwhsie, it might have
> +	 * We should support FLR. Otherwise, it might have
>  	 * problem passing it through to userland via Linux
>  	 * VFIO infrastructure
>  	 */
> @@ -1347,6 +1370,10 @@ static uint32_t npu2_populate_pcie_cap(struct npu2_dev *dev,
>  	       (PCICAP_EXP_DEVCAP_FUNC_RESET));
>  	PCI_VIRT_CFG_INIT_RO(pvd, start + PCICAP_EXP_DEVCAP, 4, val);
>  
> +	pci_virt_add_filter(pvd, start + PCICAP_EXP_DEVCTL, 2,
> +			    PCI_REG_FLAG_WRITE,
> +			    npu2_dev_cfg_exp_devcap, NULL);
> +
>  	/* 0x08 - Device control and status */
>  	PCI_VIRT_CFG_INIT(pvd, start + PCICAP_EXP_DEVCTL, 4, 0x00002810,
>  			  0xffff0000, 0x000f0000);
> diff --git a/include/npu2.h b/include/npu2.h
> index ef05f46..f11a13a 100644
> --- a/include/npu2.h
> +++ b/include/npu2.h
> @@ -155,6 +155,7 @@ void npu2_write_mask(struct npu2 *p, uint64_t reg, uint64_t val, uint64_t mask);
>  int64_t npu2_dev_procedure(void *dev, struct pci_cfg_reg_filter *pcrf,
>  			   uint32_t offset, uint32_t len, uint32_t *data,
>  			   bool write);
> +void npu2_dev_procedure_reset(struct npu2_dev *dev);
>  void npu2_set_link_flag(struct npu2_dev *ndev, uint8_t flag);
>  void npu2_clear_link_flag(struct npu2_dev *ndev, uint8_t flag);
>  extern int nv_zcal_nominal;
> 


-- 
Alexey