22a214e461
Instead of disabling only first watchpoint, disable all available watchpoints while clearing dawr_force_enable. Callback function is used only for disabling watchpoint, rename it to disable_dawrs_cb(). And null_brk parameter is not really required while disabling watchpoint, remove it. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Michael Neuling <mikey@neuling.org> Link: https://lore.kernel.org/r/20200514111741.97993-9-ravi.bangoria@linux.ibm.com
111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* DAWR infrastructure
|
|
*
|
|
* Copyright 2019, Michael Neuling, IBM Corporation.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/export.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/debugfs.h>
|
|
#include <asm/debugfs.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/hvcall.h>
|
|
|
|
bool dawr_force_enable;
|
|
EXPORT_SYMBOL_GPL(dawr_force_enable);
|
|
|
|
int set_dawr(int nr, struct arch_hw_breakpoint *brk)
|
|
{
|
|
unsigned long dawr, dawrx, mrd;
|
|
|
|
dawr = brk->address;
|
|
|
|
dawrx = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE))
|
|
<< (63 - 58);
|
|
dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) << (63 - 59);
|
|
dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) >> 3;
|
|
/*
|
|
* DAWR length is stored in field MDR bits 48:53. Matches range in
|
|
* doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
|
|
* 0b111111=64DW.
|
|
* brk->hw_len is in bytes.
|
|
* This aligns up to double word size, shifts and does the bias.
|
|
*/
|
|
mrd = ((brk->hw_len + 7) >> 3) - 1;
|
|
dawrx |= (mrd & 0x3f) << (63 - 53);
|
|
|
|
if (ppc_md.set_dawr)
|
|
return ppc_md.set_dawr(dawr, dawrx);
|
|
|
|
if (nr == 0) {
|
|
mtspr(SPRN_DAWR0, dawr);
|
|
mtspr(SPRN_DAWRX0, dawrx);
|
|
} else {
|
|
mtspr(SPRN_DAWR1, dawr);
|
|
mtspr(SPRN_DAWRX1, dawrx);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void disable_dawrs_cb(void *info)
|
|
{
|
|
struct arch_hw_breakpoint null_brk = {0};
|
|
int i;
|
|
|
|
for (i = 0; i < nr_wp_slots(); i++)
|
|
set_dawr(i, &null_brk);
|
|
}
|
|
|
|
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};
|
|
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(0, &null_brk) != H_SUCCESS)
|
|
return -ENODEV;
|
|
|
|
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(disable_dawrs_cb, NULL, 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)
|
|
{
|
|
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 */
|
|
debugfs_create_file_unsafe("dawr_enable_dangerous", 0600,
|
|
powerpc_debugfs_root,
|
|
&dawr_force_enable,
|
|
&dawr_enable_fops);
|
|
}
|
|
return 0;
|
|
}
|
|
arch_initcall(dawr_force_setup);
|