mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
80d8381226
GCC unescapes escaped string section names while Clang does not. Because __section uses the `#` stringification operator for the section name, it doesn't need to be escaped. This antipattern was found with: $ grep -e __section\(\" -e __section__\(\" -r Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
126 lines
2.9 KiB
C
126 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Spin Table SMP initialisation
|
|
*
|
|
* Copyright (C) 2013 ARM Ltd.
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/init.h>
|
|
#include <linux/of.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/types.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cpu_ops.h>
|
|
#include <asm/cputype.h>
|
|
#include <asm/io.h>
|
|
#include <asm/smp_plat.h>
|
|
|
|
extern void secondary_holding_pen(void);
|
|
volatile unsigned long __section(.mmuoff.data.read)
|
|
secondary_holding_pen_release = INVALID_HWID;
|
|
|
|
static phys_addr_t cpu_release_addr[NR_CPUS];
|
|
|
|
/*
|
|
* Write secondary_holding_pen_release in a way that is guaranteed to be
|
|
* visible to all observers, irrespective of whether they're taking part
|
|
* in coherency or not. This is necessary for the hotplug code to work
|
|
* reliably.
|
|
*/
|
|
static void write_pen_release(u64 val)
|
|
{
|
|
void *start = (void *)&secondary_holding_pen_release;
|
|
unsigned long size = sizeof(secondary_holding_pen_release);
|
|
|
|
secondary_holding_pen_release = val;
|
|
__flush_dcache_area(start, size);
|
|
}
|
|
|
|
|
|
static int smp_spin_table_cpu_init(unsigned int cpu)
|
|
{
|
|
struct device_node *dn;
|
|
int ret;
|
|
|
|
dn = of_get_cpu_node(cpu, NULL);
|
|
if (!dn)
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* Determine the address from which the CPU is polling.
|
|
*/
|
|
ret = of_property_read_u64(dn, "cpu-release-addr",
|
|
&cpu_release_addr[cpu]);
|
|
if (ret)
|
|
pr_err("CPU %d: missing or invalid cpu-release-addr property\n",
|
|
cpu);
|
|
|
|
of_node_put(dn);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int smp_spin_table_cpu_prepare(unsigned int cpu)
|
|
{
|
|
__le64 __iomem *release_addr;
|
|
|
|
if (!cpu_release_addr[cpu])
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* The cpu-release-addr may or may not be inside the linear mapping.
|
|
* As ioremap_cache will either give us a new mapping or reuse the
|
|
* existing linear mapping, we can use it to cover both cases. In
|
|
* either case the memory will be MT_NORMAL.
|
|
*/
|
|
release_addr = ioremap_cache(cpu_release_addr[cpu],
|
|
sizeof(*release_addr));
|
|
if (!release_addr)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* We write the release address as LE regardless of the native
|
|
* endianess of the kernel. Therefore, any boot-loaders that
|
|
* read this address need to convert this address to the
|
|
* boot-loader's endianess before jumping. This is mandated by
|
|
* the boot protocol.
|
|
*/
|
|
writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr);
|
|
__flush_dcache_area((__force void *)release_addr,
|
|
sizeof(*release_addr));
|
|
|
|
/*
|
|
* Send an event to wake up the secondary CPU.
|
|
*/
|
|
sev();
|
|
|
|
iounmap(release_addr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int smp_spin_table_cpu_boot(unsigned int cpu)
|
|
{
|
|
/*
|
|
* Update the pen release flag.
|
|
*/
|
|
write_pen_release(cpu_logical_map(cpu));
|
|
|
|
/*
|
|
* Send an event, causing the secondaries to read pen_release.
|
|
*/
|
|
sev();
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct cpu_operations smp_spin_table_ops = {
|
|
.name = "spin-table",
|
|
.cpu_init = smp_spin_table_cpu_init,
|
|
.cpu_prepare = smp_spin_table_cpu_prepare,
|
|
.cpu_boot = smp_spin_table_cpu_boot,
|
|
};
|