Re: [PATCH v7 23/50] powerpc/powernv: Use PE instead of number during setup and release

Alexey Kardashevskiy
2015-11-17T05:08:37Z

On 11/05/2015 12:12 AM, Gavin Shan wrote:
> In current implementation, the PEs that are allocated or picked
> from the reserved list are identified by PE number. The PE instance
> has to be picked according to the PE number eventually. We have
> same issue when PE is released.
>
> For pnv_ioda_pick_m64_pe() and pnv_ioda_alloc_pe(), this returns
> PE instance so that pnv_ioda_setup_bus_PE() can use the allocated
> or reserved PE instance directly. Also, pnv_ioda_setup_bus_PE()
> returns the reserved/allocated PE instance to be used in subsequent
> patches. On the other hand, pnv_ioda_free_pe() uses PE instance
> (not number) as its argument. No logical changes introduced.
>
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
> arch/powerpc/platforms/powernv/pci-ioda.c | 81 +++++++++++++++++--------------
> arch/powerpc/platforms/powernv/pci.h | 2 +-
> 2 files changed, 46 insertions(+), 37 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 488e0f8..ae82df1 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -152,7 +152,7 @@ static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no)
> pnv_ioda_init_pe(phb, pe_no);
> }
>
> -static int pnv_ioda_alloc_pe(struct pnv_phb *phb)
> +static struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb)
> {
> unsigned long pe;
>
> @@ -160,19 +160,20 @@ static int pnv_ioda_alloc_pe(struct pnv_phb *phb)
> pe = find_next_zero_bit(phb->ioda.pe_alloc,
> phb->ioda.total_pe_num, 0);
> if (pe >= phb->ioda.total_pe_num)
> - return IODA_INVALID_PE;
> + return NULL;
> } while(test_and_set_bit(pe, phb->ioda.pe_alloc));
>
> - pnv_ioda_init_pe(phb, pe);
> - return pe;
> + return pnv_ioda_init_pe(phb, pe);
> }
>
> -static void pnv_ioda_free_pe(struct pnv_phb *phb, int pe)
> +static void pnv_ioda_free_pe(struct pnv_ioda_pe *pe)
> {
> - WARN_ON(phb->ioda.pe_array[pe].pdev);
> + struct pnv_phb *phb = pe->phb;
> +
> + WARN_ON(pe->pdev);
>
> - memset(&phb->ioda.pe_array[pe], 0, sizeof(struct pnv_ioda_pe));
> - clear_bit(pe, phb->ioda.pe_alloc);
> + memset(pe, 0, sizeof(struct pnv_ioda_pe));
> + clear_bit(pe->pe_number, phb->ioda.pe_alloc);
> }
>
> /* The default M64 BAR is shared by all PEs */
> @@ -332,7 +333,7 @@ static void pnv_ioda_reserve_m64_pe(struct pci_bus *bus,
> }
> }
>
> -static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
> +static struct pnv_ioda_pe *pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
> {
> struct pci_controller *hose = pci_bus_to_host(bus);
> struct pnv_phb *phb = hose->private_data;
> @@ -342,7 +343,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>
> /* Root bus shouldn't use M64 */
> if (pci_is_root_bus(bus))
> - return IODA_INVALID_PE;
> + return NULL;
>
> /* Allocate bitmap */
> size = _ALIGN_UP(phb->ioda.total_pe_num / 8, sizeof(unsigned long));
> @@ -350,7 +351,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
> if (!pe_alloc) {
> pr_warn("%s: Out of memory !\n",
> __func__);
> - return IODA_INVALID_PE;
> + return NULL;
> }
>
> /* Figure out reserved PE numbers by the PE */
> @@ -363,7 +364,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
> */
> if (bitmap_empty(pe_alloc, phb->ioda.total_pe_num)) {
> kfree(pe_alloc);
> - return IODA_INVALID_PE;
> + return NULL;
> }
>
> /*
> @@ -409,7 +410,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
> }
>
> kfree(pe_alloc);
> - return master_pe->pe_number;
> + return master_pe;
> }
>
> static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb)
> @@ -988,28 +989,26 @@ static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe)
> * subordinate PCI devices and buses. The second type of PE is normally
> * orgiriated by PCIe-to-PCI bridge or PLX switch downstream ports.
> */
> -static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
> +static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
> {
> struct pci_controller *hose = pci_bus_to_host(bus);
> struct pnv_phb *phb = hose->private_data;
> - struct pnv_ioda_pe *pe;
> - int pe_num = IODA_INVALID_PE;
> + struct pnv_ioda_pe *pe = NULL;
>
> /* Check if PE is determined by M64 */
> if (phb->pick_m64_pe)
> - pe_num = phb->pick_m64_pe(bus, all);
> + pe = phb->pick_m64_pe(bus, all);
>
> /* The PE number isn't pinned by M64 */
> - if (pe_num == IODA_INVALID_PE)
> - pe_num = pnv_ioda_alloc_pe(phb);
> + if (!pe)
> + pe = pnv_ioda_alloc_pe(phb);
>
> - if (pe_num == IODA_INVALID_PE) {
> + if (!pe) {
> pr_warning("%s: Not enough PE# available for PCI bus %04x:%02x\n",
> __func__, pci_domain_nr(bus), bus->number);
> - return;
> + return NULL;
> }
>
> - pe = &phb->ioda.pe_array[pe_num];
> pe->flags |= (all ? PNV_IODA_PE_BUS_ALL : PNV_IODA_PE_BUS);
> pe->pbus = bus;
> pe->pdev = NULL;
> @@ -1018,17 +1017,16 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>
> if (all)
> pe_info(pe, "Secondary bus %d..%d associated with PE#%d\n",
> - bus->busn_res.start, bus->busn_res.end, pe_num);
> + bus->busn_res.start, bus->busn_res.end, pe->pe_number);
> else
> pe_info(pe, "Secondary bus %d associated with PE#%d\n",
> - bus->busn_res.start, pe_num);
> + bus->busn_res.start, pe->pe_number);
>
> if (pnv_ioda_configure_pe(phb, pe)) {
> /* XXX What do we do here ? */
> - if (pe_num)
> - pnv_ioda_free_pe(phb, pe_num);
> + pnv_ioda_free_pe(pe);
> pe->pbus = NULL;
> - return;
> + return NULL;
> }
>
> /* Associate it with all child devices */
> @@ -1036,6 +1034,8 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>
> /* Put PE to the list */
> list_add_tail(&pe->list, &phb->ioda.pe_list);
> +
> + return pe;
> }
>
> static void pnv_ioda_setup_PEs(struct pci_bus *bus)
> @@ -1267,7 +1267,7 @@ static void pnv_ioda_release_vf_PE(struct pci_dev *pdev)
>
> pnv_ioda_deconfigure_pe(phb, pe);
>
> - pnv_ioda_free_pe(phb, pe->pe_number);
> + pnv_ioda_free_pe(pe);
> }
> }
>
> @@ -1276,6 +1276,7 @@ void pnv_pci_sriov_disable(struct pci_dev *pdev)
> struct pci_bus *bus;
> struct pci_controller *hose;
> struct pnv_phb *phb;
> + struct pnv_ioda_pe *pe;
> struct pci_dn *pdn;
> struct pci_sriov *iov;
> u16 num_vfs, i;
> @@ -1300,8 +1301,11 @@ void pnv_pci_sriov_disable(struct pci_dev *pdev)
> /* Release PE numbers */
> if (pdn->m64_single_mode) {
> for (i = 0; i < num_vfs; i++) {
> - if (pdn->pe_num_map[i] != IODA_INVALID_PE)
> - pnv_ioda_free_pe(phb, pdn->pe_num_map[i]);
> + if (pdn->pe_num_map[i] == IODA_INVALID_PE)
> + continue;
> +
> + pe = &phb->ioda.pe_array[pdn->pe_num_map[i]];
> + pnv_ioda_free_pe(pe);
> }
> } else
> bitmap_clear(phb->ioda.pe_alloc, *pdn->pe_num_map, num_vfs);
> @@ -1354,9 +1358,8 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
>
> if (pnv_ioda_configure_pe(phb, pe)) {
> /* XXX What do we do here ? */
> - if (pe_num)
> - pnv_ioda_free_pe(phb, pe_num);
> pe->pdev = NULL;
> + pnv_ioda_free_pe(pe);

pnv_ioda_free_pe() does WARN_ON(pdev). Before this patch you would free PE
first and then reset pe->pdev, now you reset it first, then call
pnv_ioda_free_pe(). This change is not just about "Use PE instead of number
during setup and release", is/was that a bug?

And I fail to see when pe->pdev could get initialized in
pnv_ioda_configure_pe() as pnv_pci_dma_dev_setup() should not be called
while pnv_ioda_setup_vf_PE() is working.

> continue;
> }
>
> @@ -1374,6 +1377,7 @@ int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
> struct pci_bus *bus;
> struct pci_controller *hose;
> struct pnv_phb *phb;
> + struct pnv_ioda_pe *pe;
> struct pci_dn *pdn;
> int ret;
> u16 i;
> @@ -1416,11 +1420,13 @@ int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
> /* Calculate available PE for required VFs */
> if (pdn->m64_single_mode) {
> for (i = 0; i < num_vfs; i++) {
> - pdn->pe_num_map[i] = pnv_ioda_alloc_pe(phb);
> - if (pdn->pe_num_map[i] == IODA_INVALID_PE) {
> + pe = pnv_ioda_alloc_pe(phb);
> + if (!pe) {
> ret = -EBUSY;
> goto m64_failed;
> }
> +
> + pdn->pe_num_map[i] = pe->pe_number;
> }
> } else {
> mutex_lock(&phb->ioda.pe_alloc_mutex);
> @@ -1465,8 +1471,11 @@ int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
> m64_failed:
> if (pdn->m64_single_mode) {
> for (i = 0; i < num_vfs; i++) {
> - if (pdn->pe_num_map[i] != IODA_INVALID_PE)
> - pnv_ioda_free_pe(phb, pdn->pe_num_map[i]);
> + if (pdn->pe_num_map[i] == IODA_INVALID_PE)
> + continue;
> +
> + pe = &phb->ioda.pe_array[pdn->pe_num_map[i]];
> + pnv_ioda_free_pe(pe);
> }
> } else
> bitmap_clear(phb->ioda.pe_alloc, *pdn->pe_num_map, num_vfs);
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 5df945f..e55ab0e 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -105,7 +105,7 @@ struct pnv_phb {
> int (*init_m64)(struct pnv_phb *phb);
> void (*reserve_m64_pe)(struct pci_bus *bus,
> unsigned long *pe_bitmap, bool all);
> - int (*pick_m64_pe)(struct pci_bus *bus, bool all);
> + struct pnv_ioda_pe *(*pick_m64_pe)(struct pci_bus *bus, bool all);
> int (*get_pe_state)(struct pnv_phb *phb, int pe_no);
> void (*freeze_pe)(struct pnv_phb *phb, int pe_no);
> int (*unfreeze_pe)(struct pnv_phb *phb, int pe_no, int opt);
>

--
Alexey