Re: [Qemu-devel] [PATCH v2 01/14] spapr: populate DRC entries for root dt node

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Alexey Kardashevskiy (2013-12-15 22:54:42)
> On 12/16/2013 01:59 PM, Alexey Kardashevskiy wrote:
> > On 12/06/2013 09:32 AM, Michael Roth wrote:
> >> From: Nathan Fontenot <nfont@linux.vnet.ibm.com>
> >>
> >> This add entries to the root OF node to advertise our PHBs as being
> >> DR-capable in according with PAPR specification.
> >>
> >> Each PHB is given a name of PHB<bus#>, advertised as a PHB type,
> >> and associated with a power domain of -1 (indicating to guests that
> >> power management is handled automatically by hardware).
> >>
> >> We currently allocate entries for up to 32 DR-capable PHBs, though
> >> this limit can be increased later.
> >>
> >> DrcEntry objects to track the state of the DR-connector associated
> >> with each PHB are stored in a 32-entry array, and each DrcEntry has
> >> in turn have a dynamically-sized number of child DR-connectors,
> >> which we will use later to track the state of DR-connectors
> >> associated with a PHB's physical slots.
> >>
> >> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
> >> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> >> ---
> >>  hw/ppc/spapr.c         |  132 ++++++++++++++++++++++++++++++++++++++++++++++++
> >>  include/hw/ppc/spapr.h |   33 ++++++++++++
> >>  2 files changed, 165 insertions(+)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index 7e53a5f..ec3ba43 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -81,6 +81,7 @@
> >>  #define HTAB_SIZE(spapr)        (1ULL << ((spapr)->htab_shift))
> >>  
> >>  sPAPREnvironment *spapr;
> >> +DrcEntry drc_table[SPAPR_DRC_TABLE_SIZE];
> >>  
> >>  int spapr_allocate_irq(int hint, bool lsi)
> >>  {
> >> @@ -276,6 +277,130 @@ static size_t create_page_sizes_prop(CPUPPCState *env, uint32_t *prop,
> >>      return (p - prop) * sizeof(uint32_t);
> >>  }
> >>  
> >> +static void spapr_init_drc_table(void)
> >> +{
> >> +    int i;
> >> +
> >> +    memset(drc_table, 0, sizeof(drc_table));
> >> +
> >> +    /* For now we only care about PHB entries */
> >> +    for (i = 0; i < SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        drc_table[i].drc_index = 0x2000001 + i;
> >> +    }
> >> +}
> >> +
> >> +DrcEntry *spapr_add_phb_to_drc_table(uint64_t buid, uint32_t state)
> >> +{
> >> +    DrcEntry *empty_drc = NULL;
> >> +    DrcEntry *found_drc = NULL;
> >> +    int i, phb_index;
> >> +
> >> +    for (i = 0; i < SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        if (drc_table[i].phb_buid == 0) {
> >> +            empty_drc = &drc_table[i];
> >> +        }
> >> +
> >> +        if (drc_table[i].phb_buid == buid) {
> >> +            found_drc = &drc_table[i];
> >> +            break;
> >> +        }
> >> +    }
> >> +
> >> +    if (found_drc) {
> >> +        return found_drc;
> >> +    }
> >> +
> >> +    if (empty_drc) {
> >> +        empty_drc->phb_buid = buid;
> >> +        empty_drc->state = state;
> >> +        empty_drc->cc_state.fdt = NULL;
> >> +        empty_drc->cc_state.offset = 0;
> >> +        empty_drc->cc_state.depth = 0;
> >> +        empty_drc->cc_state.state = CC_STATE_IDLE;
> >> +        empty_drc->child_entries =
> >> +            g_malloc0(sizeof(DrcEntry) * SPAPR_DRC_PHB_SLOT_MAX);
> >> +        phb_index = buid - SPAPR_PCI_BASE_BUID;
> >> +        for (i = 0; i < SPAPR_DRC_PHB_SLOT_MAX; i++) {
> >> +            empty_drc->child_entries[i].drc_index =
> >> +                SPAPR_DRC_DEV_ID_BASE + (phb_index << 8) + (i << 3);
> >> +        }
> >> +        return empty_drc;
> >> +    }
> >> +
> >> +    return NULL;
> >> +}
> >> +
> >> +static void spapr_create_drc_dt_entries(void *fdt)
> >> +{
> >> +    char char_buf[1024];
> >> +    uint32_t int_buf[SPAPR_DRC_TABLE_SIZE + 1];
> >> +    uint32_t *entries;
> >> +    int offset, fdt_offset;
> >> +    int i, ret;
> >> +
> >> +    fdt_offset = fdt_path_offset(fdt, "/");
> >> +
> >> +    /* ibm,drc-indexes */
> >> +    memset(int_buf, 0, sizeof(int_buf));
> >> +    int_buf[0] = SPAPR_DRC_TABLE_SIZE;
> >> +
> >> +    for (i = 1; i <= SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        int_buf[i] = drc_table[i-1].drc_index;
> >> +    }
> >> +
> >> +    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-indexes", int_buf,
> >> +                      sizeof(int_buf));
> >> +    if (ret) {
> >> +        fprintf(stderr, "Couldn't finalize ibm,drc-indexes property\n");
> >> +    }
> >> +
> >> +    /* ibm,drc-power-domains */
> >> +    memset(int_buf, 0, sizeof(int_buf));
> >> +    int_buf[0] = SPAPR_DRC_TABLE_SIZE;
> >> +
> >> +    for (i = 1; i <= SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        int_buf[i] = 0xffffffff;
> >> +    }
> >> +
> >> +    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-power-domains", int_buf,
> >> +                      sizeof(int_buf));
> >> +    if (ret) {
> >> +        fprintf(stderr, "Couldn't finalize ibm,drc-power-domains property\n");
> >> +    }
> >> +
> >> +    /* ibm,drc-names */
> >> +    memset(char_buf, 0, sizeof(char_buf));
> >> +    entries = (uint32_t *)&char_buf[0];
> >> +    *entries = SPAPR_DRC_TABLE_SIZE;
> >> +    offset = sizeof(*entries);
> >> +
> >> +    for (i = 0; i < SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        offset += sprintf(char_buf + offset, "PHB %d", i + 1);
> >> +        char_buf[offset++] = '\0';
> >> +    }
> >> +
> >> +    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-names", char_buf, offset);
> >> +    if (ret) {
> >> +        fprintf(stderr, "Couldn't finalize ibm,drc-names property\n");
> >> +    }
> >> +
> >> +    /* ibm,drc-types */
> >> +    memset(char_buf, 0, sizeof(char_buf));
> >> +    entries = (uint32_t *)&char_buf[0];
> >> +    *entries = SPAPR_DRC_TABLE_SIZE;
> >> +    offset = sizeof(*entries);
> >> +
> >> +    for (i = 0; i < SPAPR_DRC_TABLE_SIZE; i++) {
> >> +        offset += sprintf(char_buf + offset, "PHB");
> >> +        char_buf[offset++] = '\0';
> >> +    }
> >> +
> >> +    ret = fdt_setprop(fdt, fdt_offset, "ibm,drc-types", char_buf, offset);
> >> +    if (ret) {
> >> +        fprintf(stderr, "Couldn't finalize ibm,drc-types property\n");
> >> +    }
> >> +}
> >> +
> >>  #define _FDT(exp) \
> >>      do { \
> >>          int ret = (exp);                                           \
> >> @@ -307,6 +432,8 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
> >>      int i, smt = kvmppc_smt_threads();
> >>      unsigned char vec5[] = {0x0, 0x0, 0x0, 0x0, 0x0, 0x80};
> >>  
> >> +    spapr_init_drc_table();
> >> +
> >>      fdt = g_malloc0(FDT_MAX_SIZE);
> >>      _FDT((fdt_create(fdt, FDT_MAX_SIZE)));
> >>  
> >> @@ -590,6 +717,7 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
> >>      int ret;
> >>      void *fdt;
> >>      sPAPRPHBState *phb;
> >> +    DrcEntry *drc_entry;
> >>  
> >>      fdt = g_malloc(FDT_MAX_SIZE);
> >>  
> >> @@ -609,6 +737,8 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
> >>      }
> >>  
> >>      QLIST_FOREACH(phb, &spapr->phbs, list) {
> >> +        drc_entry = spapr_add_phb_to_drc_table(phb->buid, 2 /* Unusable */);
> >> +        g_assert(drc_entry);
> >>          ret = spapr_populate_pci_dt(phb, PHANDLE_XICP, fdt);
> >>      }
> >>  
> >> @@ -633,6 +763,8 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
> >>          spapr_populate_chosen_stdout(fdt, spapr->vio_bus);
> >>      }
> >>  
> >> +    spapr_create_drc_dt_entries(fdt);
> >> +
> >>      _FDT((fdt_pack(fdt)));
> >>  
> >>      if (fdt_totalsize(fdt) > FDT_MAX_SIZE) {
> >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> >> index b2f11e9..0f2e705 100644
> >> --- a/include/hw/ppc/spapr.h
> >> +++ b/include/hw/ppc/spapr.h
> >> @@ -299,6 +299,39 @@ typedef struct sPAPREnvironment {
> >>  #define KVMPPC_H_LOGICAL_MEMOP  (KVMPPC_HCALL_BASE + 0x1)
> >>  #define KVMPPC_HCALL_MAX        KVMPPC_H_LOGICAL_MEMOP
> >>  
> >> +/* For dlparable/hotpluggable slots */
> >> +#define SPAPR_DRC_TABLE_SIZE    32
> >> +#define SPAPR_DRC_PHB_SLOT_MAX  32
> >> +#define SPAPR_DRC_DEV_ID_BASE   0x40000000
> >> +
> >> +typedef struct ConfigureConnectorState {
> >> +    void *fdt;
> >> +    int offset_start;
> >> +    int offset;
> >> +    int depth;
> >> +    PCIDevice *dev;
> >> +    enum {
> >> +        CC_STATE_IDLE = 0,
> >> +        CC_STATE_PENDING = 1,
> >> +        CC_STATE_ACTIVE,
> >> +    } state;
> >> +} ConfigureConnectorState;
> >> +
> >> +typedef struct DrcEntry DrcEntry;
> >> +
> >> +struct DrcEntry {
> >> +    uint32_t drc_index;
> >> +    uint64_t phb_buid;
> >> +    void *fdt;
> >> +    int fdt_offset;
> >> +    uint32_t state;
> >> +    ConfigureConnectorState cc_state;
> >> +    DrcEntry *child_entries;
> >> +};
> >> +
> >> +extern DrcEntry drc_table[SPAPR_DRC_TABLE_SIZE];
> >> +DrcEntry *spapr_add_phb_to_drc_table(uint64_t buid, uint32_t state);
> >> +
> >>  extern sPAPREnvironment *spapr;
> > 
> > So far we were trying to keep everything sPAPR-related in sPAPREnvironment.
> > Is @drc_table really that special?
> 
> 
> One more note - we are trying to add a "spapr" or "sPAPR" prefix to all
> global types defines in headers (such as sPAPRPHBState, spapr_pci_lsi,
> VIOsPAPRBus, sPAPREnvironment), it would be nice to have "spapr" in some
> form in these new types too.
> 
> Or we could move the whole patch (except spapr_create_drc_dt_entries()) to
> hw/ppc/spapr_pci.c (and keep the original names) as it seems to be the only
> user of the whole DrcEntry and ConfigureConnectorState thing.
> And put a pointer to drc_table[] into @spapr (or make it static?)

That would work, but I think we'd need to move spapr_create_drc_dt_entries()
as well, or the bits that rely on DrcEntry at least. Though I worry
about scoping DrcEntry to spapr_pci.c at this early stage, as DR-capable
components other than PCI may come to rely on state that's captured by the
DrcEntry nodes, such as boot-time FDT generation and run-time management
(via ibm,configure-connector) of CPUs and memory.

Assuming that seems like a reasonable expectation, I think I'd prefer the
first option of using spapr-specific prefixes for global types and moving
drc_table into sPAPREnvironment

> 
> The only remaining user of DrcEntry is spapr_hotplug_req_event() but this
> can be easily fixed by small helper like this:
> 
> int spapr_phb_slot_to_drc_index(uint64_t buid, int slot)
> {
>         DrcEntry *drc_entry = spapr_phb_to_drc_entry(phb->buid);
>         if (!drc_entry) {
>                 drc_entry = spapr_add_phb_to_drc_table(phb->buid, 2);
>         }
>         return drc_entry->child_entries[slot].drc_index;
> }
> 
> 
> > 
> > 
> >>  
> >>  /*#define DEBUG_SPAPR_HCALLS*/
> >>
> > 
> > 
> 
> 
> -- 
> Alexey