Re: [PATCH v1 1/1] EDAC/skx: Use the mcmtr register to retrieve close_pg/bank_xor_enable

[Aristeu Rozanski <aris@redhat.com>]

On Fri, May 15, 2020 at 02:01:46PM -0700, Tony Luck wrote:
> From: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
> 
> The skx_edac driver wrongly uses the mtr register to retrieve two fields
> close_pg and bank_xor_enable. Fix it by using the correct mcmtr register
> to get the two fields.
> 
> Cc: <stable@vger.kernel.org>
> Reported-by: Matthew Riley <mattdr@google.com>
> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> 
> ---
>  drivers/edac/i10nm_base.c |  2 +-
>  drivers/edac/skx_base.c   | 20 ++++++++------------
>  drivers/edac/skx_common.c |  6 +++---
>  drivers/edac/skx_common.h |  2 +-
>  4 files changed, 13 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/edac/i10nm_base.c b/drivers/edac/i10nm_base.c
> index ea8f2127e238..c8d11da85bec 100644
> --- a/drivers/edac/i10nm_base.c
> +++ b/drivers/edac/i10nm_base.c
> @@ -175,7 +175,7 @@ static int i10nm_get_dimm_config(struct mem_ctl_info *mci)
>  				 mtr, mcddrtcfg, imc->mc, i, j);
>  
>  			if (IS_DIMM_PRESENT(mtr))
> -				ndimms += skx_get_dimm_info(mtr, 0, dimm,
> +				ndimms += skx_get_dimm_info(mtr, 0, 0, dimm,
>  							    imc, i, j);
>  			else if (IS_NVDIMM_PRESENT(mcddrtcfg, j))
>  				ndimms += skx_get_nvdimm_info(dimm, imc, i, j,
> diff --git a/drivers/edac/skx_base.c b/drivers/edac/skx_base.c
> index 1ff22136cf72..2c7db95df326 100644
> --- a/drivers/edac/skx_base.c
> +++ b/drivers/edac/skx_base.c
> @@ -169,27 +169,23 @@ static const struct x86_cpu_id skx_cpuids[] = {
>  };
>  MODULE_DEVICE_TABLE(x86cpu, skx_cpuids);
>  
> -#define SKX_GET_MTMTR(dev, reg) \
> -	pci_read_config_dword((dev), 0x87c, &(reg))
> -
> -static bool skx_check_ecc(struct pci_dev *pdev)
> +static bool skx_check_ecc(u32 mcmtr)
>  {
> -	u32 mtmtr;
> -
> -	SKX_GET_MTMTR(pdev, mtmtr);
> -
> -	return !!GET_BITFIELD(mtmtr, 2, 2);
> +	return !!GET_BITFIELD(mcmtr, 2, 2);
>  }
>  
>  static int skx_get_dimm_config(struct mem_ctl_info *mci)
>  {
>  	struct skx_pvt *pvt = mci->pvt_info;
> +	u32 mtr, mcmtr, amap, mcddrtcfg;
>  	struct skx_imc *imc = pvt->imc;
> -	u32 mtr, amap, mcddrtcfg;
>  	struct dimm_info *dimm;
>  	int i, j;
>  	int ndimms;
>  
> +	/* Only the mcmtr on the first channel is effective */
> +	pci_read_config_dword(imc->chan[0].cdev, 0x87c, &mcmtr);
> +
>  	for (i = 0; i < SKX_NUM_CHANNELS; i++) {
>  		ndimms = 0;
>  		pci_read_config_dword(imc->chan[i].cdev, 0x8C, &amap);
> @@ -199,14 +195,14 @@ static int skx_get_dimm_config(struct mem_ctl_info *mci)
>  			pci_read_config_dword(imc->chan[i].cdev,
>  					      0x80 + 4 * j, &mtr);
>  			if (IS_DIMM_PRESENT(mtr)) {
> -				ndimms += skx_get_dimm_info(mtr, amap, dimm, imc, i, j);
> +				ndimms += skx_get_dimm_info(mtr, mcmtr, amap, dimm, imc, i, j);
>  			} else if (IS_NVDIMM_PRESENT(mcddrtcfg, j)) {
>  				ndimms += skx_get_nvdimm_info(dimm, imc, i, j,
>  							      EDAC_MOD_STR);
>  				nvdimm_count++;
>  			}
>  		}
> -		if (ndimms && !skx_check_ecc(imc->chan[0].cdev)) {
> +		if (ndimms && !skx_check_ecc(mcmtr)) {
>  			skx_printk(KERN_ERR, "ECC is disabled on imc %d\n", imc->mc);
>  			return -ENODEV;
>  		}
> diff --git a/drivers/edac/skx_common.c b/drivers/edac/skx_common.c
> index abc9ddd2b7d1..46be1a77bd1d 100644
> --- a/drivers/edac/skx_common.c
> +++ b/drivers/edac/skx_common.c
> @@ -303,7 +303,7 @@ static int skx_get_dimm_attr(u32 reg, int lobit, int hibit, int add,
>  #define numrow(reg)	skx_get_dimm_attr(reg, 2, 4, 12, 1, 6, "rows")
>  #define numcol(reg)	skx_get_dimm_attr(reg, 0, 1, 10, 0, 2, "cols")
>  
> -int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
> +int skx_get_dimm_info(u32 mtr, u32 mcmtr, u32 amap, struct dimm_info *dimm,
>  		      struct skx_imc *imc, int chan, int dimmno)
>  {
>  	int  banks = 16, ranks, rows, cols, npages;
> @@ -323,8 +323,8 @@ int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
>  		 imc->mc, chan, dimmno, size, npages,
>  		 banks, 1 << ranks, rows, cols);
>  
> -	imc->chan[chan].dimms[dimmno].close_pg = GET_BITFIELD(mtr, 0, 0);
> -	imc->chan[chan].dimms[dimmno].bank_xor_enable = GET_BITFIELD(mtr, 9, 9);
> +	imc->chan[chan].dimms[dimmno].close_pg = GET_BITFIELD(mcmtr, 0, 0);
> +	imc->chan[chan].dimms[dimmno].bank_xor_enable = GET_BITFIELD(mcmtr, 9, 9);
>  	imc->chan[chan].dimms[dimmno].fine_grain_bank = GET_BITFIELD(amap, 0, 0);
>  	imc->chan[chan].dimms[dimmno].rowbits = rows;
>  	imc->chan[chan].dimms[dimmno].colbits = cols;
> diff --git a/drivers/edac/skx_common.h b/drivers/edac/skx_common.h
> index 19dd8c099520..78f8c1de0b71 100644
> --- a/drivers/edac/skx_common.h
> +++ b/drivers/edac/skx_common.h
> @@ -135,7 +135,7 @@ int skx_get_all_bus_mappings(struct res_config *cfg, struct list_head **list);
>  
>  int skx_get_hi_lo(unsigned int did, int off[], u64 *tolm, u64 *tohm);
>  
> -int skx_get_dimm_info(u32 mtr, u32 amap, struct dimm_info *dimm,
> +int skx_get_dimm_info(u32 mtr, u32 mcmtr, u32 amap, struct dimm_info *dimm,
>  		      struct skx_imc *imc, int chan, int dimmno);
>  
>  int skx_get_nvdimm_info(struct dimm_info *dimm, struct skx_imc *imc,

Acked-by: Aristeu Rozanski <aris@redhat.com>

-- 
Aristeu