linux-stable/arch/powerpc/platforms/85xx/qemu_e500.c
Tobias Waldekranz f529edd1b6 powerpc/e500/qemu-e500: allow core to idle without waiting
This means an idle guest won't needlessly consume an entire core on
the host, waiting for work to show up.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220112112459.1033754-1-troglobit@gmail.com
2022-01-31 13:45:24 +11:00

75 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Paravirt target for a generic QEMU e500 machine
*
* This is intended to be a flexible device-tree-driven platform, not fixed
* to a particular piece of hardware or a particular spec of virtual hardware,
* beyond the assumption of an e500-family CPU. Some things are still hardcoded
* here, such as MPIC, but this is a limitation of the current code rather than
* an interface contract with QEMU.
*
* Copyright 2012 Freescale Semiconductor Inc.
*/
#include <linux/kernel.h>
#include <linux/of_fdt.h>
#include <linux/pgtable.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/udbg.h>
#include <asm/mpic.h>
#include <asm/swiotlb.h>
#include <sysdev/fsl_soc.h>
#include <sysdev/fsl_pci.h>
#include "smp.h"
#include "mpc85xx.h"
void __init qemu_e500_pic_init(void)
{
struct mpic *mpic;
unsigned int flags = MPIC_BIG_ENDIAN | MPIC_SINGLE_DEST_CPU |
MPIC_ENABLE_COREINT;
mpic = mpic_alloc(NULL, 0, flags, 0, 256, " OpenPIC ");
BUG_ON(mpic == NULL);
mpic_init(mpic);
}
static void __init qemu_e500_setup_arch(void)
{
ppc_md.progress("qemu_e500_setup_arch()", 0);
fsl_pci_assign_primary();
swiotlb_detect_4g();
mpc85xx_smp_init();
}
/*
* Called very early, device-tree isn't unflattened
*/
static int __init qemu_e500_probe(void)
{
return !!of_machine_is_compatible("fsl,qemu-e500");
}
machine_arch_initcall(qemu_e500, mpc85xx_common_publish_devices);
define_machine(qemu_e500) {
.name = "QEMU e500",
.probe = qemu_e500_probe,
.setup_arch = qemu_e500_setup_arch,
.init_IRQ = qemu_e500_pic_init,
#ifdef CONFIG_PCI
.pcibios_fixup_bus = fsl_pcibios_fixup_bus,
.pcibios_fixup_phb = fsl_pcibios_fixup_phb,
#endif
.get_irq = mpic_get_coreint_irq,
.calibrate_decr = generic_calibrate_decr,
.progress = udbg_progress,
#ifdef CONFIG_PPC64
.power_save = book3e_idle,
#else
.power_save = e500_idle,
#endif
};