Re: [PATCH v3 09/14] PCI: cadence: Add MSI-X support to Endpoint driver

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi Rob,

On 4/30/2020 7:25 AM, Rob Herring wrote:
> On Fri, Apr 17, 2020 at 06:27:48PM +0530, Kishon Vijay Abraham I wrote:
>> From: Alan Douglas <adouglas@cadence.com>
>>
>> Implement ->set_msix() and ->get_msix() callback functions in order
>> to configure MSIX capability in the PCIe endpoint controller.
>>
>> Add cdns_pcie_ep_send_msix_irq() to send MSIX interrupts to Host.
>> cdns_pcie_ep_send_msix_irq() gets the MSIX table address (virtual
>> address) from "struct cdns_pcie_epf" that gets initialized in
>> ->set_bar() call back function.
>>
>> [kishon@ti.com: Re-implement MSIX support in accordance with the
>>  re-designed core MSI-X interfaces]
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> Signed-off-by: Alan Douglas <adouglas@cadence.com>
> 
> Your Sob should be last.

Will fix this!

Thanks
Kishon
> 
>> ---
>>  .../pci/controller/cadence/pcie-cadence-ep.c  | 112 +++++++++++++++++-
>>  drivers/pci/controller/cadence/pcie-cadence.h |  10 ++
>>  2 files changed, 121 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
>> index 14021d760482..c43340ca0630 100644
>> --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
>> +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
>> @@ -51,6 +51,7 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
>>  				struct pci_epf_bar *epf_bar)
>>  {
>>  	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
>> +	struct cdns_pcie_epf *epf = &ep->epf[fn];
>>  	struct cdns_pcie *pcie = &ep->pcie;
>>  	dma_addr_t bar_phys = epf_bar->phys_addr;
>>  	enum pci_barno bar = epf_bar->barno;
>> @@ -111,6 +112,8 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
>>  		CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
>>  	cdns_pcie_writel(pcie, reg, cfg);
>>  
>> +	epf->epf_bar[bar] = epf_bar;
>> +
>>  	return 0;
>>  }
>>  
>> @@ -118,6 +121,7 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
>>  				   struct pci_epf_bar *epf_bar)
>>  {
>>  	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
>> +	struct cdns_pcie_epf *epf = &ep->epf[fn];
>>  	struct cdns_pcie *pcie = &ep->pcie;
>>  	enum pci_barno bar = epf_bar->barno;
>>  	u32 reg, cfg, b, ctrl;
>> @@ -139,6 +143,8 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
>>  
>>  	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0);
>>  	cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0);
>> +
>> +	epf->epf_bar[bar] = NULL;
>>  }
>>  
>>  static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr,
>> @@ -224,6 +230,50 @@ static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
>>  	return mme;
>>  }
>>  
>> +static int cdns_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no)
>> +{
>> +	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
>> +	struct cdns_pcie *pcie = &ep->pcie;
>> +	u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
>> +	u32 val, reg;
>> +
>> +	reg = cap + PCI_MSIX_FLAGS;
>> +	val = cdns_pcie_ep_fn_readw(pcie, func_no, reg);
>> +	if (!(val & PCI_MSIX_FLAGS_ENABLE))
>> +		return -EINVAL;
>> +
>> +	val &= PCI_MSIX_FLAGS_QSIZE;
>> +
>> +	return val;
>> +}
>> +
>> +static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u16 interrupts,
>> +				 enum pci_barno bir, u32 offset)
>> +{
>> +	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
>> +	struct cdns_pcie *pcie = &ep->pcie;
>> +	u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
>> +	u32 val, reg;
>> +
>> +	reg = cap + PCI_MSIX_FLAGS;
>> +	val = cdns_pcie_ep_fn_readw(pcie, fn, reg);
>> +	val &= ~PCI_MSIX_FLAGS_QSIZE;
>> +	val |= interrupts;
>> +	cdns_pcie_ep_fn_writew(pcie, fn, reg, val);
>> +
>> +	/* Set MSIX BAR and offset */
>> +	reg = cap + PCI_MSIX_TABLE;
>> +	val = offset | bir;
>> +	cdns_pcie_ep_fn_writel(pcie, fn, reg, val);
>> +
>> +	/* Set PBA BAR and offset.  BAR must match MSIX BAR */
>> +	reg = cap + PCI_MSIX_PBA;
>> +	val = (offset + (interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
>> +	cdns_pcie_ep_fn_writel(pcie, fn, reg, val);
>> +
>> +	return 0;
>> +}
>> +
>>  static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
>>  				     u8 intx, bool is_asserted)
>>  {
>> @@ -330,6 +380,56 @@ static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
>>  	return 0;
>>  }
>>  
>> +static int cdns_pcie_ep_send_msix_irq(struct cdns_pcie_ep *ep, u8 fn,
>> +				      u16 interrupt_num)
>> +{
>> +	u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
>> +	u32 tbl_offset, msg_data, reg, vec_ctrl;
>> +	struct cdns_pcie *pcie = &ep->pcie;
>> +	struct pci_epf_msix_tbl *msix_tbl;
>> +	struct pci_epf_bar *epf_bar;
>> +	struct cdns_pcie_epf *epf;
>> +	u64 pci_addr_mask = 0xff;
>> +	u64 msg_addr;
>> +	u16 flags;
>> +	u8 bir;
>> +
>> +	/* Check whether the MSI-X feature has been enabled by the PCI host. */
>> +	flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSIX_FLAGS);
>> +	if (!(flags & PCI_MSIX_FLAGS_ENABLE))
>> +		return -EINVAL;
>> +
>> +	reg = cap + PCI_MSIX_TABLE;
>> +	tbl_offset = cdns_pcie_ep_fn_readl(pcie, fn, reg);
>> +	bir = tbl_offset & PCI_MSIX_TABLE_BIR;
>> +	tbl_offset &= PCI_MSIX_TABLE_OFFSET;
>> +
>> +	epf = &ep->epf[fn];
>> +	epf_bar = epf->epf_bar[bir];
>> +	msix_tbl = epf_bar->addr;
>> +	msix_tbl = (struct pci_epf_msix_tbl *)((char *)msix_tbl + tbl_offset);
>> +
>> +	msg_addr = msix_tbl[(interrupt_num - 1)].msg_addr;
>> +	msg_data = msix_tbl[(interrupt_num - 1)].msg_data;
>> +	vec_ctrl = msix_tbl[(interrupt_num - 1)].vector_ctrl;
>> +
>> +	/* Set the outbound region if needed. */
>> +	if (ep->irq_pci_addr != (msg_addr & ~pci_addr_mask) ||
>> +	    ep->irq_pci_fn != fn) {
>> +		/* First region was reserved for IRQ writes. */
>> +		cdns_pcie_set_outbound_region(pcie, fn, 0,
>> +					      false,
>> +					      ep->irq_phys_addr,
>> +					      msg_addr & ~pci_addr_mask,
>> +					      pci_addr_mask + 1);
>> +		ep->irq_pci_addr = (msg_addr & ~pci_addr_mask);
>> +		ep->irq_pci_fn = fn;
>> +	}
>> +	writel(msg_data, ep->irq_cpu_addr + (msg_addr & pci_addr_mask));
>> +
>> +	return 0;
>> +}
>> +
>>  static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
>>  				  enum pci_epc_irq_type type,
>>  				  u16 interrupt_num)
>> @@ -343,6 +443,9 @@ static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
>>  	case PCI_EPC_IRQ_MSI:
>>  		return cdns_pcie_ep_send_msi_irq(ep, fn, interrupt_num);
>>  
>> +	case PCI_EPC_IRQ_MSIX:
>> +		return cdns_pcie_ep_send_msix_irq(ep, fn, interrupt_num);
>> +
>>  	default:
>>  		break;
>>  	}
>> @@ -380,7 +483,7 @@ static int cdns_pcie_ep_start(struct pci_epc *epc)
>>  static const struct pci_epc_features cdns_pcie_epc_features = {
>>  	.linkup_notifier = false,
>>  	.msi_capable = true,
>> -	.msix_capable = false,
>> +	.msix_capable = true,
>>  };
>>  
>>  static const struct pci_epc_features*
>> @@ -397,6 +500,8 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
>>  	.unmap_addr	= cdns_pcie_ep_unmap_addr,
>>  	.set_msi	= cdns_pcie_ep_set_msi,
>>  	.get_msi	= cdns_pcie_ep_get_msi,
>> +	.set_msix	= cdns_pcie_ep_set_msix,
>> +	.get_msix	= cdns_pcie_ep_get_msix,
>>  	.raise_irq	= cdns_pcie_ep_raise_irq,
>>  	.start		= cdns_pcie_ep_start,
>>  	.get_features	= cdns_pcie_ep_get_features,
>> @@ -455,6 +560,11 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
>>  	if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
>>  		epc->max_functions = 1;
>>  
>> +	ep->epf = devm_kcalloc(dev, epc->max_functions, sizeof(*ep->epf),
>> +			       GFP_KERNEL);
>> +	if (!ep->epf)
>> +		return -ENOMEM;
>> +
>>  	ret = pci_epc_mem_init(epc, pcie->mem_res->start,
>>  			       resource_size(pcie->mem_res));
>>  	if (ret < 0) {
>> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
>> index 16a6b0ee547c..ea850290a602 100644
>> --- a/drivers/pci/controller/cadence/pcie-cadence.h
>> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
>> @@ -99,6 +99,7 @@
>>  #define CDNS_PCIE_EP_FUNC_BASE(fn)	(((fn) << 12) & GENMASK(19, 12))
>>  
>>  #define CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET	0x90
>> +#define CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET	0xb0
>>  
>>  /*
>>   * Root Port Registers (PCI configuration space for the root port function)
>> @@ -280,6 +281,14 @@ struct cdns_pcie_rc {
>>  	u32			device_id;
>>  };
>>  
>> +/**
>> + * struct cdns_pcie_epf - Structure to hold info about endpoint function
>> + * @epf_bar: reference to the pci_epf_bar for the six Base Address Registers
>> + */
>> +struct cdns_pcie_epf {
>> +	struct pci_epf_bar *epf_bar[PCI_STD_NUM_BARS];
>> +};
>> +
>>  /**
>>   * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver
>>   * @pcie: Cadence PCIe controller
>> @@ -307,6 +316,7 @@ struct cdns_pcie_ep {
>>  	u64			irq_pci_addr;
>>  	u8			irq_pci_fn;
>>  	u8			irq_pending;
>> +	struct cdns_pcie_epf	*epf;
>>  };
>>  
>>  
>> -- 
>> 2.17.1
>>