lkml.org 
[lkml]   [2022]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 12/30] s390/pci: get SHM information from list pci
    On Tue, 18 Jan 2022 11:36:06 +0100
    Pierre Morel <pmorel@linux.ibm.com> wrote:

    > On 1/14/22 21:31, Matthew Rosato wrote:
    > > 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. Extend clp_list_pci_req to
    > > also fetch the model-dependent-data field that holds this mask.
    > >
    > > Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
    > > ---
    > > arch/s390/include/asm/pci.h | 1 +
    > > arch/s390/include/asm/pci_clp.h | 2 +-
    > > arch/s390/pci/pci_clp.c | 28 +++++++++++++++++++++++++---
    > > 3 files changed, 27 insertions(+), 4 deletions(-)
    > >
    > > diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
    > > index 00a2c24d6d2b..f3cd2da8128c 100644
    > > --- a/arch/s390/include/asm/pci.h
    > > +++ b/arch/s390/include/asm/pci.h
    > > @@ -227,6 +227,7 @@ 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_get_state(u32 fid, enum zpci_state *state);
    > > int clp_refresh_fh(u32 fid, u32 *fh);
    > > +int zpci_get_mdd(u32 *mdd);
    > >
    > > /* UID */
    > > void update_uid_checking(bool new);
    > > 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_clp.c b/arch/s390/pci/pci_clp.c
    > > index bc7446566cbc..308ffb93413f 100644
    > > --- a/arch/s390/pci/pci_clp.c
    > > +++ b/arch/s390/pci/pci_clp.c
    > > @@ -328,7 +328,7 @@ int clp_disable_fh(struct zpci_dev *zdev, u32 *fh)
    > > }
    > >
    > > static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
    > > - u64 *resume_token, int *nentries)
    > > + u64 *resume_token, int *nentries, u32 *mdd)
    > > {
    > > int rc;
    > >
    > > @@ -354,6 +354,8 @@ static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
    > > *nentries = (rrb->response.hdr.len - LIST_PCI_HDR_LEN) /
    > > rrb->response.entry_size;
    > > *resume_token = rrb->response.resume_token;
    > > + if (mdd)
    > > + *mdd = rrb->response.mdd;
    > >
    > > return rc;
    > > }
    > > @@ -365,7 +367,7 @@ static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
    > > int nentries, i, rc;
    > >
    > > do {
    > > - rc = clp_list_pci_req(rrb, &resume_token, &nentries);
    > > + rc = clp_list_pci_req(rrb, &resume_token, &nentries, NULL);
    > > if (rc)
    > > return rc;
    > > for (i = 0; i < nentries; i++)
    > > @@ -383,7 +385,7 @@ static int clp_find_pci(struct clp_req_rsp_list_pci *rrb, u32 fid,
    > > int nentries, i, rc;
    > >
    > > do {
    > > - rc = clp_list_pci_req(rrb, &resume_token, &nentries);
    > > + rc = clp_list_pci_req(rrb, &resume_token, &nentries, NULL);
    > > if (rc)
    > > return rc;
    > > fh_list = rrb->response.fh_list;
    > > @@ -468,6 +470,26 @@ int clp_get_state(u32 fid, enum zpci_state *state)
    > > return rc;
    > > }
    > >
    > > +int zpci_get_mdd(u32 *mdd)
    > > +{
    > > + struct clp_req_rsp_list_pci *rrb;
    > > + u64 resume_token = 0;
    > > + int nentries, rc;
    > > +
    > > + if (!mdd)
    > > + return -EINVAL;
    >
    > I think this tests is not useful.
    > The caller must take care not to call with a NULL pointer,
    > what the only caller today make sure.

    what if the caller does it anyway?

    I think the test is useful. if passing NULL is a bug, then maybe
    consider using BUG_ON, or WARN_ONCE

    >
    >
    > > +
    > > + rrb = clp_alloc_block(GFP_KERNEL);
    > > + if (!rrb)
    > > + return -ENOMEM;
    > > +
    > > + rc = clp_list_pci_req(rrb, &resume_token, &nentries, mdd);
    > > +
    > > + clp_free_block(rrb);
    > > + return rc;
    > > +}
    > > +EXPORT_SYMBOL_GPL(zpci_get_mdd);
    > > +
    > > static int clp_base_slpc(struct clp_req *req, struct clp_req_rsp_slpc *lpcb)
    > > {
    > > unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
    > >
    >

    \
     
     \ /
      Last update: 2022-01-26 11:13    [W:3.156 / U:0.160 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site