Re: [PATCH v13 14/21] PCI: microchip: Add get_events() callback and add PLDA get_event()

From: Minda Chen
Date: Thu Dec 28 2023 - 05:04:25 EST



On 2023/12/28 0:31, Lorenzo Pieralisi wrote:
> On Thu, Dec 14, 2023 at 03:28:32PM +0800, Minda Chen wrote:
>> PolarFire implements its own PCIe interrupts, additional to the regular
>> PCIe interrupts, due to lack of an MSI controller, so the interrupt to
>> event number mapping is different to the PLDA local interrupts,
>
> I am sorry I don't understand what you mean here.
>
> "its own PCIe interrupts" ?
>
> "regular PCIe interrupts" ?
>
> "PLDA local interrupts" ?
>
> Can you spell out what those are referring to please ?
>
> Thanks,
> Lorenzo
>

"its own PCIe interrupts" ?

PolarFire SoC PCIe implement 11 interrupt in their platform.
(can be found in pcie-microchip-host.c:87)

#define EVENT_PCIE_L2_EXIT 0
#define EVENT_PCIE_HOTRST_EXIT 1
#define EVENT_PCIE_DLUP_EXIT 2
#define EVENT_SEC_TX_RAM_SEC_ERR 3
#define EVENT_SEC_RX_RAM_SEC_ERR 4
#define EVENT_SEC_PCIE2AXI_RAM_SEC_ERR 5
#define EVENT_SEC_AXI2PCIE_RAM_SEC_ERR 6
#define EVENT_DED_TX_RAM_DED_ERR 7
#define EVENT_DED_RX_RAM_DED_ERR 8
#define EVENT_DED_PCIE2AXI_RAM_DED_ERR 9
#define EVENT_DED_AXI2PCIE_RAM_DED_ERR 10

"regular PCIe interrupts" ?

"PLDA local interrupts" ?

Actually they are the same. I will change this.
PLDA interrupt register graph in this patch.

>> necessitating a custom get_events() implementation.
>>
>> plda_get_events() adds interrupt register to PLDA local event num mapping
>> codes except DMA engine interrupt events. The DMA engine interrupt events
>> are implemented by vendors.
>>
>> Signed-off-by: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
>> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>> ---
>> .../pci/controller/plda/pcie-microchip-host.c | 35 ++++++++++++++++++-
>> drivers/pci/controller/plda/pcie-plda.h | 33 +++++++++++++++++
>> 2 files changed, 67 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/controller/plda/pcie-microchip-host.c b/drivers/pci/controller/plda/pcie-microchip-host.c
>> index 00250781b11c..fd0d92c3d03f 100644
>> --- a/drivers/pci/controller/plda/pcie-microchip-host.c
>> +++ b/drivers/pci/controller/plda/pcie-microchip-host.c
>> @@ -627,6 +627,26 @@ static u32 mc_get_events(struct plda_pcie_rp *port)
>> return events;
>> }
>>
>> +static u32 plda_get_events(struct plda_pcie_rp *port)
>> +{
>> + u32 events, val, origin;
>> +
>> + origin = readl_relaxed(port->bridge_addr + ISTATUS_LOCAL);
>> +
>> + /* Error events and doorbell events */
>> + events = (origin & ERROR_AND_DOORBELL_MASK) >> A_ATR_EVT_POST_ERR_SHIFT;
>> +
>> + /* INTx events */
>> + if (origin & PM_MSI_INT_INTX_MASK)
>> + events |= BIT(EVENT_PM_MSI_INT_INTX);
>> +
>> + /* MSI event and sys events */
>> + val = (origin & SYS_AND_MSI_MASK) >> PM_MSI_INT_MSI_SHIFT;
>> + events |= val << EVENT_PM_MSI_INT_MSI;
>> +
>> + return events;
>> +}
>> +
>> static irqreturn_t mc_event_handler(int irq, void *dev_id)
>> {
>> struct plda_pcie_rp *port = dev_id;
>> @@ -657,7 +677,7 @@ static void plda_handle_event(struct irq_desc *desc)
>>
>> chained_irq_enter(chip, desc);
>>
>> - events = mc_get_events(port);
>> + events = port->event_ops->get_events(port);
>>
>> for_each_set_bit(bit, &events, port->num_events)
>> generic_handle_domain_irq(port->event_domain, bit);
>> @@ -751,6 +771,10 @@ static struct irq_chip mc_event_irq_chip = {
>> .irq_unmask = mc_unmask_event_irq,
>> };
>>
>> +static const struct plda_event_ops plda_event_ops = {
>> + .get_events = plda_get_events,
>> +};
>> +
>> static int plda_pcie_event_map(struct irq_domain *domain, unsigned int irq,
>> irq_hw_number_t hwirq)
>> {
>> @@ -816,6 +840,10 @@ static int mc_request_event_irq(struct plda_pcie_rp *plda, int event_irq,
>> 0, event_cause[event].sym, plda);
>> }
>>
>> +static const struct plda_event_ops mc_event_ops = {
>> + .get_events = mc_get_events,
>> +};
>> +
>> static const struct plda_event mc_event = {
>> .request_event_irq = mc_request_event_irq,
>> .intx_event = EVENT_LOCAL_PM_MSI_INT_INTX,
>> @@ -932,6 +960,9 @@ static int plda_init_interrupts(struct platform_device *pdev,
>> int i, intx_irq, msi_irq, event_irq;
>> int ret;
>>
>> + if (!port->event_ops)
>> + port->event_ops = &plda_event_ops;
>> +
>> ret = plda_pcie_init_irq_domains(port);
>> if (ret) {
>> dev_err(dev, "failed creating IRQ domains\n");
>> @@ -1008,6 +1039,8 @@ static int mc_platform_init(struct pci_config_window *cfg)
>> if (ret)
>> return ret;
>>
>> + port->plda.event_ops = &mc_event_ops;
>> +
>> /* Address translation is up; safe to enable interrupts */
>> ret = plda_init_interrupts(pdev, &port->plda, &mc_event);
>> if (ret)
>> diff --git a/drivers/pci/controller/plda/pcie-plda.h b/drivers/pci/controller/plda/pcie-plda.h
>> index fba7343f9a96..dd8bc2750bfc 100644
>> --- a/drivers/pci/controller/plda/pcie-plda.h
>> +++ b/drivers/pci/controller/plda/pcie-plda.h
>> @@ -40,6 +40,7 @@
>> #define P_ATR_EVT_DISCARD_ERR_SHIFT 22
>> #define P_ATR_EVT_DOORBELL_MASK 0x00000000u
>> #define P_ATR_EVT_DOORBELL_SHIFT 23
>> +#define ERROR_AND_DOORBELL_MASK GENMASK(23, 16)
>> #define PM_MSI_INT_INTA_MASK 0x01000000u
>> #define PM_MSI_INT_INTA_SHIFT 24
>> #define PM_MSI_INT_INTB_MASK 0x02000000u
>> @@ -58,6 +59,7 @@
>> #define PM_MSI_INT_EVENTS_SHIFT 30
>> #define PM_MSI_INT_SYS_ERR_MASK 0x80000000u
>> #define PM_MSI_INT_SYS_ERR_SHIFT 31
>> +#define SYS_AND_MSI_MASK GENMASK(31, 28)
>> #define NUM_LOCAL_EVENTS 15
>> #define ISTATUS_LOCAL 0x184
>> #define IMASK_HOST 0x188
>> @@ -102,6 +104,36 @@
>> #define EVENT_PM_MSI_INT_SYS_ERR 12
>> #define NUM_PLDA_EVENTS 13
>>
>> +/*
>> + * PLDA local interrupt register
>> + *
>> + * 31 27 23 15 7 0
>> + * +--+--+--+-+------+-+-+-+-+-+-+-+-+-----------+-----------+
>> + * |12|11|10|9| intx |7|6|5|4|3|2|1|0| DMA error | DMA end |
>> + * +--+--+--+-+------+-+-+-+-+-+-+-+-+-----------+-----------+
>> + * 0: AXI post error
>> + * 1: AXI fetch error
>> + * 2: AXI discard error
>> + * 3: AXI doorbell
>> + * 4: PCIe post error
>> + * 5: PCIe fetch error
>> + * 6: PCIe discard error
>> + * 7: PCIe doorbell
>> + * 8: 4 INTx interruts
>> + * 9: MSI interrupt
>> + * 10: AER event
>> + * 11: PM/LTR/Hotplug
>> + * 12: System error
>> + * DMA error : reserved for vendor implement
>> + * DMA end : reserved for vendor implement
>> + */
"PLDA local interrupts" ?

They are all the PLDA PCIe interrupts .

>> +
>> +struct plda_pcie_rp;
>> +
>> +struct plda_event_ops {
>> + u32 (*get_events)(struct plda_pcie_rp *pcie);
>> +};
>> +
>> struct plda_msi {
>> struct mutex lock; /* Protect used bitmap */
>> struct irq_domain *msi_domain;
>> @@ -117,6 +149,7 @@ struct plda_pcie_rp {
>> struct irq_domain *event_domain;
>> raw_spinlock_t lock;
>> struct plda_msi msi;
>> + const struct plda_event_ops *event_ops;
>> void __iomem *bridge_addr;
>> int num_events;
>> };
>> --
>> 2.17.1
>>