Re: [PATCH 12/32] s390/pci: get SHM information from list pci

Christian Borntraeger
2021-12-09T15:47:14Z

Am 07.12.21 um 21:57 schrieb Matthew Rosato:
> KVM will need information on the special handle mask used to indicate
> emulated devices. In order to obtain this, a new type of list pci call
> must be made to gather the information. Remove the unused data pointer
> from clp_list_pci and __clp_add and instead optionally pass a pointer to
> a model-dependent-data field. Additionally, allow for clp_list_pci calls
> that don't specify a callback - in this case, just do the first pass of
> list pci and exit.
>
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
> arch/s390/include/asm/pci.h | 6 ++++++
> arch/s390/include/asm/pci_clp.h | 2 +-
> arch/s390/pci/pci.c | 19 +++++++++++++++++++
> arch/s390/pci/pci_clp.c | 16 ++++++++++------
> 4 files changed, 36 insertions(+), 7 deletions(-)
>
> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> index 00a2c24d6d2b..86f43644756d 100644
> --- a/arch/s390/include/asm/pci.h
> +++ b/arch/s390/include/asm/pci.h
> @@ -219,12 +219,18 @@ int zpci_unregister_ioat(struct zpci_dev *, u8);
> void zpci_remove_reserved_devices(void);
> void zpci_update_fh(struct zpci_dev *zdev, u32 fh);
>
> +int zpci_get_mdd(u32 *mdd);
> +
> /* CLP */
> +void *clp_alloc_block(gfp_t gfp_mask);
> +void clp_free_block(void *ptr);
> int clp_setup_writeback_mio(void);
> int clp_scan_pci_devices(void);
> int clp_query_pci_fn(struct zpci_dev *zdev);
> int clp_enable_fh(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as);
> int clp_disable_fh(struct zpci_dev *zdev, u32 *fh);
> +int clp_list_pci(struct clp_req_rsp_list_pci *rrb, u32 *mdd,
> + void (*cb)(struct clp_fh_list_entry *));
> int clp_get_state(u32 fid, enum zpci_state *state);
> int clp_refresh_fh(u32 fid, u32 *fh);
>
> diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
> index 124fadfb74b9..d6bc324763f3 100644
> --- a/arch/s390/include/asm/pci_clp.h
> +++ b/arch/s390/include/asm/pci_clp.h
> @@ -76,7 +76,7 @@ struct clp_req_list_pci {
> struct clp_rsp_list_pci {
> struct clp_rsp_hdr hdr;
> u64 resume_token;
> - u32 reserved2;
> + u32 mdd;
> u16 max_fn;
> u8 : 7;
> u8 uid_checking : 1;
> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> index af1c0ae017b1..175854c861cd 100644
> --- a/arch/s390/pci/pci.c
> +++ b/arch/s390/pci/pci.c
> @@ -531,6 +531,25 @@ void zpci_update_fh(struct zpci_dev *zdev, u32 fh)
> zpci_do_update_iomap_fh(zdev, fh);
> }
>
> +int zpci_get_mdd(u32 *mdd)
> +{
> + struct clp_req_rsp_list_pci *rrb;
> + int rc;
> +
> + if (!mdd)
> + return -EINVAL;
> +
> + rrb = clp_alloc_block(GFP_KERNEL);
> + if (!rrb)
> + return -ENOMEM;
> +
> + rc = clp_list_pci(rrb, mdd, NULL);
> +
> + clp_free_block(rrb);
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(zpci_get_mdd);

Maybe move this into pci_clp.c to avoid the export of clp_alloc_block and void clp_free_block?
Niklas?
In any case the code looks correct from a HW perspective.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>

> +
> static struct resource *__alloc_res(struct zpci_dev *zdev, unsigned long start,
> unsigned long size, unsigned long flags)
> {
> diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
> index bc7446566cbc..e18a548ac22d 100644
> --- a/arch/s390/pci/pci_clp.c
> +++ b/arch/s390/pci/pci_clp.c
> @@ -84,12 +84,12 @@ static __always_inline int clp_req(void *data, unsigned int lps)
> return cc;
> }
>
> -static void *clp_alloc_block(gfp_t gfp_mask)
> +void *clp_alloc_block(gfp_t gfp_mask)
> {
> return (void *) __get_free_pages(gfp_mask, get_order(CLP_BLK_SIZE));
> }
>
> -static void clp_free_block(void *ptr)
> +void clp_free_block(void *ptr)
> {
> free_pages((unsigned long) ptr, get_order(CLP_BLK_SIZE));
> }
> @@ -358,8 +358,8 @@ static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
> return rc;
> }
>
> -static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
> - void (*cb)(struct clp_fh_list_entry *, void *))
> +int clp_list_pci(struct clp_req_rsp_list_pci *rrb, u32 *mdd,
> + void (*cb)(struct clp_fh_list_entry *))
> {
> u64 resume_token = 0;
> int nentries, i, rc;
> @@ -368,8 +368,12 @@ static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
> rc = clp_list_pci_req(rrb, &resume_token, &nentries);
> if (rc)
> return rc;
> + if (mdd)
> + *mdd = rrb->response.mdd;
> + if (!cb)
> + return 0;
> for (i = 0; i < nentries; i++)
> - cb(&rrb->response.fh_list[i], data);
> + cb(&rrb->response.fh_list[i]);
> } while (resume_token);
>
> return rc;
> @@ -398,7 +402,7 @@ static int clp_find_pci(struct clp_req_rsp_list_pci *rrb, u32 fid,
> return -ENODEV;
> }
>
> -static void __clp_add(struct clp_fh_list_entry *entry, void *data)
> +static void __clp_add(struct clp_fh_list_entry *entry)
> {
> struct zpci_dev *zdev;
>
>