On 2/8/2016 1:30 PM, Dan Williams wrote:
> ACPI 6.1 clarified that multi-interface dimms require multiple control
> region entries (DCRs) per dimm. Previously we were assuming that a
> control region is only present when block-data-windows are present.
We need to give this a quick test with NVDIMM-N because those types of
NVDIMMs have control regions without block-data-windows. We've fixed
bugs related to that assumption a couple of times.
> This implementation was done with an eye to be compatibility with the
> looser ACPI 6.0 interpretation of this table.
>
> 1/ When coalescing the memory device (MEMDEV) tables for a single dimm,
> coalesce on device_handle rather than control region index.
>
> 2/ Whenever we disocver a control region with non-zero block windows
discover
> re-scan for block-data-window (BDW) entries.
>
> We may need to revisit this if a DIMM ever implements a format interface
> outside of blk or pmem, but that is not on the foreseeable horizon.
>
> Cc: <sta...@vger.kernel.org>
> Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
> ---
> drivers/acpi/nfit.c | 71
> +++++++++++++++++++++++++--------------------------
> 1 file changed, 35 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
> index ad6d8c6b777e..424b362e8fdc 100644
> --- a/drivers/acpi/nfit.c
> +++ b/drivers/acpi/nfit.c
> @@ -469,37 +469,16 @@ static void nfit_mem_find_spa_bdw(struct acpi_nfit_desc
> *acpi_desc,
> nfit_mem->bdw = NULL;
> }
>
> -static int nfit_mem_add(struct acpi_nfit_desc *acpi_desc,
> +static void nfit_mem_init_bdw(struct acpi_nfit_desc *acpi_desc,
> struct nfit_mem *nfit_mem, struct acpi_nfit_system_address *spa)
> {
> u16 dcr = __to_nfit_memdev(nfit_mem)->region_index;
> struct nfit_memdev *nfit_memdev;
> struct nfit_flush *nfit_flush;
> - struct nfit_dcr *nfit_dcr;
> struct nfit_bdw *nfit_bdw;
> struct nfit_idt *nfit_idt;
> u16 idt_idx, range_index;
>
> - list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
> - if (nfit_dcr->dcr->region_index != dcr)
> - continue;
> - nfit_mem->dcr = nfit_dcr->dcr;
> - break;
> - }
> -
> - if (!nfit_mem->dcr) {
> - dev_dbg(acpi_desc->dev, "SPA %d missing:%s%s\n",
> - spa->range_index, __to_nfit_memdev(nfit_mem)
> - ? "" : " MEMDEV", nfit_mem->dcr ? "" : " DCR");
> - return -ENODEV;
> - }
> -
> - /*
> - * We've found enough to create an nvdimm, optionally
> - * find an associated BDW
> - */
> - list_add(&nfit_mem->list, &acpi_desc->dimms);
> -
> list_for_each_entry(nfit_bdw, &acpi_desc->bdws, list) {
> if (nfit_bdw->bdw->region_index != dcr)
> continue;
> @@ -508,12 +487,12 @@ static int nfit_mem_add(struct acpi_nfit_desc
> *acpi_desc,
> }
>
> if (!nfit_mem->bdw)
> - return 0;
> + return;
>
> nfit_mem_find_spa_bdw(acpi_desc, nfit_mem);
>
> if (!nfit_mem->spa_bdw)
> - return 0;
> + return;
>
> range_index = nfit_mem->spa_bdw->range_index;
> list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
> @@ -538,8 +517,6 @@ static int nfit_mem_add(struct acpi_nfit_desc *acpi_desc,
> }
> break;
> }
> -
> - return 0;
> }
>
> static int nfit_mem_dcr_init(struct acpi_nfit_desc *acpi_desc,
> @@ -548,7 +525,6 @@ static int nfit_mem_dcr_init(struct acpi_nfit_desc
> *acpi_desc,
> struct nfit_mem *nfit_mem, *found;
> struct nfit_memdev *nfit_memdev;
> int type = nfit_spa_type(spa);
> - u16 dcr;
>
> switch (type) {
> case NFIT_SPA_DCR:
> @@ -559,14 +535,18 @@ static int nfit_mem_dcr_init(struct acpi_nfit_desc
> *acpi_desc,
> }
>
> list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
> - int rc;
> + struct nfit_dcr *nfit_dcr;
> + u32 device_handle;
> + u16 dcr;
>
> if (nfit_memdev->memdev->range_index != spa->range_index)
> continue;
> found = NULL;
> dcr = nfit_memdev->memdev->region_index;
> + device_handle = nfit_memdev->memdev->device_handle;
> list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
> - if (__to_nfit_memdev(nfit_mem)->region_index == dcr) {
> + if (__to_nfit_memdev(nfit_mem)->device_handle
> + == device_handle) {
> found = nfit_mem;
> break;
> }
> @@ -579,6 +559,31 @@ static int nfit_mem_dcr_init(struct acpi_nfit_desc
> *acpi_desc,
> if (!nfit_mem)
> return -ENOMEM;
> INIT_LIST_HEAD(&nfit_mem->list);
> + list_add(&nfit_mem->list, &acpi_desc->dimms);
> + }
> +
> + list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
> + if (nfit_dcr->dcr->region_index != dcr)
> + continue;
> + /*
> + * Record the control region for the dimm. For
> + * the ACPI 6.1 case, where there are separate
> + * control regions for the pmem vs blk
> + * interfaces, be sure to record the extended
> + * blk details.
> + */
> + if (!nfit_mem->dcr)
> + nfit_mem->dcr = nfit_dcr->dcr;
> + else if (nfit_mem->dcr->windows == 0
> + && nfit_dcr->dcr->windows)
> + nfit_mem->dcr = nfit_dcr->dcr;
> + break;
> + }
> +
> + if (dcr && !nfit_mem->dcr) {
> + dev_err(acpi_desc->dev, "SPA %d missing DCR %d\n",
> + spa->range_index, dcr);
> + return -ENODEV;
> }
>
> if (type == NFIT_SPA_DCR) {
> @@ -595,6 +600,7 @@ static int nfit_mem_dcr_init(struct acpi_nfit_desc
> *acpi_desc,
> nfit_mem->idt_dcr = nfit_idt->idt;
> break;
> }
> + nfit_mem_init_bdw(acpi_desc, nfit_mem, spa);
> } else {
> /*
> * A single dimm may belong to multiple SPA-PM
> @@ -603,13 +609,6 @@ static int nfit_mem_dcr_init(struct acpi_nfit_desc
> *acpi_desc,
> */
> nfit_mem->memdev_pmem = nfit_memdev->memdev;
> }
> -
> - if (found)
> - continue;
> -
> - rc = nfit_mem_add(acpi_desc, nfit_mem, spa);
> - if (rc)
> - return rc;
> }
>
> return 0;
>
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