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powerpc: Fix compile issue with force DAWR

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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/Kconfig
View File

@ -236,6 +236,7 @@ config PPC
select OLD_SIGSUSPEND
select PCI_DOMAINS if PCI
select PCI_SYSCALL if PCI
select PPC_DAWR if PPC64
select RTC_LIB
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
@ -372,6 +373,9 @@ config PPC_ADV_DEBUG_DAC_RANGE
depends on PPC_ADV_DEBUG_REGS && 44x
default y
config PPC_DAWR
bool
config ZONE_DMA
bool
default y if PPC_BOOK3E_64

21
arch/powerpc/include/asm/hw_breakpoint.h
View File

@ -90,18 +90,25 @@ static inline void hw_breakpoint_disable(void)
extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
int hw_breakpoint_handler(struct die_args *args);
extern int set_dawr(struct arch_hw_breakpoint *brk);
#else /* CONFIG_HAVE_HW_BREAKPOINT */
static inline void hw_breakpoint_disable(void) { }
static inline void thread_change_pc(struct task_struct *tsk,
struct pt_regs *regs) { }
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifdef CONFIG_PPC_DAWR
extern bool dawr_force_enable;
static inline bool dawr_enabled(void)
{
return dawr_force_enable;
}
#else /* CONFIG_HAVE_HW_BREAKPOINT */
static inline void hw_breakpoint_disable(void) { }
static inline void thread_change_pc(struct task_struct *tsk,
struct pt_regs *regs) { }
int set_dawr(struct arch_hw_breakpoint *brk);
#else
static inline bool dawr_enabled(void) { return false; }
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
static inline int set_dawr(struct arch_hw_breakpoint *brk) { return -1; }
#endif
#endif /* __KERNEL__ */
#endif /* _PPC_BOOK3S_64_HW_BREAKPOINT_H */

1
arch/powerpc/kernel/Makefile
View File

@ -56,6 +56,7 @@ obj-$(CONFIG_PPC64) += setup_64.o sys_ppc32.o \
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_DAWR) += dawr.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o

101
arch/powerpc/kernel/dawr.c Normal file
View File

@ -0,0 +1,101 @@
// 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(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->len is in bytes.
* This aligns up to double word size, shifts and does the bias.
*/
mrd = ((brk->len + 7) >> 3) - 1;
dawrx |= (mrd & 0x3f) << (63 - 53);
if (ppc_md.set_dawr)
return ppc_md.set_dawr(dawr, dawrx);
mtspr(SPRN_DAWR, dawr);
mtspr(SPRN_DAWRX, dawrx);
return 0;
}
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 -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(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)
{
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);

61
arch/powerpc/kernel/hw_breakpoint.c
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);

28
arch/powerpc/kernel/process.c
View File

@ -797,34 +797,6 @@ static inline int set_dabr(struct arch_hw_breakpoint *brk)
return __set_dabr(dabr, dabrx);
}
int set_dawr(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); //* read/write bits */
dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
<< (63 - 59); //* translate */
dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
>> 3; //* PRIM bits */
/* 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->len is in bytes.
This aligns up to double word size, shifts and does the bias.
*/
mrd = ((brk->len + 7) >> 3) - 1;
dawrx |= (mrd & 0x3f) << (63 - 53);
if (ppc_md.set_dawr)
return ppc_md.set_dawr(dawr, dawrx);
mtspr(SPRN_DAWR, dawr);
mtspr(SPRN_DAWRX, dawrx);
return 0;
}
void __set_breakpoint(struct arch_hw_breakpoint *brk)
{
memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));

1
arch/powerpc/kvm/Kconfig
View File

@ -38,6 +38,7 @@ config KVM_BOOK3S_32_HANDLER
config KVM_BOOK3S_64_HANDLER
bool
select KVM_BOOK3S_HANDLER
select PPC_DAWR_FORCE_ENABLE
config KVM_BOOK3S_PR_POSSIBLE
bool