linux_dsm_epyc7002/arch/mips/kernel/mips-cpc.c
Paul Burton f875a832d2 MIPS: Abstract CPU core & VP(E) ID access through accessor functions
We currently have fields in struct cpuinfo_mips for the core & VP(E) ID
of a particular CPU, and various pieces of code directly access those
fields. This patch abstracts such access by introducing accessor
functions cpu_core(), cpu_set_core(), cpu_vpe_id() & cpu_set_vpe_id()
and having code that needs to access these values call those functions
rather than directly accessing the struct cpuinfo_mips fields. This
prepares us for changes to the way in which those values are stored in
later patches.

The cpu_vpe_id() function is introduced even though we already had a
cpu_vpe_id() macro for a couple of reasons:

  1) It's more consistent with the core, and future cluster, accessors.

  2) It ensures a sensible return type without explicit casts.

  3) It's generally preferable to use functions rather than macros.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17009/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-30 00:57:26 +02:00

114 lines
2.7 KiB
C

/*
* Copyright (C) 2013 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/spinlock.h>
#include <asm/mips-cm.h>
#include <asm/mips-cpc.h>
void __iomem *mips_cpc_base;
static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock);
static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags);
phys_addr_t __weak mips_cpc_default_phys_base(void)
{
return 0;
}
/**
* mips_cpc_phys_base - retrieve the physical base address of the CPC
*
* This function returns the physical base address of the Cluster Power
* Controller memory mapped registers, or 0 if no Cluster Power Controller
* is present.
*/
static phys_addr_t mips_cpc_phys_base(void)
{
unsigned long cpc_base;
if (!mips_cm_present())
return 0;
if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX))
return 0;
/* If the CPC is already enabled, leave it so */
cpc_base = read_gcr_cpc_base();
if (cpc_base & CM_GCR_CPC_BASE_CPCEN)
return cpc_base & CM_GCR_CPC_BASE_CPCBASE;
/* Otherwise, use the default address */
cpc_base = mips_cpc_default_phys_base();
if (!cpc_base)
return cpc_base;
/* Enable the CPC, mapped at the default address */
write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN);
return cpc_base;
}
int mips_cpc_probe(void)
{
phys_addr_t addr;
unsigned int cpu;
for_each_possible_cpu(cpu)
spin_lock_init(&per_cpu(cpc_core_lock, cpu));
addr = mips_cpc_phys_base();
if (!addr)
return -ENODEV;
mips_cpc_base = ioremap_nocache(addr, 0x8000);
if (!mips_cpc_base)
return -ENXIO;
return 0;
}
void mips_cpc_lock_other(unsigned int core)
{
unsigned int curr_core;
if (mips_cm_revision() >= CM_REV_CM3)
/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
return;
preempt_disable();
curr_core = cpu_core(&current_cpu_data);
spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
per_cpu(cpc_core_lock_flags, curr_core));
write_cpc_cl_other(core << __ffs(CPC_Cx_OTHER_CORENUM));
/*
* Ensure the core-other region reflects the appropriate core &
* VP before any accesses to it occur.
*/
mb();
}
void mips_cpc_unlock_other(void)
{
unsigned int curr_core;
if (mips_cm_revision() >= CM_REV_CM3)
/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
return;
curr_core = cpu_core(&current_cpu_data);
spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
per_cpu(cpc_core_lock_flags, curr_core));
preempt_enable();
}