[patch v3 06/36] Hexagon: Add processor and system headers

Richard Kuo
2011-09-09T01:08:53Z

[-- Attachment #1: processor.diff --]
[-- Type: text/plain, Size: 16852 bytes --]

Adds Hexagon information for processor/system type stuff
like context switching, register access, and irqflags.

Changed cpu_relax() to call __vmyield().

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Linas Vepstas <linas@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

---
arch/hexagon/include/asm/asm-offsets.h | 1
arch/hexagon/include/asm/irqflags.h | 62 ++++++++
arch/hexagon/include/asm/processor.h | 123 +++++++++++++++++
arch/hexagon/include/asm/registers.h | 236 +++++++++++++++++++++++++++++++++
arch/hexagon/include/asm/system.h | 126 +++++++++++++++++
5 files changed, 548 insertions(+)

Index: linux-hexagon-kernel/arch/hexagon/include/asm/irqflags.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/irqflags.h 2011-09-03 20:14:59.534980859 -0500
@@ -0,0 +1,62 @@
+/*
+ * IRQ support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_IRQFLAGS_H
+#define _ASM_IRQFLAGS_H
+
+#include <asm/hexagon_vm.h>
+#include <linux/types.h>
+
+static inline unsigned long arch_local_save_flags(void)
+{
+ return __vmgetie();
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+ return __vmsetie(VM_INT_DISABLE);
+}
+
+static inline bool arch_irqs_disabled_flags(unsigned long flags)
+{
+ return !flags;
+}
+
+static inline bool arch_irqs_disabled(void)
+{
+ return !__vmgetie();
+}
+
+static inline void arch_local_irq_enable(void)
+{
+ __vmsetie(VM_INT_ENABLE);
+}
+
+static inline void arch_local_irq_disable(void)
+{
+ __vmsetie(VM_INT_DISABLE);
+}
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+ __vmsetie(flags);
+}
+
+#endif
Index: linux-hexagon-kernel/arch/hexagon/include/asm/processor.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/processor.h 2011-09-07 13:00:30.940646803 -0500
@@ -0,0 +1,123 @@
+/*
+ * Process/processor support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_PROCESSOR_H
+#define _ASM_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/mem-layout.h>
+#include <asm/registers.h>
+#include <asm/hexagon_vm.h>
+
+/* must be a macro */
+#define current_text_addr() ({ __label__ _l; _l: &&_l; })
+
+/* task_struct, defined elsewhere, is the "process descriptor" */
+struct task_struct;
+
+/* this is defined in arch/process.c */
+extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
+extern unsigned long thread_saved_pc(struct task_struct *tsk);
+
+extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
+
+/*
+ * thread_struct is supposed to be for context switch data.
+ * Specifically, to hold the state necessary to perform switch_to...
+ */
+struct thread_struct {
+ void *switch_sp;
+};
+
+/*
+ * initializes thread_struct
+ * The only thing we have in there is switch_sp
+ * which doesn't really need to be initialized.
+ */
+
+#define INIT_THREAD { \
+}
+
+#define cpu_relax() __vmyield()
+
+/*
+ * "Unlazying all lazy status" occurs here.
+ */
+static inline void prepare_to_copy(struct task_struct *tsk)
+{
+}
+
+/*
+ * Decides where the kernel will search for a free chunk of vm space during
+ * mmaps.
+ * See also arch_get_unmapped_area.
+ * Doesn't affect if you have MAX_FIXED in the page flags set though...
+ *
+ * Apparently the convention is that ld.so will ask for "unmapped" private
+ * memory to be allocated SOMEWHERE, but it also asks for memory explicitly
+ * via MAP_FIXED at the lower * addresses starting at VA=0x0.
+ *
+ * If the two requests collide, you get authentic segfaulting action, so
+ * you have to kick the "unmapped" base requests higher up.
+ */
+#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE/3))
+
+
+#define task_pt_regs(task) \
+ ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1)
+
+#define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
+#define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))
+
+/* Free all resources held by a thread; defined in process.c */
+extern void release_thread(struct task_struct *dead_task);
+
+/* Get wait channel for task P. */
+extern unsigned long get_wchan(struct task_struct *p);
+
+/* The following stuff is pretty HEXAGON specific. */
+
+/* This is really just here for __switch_to.
+ Offsets are pulled via asm-offsets.c */
+
+/*
+ * No real reason why VM and native switch stacks should be different.
+ * Ultimately this should merge. Note that Rev C. ABI called out only
+ * R24-27 as callee saved GPRs needing explicit attention (R29-31 being
+ * dealt with automagically by allocframe), but the current ABI has
+ * more, R16-R27. By saving more, the worst case is that we waste some
+ * cycles if building with the old compilers.
+ */
+
+struct hexagon_switch_stack {
+ unsigned long long r1716;
+ unsigned long long r1918;
+ unsigned long long r2120;
+ unsigned long long r2322;
+ unsigned long long r2524;
+ unsigned long long r2726;
+ unsigned long fp;
+ unsigned long lr;
+};
+
+#endif /* !__ASSEMBLY__ */
+
+#endif
Index: linux-hexagon-kernel/arch/hexagon/include/asm/registers.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/registers.h 2011-09-03 20:14:59.544980887 -0500
@@ -0,0 +1,236 @@
+/*
+ * Register definitions for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_REGISTERS_H
+#define _ASM_REGISTERS_H
+
+#define SP r29
+
+#ifndef __ASSEMBLY__
+
+/* See kernel/entry.S for further documentation. */
+
+/*
+ * Entry code copies the event record out of guest registers into
+ * this structure (which is on the stack).
+ */
+
+struct hvm_event_record {
+ unsigned long vmel; /* Event Linkage (return address) */
+ unsigned long vmest; /* Event context - pre-event SSR values */
+ unsigned long vmpsp; /* Previous stack pointer */
+ unsigned long vmbadva; /* Bad virtual address for addressing events */
+};
+
+struct pt_regs {
+ long restart_r0; /* R0 checkpoint for syscall restart */
+ long syscall_nr; /* Only used in system calls */
+ union {
+ struct {
+ unsigned long usr;
+ unsigned long preds;
+ };
+ long long int predsusr;
+ };
+ union {
+ struct {
+ unsigned long m0;
+ unsigned long m1;
+ };
+ long long int m1m0;
+ };
+ union {
+ struct {
+ unsigned long sa1;
+ unsigned long lc1;
+ };
+ long long int lc1sa1;
+ };
+ union {
+ struct {
+ unsigned long sa0;
+ unsigned long lc0;
+ };
+ long long int lc0sa0;
+ };
+ union {
+ struct {
+ unsigned long gp;
+ unsigned long ugp;
+ };
+ long long int ugpgp;
+ };
+ /*
+ * Be extremely careful with rearranging these, if at all. Some code
+ * assumes the 32 registers exist exactly like this in memory;
+ * e.g. kernel/ptrace.c
+ * e.g. kernel/signal.c (restore_sigcontext)
+ */
+ union {
+ struct {
+ unsigned long r00;
+ unsigned long r01;
+ };
+ long long int r0100;
+ };
+ union {
+ struct {
+ unsigned long r02;
+ unsigned long r03;
+ };
+ long long int r0302;
+ };
+ union {
+ struct {
+ unsigned long r04;
+ unsigned long r05;
+ };
+ long long int r0504;
+ };
+ union {
+ struct {
+ unsigned long r06;
+ unsigned long r07;
+ };
+ long long int r0706;
+ };
+ union {
+ struct {
+ unsigned long r08;
+ unsigned long r09;
+ };
+ long long int r0908;
+ };
+ union {
+ struct {
+ unsigned long r10;
+ unsigned long r11;
+ };
+ long long int r1110;
+ };
+ union {
+ struct {
+ unsigned long r12;
+ unsigned long r13;
+ };
+ long long int r1312;
+ };
+ union {
+ struct {
+ unsigned long r14;
+ unsigned long r15;
+ };
+ long long int r1514;
+ };
+ union {
+ struct {
+ unsigned long r16;
+ unsigned long r17;
+ };
+ long long int r1716;
+ };
+ union {
+ struct {
+ unsigned long r18;
+ unsigned long r19;
+ };
+ long long int r1918;
+ };
+ union {
+ struct {
+ unsigned long r20;
+ unsigned long r21;
+ };
+ long long int r2120;
+ };
+ union {
+ struct {
+ unsigned long r22;
+ unsigned long r23;
+ };
+ long long int r2322;
+ };
+ union {
+ struct {
+ unsigned long r24;
+ unsigned long r25;
+ };
+ long long int r2524;
+ };
+ union {
+ struct {
+ unsigned long r26;
+ unsigned long r27;
+ };
+ long long int r2726;
+ };
+ union {
+ struct {
+ unsigned long r28;
+ unsigned long r29;
+ };
+ long long int r2928;
+ };
+ union {
+ struct {
+ unsigned long r30;
+ unsigned long r31;
+ };
+ long long int r3130;
+ };
+ /* VM dispatch pushes event record onto stack - we can build on it */
+ struct hvm_event_record hvmer;
+};
+
+/* Defines to conveniently access the values */
+
+/*
+ * As of the VM spec 0.5, these registers are now set/retrieved via a
+ * VM call. On the in-bound side, we just fetch the values
+ * at the entry points and stuff them into the old record in pt_regs.
+ * However, on the outbound side, probably at VM rte, we set the
+ * registers back.
+ */
+
+#define pt_elr(regs) ((regs)->hvmer.vmel)
+#define pt_set_elr(regs, val) ((regs)->hvmer.vmel = (val))
+#define pt_cause(regs) ((regs)->hvmer.vmest & (HVM_VMEST_CAUSE_MSK))
+#define user_mode(regs) \
+ (((regs)->hvmer.vmest & (HVM_VMEST_UM_MSK << HVM_VMEST_UM_SFT)) != 0)
+#define ints_enabled(regs) \
+ (((regs)->hvmer.vmest & (HVM_VMEST_IE_MSK << HVM_VMEST_IE_SFT)) != 0)
+#define pt_psp(regs) ((regs)->hvmer.vmpsp)
+#define pt_badva(regs) ((regs)->hvmer.vmbadva)
+
+#define pt_set_rte_sp(regs, sp) do {\
+ pt_psp(regs) = (sp);\
+ (regs)->SP = (unsigned long) &((regs)->hvmer);\
+ } while (0)
+
+#define pt_set_kmode(regs) \
+ (regs)->hvmer.vmest = (HVM_VMEST_IE_MSK << HVM_VMEST_IE_SFT)
+
+#define pt_set_usermode(regs) \
+ (regs)->hvmer.vmest = (HVM_VMEST_UM_MSK << HVM_VMEST_UM_SFT) \
+ | (HVM_VMEST_IE_MSK << HVM_VMEST_IE_SFT)
+
+#endif /* ifndef __ASSEMBLY */
+
+#endif
Index: linux-hexagon-kernel/arch/hexagon/include/asm/system.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/system.h 2011-09-03 20:14:59.544980887 -0500
@@ -0,0 +1,126 @@
+/*
+ * System level definitions for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_SYSTEM_H
+#define _ASM_SYSTEM_H
+
+#include <linux/linkage.h>
+#include <linux/irqflags.h>
+#include <asm/atomic.h>
+#include <asm/hexagon_vm.h>
+
+struct thread_struct;
+
+extern struct task_struct *__switch_to(struct task_struct *,
+ struct task_struct *,
+ struct task_struct *);
+
+#define switch_to(p, n, r) do {\
+ r = __switch_to((p), (n), (r));\
+} while (0)
+
+
+#define rmb() barrier()
+#define read_barrier_depends() barrier()
+#define wmb() barrier()
+#define mb() barrier()
+#define smp_rmb() barrier()
+#define smp_read_barrier_depends() barrier()
+#define smp_wmb() barrier()
+#define smp_mb() barrier()
+#define smp_mb__before_atomic_dec() barrier()
+#define smp_mb__after_atomic_dec() barrier()
+#define smp_mb__before_atomic_inc() barrier()
+#define smp_mb__after_atomic_inc() barrier()
+
+/*
+ * __xchg - atomically exchange a register and a memory location
+ * @x: value to swap
+ * @ptr: pointer to memory
+ * @size: size of the value
+ *
+ * Only 4 bytes supported currently.
+ *
+ * Note: there was an errata for V2 about .new's and memw_locked.
+ *
+ */
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+ int size)
+{
+ unsigned long retval;
+
+ /* Can't seem to use printk or panic here, so just stop */
+ if (size != 4) do { asm volatile("brkpt;\n"); } while (1);
+
+ __asm__ __volatile__ (
+ "1: %0 = memw_locked(%1);\n" /* load into retval */
+ " memw_locked(%1,P0) = %2;\n" /* store into memory */
+ " if !P0 jump 1b;\n"
+ : "=&r" (retval)
+ : "r" (ptr), "r" (x)
+ : "memory", "p0"
+ );
+ return retval;
+}
+
+/*
+ * Atomically swap the contents of a register with memory. Should be atomic
+ * between multiple CPU's and within interrupts on the same CPU.
+ */
+#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
+ sizeof(*(ptr))))
+
+/* Set a value and use a memory barrier. Used by the scheduler somewhere. */
+#define set_mb(var, value) \
+ do { var = value; mb(); } while (0)
+
+/*
+ * see rt-mutex-design.txt; cmpxchg supposedly checks if *ptr == A and swaps.
+ * looks just like atomic_cmpxchg on our arch currently with a bunch of
+ * variable casting.
+ */
+#define __HAVE_ARCH_CMPXCHG 1
+
+#define cmpxchg(ptr, old, new) \
+({ \
+ __typeof__(ptr) __ptr = (ptr); \
+ __typeof__(*(ptr)) __old = (old); \
+ __typeof__(*(ptr)) __new = (new); \
+ __typeof__(*(ptr)) __oldval = 0; \
+ \
+ asm volatile( \
+ "1: %0 = memw_locked(%1);\n" \
+ " { P0 = cmp.eq(%0,%2);\n" \
+ " if (!P0.new) jump:nt 2f; }\n" \
+ " memw_locked(%1,p0) = %3;\n" \
+ " if (!P0) jump 1b;\n" \
+ "2:\n" \
+ : "=&r" (__oldval) \
+ : "r" (__ptr), "r" (__old), "r" (__new) \
+ : "memory", "p0" \
+ ); \
+ __oldval; \
+})
+
+/* Should probably shoot for an 8-byte aligned stack pointer */
+#define STACK_MASK (~7)
+#define arch_align_stack(x) (x & STACK_MASK)
+
+#endif
Index: linux-hexagon-kernel/arch/hexagon/include/asm/asm-offsets.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/asm-offsets.h 2011-09-03 20:14:59.544980887 -0500
@@ -0,0 +1 @@
+#include <generated/asm-offsets.h>