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

Gavin Shan
2015-11-17T09:03:20Z

On Tue, Nov 17, 2015 at 04:08:30PM +1100, Alexey Kardashevskiy wrote:
>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.
>

It wasn't or isn't a bug as pe->pdev is initialized in arch/powerpc/platform/powernv/pci.c::
pnv_pci_dma_dev_setup()

>
>> 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);
>>

Thanks,
Gavin