Re: [PATCH v6 15/42] powerpc/powernv: PE oriented during configuration

Gavin Shan
2015-08-11T00:39:30Z

On Mon, Aug 10, 2015 at 08:02:20PM +1000, Alexey Kardashevskiy wrote:
>On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>Several functions used to configure PE take pe_number to indentify
>>PE instance. As the pe_number is included in PE instance after it
>>is reserved or allocated. It's convienent for those functions to
>>return PE instance which includes the required pe_number.
>
>This is a description for the half of the patch but this patch also adds a
>return value to functions which did not have it before and I am not sure you
>need all of them to return something. It would be cleaner if you added
>"return" when/where you really need it, not just because it seems that it may
>be convenient later.
>

Fair enough. I'll change the commit log accordingly.

>>
>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>---
>> arch/powerpc/platforms/powernv/pci-ioda.c | 51 ++++++++++++++++---------------
>> arch/powerpc/platforms/powernv/pci.h | 2 +-
>> 2 files changed, 27 insertions(+), 26 deletions(-)
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>index 3094c61..9f53682 100644
>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>@@ -132,12 +132,12 @@ static inline bool pnv_pci_is_mem_pref_64(unsigned long flags)
>> (IORESOURCE_MEM_64 | IORESOURCE_PREFETCH));
>> }
>>
>>-static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no)
>>+static struct pnv_ioda_pe *pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no)
>> {
>> if (!(pe_no >= 0 && pe_no < phb->ioda.total_pe)) {
>> pr_warn("%s: Invalid PE %d on PHB#%x\n",
>> __func__, pe_no, phb->hose->global_number);
>>- return;
>>+ return NULL;
>> }
>>
>> if (test_and_set_bit(pe_no, phb->ioda.pe_alloc))
>>@@ -146,9 +146,11 @@ static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no)
>>
>> phb->ioda.pe_array[pe_no].phb = phb;
>> phb->ioda.pe_array[pe_no].pe_number = pe_no;
>>+
>>+ return &phb->ioda.pe_array[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;
>>
>>@@ -156,12 +158,12 @@ static int pnv_ioda_alloc_pe(struct pnv_phb *phb)
>> pe = find_next_zero_bit(phb->ioda.pe_alloc,
>> phb->ioda.total_pe, 0);
>> if (pe >= phb->ioda.total_pe)
>>- return IODA_INVALID_PE;
>>+ return NULL;
>> } while(test_and_set_bit(pe, phb->ioda.pe_alloc));
>>
>> phb->ioda.pe_array[pe].phb = phb;
>> phb->ioda.pe_array[pe].pe_number = pe;
>>- return pe;
>>+ return &phb->ioda.pe_array[pe];
>> }
>>
>> static void pnv_ioda_free_pe(struct pnv_phb *phb, int pe)
>>@@ -334,7 +336,7 @@ 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;
>>@@ -344,7 +346,7 @@ 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 / 8, sizeof(unsigned long));
>>@@ -352,7 +354,7 @@ 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 */
>>@@ -365,7 +367,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>> */
>> if (bitmap_empty(pe_alloc, phb->ioda.total_pe)) {
>> kfree(pe_alloc);
>>- return IODA_INVALID_PE;
>>+ return NULL;
>> }
>>
>> /*
>>@@ -416,7 +418,7 @@ 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)
>>@@ -1069,28 +1071,26 @@ 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) {
>>- pr_warning("%s: Not enough PE# available for PCI bus %04x:%02x\n",
>>+ if (!pe) {
>>+ pr_warning("%s: No enough PE# 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;
>>@@ -1101,17 +1101,16 @@ 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(phb, pe->pe_number);
>> pe->pbus = NULL;
>>- return;
>>+ return NULL;
>> }
>>
>> /* Associate it with all child devices */
>>@@ -1122,6 +1121,8 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>>
>> /* Link the PE */
>> pnv_ioda_link_pe_by_weight(phb, pe);
>>+
>>+ return pe;
>> }
>>
>> static void pnv_ioda_setup_PEs(struct pci_bus *bus)
>>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>index 6f8568e..c0bc57f 100644
>>--- a/arch/powerpc/platforms/powernv/pci.h
>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>@@ -121,7 +121,7 @@ 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