qemu-e2k/target-unicore32/cpu.c

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/*
* QEMU UniCore32 CPU
*
* Copyright (c) 2010-2012 Guan Xuetao
* Copyright (c) 2012 SUSE LINUX Products GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Contributions from 2012-04-01 on are considered under GPL version 2,
* or (at your option) any later version.
*/
#include "qemu/osdep.h"
2016-03-14 09:01:28 +01:00
#include "qapi/error.h"
#include "cpu.h"
#include "qemu-common.h"
#include "migration/vmstate.h"
#include "exec/exec-all.h"
static void uc32_cpu_set_pc(CPUState *cs, vaddr value)
{
UniCore32CPU *cpu = UNICORE32_CPU(cs);
cpu->env.regs[31] = value;
}
static bool uc32_cpu_has_work(CPUState *cs)
{
return cs->interrupt_request &
(CPU_INTERRUPT_HARD | CPU_INTERRUPT_EXITTB);
}
static inline void set_feature(CPUUniCore32State *env, int feature)
{
env->features |= feature;
}
/* CPU models */
static ObjectClass *uc32_cpu_class_by_name(const char *cpu_model)
{
ObjectClass *oc;
char *typename;
if (cpu_model == NULL) {
return NULL;
}
typename = g_strdup_printf("%s-" TYPE_UNICORE32_CPU, cpu_model);
oc = object_class_by_name(typename);
g_free(typename);
if (oc != NULL && (!object_class_dynamic_cast(oc, TYPE_UNICORE32_CPU) ||
object_class_is_abstract(oc))) {
oc = NULL;
}
return oc;
}
typedef struct UniCore32CPUInfo {
const char *name;
void (*instance_init)(Object *obj);
} UniCore32CPUInfo;
static void unicore_ii_cpu_initfn(Object *obj)
{
UniCore32CPU *cpu = UNICORE32_CPU(obj);
CPUUniCore32State *env = &cpu->env;
env->cp0.c0_cpuid = 0x4d000863;
env->cp0.c0_cachetype = 0x0d152152;
env->cp0.c1_sys = 0x2000;
env->cp0.c2_base = 0x0;
env->cp0.c3_faultstatus = 0x0;
env->cp0.c4_faultaddr = 0x0;
env->ucf64.xregs[UC32_UCF64_FPSCR] = 0;
set_feature(env, UC32_HWCAP_CMOV);
set_feature(env, UC32_HWCAP_UCF64);
softfloat: Implement run-time-configurable meaning of signaling NaN bit This patch modifies SoftFloat library so that it can be configured in run-time in relation to the meaning of signaling NaN bit, while, at the same time, strictly preserving its behavior on all existing platforms. Background: In floating-point calculations, there is a need for denoting undefined or unrepresentable values. This is achieved by defining certain floating-point numerical values to be NaNs (which stands for "not a number"). For additional reasons, virtually all modern floating-point unit implementations use two kinds of NaNs: quiet and signaling. The binary representations of these two kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally, the first bit of mantissa). Up to 2008, standards for floating-point did not specify all details about binary representation of NaNs. More specifically, the meaning of the bit that is used for distinguishing between signaling and quiet NaNs was not strictly prescribed. (IEEE 754-2008 was the first floating-point standard that defined that meaning clearly, see [1], p. 35) As a result, different platforms took different approaches, and that presented considerable challenge for multi-platform emulators like QEMU. Mips platform represents the most complex case among QEMU-supported platforms regarding signaling NaN bit. Up to the Release 6 of Mips architecture, "1" in signaling NaN bit denoted signaling NaN, which is opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of that, Mips architecture for SIMD (also known as MSA, or vector instructions) also specifies signaling bit in accordance to IEEE standard. MSA unit can be implemented with both pre-Release 6 and Release 6 main processor units. QEMU uses SoftFloat library to implement various floating-point-related instructions on all platforms. The current QEMU implementation allows for defining meaning of signaling NaN bit during build time, and is implemented via preprocessor macro called SNAN_BIT_IS_ONE. On the other hand, the change in this patch enables SoftFloat library to be configured in run-time. This configuration is meant to occur during CPU initialization, at the moment when it is definitely known what desired behavior for particular CPU (or any additional FPUs) is. The change is implemented so that it is consistent with existing implementation of similar cases. This means that structure float_status is used for passing the information about desired signaling NaN bit on each invocation of SoftFloat functions. The additional field in float_status is called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE. IMPORTANT: This change is not meant to create any change in emulator behavior or functionality on any platform. It just provides the means for SoftFloat library to be used in a more flexible way - in other words, it will just prepare SoftFloat library for usage related to Mips platform and its specifics regarding signaling bit meaning, which is done in some of subsequent patches from this series. Further break down of changes: 1) Added field snan_bit_is_one to the structure float_status, and correspondent setter function set_snan_bit_is_one(). 2) Constants <float16|float32|float64|floatx80|float128>_default_nan (used both internally and externally) converted to functions <float16|float32|float64|floatx80|float128>_default_nan(float_status*). This is necessary since they are dependent on signaling bit meaning. At the same time, for the sake of code cleanup and simplicity, constants <floatx80|float128>_default_nan_<low|high> (used only internally within SoftFloat library) are removed, as not needed. 3) Added a float_status* argument to SoftFloat library functions XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_), XXX_maybe_silence_nan(XXX a_). This argument must be present in order to enable correct invocation of new version of functions XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128> here) 4) Updated code for all platforms to reflect changes in SoftFloat library. This change is twofolds: it includes modifications of SoftFloat library functions invocations, and an addition of invocation of function set_snan_bit_is_one() during CPU initialization, with arguments that are appropriate for each particular platform. It was established that all platforms zero their main CPU data structures, so snan_bit_is_one(0) in appropriate places is not added, as it is not needed. [1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer Society, August 29, 2008. Signed-off-by: Thomas Schwinge <thomas@codesourcery.com> Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Tested-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [leon.alrae@imgtec.com: * cherry-picked 2 chunks from patch #2 to fix compilation warnings] Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-06-10 11:57:28 +02:00
set_snan_bit_is_one(1, &env->ucf64.fp_status);
}
static void uc32_any_cpu_initfn(Object *obj)
{
UniCore32CPU *cpu = UNICORE32_CPU(obj);
CPUUniCore32State *env = &cpu->env;
env->cp0.c0_cpuid = 0xffffffff;
env->ucf64.xregs[UC32_UCF64_FPSCR] = 0;
set_feature(env, UC32_HWCAP_CMOV);
set_feature(env, UC32_HWCAP_UCF64);
softfloat: Implement run-time-configurable meaning of signaling NaN bit This patch modifies SoftFloat library so that it can be configured in run-time in relation to the meaning of signaling NaN bit, while, at the same time, strictly preserving its behavior on all existing platforms. Background: In floating-point calculations, there is a need for denoting undefined or unrepresentable values. This is achieved by defining certain floating-point numerical values to be NaNs (which stands for "not a number"). For additional reasons, virtually all modern floating-point unit implementations use two kinds of NaNs: quiet and signaling. The binary representations of these two kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally, the first bit of mantissa). Up to 2008, standards for floating-point did not specify all details about binary representation of NaNs. More specifically, the meaning of the bit that is used for distinguishing between signaling and quiet NaNs was not strictly prescribed. (IEEE 754-2008 was the first floating-point standard that defined that meaning clearly, see [1], p. 35) As a result, different platforms took different approaches, and that presented considerable challenge for multi-platform emulators like QEMU. Mips platform represents the most complex case among QEMU-supported platforms regarding signaling NaN bit. Up to the Release 6 of Mips architecture, "1" in signaling NaN bit denoted signaling NaN, which is opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of that, Mips architecture for SIMD (also known as MSA, or vector instructions) also specifies signaling bit in accordance to IEEE standard. MSA unit can be implemented with both pre-Release 6 and Release 6 main processor units. QEMU uses SoftFloat library to implement various floating-point-related instructions on all platforms. The current QEMU implementation allows for defining meaning of signaling NaN bit during build time, and is implemented via preprocessor macro called SNAN_BIT_IS_ONE. On the other hand, the change in this patch enables SoftFloat library to be configured in run-time. This configuration is meant to occur during CPU initialization, at the moment when it is definitely known what desired behavior for particular CPU (or any additional FPUs) is. The change is implemented so that it is consistent with existing implementation of similar cases. This means that structure float_status is used for passing the information about desired signaling NaN bit on each invocation of SoftFloat functions. The additional field in float_status is called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE. IMPORTANT: This change is not meant to create any change in emulator behavior or functionality on any platform. It just provides the means for SoftFloat library to be used in a more flexible way - in other words, it will just prepare SoftFloat library for usage related to Mips platform and its specifics regarding signaling bit meaning, which is done in some of subsequent patches from this series. Further break down of changes: 1) Added field snan_bit_is_one to the structure float_status, and correspondent setter function set_snan_bit_is_one(). 2) Constants <float16|float32|float64|floatx80|float128>_default_nan (used both internally and externally) converted to functions <float16|float32|float64|floatx80|float128>_default_nan(float_status*). This is necessary since they are dependent on signaling bit meaning. At the same time, for the sake of code cleanup and simplicity, constants <floatx80|float128>_default_nan_<low|high> (used only internally within SoftFloat library) are removed, as not needed. 3) Added a float_status* argument to SoftFloat library functions XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_), XXX_maybe_silence_nan(XXX a_). This argument must be present in order to enable correct invocation of new version of functions XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128> here) 4) Updated code for all platforms to reflect changes in SoftFloat library. This change is twofolds: it includes modifications of SoftFloat library functions invocations, and an addition of invocation of function set_snan_bit_is_one() during CPU initialization, with arguments that are appropriate for each particular platform. It was established that all platforms zero their main CPU data structures, so snan_bit_is_one(0) in appropriate places is not added, as it is not needed. [1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer Society, August 29, 2008. Signed-off-by: Thomas Schwinge <thomas@codesourcery.com> Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Tested-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [leon.alrae@imgtec.com: * cherry-picked 2 chunks from patch #2 to fix compilation warnings] Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-06-10 11:57:28 +02:00
set_snan_bit_is_one(1, &env->ucf64.fp_status);
}
static const UniCore32CPUInfo uc32_cpus[] = {
{ .name = "UniCore-II", .instance_init = unicore_ii_cpu_initfn },
{ .name = "any", .instance_init = uc32_any_cpu_initfn },
};
static void uc32_cpu_realizefn(DeviceState *dev, Error **errp)
{
UniCore32CPUClass *ucc = UNICORE32_CPU_GET_CLASS(dev);
qemu_init_vcpu(CPU(dev));
ucc->parent_realize(dev, errp);
}
static void uc32_cpu_initfn(Object *obj)
{
CPUState *cs = CPU(obj);
UniCore32CPU *cpu = UNICORE32_CPU(obj);
CPUUniCore32State *env = &cpu->env;
static bool inited;
cs->env_ptr = env;
cpu_exec_init(cs, &error_abort);
#ifdef CONFIG_USER_ONLY
env->uncached_asr = ASR_MODE_USER;
env->regs[31] = 0;
#else
env->uncached_asr = ASR_MODE_PRIV;
env->regs[31] = 0x03000000;
#endif
tlb_flush(cs, 1);
if (tcg_enabled() && !inited) {
inited = true;
uc32_translate_init();
}
}
static const VMStateDescription vmstate_uc32_cpu = {
.name = "cpu",
.unmigratable = 1,
};
static void uc32_cpu_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
CPUClass *cc = CPU_CLASS(oc);
UniCore32CPUClass *ucc = UNICORE32_CPU_CLASS(oc);
ucc->parent_realize = dc->realize;
dc->realize = uc32_cpu_realizefn;
cc->class_by_name = uc32_cpu_class_by_name;
cc->has_work = uc32_cpu_has_work;
cc->do_interrupt = uc32_cpu_do_interrupt;
cc->cpu_exec_interrupt = uc32_cpu_exec_interrupt;
cc->dump_state = uc32_cpu_dump_state;
cc->set_pc = uc32_cpu_set_pc;
#ifdef CONFIG_USER_ONLY
cc->handle_mmu_fault = uc32_cpu_handle_mmu_fault;
#else
cc->get_phys_page_debug = uc32_cpu_get_phys_page_debug;
#endif
dc->vmsd = &vmstate_uc32_cpu;
qdev: Protect device-list-properties against broken devices Several devices don't survive object_unref(object_new(T)): they crash or hang during cleanup, or they leave dangling pointers behind. This breaks at least device-list-properties, because qmp_device_list_properties() needs to create a device to find its properties. Broken in commit f4eb32b "qmp: show QOM properties in device-list-properties", v2.1. Example reproducer: $ qemu-system-aarch64 -nodefaults -display none -machine none -S -qmp stdio {"QMP": {"version": {"qemu": {"micro": 50, "minor": 4, "major": 2}, "package": ""}, "capabilities": []}} { "execute": "qmp_capabilities" } {"return": {}} { "execute": "device-list-properties", "arguments": { "typename": "pxa2xx-pcmcia" } } qemu-system-aarch64: /home/armbru/work/qemu/memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed. Aborted (core dumped) [Exit 134 (SIGABRT)] Unfortunately, I can't fix the problems in these devices right now. Instead, add DeviceClass member cannot_destroy_with_object_finalize_yet to mark them: * Hang during cleanup (didn't debug, so I can't say why): "realview_pci", "versatile_pci". * Dangling pointer in cpus: most CPUs, plus "allwinner-a10", "digic", "fsl,imx25", "fsl,imx31", "xlnx,zynqmp", because they create such CPUs * Assert kvm_enabled(): "host-x86_64-cpu", host-i386-cpu", "host-powerpc64-cpu", "host-embedded-powerpc-cpu", "host-powerpc-cpu" (the powerpc ones can't currently reach the assertion, because the CPUs are only registered when KVM is enabled, but the assertion is arguably in the wrong place all the same) Make qmp_device_list_properties() fail cleanly when the device is so marked. This improves device-list-properties from "crashes, hangs or leaves dangling pointers behind" to "fails". Not a complete fix, just a better-than-nothing work-around. In the above reproducer, device-list-properties now fails with "Can't list properties of device 'pxa2xx-pcmcia'". This also protects -device FOO,help, which uses the same machinery since commit ef52358 "qdev-monitor: include QOM properties in -device FOO, help output", v2.2. Example reproducer: $ qemu-system-aarch64 -machine none -device pxa2xx-pcmcia,help Before: qemu-system-aarch64: .../memory.c:1307: memory_region_finalize: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed. After: Can't list properties of device 'pxa2xx-pcmcia' Cc: "Andreas Färber" <afaerber@suse.de> Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com> Cc: Alexander Graf <agraf@suse.de> Cc: Anthony Green <green@moxielogic.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Cc: Blue Swirl <blauwirbel@gmail.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Jia Liu <proljc@gmail.com> Cc: Leon Alrae <leon.alrae@imgtec.com> Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Walle <michael@walle.cc> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Richard Henderson <rth@twiddle.net> Cc: qemu-ppc@nongnu.org Cc: qemu-stable@nongnu.org Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com> Message-Id: <1443689999-12182-10-git-send-email-armbru@redhat.com>
2015-10-01 10:59:58 +02:00
/*
* Reason: uc32_cpu_initfn() calls cpu_exec_init(), which saves
* the object in cpus -> dangling pointer after final
* object_unref().
*/
dc->cannot_destroy_with_object_finalize_yet = true;
}
static void uc32_register_cpu_type(const UniCore32CPUInfo *info)
{
TypeInfo type_info = {
.parent = TYPE_UNICORE32_CPU,
.instance_init = info->instance_init,
};
type_info.name = g_strdup_printf("%s-" TYPE_UNICORE32_CPU, info->name);
type_register(&type_info);
g_free((void *)type_info.name);
}
static const TypeInfo uc32_cpu_type_info = {
.name = TYPE_UNICORE32_CPU,
.parent = TYPE_CPU,
.instance_size = sizeof(UniCore32CPU),
.instance_init = uc32_cpu_initfn,
.abstract = true,
.class_size = sizeof(UniCore32CPUClass),
.class_init = uc32_cpu_class_init,
};
static void uc32_cpu_register_types(void)
{
int i;
type_register_static(&uc32_cpu_type_info);
for (i = 0; i < ARRAY_SIZE(uc32_cpus); i++) {
uc32_register_cpu_type(&uc32_cpus[i]);
}
}
type_init(uc32_cpu_register_types)