Re: [PATCH v4 4/8] hw/pci-bridge/cxl_root_port: Wire up MSI

[Dave Jiang]

On 2/17/23 10:29 AM, Jonathan Cameron wrote:
> Done to avoid fixing ACPI route description of traditional PCI interrupts on q35
> and because we should probably move with the times anyway.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>   hw/pci-bridge/cxl_root_port.c | 61 +++++++++++++++++++++++++++++++++++
>   1 file changed, 61 insertions(+)
>
> diff --git a/hw/pci-bridge/cxl_root_port.c b/hw/pci-bridge/cxl_root_port.c
> index 00195257f7..7dfd20aa67 100644
> --- a/hw/pci-bridge/cxl_root_port.c
> +++ b/hw/pci-bridge/cxl_root_port.c
> @@ -22,6 +22,7 @@
>   #include "qemu/range.h"
>   #include "hw/pci/pci_bridge.h"
>   #include "hw/pci/pcie_port.h"
> +#include "hw/pci/msi.h"
>   #include "hw/qdev-properties.h"
>   #include "hw/sysbus.h"
>   #include "qapi/error.h"
> @@ -29,6 +30,10 @@
>   
>   #define CXL_ROOT_PORT_DID 0x7075
>   
> +#define CXL_RP_MSI_OFFSET               0x60
> +#define CXL_RP_MSI_SUPPORTED_FLAGS      PCI_MSI_FLAGS_MASKBIT
> +#define CXL_RP_MSI_NR_VECTOR            2
> +
>   /* Copied from the gen root port which we derive */
>   #define GEN_PCIE_ROOT_PORT_AER_OFFSET 0x100
>   #define GEN_PCIE_ROOT_PORT_ACS_OFFSET \
> @@ -47,6 +52,49 @@ typedef struct CXLRootPort {
>   #define TYPE_CXL_ROOT_PORT "cxl-rp"
>   DECLARE_INSTANCE_CHECKER(CXLRootPort, CXL_ROOT_PORT, TYPE_CXL_ROOT_PORT)
>   
> +/*
> + * If two MSI vector are allocated, Advanced Error Interrupt Message Number
> + * is 1. otherwise 0.
> + * 17.12.5.10 RPERRSTS,  32:27 bit Advanced Error Interrupt Message Number.
> + */
> +static uint8_t cxl_rp_aer_vector(const PCIDevice *d)
> +{
> +    switch (msi_nr_vectors_allocated(d)) {
> +    case 1:
> +        return 0;
> +    case 2:
> +        return 1;
> +    case 4:
> +    case 8:
> +    case 16:
> +    case 32:
> +    default:
> +        break;
> +    }
> +    abort();
> +    return 0;
> +}
> +
> +static int cxl_rp_interrupts_init(PCIDevice *d, Error **errp)
> +{
> +    int rc;
> +
> +    rc = msi_init(d, CXL_RP_MSI_OFFSET, CXL_RP_MSI_NR_VECTOR,
> +                  CXL_RP_MSI_SUPPORTED_FLAGS & PCI_MSI_FLAGS_64BIT,
> +                  CXL_RP_MSI_SUPPORTED_FLAGS & PCI_MSI_FLAGS_MASKBIT,
> +                  errp);
> +    if (rc < 0) {
> +        assert(rc == -ENOTSUP);
> +    }
> +
> +    return rc;
> +}
> +
> +static void cxl_rp_interrupts_uninit(PCIDevice *d)
> +{
> +    msi_uninit(d);
> +}
> +
>   static void latch_registers(CXLRootPort *crp)
>   {
>       uint32_t *reg_state = crp->cxl_cstate.crb.cache_mem_registers;
> @@ -183,6 +231,15 @@ static void cxl_rp_dvsec_write_config(PCIDevice *dev, 
> uint32_t addr,
>       }
>   }
>   
> +static void cxl_rp_aer_vector_update(PCIDevice *d)
> +{
> +    PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d);
> +
> +    if (rpc->aer_vector) {
> +        pcie_aer_root_set_vector(d, rpc->aer_vector(d));
> +    }
> +}
> +
>   static void cxl_rp_write_config(PCIDevice *d, uint32_t address, uint32_t val,
>                                   int len)
>   {
> @@ -192,6 +249,7 @@ static void cxl_rp_write_config(PCIDevice *d, uint32_t 
> address, uint32_t val,
>   
>       pcie_cap_slot_get(d, &slt_ctl, &slt_sta);
>       pci_bridge_write_config(d, address, val, len);
> +    cxl_rp_aer_vector_update(d);
>       pcie_cap_flr_write_config(d, address, val, len);
>       pcie_cap_slot_write_config(d, slt_ctl, slt_sta, address, val, len);
>       pcie_aer_write_config(d, address, val, len);
> @@ -220,6 +278,9 @@ static void cxl_root_port_class_init(ObjectClass *oc, void 
> *data)
>   
>       rpc->aer_offset = GEN_PCIE_ROOT_PORT_AER_OFFSET;
>       rpc->acs_offset = GEN_PCIE_ROOT_PORT_ACS_OFFSET;
> +    rpc->aer_vector = cxl_rp_aer_vector;
> +    rpc->interrupts_init = cxl_rp_interrupts_init;
> +    rpc->interrupts_uninit = cxl_rp_interrupts_uninit;
>   
>       dc->hotpluggable = false;
>   }