powerpc: Fix compile issue with force DAWR

If you compile with KVM but without CONFIG_HAVE_HW_BREAKPOINT you fail
at linking with:
  arch/powerpc/kvm/book3s_hv_rmhandlers.o:(.text+0x708): undefined reference to `dawr_force_enable'

This was caused by commit c1fe190c06 ("powerpc: Add force enable of
DAWR on P9 option").

This moves a bunch of code around to fix this. It moves a lot of the
DAWR code in a new file and creates a new CONFIG_PPC_DAWR to enable
compiling it.

Fixes: c1fe190c06 ("powerpc: Add force enable of DAWR on P9 option")
Signed-off-by: Michael Neuling <mikey@neuling.org>
[mpe: Minor formatting in set_dawr()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Michael Neuling 2019-06-04 13:00:37 +10:00 committed by Michael Ellerman
parent 548c54acba
commit a278e7ea60
7 changed files with 121 additions and 96 deletions

View file

@ -380,64 +380,3 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
{
/* TODO */
}
bool dawr_force_enable;
EXPORT_SYMBOL_GPL(dawr_force_enable);
static void set_dawr_cb(void *info)
{
set_dawr(info);
}
static ssize_t dawr_write_file_bool(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
struct arch_hw_breakpoint null_brk = {0, 0, 0};
size_t rc;
/* Send error to user if they hypervisor won't allow us to write DAWR */
if ((!dawr_force_enable) &&
(firmware_has_feature(FW_FEATURE_LPAR)) &&
(set_dawr(&null_brk) != H_SUCCESS))
return -1;
rc = debugfs_write_file_bool(file, user_buf, count, ppos);
if (rc)
return rc;
/* If we are clearing, make sure all CPUs have the DAWR cleared */
if (!dawr_force_enable)
smp_call_function(set_dawr_cb, &null_brk, 0);
return rc;
}
static const struct file_operations dawr_enable_fops = {
.read = debugfs_read_file_bool,
.write = dawr_write_file_bool,
.open = simple_open,
.llseek = default_llseek,
};
static int __init dawr_force_setup(void)
{
dawr_force_enable = false;
if (cpu_has_feature(CPU_FTR_DAWR)) {
/* Don't setup sysfs file for user control on P8 */
dawr_force_enable = true;
return 0;
}
if (PVR_VER(mfspr(SPRN_PVR)) == PVR_POWER9) {
/* Turn DAWR off by default, but allow admin to turn it on */
dawr_force_enable = false;
debugfs_create_file_unsafe("dawr_enable_dangerous", 0600,
powerpc_debugfs_root,
&dawr_force_enable,
&dawr_enable_fops);
}
return 0;
}
arch_initcall(dawr_force_setup);