On 3/8/26 8:35 PM, jrossi@linux.ibm.com wrote:
> From: Jared Rossi <jrossi@linux.ibm.com>
>
> Call Logical Processor (CLP) Architecture is used for managing PCI functions on
> s390x. Define and include the structures and routines needed to interact with
> PCI devices during IPL.
>
> Acked-by: Thomas Huth <thuth@redhat.com>
> Reviewed-by: Eric Farman <farman@linux.ibm.com>
> Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
> pc-bios/s390-ccw/Makefile | 2 +-
> pc-bios/s390-ccw/clp.c | 99 +++++++++++++++++++++++++++++++++++++++
> pc-bios/s390-ccw/clp.h | 24 ++++++++++
> 3 files changed, 124 insertions(+), 1 deletion(-)
> create mode 100644 pc-bios/s390-ccw/clp.c
> create mode 100644 pc-bios/s390-ccw/clp.h
>
> diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
> index 259cff09db..9c29548f84 100644
> --- a/pc-bios/s390-ccw/Makefile
> +++ b/pc-bios/s390-ccw/Makefile
> @@ -35,7 +35,7 @@ QEMU_DGFLAGS = -MMD -MP -MT $@ -MF $(@D)/$(*F).d
>
> OBJECTS = start.o main.o bootmap.o jump2ipl.o sclp.o menu.o netmain.o \
> virtio.o virtio-net.o virtio-scsi.o virtio-blkdev.o cio.o dasd-ipl.o \
> - virtio-ccw.o
> + virtio-ccw.o clp.o
>
> SLOF_DIR := $(SRC_PATH)/../../roms/SLOF
>
> diff --git a/pc-bios/s390-ccw/clp.c b/pc-bios/s390-ccw/clp.c
> new file mode 100644
> index 0000000000..8c04738bbf
> --- /dev/null
> +++ b/pc-bios/s390-ccw/clp.c
> @@ -0,0 +1,99 @@
> +/*
> + * Call Logical Processor (CLP) architecture
> + *
> + * Copyright 2025 IBM Corp.
> + * Author(s): Jared Rossi <jrossi@linux.ibm.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include "clp.h"
> +#include <stdio.h>
> +#include <string.h>
> +
> +int clp_pci(void *data)
> +{
> + struct { uint8_t _[CLP_BLK_SIZE]; } *req = data;
> + int cc = 3;
> +
> + asm volatile (
> + " .insn rrf,0xb9a00000,0,%[req],0,2\n"
> + " ipm %[cc]\n"
> + " srl %[cc],28\n"
> + : [cc] "+d" (cc), "+m" (*req)
> + : [req] "a" (req)
> + : "cc");
> + if (cc) {
> + printf("CLP returned with non-zero condition code %d\n", cc);
> + }
> + return cc;
> +}
> +
> +/*
> + * Get the PCI function entry for a given function ID
> + * Return 0 on success, 1 if the FID is not found, or a negative RC on error
> + */
> +int find_pci_function(uint32_t fid, ClpFhListEntry *entry)
> +{
> + int count = 0;
> + int limit = PCI_MAX_FUNCTIONS;
> + ClpReqRspListPci rrb;
> +
> + rrb.request.hdr.len = sizeof(ClpReqListPci);
> + rrb.request.hdr.cmd = 0x02;
> + rrb.request.resume_token = 0;
> + rrb.response.hdr.len = sizeof(ClpRspListPci);
> +
> + do {
> + if (clp_pci(&rrb) || rrb.response.hdr.rsp != 0x0010) {
> + puts("Failed to list PCI functions");
> + return -1;
> + }
> +
> + /* Resume token set when max enteries are returned */
> + if (rrb.response.resume_token) {
> + count = CLP_FH_LIST_NR_ENTRIES;
> + rrb.request.resume_token = rrb.response.resume_token;
> + } else {
> + count = (rrb.response.hdr.len - 32) / sizeof(ClpFhListEntry);
> + }
> +
> + limit -= count;
> +
> + for (int i = 0; i < count; i++) {
> + if (rrb.response.fh_list[i].fid == fid) {
> + memcpy(entry, &rrb.response.fh_list[i], sizeof(ClpFhListEntry));
> + return 0;
> + }
> + }
> +
> + } while (rrb.request.resume_token && limit > 0);
> +
> + puts("No function entry found for FID!");
> +
> + return 1;
> +}
> +
> +/*
> + * Enable the PCI function associated with a given handle
> + * Return 0 on success or a negative RC on error
> + */
> +int enable_pci_function(uint32_t *fhandle)
> +{
> + ClpReqRspSetPci rrb;
> +
> + rrb.request.hdr.len = sizeof(ClpReqSetPci);
> + rrb.request.hdr.cmd = 0x05;
> + rrb.request.fh = *fhandle;
> + rrb.request.oc = 0;
> + rrb.request.ndas = 1;
> + rrb.response.hdr.len = sizeof(ClpRspSetPci);
> +
> + if (clp_pci(&rrb) || rrb.response.hdr.rsp != 0x0010) {
> + puts("Failed to enable PCI function");
> + return -1;
> + }
> +
> + *fhandle = rrb.response.fh;
> + return 0;
> +}
> diff --git a/pc-bios/s390-ccw/clp.h b/pc-bios/s390-ccw/clp.h
> new file mode 100644
> index 0000000000..1ac2f8c177
> --- /dev/null
> +++ b/pc-bios/s390-ccw/clp.h
> @@ -0,0 +1,24 @@
> +/*
> + * Call Logical Processor (CLP) architecture definitions
> + *
> + * Copyright 2025 IBM Corp.
> + * Author(s): Jared Rossi <jrossi@linux.ibm.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#ifndef CLP_H
> +#define CLP_H
> +
> +#ifndef QEMU_PACKED
> +#define QEMU_PACKED __attribute__((packed))
> +#endif
> +
> +#include <stdint.h>
> +#include <s390-pci-clp.h>
> +
> +int clp_pci(void *data);
> +int find_pci_function(uint32_t fid, ClpFhListEntry *entry);
> +int enable_pci_function(uint32_t *fhandle);
> +
> +#endif