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hw: re-implement lazy FPU context switch 

The new implementation of the FPU and FPU context is taken out to
separate architecture-dependent header files. The generic Cpu_lazy_state
is deleted. There is no hint about the existence of something like an
FPU in the generic non-architexture-dependent code anymore. Instead the
architecture-dependent CPU context of a thread is extended by an FPU
context where supported.

Moreover, the current FPU implementations are enhanced so that threads
that get deleted now release the FPU when still obtaining it.

Fix #1855
This commit is contained in:
Stefan Kalkowski 2016-01-19 13:33:04 +01:00 committed by Christian Helmuth
parent f9ccfe3a04
commit c3d4802ac8
26 changed files with 615 additions and 573 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
repos/base-hw/lib/mk/spec/cortex_a9/core.inc
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@ -11,6 +11,7 @@ INC_DIR += $(REP_DIR)/src/core/include/spec/arm_gic
# add C++ sources
SRC_CC += spec/cortex_a9/kernel/cpu.cc
SRC_CC += spec/cortex_a9/cpu.cc
SRC_CC += spec/cortex_a9/fpu.cc
SRC_CC += spec/arm/smp/kernel/thread_update_pd.cc
SRC_CC += spec/arm/smp/kernel/cpu.cc
SRC_CC += spec/arm/kernel/cpu_context.cc

1
repos/base-hw/lib/mk/spec/x86/core.inc
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@ -16,6 +16,7 @@ SRC_CC += spec/x86/kernel/cpu.cc
SRC_CC += spec/x86/kernel/thread.cc
SRC_CC += spec/x86/platform_support.cc
SRC_CC += spec/x86/cpu.cc
SRC_CC += spec/x86/fpu.cc
SRC_CC += spec/x86/bios_data_area.cc
SRC_CC += spec/x86/io_port_session_component.cc
SRC_CC += spec/x86/platform_services.cc

8
repos/base-hw/src/core/include/kernel/cpu.h
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@ -117,12 +117,11 @@ class Kernel::Cpu_domain_update : public Double_list_item
virtual void _cpu_domain_update_unblocks() = 0;
};
class Kernel::Cpu_job : public Cpu_share
class Kernel::Cpu_job : public Genode::Cpu::User_context, public Cpu_share
{
protected:
Cpu * _cpu;
Cpu_lazy_state _lazy_state;
Cpu * _cpu;
/**
* Handle interrupt exception that occured during execution on CPU 'id'
@ -196,10 +195,9 @@ class Kernel::Cpu_job : public Cpu_share
***************/
void cpu(Cpu * const cpu) { _cpu = cpu; }
Cpu_lazy_state * lazy_state() { return &_lazy_state; }
};
class Kernel::Cpu_idle : public Genode::Cpu::User_context, public Cpu_job
class Kernel::Cpu_idle : public Cpu_job
{
private:

7
repos/base-hw/src/core/include/kernel/thread.h
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@ -77,9 +77,8 @@ class Kernel::Thread_event : public Signal_ack_handler
*/
class Kernel::Thread
:
public Kernel::Object, public Cpu::User_context, public Cpu_domain_update,
public Ipc_node, public Signal_context_killer, public Signal_handler,
public Cpu_job
public Kernel::Object, public Cpu_job, public Cpu_domain_update,
public Ipc_node, public Signal_context_killer, public Signal_handler
{
friend class Thread_event;
friend class Core_thread;
@ -190,7 +189,7 @@ class Kernel::Thread
void _call();
/**
* Return amount of timer tics that 'quota' is worth
* Return amount of timer tics that 'quota' is worth
*/
size_t _core_to_kernel_quota(size_t const quota) const;

9
repos/base-hw/src/core/include/spec/arm/cpu_support.h
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@ -28,13 +28,8 @@ namespace Kernel { class Pd; }
namespace Genode
{
/**
* CPU driver for core
*/
class Arm;
class Cpu_lazy_state;
typedef Genode::uint64_t sizet_arithm_t;
}
@ -544,8 +539,8 @@ class Genode::Arm
** Dummies **
*************/
void prepare_proceeding(Cpu_lazy_state *, Cpu_lazy_state *) { }
bool retry_undefined_instr(Cpu_lazy_state *) { return false; }
void switch_to(User_context&) { }
bool retry_undefined_instr(Context&) { return false; }
/**
* Return kernel name of the executing CPU

246
repos/base-hw/src/core/include/spec/arm/fpu.h Normal file
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@ -0,0 +1,246 @@
/*
* \brief ARM-specific FPU driver for core
* \author Stefan Kalkowski
* \author Martin stein
* \date 2016-01-19
*/
/*
* Copyright (C) 2016 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _SPEC__ARM__FPU_H_
#define _SPEC__ARM__FPU_H_
#include <util/register.h>
namespace Genode { class Fpu; }
/**
* FPU driver for the ARM VFPv3-D16 architecture
*/
class Genode::Fpu
{
private:
/**
* Floating-point Status and Control Register
*/
struct Fpscr : Register<32>
{
/**
* Read register value
*/
static access_t read()
{
/* FIXME: See annotation 1. */
access_t v;
asm volatile ("mrc p10, 7, %[v], cr1, cr0, 0" : [v] "=r" (v) ::);
return v;
}
/**
* Override register value
*
* \param v write value
*/
static void write(access_t const v)
{
/* FIXME: See annotation 1. */
asm volatile ("mcr p10, 7, %[v], cr1, cr0, 0" :: [v] "r" (v) :);
}
};
/**
* Floating-Point Exception Control register
*/
struct Fpexc : Register<32>
{
struct En : Bitfield<30, 1> { };
/**
* Read register value
*/
static access_t read()
{
/* FIXME: See annotation 1. */
access_t v;
asm volatile ("mrc p10, 7, %[v], cr8, cr0, 0" : [v] "=r" (v) ::);
return v;
}
/**
* Override register value
*
* \param v write value
*/
static void write(access_t const v)
{
/* FIXME: See annotation 1. */
asm volatile ("mcr p10, 7, %[v], cr8, cr0, 0" :: [v] "r" (v) :);
}
};
public:
class Context
{
private:
friend class Fpu;
/* advanced FP/SIMD - system registers */
uint32_t fpscr;
uint32_t fpexc;
/* advanced FP/SIMD - general purpose registers d0-d15 */
uint64_t d0, d1, d2, d3, d4, d5, d6, d7;
uint64_t d8, d9, d10, d11, d12, d13, d14, d15;
Fpu * _fpu = nullptr;
public:
Context() : fpexc(Fpexc::En::bits(1)) { }
~Context() { if (_fpu) _fpu->unset(*this); }
};
private:
Context * _context = nullptr;
/**
* Enable FPU
*/
void _enable()
{
Fpexc::access_t fpexc = Fpexc::read();
Fpexc::En::set(fpexc, 1);
Fpexc::write(fpexc);
}
/**
* Disable FPU
*/
void _disable()
{
Fpexc::access_t fpexc = Fpexc::read();
Fpexc::En::set(fpexc, 0);
Fpexc::write(fpexc);
}
/**
* Save FPU context
*/
void _save()
{
/* save system registers */
_context->fpexc = Fpexc::read();
_context->fpscr = Fpscr::read();
/*
* Save D0 - D15
*
* FIXME: See annotation 2.
*/
void * const d0_d15_base = &_context->d0;
asm volatile (
"stc p11, cr0, [%[d0_d15_base]], #128"
:: [d0_d15_base] "r" (d0_d15_base) : );
}
/**
* Load context to FPU
*/
void _load()
{
/* load system registers */
Fpexc::write(_context->fpexc);
Fpscr::write(_context->fpscr);
/*
* Load D0 - D15
*
* FIXME: See annotation 2.
*/
void * const d0_d15_base = &_context->d0;
asm volatile (
"ldc p11, cr0, [%[d0_d15_base]], #128"
:: [d0_d15_base] "r" (d0_d15_base) : );
}
/**
* Return wether the FPU is enabled
*/
bool _enabled()
{
Fpexc::access_t fpexc = Fpexc::read();
return Fpexc::En::get(fpexc);
}
public:
/**
* Initialize FPU
*/
void init();
void switch_to(Context & context)
{
if (_context == &context) return;
_disable();
}
/**
* Return wether the FPU fault can be solved
*
* \param state CPU state of the user
*/
bool fault(Context & context)
{
if (_enabled()) { return false; }
_enable();
if (_context != &context) {
if (_context) {
_save();
_context->_fpu = nullptr;
}
_context = &context;
_context->_fpu = this;
_load();
}
return true;
}
/**
* Unset FPU context
*/
void unset(Context &context) {
if (_context == &context) _context = nullptr; }
};
/*
* Annotation 1
*
* According to the ARMv7 manual this should be done via vmsr/vmrs instruction
* but it seems that binutils 2.22 doesn't fully support this yet. Hence, we
* use a co-processor instruction instead. The parameters to target the
* register this way can be determined via 'sys/arm/include/vfp.h' and
* 'sys/arm/arm/vfp.c' of the FreeBSD head branch as from 2014.04.17.
*/
/*
* Annotation 2
*
* According to the ARMv7 manual this should be done via vldm/vstm instruction
* but it seems that binutils 2.22 doesn't fully support this yet. Hence, we
* use a co-processor instruction instead. The parameters to target the
* register this way can be determined via 'sys/arm/arm/vfp.c' of the FreeBSD
* head branch as from 2014.04.17.
*/
#endif /* _SPEC__ARM__FPU_H_ */

22
repos/base-hw/src/core/include/spec/arm_v6/cpu.h
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@ -20,22 +20,8 @@
#include <assert.h>
#include <board.h>
namespace Genode
{
/**
* Part of CPU state that is not switched on every mode transition
*/
class Cpu_lazy_state { };
namespace Genode { class Cpu; }
/**
* CPU driver for core
*/
class Cpu;
}
namespace Kernel {
using Genode::Cpu_lazy_state;
}
class Genode::Cpu : public Arm
{
@ -90,11 +76,6 @@ class Genode::Cpu : public Arm
invalidate_tlb();
}
/**
* Return wether to retry an undefined user instruction after this call
*/
bool retry_undefined_instr(Cpu_lazy_state *) { return false; }
/**
* Post processing after a translation was added to a translation table
*
@ -108,7 +89,6 @@ class Genode::Cpu : public Arm
** Dummies **
*************/
static void prepare_proceeding(Cpu_lazy_state *, Cpu_lazy_state *) { }
static void wait_for_interrupt() { /* FIXME */ }
static void data_synchronization_barrier() { /* FIXME */ }
static void invalidate_control_flow_predictions() { /* FIXME */ }

22
repos/base-hw/src/core/include/spec/cortex_a15/cpu.h
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@ -18,20 +18,8 @@
/* core includes */
#include <spec/arm_v7/cpu_support.h>
namespace Genode
{
/**
* Part of CPU state that is not switched on every mode transition
*/
class Cpu_lazy_state { };
namespace Genode { class Cpu; }
/**
* CPU driver for core
*/
class Cpu;
}
namespace Kernel { using Genode::Cpu_lazy_state; }
class Genode::Cpu : public Arm_v7
{
@ -408,11 +396,6 @@ class Genode::Cpu : public Arm_v7
};
/**
* Return wether to retry an undefined user instruction after this call
*/
bool retry_undefined_instr(Cpu_lazy_state *) { return false; }
/**
* Return kernel name of the executing CPU
*/
@ -455,7 +438,8 @@ class Genode::Cpu : public Arm_v7
** Dummies **
*************/
static void prepare_proceeding(Cpu_lazy_state *, Cpu_lazy_state *) { }
void switch_to(User_context&) { }
bool retry_undefined_instr(Context&) { return false; }
};
#endif /* _CPU_H_ */

14
repos/base-hw/src/core/include/spec/cortex_a8/cpu.h
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@ -18,20 +18,8 @@
/* core includes */
#include <spec/arm_v7/cpu_support.h>
namespace Genode
{
/**
* Part of CPU state that is not switched on every mode transition
*/
class Cpu_lazy_state { };
namespace Genode { class Cpu; }
/**
* CPU driver for core
*/
class Cpu;
}
namespace Kernel { using Genode::Cpu_lazy_state; }
class Genode::Cpu : public Arm_v7
{

239
repos/base-hw/src/core/include/spec/cortex_a9/cpu_support.h
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@ -16,51 +16,19 @@
#define _SPEC__CORTEX_A9__CPU_SUPPORT_H_
/* core includes */
#include <spec/arm/fpu.h>
#include <spec/arm_v7/cpu_support.h>
#include <board.h>
namespace Genode
{
/**
* Part of CPU state that is not switched on every mode transition
*/
class Cpu_lazy_state;
/**
* CPU driver for core
*/
class Cortex_a9;
}
namespace Kernel { using Genode::Cpu_lazy_state; }
class Genode::Cpu_lazy_state
{
friend class Cortex_a9;
private:
/* advanced FP/SIMD - system registers */
uint32_t fpscr;
uint32_t fpexc;
/* advanced FP/SIMD - general purpose registers d0-d15 */
uint64_t d0, d1, d2, d3, d4, d5, d6, d7;
uint64_t d8, d9, d10, d11, d12, d13, d14, d15;
public:
/**
* Constructor
*/
inline Cpu_lazy_state();
};
namespace Genode { class Cortex_a9; }
class Genode::Cortex_a9 : public Arm_v7
{
friend class Cpu_lazy_state;
protected:
private:
Fpu _fpu;
public:
/**
* Coprocessor Access Control Register
@ -85,135 +53,10 @@ class Genode::Cortex_a9 : public Arm_v7
*
* \param v write value
*/
static void write(access_t const v)
{
asm volatile ("mcr p15, 0, %[v], c1, c0, 2" :: [v]"r"(v) :);
}
static void write(access_t const v) {
asm volatile ("mcr p15, 0, %[v], c1, c0, 2" :: [v]"r"(v) :); }
};
/**
* Floating-point Status and Control Register
*/
struct Fpscr : Register<32>
{
/**
* Read register value
*/
static access_t read()
{
/* FIXME: See annotation 1. */
access_t v;
asm volatile ("mrc p10, 7, %[v], cr1, cr0, 0" : [v] "=r" (v) ::);
return v;
}
/**
* Override register value
*
* \param v write value
*/
static void write(access_t const v)
{
/* FIXME: See annotation 1. */
asm volatile ("mcr p10, 7, %[v], cr1, cr0, 0" :: [v] "r" (v) :);
}
};
/**
* Floating-Point Exception Control register
*/
struct Fpexc : Register<32>
{
struct En : Bitfield<30, 1> { };
/**
* Read register value
*/
static access_t read()
{
/* FIXME: See annotation 1. */
access_t v;
asm volatile ("mrc p10, 7, %[v], cr8, cr0, 0" : [v] "=r" (v) ::);
return v;
}
/**
* Override register value
*
* \param v write value
*/
static void write(access_t const v)
{
/* FIXME: See annotation 1. */
asm volatile ("mcr p10, 7, %[v], cr8, cr0, 0" :: [v] "r" (v) :);
}
};
Cpu_lazy_state * _advanced_fp_simd_state;
/**
* Enable or disable the advanced FP/SIMD extension
*
* \param enabled wether to enable or to disable advanced FP/SIMD
*/
static void _toggle_advanced_fp_simd(bool const enabled)
{
Fpexc::access_t fpexc = Fpexc::read();
Fpexc::En::set(fpexc, enabled);
Fpexc::write(fpexc);
}
/**
* Save state of the advanced FP/SIMD extension into 'state'
*/
static void _save_advanced_fp_simd_state(Cpu_lazy_state * const state)
{
/* save system registers */
state->fpexc = Fpexc::read();
state->fpscr = Fpscr::read();
/*
* Save D0 - D15
*
* FIXME: See annotation 2.
*/
void * const d0_d15_base = &state->d0;
asm volatile (
"stc p11, cr0, [%[d0_d15_base]], #128"
:: [d0_d15_base] "r" (d0_d15_base) : );
}
/**
* Load state of the advanced FP/SIMD extension from 'state'
*/
static void _load_advanced_fp_simd_state(Cpu_lazy_state * const state)
{
/* load system registers */
Fpexc::write(state->fpexc);
Fpscr::write(state->fpscr);
/*
* Load D0 - D15
*
* FIXME: See annotation 2.
*/
void * const d0_d15_base = &state->d0;
asm volatile (
"ldc p11, cr0, [%[d0_d15_base]], #128"
:: [d0_d15_base] "r" (d0_d15_base) : );
}
/**
* Return wether the advanced FP/SIMD extension is enabled
*/
static bool _advanced_fp_simd_enabled()
{
Fpexc::access_t fpexc = Fpexc::read();
return Fpexc::En::get(fpexc);
}
public:
/**
* Auxiliary Control Register
*/
@ -239,54 +82,22 @@ class Genode::Cortex_a9 : public Arm_v7
}
};
/**
* Constructor
*/
Cortex_a9() : _advanced_fp_simd_state(0) { }
struct User_context : Arm::User_context, Fpu::Context { };
/**
* Initialize advanced FP/SIMD extension
*/
static void init_advanced_fp_simd()
{
Cpacr::access_t cpacr = Cpacr::read();
Cpacr::Cp10::set(cpacr, 3);
Cpacr::Cp11::set(cpacr, 3);
Cpacr::write(cpacr);
_toggle_advanced_fp_simd(false);
}
/**
* Prepare for the proceeding of a user
* Next cpu context to switch to
*
* \param old_state CPU state of the last user
* \param new_state CPU state of the next user
* \param context context to switch to
*/
static void prepare_proceeding(Cpu_lazy_state * const old_state,
Cpu_lazy_state * const new_state)
{
if (old_state == new_state) { return; }
_toggle_advanced_fp_simd(false);
}
void switch_to(User_context & context) { _fpu.switch_to(context); }
/**
* Return wether to retry an undefined user instruction after this call
*
* \param state CPU state of the user
*/
bool retry_undefined_instr(Cpu_lazy_state * const state)
{
if (_advanced_fp_simd_enabled()) { return false; }
_toggle_advanced_fp_simd(true);
if (_advanced_fp_simd_state != state) {
if (_advanced_fp_simd_state) {
_save_advanced_fp_simd_state(_advanced_fp_simd_state);
}
_load_advanced_fp_simd_state(state);
_advanced_fp_simd_state = state;
}
return true;
}
bool retry_undefined_instr(User_context & context) {
return _fpu.fault(context); }
/**
* Write back dirty cache lines and invalidate whole data cache
@ -329,26 +140,4 @@ class Genode::Cortex_a9 : public Arm_v7
static void translation_added(addr_t, size_t) { }
};
Genode::Cpu_lazy_state::Cpu_lazy_state() { fpexc = Cortex_a9::Fpexc::En::bits(1); }
/*
* Annotation 1
*
* According to the ARMv7 manual this should be done via vmsr/vmrs instruction
* but it seems that binutils 2.22 doesn't fully support this yet. Hence, we
* use a co-processor instruction instead. The parameters to target the
* register this way can be determined via 'sys/arm/include/vfp.h' and
* 'sys/arm/arm/vfp.c' of the FreeBSD head branch as from 2014.04.17.
*/
/*
* Annotation 2
*
* According to the ARMv7 manual this should be done via vldm/vstm instruction
* but it seems that binutils 2.22 doesn't fully support this yet. Hence, we
* use a co-processor instruction instead. The parameters to target the
* register this way can be determined via 'sys/arm/arm/vfp.c' of the FreeBSD
* head branch as from 2014.04.17.
*/
#endif /* _SPEC__CORTEX_A9__CPU_SUPPORT_H_ */

330
repos/base-hw/src/core/include/spec/x86/cpu_support.h
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@ -25,6 +25,7 @@
#include <unmanaged_singleton.h>
/* core includes */
#include <fpu.h>
#include <gdt.h>
#include <idt.h>
#include <tss.h>
@ -33,214 +34,19 @@
extern int _mt_idt;
extern int _mt_tss;
namespace Genode
{
/**
* Part of CPU state that is not switched on every mode transition
*/
class Cpu_lazy_state;
/**
* CPU driver for core
*/
class Cpu;
}
namespace Kernel
{
using Genode::Cpu_lazy_state;
class Pd;
}
class Genode::Cpu_lazy_state
{
friend class Cpu;
private:
enum { MXCSR_DEFAULT = 0x1f80 };
/*
* FXSAVE area providing storage for x87 FPU, MMX, XMM, and MXCSR
* registers.
*
* For further details see Intel SDM Vol. 2A, 'FXSAVE instruction'.
*/
char fxsave_area[527];
/* 16-byte aligned start of FXSAVE area. */
char *start;
/**
* Load x87 FPU State from fxsave area.
*/
inline void load()
{
if (!start) {
set_start();
init();
return;
}
asm volatile ("fxrstor %0" : : "m" (*start));
}
/**
* Save x87 FPU State to fxsave area.
*/
inline void save() { asm volatile ("fxsave %0" : "=m" (*start)); }
/**
* Return current value of MXCSR register.
*/
static inline unsigned get_mxcsr()
{
unsigned value;
asm volatile ("stmxcsr %0" : "=m" (value));
return value;
}
/**
* Set MXCSR register to given value.
*/
static inline void set_mxcsr(unsigned value)
{
asm volatile ("ldmxcsr %0" : : "m" (value));
}
/**
* Initialize FPU
*
* Doesn't check for pending unmasked floating-point exceptions and
* explicitly sets the MXCSR to the default value.
*/
inline void init()
{
asm volatile ("fninit");
set_mxcsr(MXCSR_DEFAULT);
};
/**
* Set 16-byte aligned start of fxsave area.
*/
inline void set_start()
{
start = fxsave_area;
if((addr_t)start & 15)
start = (char *)((addr_t)start & ~15) + 16;
};
public:
/**
* Constructor
*/
inline Cpu_lazy_state() : start(0) { };
} __attribute__((aligned(16)));
namespace Genode { class Cpu; }
class Genode::Cpu
{
friend class Cpu_lazy_state;
protected:
Idt *_idt;
Tss *_tss;
Cpu_lazy_state *_fpu_state;
struct Cr0; /* Control register 0 */
struct Cr4; /* Control register 4 */
/**
* Disable FPU by setting the TS flag in CR0.
*/
static void _disable_fpu();
/**
* Enable FPU by clearing the TS flag in CR0.
*/
static void _enable_fpu() { asm volatile ("clts"); }
/**
* Initialize all FPU-related CR flags
*
* Initialize FPU with SSE extensions by setting required CR0 and CR4
* bits to configure the FPU environment according to Intel SDM Vol.
* 3A, sections 9.2 and 9.6.
*/
static void _init_fpu();
/**
* Returns True if the FPU is enabled.
*/
static bool _fpu_enabled();
public:
Cpu() : _fpu_state(0)
{
if (primary_id() == executing_id()) {
_idt = new (&_mt_idt) Idt();
_idt->setup(Cpu::exception_entry);
struct Pd {};
_tss = new (&_mt_tss) Tss();
_tss->load();
}
_idt->load(Cpu::exception_entry);
_tss->setup(Cpu::exception_entry);
}
static constexpr addr_t exception_entry = 0xffff0000;
static constexpr addr_t mtc_size = 1 << 13;
/**
* Control register 2: Page-fault linear address
*
* See Intel SDM Vol. 3A, section 2.5.
*/
struct Cr2 : Register<64>
{
struct Addr : Bitfield<0, 63> { };
static access_t read()
{
access_t v;
asm volatile ("mov %%cr2, %0" : "=r" (v) :: );
return v;
}
};
/**
* Control register 3: Page-Directory base register
*
* See Intel SDM Vol. 3A, section 2.5.
*/
struct Cr3 : Register<64>
{
struct Pwt : Bitfield<3,1> { }; /* Page-level write-through */
struct Pcd : Bitfield<4,1> { }; /* Page-level cache disable */
struct Pdb : Bitfield<12, 36> { }; /* Page-directory base address */
static void write(access_t const v) {
asm volatile ("mov %0, %%cr3" :: "r" (v) : ); }
static access_t read()
{
access_t v;
asm volatile ("mov %%cr3, %0" : "=r" (v) :: );
return v;
}
/**
* Return initialized value
*
* \param table base of targeted translation table
*/
static access_t init(addr_t const table) {
return Pdb::masked(table); }
};
struct Cr0; /* Control register 0 */
struct Cr2; /* Control register 2 */
struct Cr3; /* Control register 3 */
struct Cr4; /* Control register 4 */
/**
* Extend basic CPU state by members relevant for 'base-hw' only
@ -263,32 +69,14 @@ class Genode::Cpu
* \param table physical base of appropriate translation table
* \param core whether it is a core thread or not
*/
void init(addr_t const table, bool core)
{
/* Constants to handle IF, IOPL values */
enum {
EFLAGS_IF_SET = 1 << 9,
EFLAGS_IOPL_3 = 3 << 12,
};
cr3 = Cr3::init(table);
/*
* Enable interrupts for all threads, set I/O privilege level
* (IOPL) to 3 for core threads to allow UART access.
*/
eflags = EFLAGS_IF_SET;
if (core) eflags |= EFLAGS_IOPL_3;
else Gdt::load(Cpu::exception_entry);
}
void init(addr_t const table, bool core);
};
struct Pd {};
/**
* An usermode execution state
*/
struct User_context : Context
struct User_context : Context, Fpu::Context
{
/**
* Support for kernel calls
@ -311,6 +99,21 @@ class Genode::Cpu
Kernel::Call_arg user_arg_7() const { return r11; }
};
protected:
Fpu _fpu;
Idt * _idt;
Tss * _tss;
public:
Cpu();
Fpu & fpu() { return _fpu; }
static constexpr addr_t exception_entry = 0xffff0000;
static constexpr addr_t mtc_size = 1 << 13;
/**
* Wait for the next interrupt as cheap as possible
*/
@ -319,26 +122,8 @@ class Genode::Cpu
/**
* Return wether to retry an undefined user instruction after this call
*/
bool retry_undefined_instr(Cpu_lazy_state *) { return false; }
bool retry_undefined_instr(Context&) { return false; }
/**
* Return whether to retry an FPU instruction after this call
*/
bool retry_fpu_instr(Cpu_lazy_state * const state)
{
if (_fpu_enabled())
return false;
_enable_fpu();
if (_fpu_state != state) {
if (_fpu_state)
_fpu_state->save();
state->load();
_fpu_state = state;
}
return true;
}
/**
* Return kernel name of the executing CPU
@ -351,21 +136,14 @@ class Genode::Cpu
static unsigned primary_id() { return 0; }
/**
* Prepare for the proceeding of a user
* Switch to new context
*
* \param old_state CPU state of the last user
* \param new_state CPU state of the next user
* \param context next CPU context
*/
static void prepare_proceeding(Cpu_lazy_state * const old_state,
Cpu_lazy_state * const new_state)
{
if (old_state == new_state)
return;
_disable_fpu();
}
void switch_to(User_context &context) { _fpu.switch_to(context); }
};
struct Genode::Cpu::Cr0 : Register<64>
{
struct Pe : Bitfield< 0, 1> { }; /* Protection Enable */
@ -391,6 +169,56 @@ struct Genode::Cpu::Cr0 : Register<64>
}
};
/**
* Control register 2: Page-fault linear address
*
* See Intel SDM Vol. 3A, section 2.5.
*/
struct Genode::Cpu::Cr2 : Register<64>
{
struct Addr : Bitfield<0, 63> { };
static access_t read()
{
access_t v;
asm volatile ("mov %%cr2, %0" : "=r" (v) :: );
return v;
}
};
/**
* Control register 3: Page-Directory base register
*
* See Intel SDM Vol. 3A, section 2.5.
*/
struct Genode::Cpu::Cr3 : Register<64>
{
struct Pwt : Bitfield<3,1> { }; /* Page-level write-through */
struct Pcd : Bitfield<4,1> { }; /* Page-level cache disable */
struct Pdb : Bitfield<12, 36> { }; /* Page-directory base address */
static void write(access_t const v) {
asm volatile ("mov %0, %%cr3" :: "r" (v) : ); }
static access_t read()
{
access_t v;
asm volatile ("mov %%cr3, %0" : "=r" (v) :: );
return v;
}
/**
* Return initialized value
*
* \param table base of targeted translation table
*/
static access_t init(addr_t const table) {
return Pdb::masked(table); }
};
struct Genode::Cpu::Cr4 : Register<64>
{
struct Vme : Bitfield< 0, 1> { }; /* Virtual-8086 Mode Extensions */

145
repos/base-hw/src/core/include/spec/x86/fpu.h Normal file
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@ -0,0 +1,145 @@
/*
* \brief x86 FPU driver for core
* \author Adrian-Ken Rueegsegger
* \author Martin stein
* \author Reto Buerki
* \author Stefan Kalkowski
* \date 2016-01-19
*/
/*
* Copyright (C) 2016 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _SPEC__X86__FPU_H_
#define _SPEC__X86__FPU_H_
/* Genode includes */
#include <base/stdint.h>
namespace Genode { class Fpu; }
class Genode::Fpu
{
public:
class Context
{
private:
friend class Fpu;
/*
* FXSAVE area providing storage for x87 FPU, MMX, XMM,
* and MXCSR registers.
*
* For further details see Intel SDM Vol. 2A,
* 'FXSAVE instruction'.
*/
char _fxsave_area[527];
/* 16-byte aligned start of FXSAVE area. */
char * _start = nullptr;
Fpu * _fpu = nullptr;
bool _init()
{
if (_start) return true;
_start = ((addr_t)_fxsave_area & 15)
? (char *)((addr_t)_fxsave_area & ~15) + 16
: _fxsave_area;
return false;
}
public:
~Context() { if (_fpu) _fpu->unset(*this); }
} __attribute__((aligned(16)));
private:
enum { MXCSR_DEFAULT = 0x1f80 };
Context * _context = nullptr;
/**
* Reset FPU
*
* Doesn't check for pending unmasked floating-point
* exceptions and explicitly sets the MXCSR to the
* default value.
*/
void _reset()
{
unsigned value = MXCSR_DEFAULT;
asm volatile ("fninit");
asm volatile ("ldmxcsr %0" : : "m" (value));
}
/**
* Load x87 FPU context
*/
void _load()
{
if (!_context->_init()) _reset();
else asm volatile ("fxrstor %0" : : "m" (*_context->_start));
}
/**
* Save x87 FPU context
*/
void _save() {
asm volatile ("fxsave %0" : "=m" (*_context->_start)); }
public:
/**
* Disable FPU by setting the TS flag in CR0.
*/
void disable();
/**
* Enable FPU by clearing the TS flag in CR0.
*/
void enable() { asm volatile ("clts"); }
/**
* Initialize all FPU-related CR flags
*
* Initialize FPU with SSE extensions by setting required CR0 and CR4
* bits to configure the FPU environment according to Intel SDM Vol.
* 3A, sections 9.2 and 9.6.
*/
void init();
/**
* Returns True if the FPU is enabled.
*/
bool enabled();
/**
* Switch to new context
*
* \param context next FPU context
*/
void switch_to(Context &context) {
if (_context != &context) disable(); }
/**
* Return whether to retry an FPU instruction after this call
*/
bool fault(Context &context);
/**
* Unset FPU context
*/
void unset(Context &context) {
if (_context == &context) _context = nullptr; }
};
#endif /* _SPEC__X86__FPU_H_ */

6
repos/base-hw/src/core/kernel/cpu.cc
View File

@ -146,10 +146,8 @@ Cpu_job & Cpu::schedule()
assert(quota);
_timer->start_one_shot(quota, _id);
/* switch between lazy state of old and new job */
Cpu_lazy_state * const old_state = old_job.lazy_state();
Cpu_lazy_state * const new_state = new_job.lazy_state();
prepare_proceeding(old_state, new_state);
/* switch to new job */
switch_to(new_job);
/* return new job */
return new_job;

2
repos/base-hw/src/core/spec/arm/kernel/thread.cc
View File

@ -38,7 +38,7 @@ void Thread::exception(unsigned const cpu)
_interrupt(cpu);
return;
case UNDEFINED_INSTRUCTION:
if (_cpu->retry_undefined_instr(&_lazy_state)) { return; }
if (_cpu->retry_undefined_instr(*this)) { return; }
PWRN("%s -> %s: undefined instruction at ip=%p",
pd_label(), label(), (void*)ip);
_stop();

1
repos/base-hw/src/core/spec/cortex_a9/cpu.cc
View File

@ -25,4 +25,3 @@ void Genode::Arm_v7::enable_mmu_and_caches(Kernel::Pd & pd)
Cpu::Sctlr::enable_mmu_and_caches();
invalidate_branch_predicts();
}

24
repos/base-hw/src/core/spec/cortex_a9/fpu.cc Normal file
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@ -0,0 +1,24 @@
/*
* \brief CPU driver for core
* \author Martin stein
* \author Stefan Kalkowski
* \date 2016-01-19
*/
/*
* Copyright (C) 2016 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#include <cpu.h>
void Genode::Fpu::init()
{
Cpu::Cpacr::access_t cpacr = Cpu::Cpacr::read();
Cpu::Cpacr::Cp10::set(cpacr, 3);
Cpu::Cpacr::Cp11::set(cpacr, 3);
Cpu::Cpacr::write(cpacr);
_disable();
}

2
repos/base-hw/src/core/spec/cortex_a9/kernel/cpu.cc
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@ -114,7 +114,7 @@ void Kernel::Cpu::init(Kernel::Pic &pic, Kernel::Pd & core_pd, Genode::Board & b
/* wait for other cores' coherency activation */
smp_coherency_enabled.wait_for(NR_OF_CPUS);
init_advanced_fp_simd();
_fpu.init();
{
Lock::Guard guard(data_lock());

2
repos/base-hw/src/core/spec/imx6/platform_support.cc
View File

@ -56,7 +56,7 @@ Native_region * Platform::_core_only_mmio_regions(unsigned const i)
}
Cpu::User_context::User_context() { cpsr = Psr::init_user(); }
Genode::Arm::User_context::User_context() { cpsr = Psr::init_user(); }
bool Cortex_a9::Board::errata(Cortex_a9::Board::Errata err)

2
repos/base-hw/src/core/spec/panda/platform_support.cc
View File

@ -71,7 +71,7 @@ void Cortex_a9::Board::wake_up_all_cpus(void * const ip)
"sev\n");
}
Cpu::User_context::User_context() { cpsr = Psr::init_user(); }
Genode::Arm::User_context::User_context() { cpsr = Psr::init_user(); }
void Cpu::Actlr::enable_smp() {

2
repos/base-hw/src/core/spec/pbxa9/platform_support.cc
View File

@ -59,4 +59,4 @@ Native_region * Platform::_core_only_mmio_regions(unsigned const i)
}
Cpu::User_context::User_context() { cpsr = Psr::init_user(); }
Genode::Arm::User_context::User_context() { cpsr = Psr::init_user(); }

39
repos/base-hw/src/core/spec/x86/cpu.cc
View File

@ -15,24 +15,35 @@
#include <cpu.h>
#include <kernel/pd.h>
void Genode::Cpu::_init_fpu()
Genode::Cpu::Cpu()
{
Cr0::access_t cr0_value = Cr0::read();
Cr4::access_t cr4_value = Cr4::read();
if (primary_id() == executing_id()) {
_idt = new (&_mt_idt) Idt();
_idt->setup(Cpu::exception_entry);
Cr0::Mp::set(cr0_value);
Cr0::Em::clear(cr0_value);
Cr0::Ts::set(cr0_value);
Cr0::Ne::set(cr0_value);
Cr0::write(cr0_value);
Cr4::Osfxsr::set(cr4_value);
Cr4::Osxmmexcpt::set(cr4_value);
Cr4::write(cr4_value);
_tss = new (&_mt_tss) Tss();
_tss->load();
}
_idt->load(Cpu::exception_entry);
_tss->setup(Cpu::exception_entry);
}
void Genode::Cpu::_disable_fpu() { Cr0::write(Cr0::read() | Cr0::Ts::bits(1)); }
void Genode::Cpu::Context::init(addr_t const table, bool core)
{
/* Constants to handle IF, IOPL values */
enum {
EFLAGS_IF_SET = 1 << 9,
EFLAGS_IOPL_3 = 3 << 12,
};
cr3 = Cr3::init(table);
bool Genode::Cpu::_fpu_enabled() { return !Cr0::Ts::get(Cr0::read()); }
/*
* Enable interrupts for all threads, set I/O privilege level
* (IOPL) to 3 for core threads to allow UART access.
*/
eflags = EFLAGS_IF_SET;
if (core) eflags |= EFLAGS_IOPL_3;
else Gdt::load(Cpu::exception_entry);
}

56
repos/base-hw/src/core/spec/x86/fpu.cc Normal file
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@ -0,0 +1,56 @@
/*
* \brief FPU implementation specific to x86
* \author Stefan Kalkowski
* \date 2016-01-19
*/
/*
* Copyright (C) 2016 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* core includes */
#include <cpu.h>
void Genode::Fpu::init()
{
Cpu::Cr0::access_t cr0_value = Cpu::Cr0::read();
Cpu::Cr4::access_t cr4_value = Cpu::Cr4::read();
Cpu::Cr0::Mp::set(cr0_value);
Cpu::Cr0::Em::clear(cr0_value);
Cpu::Cr0::Ts::set(cr0_value);
Cpu::Cr0::Ne::set(cr0_value);
Cpu::Cr0::write(cr0_value);
Cpu::Cr4::Osfxsr::set(cr4_value);
Cpu::Cr4::Osxmmexcpt::set(cr4_value);
Cpu::Cr4::write(cr4_value);
}
void Genode::Fpu::disable() {
Cpu::Cr0::write(Cpu::Cr0::read() | Cpu::Cr0::Ts::bits(1)); }
bool Genode::Fpu::enabled() { return !Cpu::Cr0::Ts::get(Cpu::Cr0::read()); }
bool Genode::Fpu::fault(Context &context)
{
if (enabled()) return false;
enable();
if (_context == &context) return true;
if (_context) {
_save();
_context->_fpu = nullptr;
}
_context = &context;
_context->_fpu = this;
_load();
return true;
}

2
repos/base-hw/src/core/spec/x86/kernel/cpu.cc
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@ -33,7 +33,7 @@ void Kernel::Cpu::init(Pic &pic, Kernel::Pd &core_pd, Genode::Board&)
{
Timer::disable_pit();
_init_fpu();
fpu().init();
/*
* Please do not remove the PINF(), because the serial constructor requires

2
repos/base-hw/src/core/spec/x86/kernel/thread_exception.cc
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@ -25,7 +25,7 @@ void Thread::exception(unsigned const cpu)
_mmu_exception();
return;
case NO_MATH_COPROC:
if (_cpu->retry_fpu_instr(&_lazy_state)) { return; }
if (_cpu->fpu().fault(*this)) { return; }
PWRN("%s -> %s: FPU error", pd_label(), label());
_stop();
return;

2
repos/base-hw/src/core/spec/x86_64/muen/kernel/thread_exception.cc
View File

@ -25,7 +25,7 @@ void Thread::exception(unsigned const cpu)
_mmu_exception();
return;
case NO_MATH_COPROC:
if (_cpu->retry_fpu_instr(&_lazy_state)) { return; }
if (_cpu->fpu().fault(*this)) { return; }
PWRN("%s -> %s: FPU error", pd_label(), label());
_stop();
return;

2
repos/base-hw/src/core/spec/zynq/platform_support.cc
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@ -64,7 +64,7 @@ Native_region * Platform::_core_only_mmio_regions(unsigned const i)
}
Cpu::User_context::User_context() { cpsr = Psr::init_user(); }
Genode::Arm::User_context::User_context() { cpsr = Psr::init_user(); }
bool Cortex_a9::Board::errata(Cortex_a9::Board::Errata err) {