Re: [PATCH v8 6/9] perf/amd/iommu: Modify amd_iommu_pc_get_set_reg_val() API to allow specifying IOMMU index

[Borislav Petkov]

On Mon, Jan 16, 2017 at 01:23:33AM -0600, Suravee Suthikulpanit wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> 
> The current amd_iommu_pc_get_set_reg_val() cannot support multiple IOMMUs
> It is also confusing since it is trying to support set and get in
> one function.
> 
> So break it down to amd_iommu_pc_[get|set]_reg(),
> and modifies them to allow callers to specify IOMMU index. This prepares

  and modify

> the driver for supporting multi-IOMMU in subsequent patch.
> 
> Also remove unnecessary function declarations in amd_iommu_proto.h.
> 
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> ---
>  arch/x86/events/amd/iommu.c     | 34 ++++++++++----------------
>  arch/x86/events/amd/iommu.h     |  7 ++++--
>  drivers/iommu/amd_iommu_init.c  | 53 ++++++++++++++++++++++++++---------------
>  drivers/iommu/amd_iommu_proto.h |  5 ----
>  4 files changed, 52 insertions(+), 47 deletions(-)

...

> diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
> index ed21307d..5b7fb6c 100644
> --- a/drivers/iommu/amd_iommu_init.c
> +++ b/drivers/iommu/amd_iommu_init.c
> @@ -253,10 +253,6 @@ enum iommu_init_state {
>  static int __init iommu_go_to_state(enum iommu_init_state state);
>  static void init_device_table_dma(void);
>  
> -static int iommu_pc_get_set_reg_val(struct amd_iommu *iommu,
> -				    u8 bank, u8 cntr, u8 fxn,
> -				    u64 *value, bool is_write);
> -
>  static inline void update_last_devid(u16 devid)
>  {
>  	if (devid > amd_iommu_last_bdf)
> @@ -1481,6 +1477,14 @@ static int __init init_iommu_all(struct acpi_table_header *table)
>  	return 0;
>  }
>  
> +#define iommu_pc_get_reg(i, b, c, f, v) \
> +	iommu_pc_get_set_reg(i, b, c, f, v, false)
> +
> +#define iommu_pc_set_reg(i, b, c, f, v) \
> +	iommu_pc_get_set_reg(i, b, c, f, v, true)


Those are completely useless indirection. Just call
iommu_pc_get_set_reg() directly.

> +
> +static int iommu_pc_get_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr,
> +				u8 fxn, u64 *value, bool is_write);
>  
>  static void init_iommu_perf_ctr(struct amd_iommu *iommu)
>  {


-- 
Regards/Gruss,
    Boris.

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