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android_kernel_xiaomi_sm8350/arch/powerpc/kernel/dt_cpu_ftrs.c
Michael Ellerman b3b357d830 powerpc/64s: Don't let DT CPU features set FSCR_DSCR 
commit 993e3d96fd08c3ebf7566e43be9b8cd622063e6d upstream.

The device tree CPU features binding includes FSCR bit numbers which
Linux is instructed to set by firmware.

Whether that's a good idea or not, in the case of the DSCR the Linux
implementation has a hard requirement that the FSCR_DSCR bit not be
set by default. We use it to track when a process reads/writes to
DSCR, so it must be clear to begin with.

So if firmware tells us to set FSCR_DSCR we must ignore it.

Currently this does not cause a bug in our DSCR handling because the
value of FSCR that the device tree CPU features code establishes is
only used by swapper. All other tasks use the value hard coded in
init_task.thread.fscr.

However we'd like to fix that in a future commit, at which point this
will become necessary.

Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200527145843.2761782-2-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22 09:31:23 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2017, Nicholas Piggin, IBM Corporation
*/
#define pr_fmt(fmt) "dt-cpu-ftrs: " fmt
#include <linux/export.h>
#include <linux/init.h>
#include <linux/jump_label.h>
#include <linux/libfdt.h>
#include <linux/memblock.h>
#include <linux/printk.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/threads.h>
#include <asm/cputable.h>
#include <asm/dt_cpu_ftrs.h>
#include <asm/mmu.h>
#include <asm/oprofile_impl.h>
#include <asm/prom.h>
#include <asm/setup.h>
/* Device-tree visible constants follow */
#define ISA_V2_07B 2070
#define ISA_V3_0B 3000
#define USABLE_PR (1U << 0)
#define USABLE_OS (1U << 1)
#define USABLE_HV (1U << 2)
#define HV_SUPPORT_HFSCR (1U << 0)
#define OS_SUPPORT_FSCR (1U << 0)
/* For parsing, we define all bits set as "NONE" case */
#define HV_SUPPORT_NONE 0xffffffffU
#define OS_SUPPORT_NONE 0xffffffffU
struct dt_cpu_feature {
const char *name;
uint32_t isa;
uint32_t usable_privilege;
uint32_t hv_support;
uint32_t os_support;
uint32_t hfscr_bit_nr;
uint32_t fscr_bit_nr;
uint32_t hwcap_bit_nr;
/* fdt parsing */
unsigned long node;
int enabled;
int disabled;
};
#define MMU_FTRS_HASH_BASE (MMU_FTRS_POWER8)
#define COMMON_USER_BASE (PPC_FEATURE_32 | PPC_FEATURE_64 | \
PPC_FEATURE_ARCH_2_06 |\
PPC_FEATURE_ICACHE_SNOOP)
#define COMMON_USER2_BASE (PPC_FEATURE2_ARCH_2_07 | \
PPC_FEATURE2_ISEL)
/*
* Set up the base CPU
*/
extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
static int hv_mode;
static struct {
u64 lpcr;
u64 lpcr_clear;
u64 hfscr;
u64 fscr;
} system_registers;
static void (*init_pmu_registers)(void);
static void __restore_cpu_cpufeatures(void)
{
u64 lpcr;
/*
* LPCR is restored by the power on engine already. It can be changed
* after early init e.g., by radix enable, and we have no unified API
* for saving and restoring such SPRs.
*
* This ->restore hook should really be removed from idle and register
* restore moved directly into the idle restore code, because this code
* doesn't know how idle is implemented or what it needs restored here.
*
* The best we can do to accommodate secondary boot and idle restore
* for now is "or" LPCR with existing.
*/
lpcr = mfspr(SPRN_LPCR);
lpcr |= system_registers.lpcr;
lpcr &= ~system_registers.lpcr_clear;
mtspr(SPRN_LPCR, lpcr);
if (hv_mode) {
mtspr(SPRN_LPID, 0);
mtspr(SPRN_HFSCR, system_registers.hfscr);
mtspr(SPRN_PCR, PCR_MASK);
}
mtspr(SPRN_FSCR, system_registers.fscr);
if (init_pmu_registers)
init_pmu_registers();
}
static char dt_cpu_name[64];
static struct cpu_spec __initdata base_cpu_spec = {
.cpu_name = NULL,
.cpu_features = CPU_FTRS_DT_CPU_BASE,
.cpu_user_features = COMMON_USER_BASE,
.cpu_user_features2 = COMMON_USER2_BASE,
.mmu_features = 0,
.icache_bsize = 32, /* minimum block size, fixed by */
.dcache_bsize = 32, /* cache info init. */
.num_pmcs = 0,
.pmc_type = PPC_PMC_DEFAULT,
.oprofile_cpu_type = NULL,
.oprofile_type = PPC_OPROFILE_INVALID,
.cpu_setup = NULL,
.cpu_restore = __restore_cpu_cpufeatures,
.machine_check_early = NULL,
.platform = NULL,
};
static void __init cpufeatures_setup_cpu(void)
{
set_cur_cpu_spec(&base_cpu_spec);
cur_cpu_spec->pvr_mask = -1;
cur_cpu_spec->pvr_value = mfspr(SPRN_PVR);
/* Initialize the base environment -- clear FSCR/HFSCR. */
hv_mode = !!(mfmsr() & MSR_HV);
if (hv_mode) {
cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
mtspr(SPRN_HFSCR, 0);
}
mtspr(SPRN_FSCR, 0);
mtspr(SPRN_PCR, PCR_MASK);
/*
* LPCR does not get cleared, to match behaviour with secondaries
* in __restore_cpu_cpufeatures. Once the idle code is fixed, this
* could clear LPCR too.
*/
}
static int __init feat_try_enable_unknown(struct dt_cpu_feature *f)
{
if (f->hv_support == HV_SUPPORT_NONE) {
} else if (f->hv_support & HV_SUPPORT_HFSCR) {
u64 hfscr = mfspr(SPRN_HFSCR);
hfscr |= 1UL << f->hfscr_bit_nr;
mtspr(SPRN_HFSCR, hfscr);
} else {
/* Does not have a known recipe */
return 0;
}
if (f->os_support == OS_SUPPORT_NONE) {
} else if (f->os_support & OS_SUPPORT_FSCR) {
u64 fscr = mfspr(SPRN_FSCR);
fscr |= 1UL << f->fscr_bit_nr;
mtspr(SPRN_FSCR, fscr);
} else {
/* Does not have a known recipe */
return 0;
}
if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
uint32_t word = f->hwcap_bit_nr / 32;
uint32_t bit = f->hwcap_bit_nr % 32;
if (word == 0)
cur_cpu_spec->cpu_user_features |= 1U << bit;
else if (word == 1)
cur_cpu_spec->cpu_user_features2 |= 1U << bit;
else
pr_err("%s could not advertise to user (no hwcap bits)\n", f->name);
}
return 1;
}
static int __init feat_enable(struct dt_cpu_feature *f)
{
if (f->hv_support != HV_SUPPORT_NONE) {
if (f->hfscr_bit_nr != -1) {
u64 hfscr = mfspr(SPRN_HFSCR);
hfscr |= 1UL << f->hfscr_bit_nr;
mtspr(SPRN_HFSCR, hfscr);
}
}
if (f->os_support != OS_SUPPORT_NONE) {
if (f->fscr_bit_nr != -1) {
u64 fscr = mfspr(SPRN_FSCR);
fscr |= 1UL << f->fscr_bit_nr;
mtspr(SPRN_FSCR, fscr);
}
}
if ((f->usable_privilege & USABLE_PR) && (f->hwcap_bit_nr != -1)) {
uint32_t word = f->hwcap_bit_nr / 32;
uint32_t bit = f->hwcap_bit_nr % 32;
if (word == 0)
cur_cpu_spec->cpu_user_features |= 1U << bit;
else if (word == 1)
cur_cpu_spec->cpu_user_features2 |= 1U << bit;
else
pr_err("CPU feature: %s could not advertise to user (no hwcap bits)\n", f->name);
}
return 1;
}
static int __init feat_disable(struct dt_cpu_feature *f)
{
return 0;
}
static int __init feat_enable_hv(struct dt_cpu_feature *f)
{
u64 lpcr;
if (!hv_mode) {
pr_err("CPU feature hypervisor present in device tree but HV mode not enabled in the CPU. Ignoring.\n");
return 0;
}
mtspr(SPRN_LPID, 0);
lpcr = mfspr(SPRN_LPCR);
lpcr &= ~LPCR_LPES0; /* HV external interrupts */
mtspr(SPRN_LPCR, lpcr);
cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
return 1;
}
static int __init feat_enable_le(struct dt_cpu_feature *f)
{
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_TRUE_LE;
return 1;
}
static int __init feat_enable_smt(struct dt_cpu_feature *f)
{
cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_SMT;
return 1;
}
static int __init feat_enable_idle_nap(struct dt_cpu_feature *f)
{
u64 lpcr;
/* Set PECE wakeup modes for ISA 207 */
lpcr = mfspr(SPRN_LPCR);
lpcr |= LPCR_PECE0;
lpcr |= LPCR_PECE1;
lpcr |= LPCR_PECE2;
mtspr(SPRN_LPCR, lpcr);
return 1;
}
static int __init feat_enable_align_dsisr(struct dt_cpu_feature *f)
{
cur_cpu_spec->cpu_features &= ~CPU_FTR_NODSISRALIGN;
return 1;
}
static int __init feat_enable_idle_stop(struct dt_cpu_feature *f)
{
u64 lpcr;
/* Set PECE wakeup modes for ISAv3.0B */
lpcr = mfspr(SPRN_LPCR);
lpcr |= LPCR_PECE0;
lpcr |= LPCR_PECE1;
lpcr |= LPCR_PECE2;
mtspr(SPRN_LPCR, lpcr);
return 1;
}
static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
{
u64 lpcr;
lpcr = mfspr(SPRN_LPCR);
lpcr &= ~LPCR_ISL;
/* VRMASD */
lpcr |= LPCR_VPM0;
lpcr &= ~LPCR_VPM1;
lpcr |= 0x10UL << LPCR_VRMASD_SH; /* L=1 LP=00 */
mtspr(SPRN_LPCR, lpcr);
cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
return 1;
}
static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
{
u64 lpcr;
system_registers.lpcr_clear |= (LPCR_ISL | LPCR_UPRT | LPCR_HR);
lpcr = mfspr(SPRN_LPCR);
lpcr &= ~(LPCR_ISL | LPCR_UPRT | LPCR_HR);
mtspr(SPRN_LPCR, lpcr);
cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
return 1;
}
static int __init feat_enable_mmu_radix(struct dt_cpu_feature *f)
{
#ifdef CONFIG_PPC_RADIX_MMU
cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU;
return 1;
#endif
return 0;
}
static int __init feat_enable_dscr(struct dt_cpu_feature *f)
{
u64 lpcr;
/*
* Linux relies on FSCR[DSCR] being clear, so that we can take the
* facility unavailable interrupt and track the task's usage of DSCR.
* See facility_unavailable_exception().
* Clear the bit here so that feat_enable() doesn't set it.
*/
f->fscr_bit_nr = -1;
feat_enable(f);
lpcr = mfspr(SPRN_LPCR);
lpcr &= ~LPCR_DPFD;
lpcr |= (4UL << LPCR_DPFD_SH);
mtspr(SPRN_LPCR, lpcr);
return 1;
}
static void hfscr_pmu_enable(void)
{
u64 hfscr = mfspr(SPRN_HFSCR);
hfscr |= PPC_BIT(60);
mtspr(SPRN_HFSCR, hfscr);
}
static void init_pmu_power8(void)
{
if (hv_mode) {
mtspr(SPRN_MMCRC, 0);
mtspr(SPRN_MMCRH, 0);
}
mtspr(SPRN_MMCRA, 0);
mtspr(SPRN_MMCR0, 0);
mtspr(SPRN_MMCR1, 0);
mtspr(SPRN_MMCR2, 0);
mtspr(SPRN_MMCRS, 0);
}
static int __init feat_enable_mce_power8(struct dt_cpu_feature *f)
{
cur_cpu_spec->platform = "power8";
cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p8;
return 1;
}
static int __init feat_enable_pmu_power8(struct dt_cpu_feature *f)
{
hfscr_pmu_enable();
init_pmu_power8();
init_pmu_registers = init_pmu_power8;
cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
if (pvr_version_is(PVR_POWER8E))
cur_cpu_spec->cpu_features |= CPU_FTR_PMAO_BUG;
cur_cpu_spec->num_pmcs = 6;
cur_cpu_spec->pmc_type = PPC_PMC_IBM;
cur_cpu_spec->oprofile_cpu_type = "ppc64/power8";
return 1;
}
static void init_pmu_power9(void)
{
if (hv_mode)
mtspr(SPRN_MMCRC, 0);
mtspr(SPRN_MMCRA, 0);
mtspr(SPRN_MMCR0, 0);
mtspr(SPRN_MMCR1, 0);
mtspr(SPRN_MMCR2, 0);
}
static int __init feat_enable_mce_power9(struct dt_cpu_feature *f)
{
cur_cpu_spec->platform = "power9";
cur_cpu_spec->machine_check_early = __machine_check_early_realmode_p9;
return 1;
}
static int __init feat_enable_pmu_power9(struct dt_cpu_feature *f)
{
hfscr_pmu_enable();
init_pmu_power9();
init_pmu_registers = init_pmu_power9;
cur_cpu_spec->cpu_features |= CPU_FTR_MMCRA;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_PSERIES_PERFMON_COMPAT;
cur_cpu_spec->num_pmcs = 6;
cur_cpu_spec->pmc_type = PPC_PMC_IBM;
cur_cpu_spec->oprofile_cpu_type = "ppc64/power9";
return 1;
}
static int __init feat_enable_tm(struct dt_cpu_feature *f)
{
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
feat_enable(f);
cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NOSC;
return 1;
#endif
return 0;
}
static int __init feat_enable_fp(struct dt_cpu_feature *f)
{
feat_enable(f);
cur_cpu_spec->cpu_features &= ~CPU_FTR_FPU_UNAVAILABLE;
return 1;
}
static int __init feat_enable_vector(struct dt_cpu_feature *f)
{
#ifdef CONFIG_ALTIVEC
feat_enable(f);
cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
cur_cpu_spec->cpu_features |= CPU_FTR_VMX_COPY;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
return 1;
#endif
return 0;
}
static int __init feat_enable_vsx(struct dt_cpu_feature *f)
{
#ifdef CONFIG_VSX
feat_enable(f);
cur_cpu_spec->cpu_features |= CPU_FTR_VSX;
cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_VSX;
return 1;
#endif
return 0;
}
static int __init feat_enable_purr(struct dt_cpu_feature *f)
{
cur_cpu_spec->cpu_features |= CPU_FTR_PURR | CPU_FTR_SPURR;
return 1;
}
static int __init feat_enable_ebb(struct dt_cpu_feature *f)
{
/*
* PPC_FEATURE2_EBB is enabled in PMU init code because it has
* historically been related to the PMU facility. This may have
* to be decoupled if EBB becomes more generic. For now, follow
* existing convention.
*/
f->hwcap_bit_nr = -1;
feat_enable(f);
return 1;
}
static int __init feat_enable_dbell(struct dt_cpu_feature *f)
{
u64 lpcr;
/* P9 has an HFSCR for privileged state */
feat_enable(f);
cur_cpu_spec->cpu_features |= CPU_FTR_DBELL;
lpcr = mfspr(SPRN_LPCR);
lpcr |= LPCR_PECEDH; /* hyp doorbell wakeup */
mtspr(SPRN_LPCR, lpcr);
return 1;
}
static int __init feat_enable_hvi(struct dt_cpu_feature *f)
{
u64 lpcr;
/*
* POWER9 XIVE interrupts including in OPAL XICS compatibility
* are always delivered as hypervisor virtualization interrupts (HVI)
* rather than EE.
*
* However LPES0 is not set here, in the chance that an EE does get
* delivered to the host somehow, the EE handler would not expect it
* to be delivered in LPES0 mode (e.g., using SRR[01]). This could
* happen if there is a bug in interrupt controller code, or IC is
* misconfigured in systemsim.
*/
lpcr = mfspr(SPRN_LPCR);
lpcr |= LPCR_HVICE; /* enable hvi interrupts */
lpcr |= LPCR_HEIC; /* disable ee interrupts when MSR_HV */
lpcr |= LPCR_PECE_HVEE; /* hvi can wake from stop */
mtspr(SPRN_LPCR, lpcr);
return 1;
}
static int __init feat_enable_large_ci(struct dt_cpu_feature *f)
{
cur_cpu_spec->mmu_features |= MMU_FTR_CI_LARGE_PAGE;
return 1;
}
struct dt_cpu_feature_match {
const char *name;
int (*enable)(struct dt_cpu_feature *f);
u64 cpu_ftr_bit_mask;
};
static struct dt_cpu_feature_match __initdata
dt_cpu_feature_match_table[] = {
{"hypervisor", feat_enable_hv, 0},
{"big-endian", feat_enable, 0},
{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
{"smt", feat_enable_smt, 0},
{"interrupt-facilities", feat_enable, 0},
{"timer-facilities", feat_enable, 0},
{"timer-facilities-v3", feat_enable, 0},
{"debug-facilities", feat_enable, 0},
{"come-from-address-register", feat_enable, CPU_FTR_CFAR},
{"branch-tracing", feat_enable, 0},
{"floating-point", feat_enable_fp, 0},
{"vector", feat_enable_vector, 0},
{"vector-scalar", feat_enable_vsx, 0},
{"vector-scalar-v3", feat_enable, 0},
{"decimal-floating-point", feat_enable, 0},
{"decimal-integer", feat_enable, 0},
{"quadword-load-store", feat_enable, 0},
{"vector-crypto", feat_enable, 0},
{"mmu-hash", feat_enable_mmu_hash, 0},
{"mmu-radix", feat_enable_mmu_radix, 0},
{"mmu-hash-v3", feat_enable_mmu_hash_v3, 0},
{"virtual-page-class-key-protection", feat_enable, 0},
{"transactional-memory", feat_enable_tm, CPU_FTR_TM},
{"transactional-memory-v3", feat_enable_tm, 0},
{"tm-suspend-hypervisor-assist", feat_enable, CPU_FTR_P9_TM_HV_ASSIST},
{"tm-suspend-xer-so-bug", feat_enable, CPU_FTR_P9_TM_XER_SO_BUG},
{"idle-nap", feat_enable_idle_nap, 0},
{"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0},
{"idle-stop", feat_enable_idle_stop, 0},
{"machine-check-power8", feat_enable_mce_power8, 0},
{"performance-monitor-power8", feat_enable_pmu_power8, 0},
{"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR},
{"event-based-branch", feat_enable_ebb, 0},
{"target-address-register", feat_enable, 0},
{"branch-history-rolling-buffer", feat_enable, 0},
{"control-register", feat_enable, CPU_FTR_CTRL},
{"processor-control-facility", feat_enable_dbell, CPU_FTR_DBELL},
{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
{"processor-utilization-of-resources-register", feat_enable_purr, 0},
{"no-execute", feat_enable, 0},
{"strong-access-ordering", feat_enable, CPU_FTR_SAO},
{"cache-inhibited-large-page", feat_enable_large_ci, 0},
{"coprocessor-icswx", feat_enable, 0},
{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
{"program-priority-register", feat_enable, CPU_FTR_HAS_PPR},
{"wait", feat_enable, 0},
{"atomic-memory-operations", feat_enable, 0},
{"branch-v3", feat_enable, 0},
{"copy-paste", feat_enable, 0},
{"decimal-floating-point-v3", feat_enable, 0},
{"decimal-integer-v3", feat_enable, 0},
{"fixed-point-v3", feat_enable, 0},
{"floating-point-v3", feat_enable, 0},
{"group-start-register", feat_enable, 0},
{"pc-relative-addressing", feat_enable, 0},
{"machine-check-power9", feat_enable_mce_power9, 0},
{"performance-monitor-power9", feat_enable_pmu_power9, 0},
{"event-based-branch-v3", feat_enable, 0},
{"random-number-generator", feat_enable, 0},
{"system-call-vectored", feat_disable, 0},
{"trace-interrupt-v3", feat_enable, 0},
{"vector-v3", feat_enable, 0},
{"vector-binary128", feat_enable, 0},
{"vector-binary16", feat_enable, 0},
{"wait-v3", feat_enable, 0},
};
static bool __initdata using_dt_cpu_ftrs;
static bool __initdata enable_unknown = true;
static int __init dt_cpu_ftrs_parse(char *str)
{
if (!str)
return 0;
if (!strcmp(str, "off"))
using_dt_cpu_ftrs = false;
else if (!strcmp(str, "known"))
enable_unknown = false;
else
return 1;
return 0;
}
early_param("dt_cpu_ftrs", dt_cpu_ftrs_parse);
static void __init cpufeatures_setup_start(u32 isa)
{
pr_info("setup for ISA %d\n", isa);
if (isa >= 3000) {
cur_cpu_spec->cpu_features |= CPU_FTR_ARCH_300;
cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_ARCH_3_00;
}
}
static bool __init cpufeatures_process_feature(struct dt_cpu_feature *f)
{
const struct dt_cpu_feature_match *m;
bool known = false;
int i;
for (i = 0; i < ARRAY_SIZE(dt_cpu_feature_match_table); i++) {
m = &dt_cpu_feature_match_table[i];
if (!strcmp(f->name, m->name)) {
known = true;
if (m->enable(f)) {
cur_cpu_spec->cpu_features |= m->cpu_ftr_bit_mask;
break;
}
pr_info("not enabling: %s (disabled or unsupported by kernel)\n",
f->name);
return false;
}
}
if (!known && (!enable_unknown || !feat_try_enable_unknown(f))) {
pr_info("not enabling: %s (unknown and unsupported by kernel)\n",
f->name);
return false;
}
if (known)
pr_debug("enabling: %s\n", f->name);
else
pr_debug("enabling: %s (unknown)\n", f->name);
return true;
}
/*
* Handle POWER9 broadcast tlbie invalidation issue using
* cpu feature flag.
*/
static __init void update_tlbie_feature_flag(unsigned long pvr)
{
if (PVR_VER(pvr) == PVR_POWER9) {
/*
* Set the tlbie feature flag for anything below
* Nimbus DD 2.3 and Cumulus DD 1.3
*/
if ((pvr & 0xe000) == 0) {
/* Nimbus */
if ((pvr & 0xfff) < 0x203)
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
} else if ((pvr & 0xc000) == 0) {
/* Cumulus */
if ((pvr & 0xfff) < 0x103)
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
} else {
WARN_ONCE(1, "Unknown PVR");
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
}
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_ERAT_BUG;
}
}
static __init void cpufeatures_cpu_quirks(void)
{
unsigned long version = mfspr(SPRN_PVR);
/*
* Not all quirks can be derived from the cpufeatures device tree.
*/
if ((version & 0xffffefff) == 0x004e0200)
; /* DD2.0 has no feature flag */
else if ((version & 0xffffefff) == 0x004e0201)
cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
else if ((version & 0xffffefff) == 0x004e0202) {
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_HV_ASSIST;
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TM_XER_SO_BUG;
cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
} else if ((version & 0xffff0000) == 0x004e0000)
/* DD2.1 and up have DD2_1 */
cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD2_1;
if ((version & 0xffff0000) == 0x004e0000) {
cur_cpu_spec->cpu_features &= ~(CPU_FTR_DAWR);
cur_cpu_spec->cpu_features |= CPU_FTR_P9_TIDR;
}
update_tlbie_feature_flag(version);
/*
* PKEY was not in the initial base or feature node
* specification, but it should become optional in the next
* cpu feature version sequence.
*/
cur_cpu_spec->cpu_features |= CPU_FTR_PKEY;
}
static void __init cpufeatures_setup_finished(void)
{
cpufeatures_cpu_quirks();
if (hv_mode && !(cur_cpu_spec->cpu_features & CPU_FTR_HVMODE)) {
pr_err("hypervisor not present in device tree but HV mode is enabled in the CPU. Enabling.\n");
cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
}
/* Make sure powerpc_base_platform is non-NULL */
powerpc_base_platform = cur_cpu_spec->platform;
system_registers.lpcr = mfspr(SPRN_LPCR);
system_registers.hfscr = mfspr(SPRN_HFSCR);
system_registers.fscr = mfspr(SPRN_FSCR);
pr_info("final cpu/mmu features = 0x%016lx 0x%08x\n",
cur_cpu_spec->cpu_features, cur_cpu_spec->mmu_features);
}
static int __init disabled_on_cmdline(void)
{
unsigned long root, chosen;
const char *p;
root = of_get_flat_dt_root();
chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
if (chosen == -FDT_ERR_NOTFOUND)
return false;
p = of_get_flat_dt_prop(chosen, "bootargs", NULL);
if (!p)
return false;
if (strstr(p, "dt_cpu_ftrs=off"))
return true;
return false;
}
static int __init fdt_find_cpu_features(unsigned long node, const char *uname,
int depth, void *data)
{
if (of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features")
&& of_get_flat_dt_prop(node, "isa", NULL))
return 1;
return 0;
}
bool __init dt_cpu_ftrs_in_use(void)
{
return using_dt_cpu_ftrs;
}
bool __init dt_cpu_ftrs_init(void *fdt)
{
using_dt_cpu_ftrs = false;
/* Setup and verify the FDT, if it fails we just bail */
if (!early_init_dt_verify(fdt))
return false;
if (!of_scan_flat_dt(fdt_find_cpu_features, NULL))
return false;
if (disabled_on_cmdline())
return false;
cpufeatures_setup_cpu();
using_dt_cpu_ftrs = true;
return true;
}
static int nr_dt_cpu_features;
static struct dt_cpu_feature *dt_cpu_features;
static int __init process_cpufeatures_node(unsigned long node,
const char *uname, int i)
{
const __be32 *prop;
struct dt_cpu_feature *f;
int len;
f = &dt_cpu_features[i];
f->node = node;
f->name = uname;
prop = of_get_flat_dt_prop(node, "isa", &len);
if (!prop) {
pr_warn("%s: missing isa property\n", uname);
return 0;
}
f->isa = be32_to_cpup(prop);
prop = of_get_flat_dt_prop(node, "usable-privilege", &len);
if (!prop) {
pr_warn("%s: missing usable-privilege property", uname);
return 0;
}
f->usable_privilege = be32_to_cpup(prop);
prop = of_get_flat_dt_prop(node, "hv-support", &len);
if (prop)
f->hv_support = be32_to_cpup(prop);
else
f->hv_support = HV_SUPPORT_NONE;
prop = of_get_flat_dt_prop(node, "os-support", &len);
if (prop)
f->os_support = be32_to_cpup(prop);
else
f->os_support = OS_SUPPORT_NONE;
prop = of_get_flat_dt_prop(node, "hfscr-bit-nr", &len);
if (prop)
f->hfscr_bit_nr = be32_to_cpup(prop);
else
f->hfscr_bit_nr = -1;
prop = of_get_flat_dt_prop(node, "fscr-bit-nr", &len);
if (prop)
f->fscr_bit_nr = be32_to_cpup(prop);
else
f->fscr_bit_nr = -1;
prop = of_get_flat_dt_prop(node, "hwcap-bit-nr", &len);
if (prop)
f->hwcap_bit_nr = be32_to_cpup(prop);
else
f->hwcap_bit_nr = -1;
if (f->usable_privilege & USABLE_HV) {
if (!(mfmsr() & MSR_HV)) {
pr_warn("%s: HV feature passed to guest\n", uname);
return 0;
}
if (f->hv_support == HV_SUPPORT_NONE && f->hfscr_bit_nr != -1) {
pr_warn("%s: unwanted hfscr_bit_nr\n", uname);
return 0;
}
if (f->hv_support == HV_SUPPORT_HFSCR) {
if (f->hfscr_bit_nr == -1) {
pr_warn("%s: missing hfscr_bit_nr\n", uname);
return 0;
}
}
} else {
if (f->hv_support != HV_SUPPORT_NONE || f->hfscr_bit_nr != -1) {
pr_warn("%s: unwanted hv_support/hfscr_bit_nr\n", uname);
return 0;
}
}
if (f->usable_privilege & USABLE_OS) {
if (f->os_support == OS_SUPPORT_NONE && f->fscr_bit_nr != -1) {
pr_warn("%s: unwanted fscr_bit_nr\n", uname);
return 0;
}
if (f->os_support == OS_SUPPORT_FSCR) {
if (f->fscr_bit_nr == -1) {
pr_warn("%s: missing fscr_bit_nr\n", uname);
return 0;
}
}
} else {
if (f->os_support != OS_SUPPORT_NONE || f->fscr_bit_nr != -1) {
pr_warn("%s: unwanted os_support/fscr_bit_nr\n", uname);
return 0;
}
}
if (!(f->usable_privilege & USABLE_PR)) {
if (f->hwcap_bit_nr != -1) {
pr_warn("%s: unwanted hwcap_bit_nr\n", uname);
return 0;
}
}
/* Do all the independent features in the first pass */
if (!of_get_flat_dt_prop(node, "dependencies", &len)) {
if (cpufeatures_process_feature(f))
f->enabled = 1;
else
f->disabled = 1;
}
return 0;
}
static void __init cpufeatures_deps_enable(struct dt_cpu_feature *f)
{
const __be32 *prop;
int len;
int nr_deps;
int i;
if (f->enabled || f->disabled)
return;
prop = of_get_flat_dt_prop(f->node, "dependencies", &len);
if (!prop) {
pr_warn("%s: missing dependencies property", f->name);
return;
}
nr_deps = len / sizeof(int);
for (i = 0; i < nr_deps; i++) {
unsigned long phandle = be32_to_cpu(prop[i]);
int j;
for (j = 0; j < nr_dt_cpu_features; j++) {
struct dt_cpu_feature *d = &dt_cpu_features[j];
if (of_get_flat_dt_phandle(d->node) == phandle) {
cpufeatures_deps_enable(d);
if (d->disabled) {
f->disabled = 1;
return;
}
}
}
}
if (cpufeatures_process_feature(f))
f->enabled = 1;
else
f->disabled = 1;
}
static int __init scan_cpufeatures_subnodes(unsigned long node,
const char *uname,
void *data)
{
int *count = data;
process_cpufeatures_node(node, uname, *count);
(*count)++;
return 0;
}
static int __init count_cpufeatures_subnodes(unsigned long node,
const char *uname,
void *data)
{
int *count = data;
(*count)++;
return 0;
}
static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
*uname, int depth, void *data)
{
const __be32 *prop;
int count, i;
u32 isa;
/* We are scanning "ibm,powerpc-cpu-features" nodes only */
if (!of_flat_dt_is_compatible(node, "ibm,powerpc-cpu-features"))
return 0;
prop = of_get_flat_dt_prop(node, "isa", NULL);
if (!prop)
/* We checked before, "can't happen" */
return 0;
isa = be32_to_cpup(prop);
/* Count and allocate space for cpu features */
of_scan_flat_dt_subnodes(node, count_cpufeatures_subnodes,
&nr_dt_cpu_features);
dt_cpu_features = memblock_alloc(sizeof(struct dt_cpu_feature) * nr_dt_cpu_features, PAGE_SIZE);
if (!dt_cpu_features)
panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
__func__,
sizeof(struct dt_cpu_feature) * nr_dt_cpu_features,
PAGE_SIZE);
cpufeatures_setup_start(isa);
/* Scan nodes into dt_cpu_features and enable those without deps */
count = 0;
of_scan_flat_dt_subnodes(node, scan_cpufeatures_subnodes, &count);
/* Recursive enable remaining features with dependencies */
for (i = 0; i < nr_dt_cpu_features; i++) {
struct dt_cpu_feature *f = &dt_cpu_features[i];
cpufeatures_deps_enable(f);
}
prop = of_get_flat_dt_prop(node, "display-name", NULL);
if (prop && strlen((char *)prop) != 0) {
strlcpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
cur_cpu_spec->cpu_name = dt_cpu_name;
}
cpufeatures_setup_finished();
memblock_free(__pa(dt_cpu_features),
sizeof(struct dt_cpu_feature)*nr_dt_cpu_features);
return 0;
}
void __init dt_cpu_ftrs_scan(void)
{
if (!using_dt_cpu_ftrs)
return;
of_scan_flat_dt(dt_cpu_ftrs_scan_callback, NULL);
}
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