Subject: Re: [PATCH v5 06/18] cxl: Isolate a few bare-metal-specific calls

From: Manoj Kumar <[email-masked]>
Date: Tue, 23 Feb 2016 13:12:48 -0600

Reviewed-by: Manoj Kumar <[email-masked]>

---
Manoj Kumar

On 2/23/2016 10:21 AM, Frederic Barrat wrote:
> A few functions are mostly common between bare-metal and guest and
> just need minor tuning. To avoid crowding the backend API, introduce a
> few 'if' based on the CPU being in HV mode.
>
> Co-authored-by: Christophe Lombard<[email-masked]>
> Signed-off-by: Frederic Barrat<[email-masked]>
> Signed-off-by: Christophe Lombard<[email-masked]>
> Acked-by: Ian Munsie<[email-masked]>
> ---
>   drivers/misc/cxl/context.c |  3 ++-
>   drivers/misc/cxl/cxl.h     |  7 +++++--
>   drivers/misc/cxl/debugfs.c |  4 ++++
>   drivers/misc/cxl/fault.c   | 19 +++++++++++--------
>   4 files changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
> index aa65262..46f9844 100644
> --- a/drivers/misc/cxl/context.c
> +++ b/drivers/misc/cxl/context.c
> @@ -95,7 +95,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
>   		return i;
>
>   	ctx->pe = i;
> -	ctx->elem = &ctx->afu->spa[i];
> +	if (cpu_has_feature(CPU_FTR_HVMODE))
> +		ctx->elem = &ctx->afu->spa[i];
>   	ctx->pe_inserted = false;
>
>   	/*
> diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
> index 02065b4..40f6783 100644
> --- a/drivers/misc/cxl/cxl.h
> +++ b/drivers/misc/cxl/cxl.h
> @@ -560,8 +560,11 @@ static inline bool cxl_adapter_link_ok(struct cxl *cxl)
>   {
>   	struct pci_dev *pdev;
>
> -	pdev = to_pci_dev(cxl->dev.parent);
> -	return !pci_channel_offline(pdev);
> +	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> +		pdev = to_pci_dev(cxl->dev.parent);
> +		return !pci_channel_offline(pdev);
> +	}
> +	return true;
>   }
>
>   static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t reg)
> diff --git a/drivers/misc/cxl/debugfs.c b/drivers/misc/cxl/debugfs.c
> index 18df6f4..5751899 100644
> --- a/drivers/misc/cxl/debugfs.c
> +++ b/drivers/misc/cxl/debugfs.c
> @@ -118,6 +118,10 @@ void cxl_debugfs_afu_remove(struct cxl_afu *afu)
>   int __init cxl_debugfs_init(void)
>   {
>   	struct dentry *ent;
> +
> +	if (!cpu_has_feature(CPU_FTR_HVMODE))
> +		return 0;
> +
>   	ent = debugfs_create_dir("cxl", NULL);
>   	if (IS_ERR(ent))
>   		return PTR_ERR(ent);
> diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
> index ab740a1..9a8650b 100644
> --- a/drivers/misc/cxl/fault.c
> +++ b/drivers/misc/cxl/fault.c
> @@ -254,14 +254,17 @@ void cxl_handle_fault(struct work_struct *fault_work)
>   	u64 dar = ctx->dar;
>   	struct mm_struct *mm = NULL;
>
> -	if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
> -	    cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
> -	    cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
> -		/* Most likely explanation is harmless - a dedicated process
> -		 * has detached and these were cleared by the PSL purge, but
> -		 * warn about it just in case */
> -		dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault regs changed\n");
> -		return;
> +	if (cpu_has_feature(CPU_FTR_HVMODE)) {
> +		if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
> +		    cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
> +		    cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
> +			/* Most likely explanation is harmless - a dedicated
> +			 * process has detached and these were cleared by the
> +			 * PSL purge, but warn about it just in case
> +			 */
> +			dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault regs changed\n");
> +			return;
> +		}
>   	}
>
>   	/* Early return if the context is being / has been detached */