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Commit 8c13f599 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Michael Ellerman
Browse files

powerpc/ptrace: Enable support for NT_PPC_CVMX 



This patch enables support for TM checkpointed VMX register
set ELF core note NT_PPC_CVMX based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding a register set REGSET_CVMX in powerpc
corresponding to the ELF core note section added. It
implements the get, set and active functions for this new
register set added.

Signed-off-by: default avatarAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: default avatarSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 19cbcbf7

arch/powerpc/include/uapi/asm/elf.h

+1 −0
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ 


#define ELF_NGREG	48	/* includes nip, msr, lr, etc. */

#define ELF_NFPREG	33	/* includes fpscr */

#define ELF_NVMX	34	/* includes all vector registers */



typedef unsigned long elf_greg_t64;

typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG];

arch/powerpc/kernel/ptrace.c

+158 −0
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ struct pt_regs_offset { 
	{.name = STR(gpr##num), .offset = offsetof(struct pt_regs, gpr[num])}

#define REG_OFFSET_END {.name = NULL, .offset = 0}



#define TVSO(f)	(offsetof(struct thread_vr_state, f))



static const struct pt_regs_offset regoffset_table[] = {

	GPR_OFFSET_NAME(0),

	GPR_OFFSET_NAME(1),
@@ -1147,6 +1149,151 @@ static int tm_cfpr_set(struct task_struct *target, 
	target->thread.fp_state.fpscr = buf[32];

	return 0;

}



/**

 * tm_cvmx_active - get active number of registers in CVMX

 * @target:	The target task.

 * @regset:	The user regset structure.

 *

 * This function checks for the active number of available

 * regisers in checkpointed VMX category.

 */

static int tm_cvmx_active(struct task_struct *target,

				const struct user_regset *regset)

{

	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return 0;



	return regset->n;

}



/**

 * tm_cvmx_get - get CMVX registers

 * @target:	The target task.

 * @regset:	The user regset structure.

 * @pos:	The buffer position.

 * @count:	Number of bytes to copy.

 * @kbuf:	Kernel buffer to copy from.

 * @ubuf:	User buffer to copy into.

 *

 * This function gets in transaction checkpointed VMX registers.

 *

 * When the transaction is active 'vr_state' and 'vr_save' hold

 * the checkpointed values for the current transaction to fall

 * back on if it aborts in between. The userspace interface buffer

 * layout is as follows.

 *

 * struct data {

 *	vector128	vr[32];

 *	vector128	vscr;

 *	vector128	vrsave;

 *};

 */

static int tm_cvmx_get(struct task_struct *target,

			const struct user_regset *regset,

			unsigned int pos, unsigned int count,

			void *kbuf, void __user *ubuf)

{

	int ret;



	BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32]));



	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return -ENODATA;



	/* Flush the state */

	flush_fp_to_thread(target);

	flush_altivec_to_thread(target);

	flush_tmregs_to_thread(target);



	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,

					&target->thread.vr_state, 0,

					33 * sizeof(vector128));

	if (!ret) {

		/*

		 * Copy out only the low-order word of vrsave.

		 */

		union {

			elf_vrreg_t reg;

			u32 word;

		} vrsave;

		memset(&vrsave, 0, sizeof(vrsave));

		vrsave.word = target->thread.vrsave;

		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,

						33 * sizeof(vector128), -1);

	}



	return ret;

}



/**

 * tm_cvmx_set - set CMVX registers

 * @target:	The target task.

 * @regset:	The user regset structure.

 * @pos:	The buffer position.

 * @count:	Number of bytes to copy.

 * @kbuf:	Kernel buffer to copy into.

 * @ubuf:	User buffer to copy from.

 *

 * This function sets in transaction checkpointed VMX registers.

 *

 * When the transaction is active 'vr_state' and 'vr_save' hold

 * the checkpointed values for the current transaction to fall

 * back on if it aborts in between. The userspace interface buffer

 * layout is as follows.

 *

 * struct data {

 *	vector128	vr[32];

 *	vector128	vscr;

 *	vector128	vrsave;

 *};

 */

static int tm_cvmx_set(struct task_struct *target,

			const struct user_regset *regset,

			unsigned int pos, unsigned int count,

			const void *kbuf, const void __user *ubuf)

{

	int ret;



	BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32]));



	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return -ENODATA;



	flush_fp_to_thread(target);

	flush_altivec_to_thread(target);

	flush_tmregs_to_thread(target);



	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

					&target->thread.vr_state, 0,

					33 * sizeof(vector128));

	if (!ret && count > 0) {

		/*

		 * We use only the low-order word of vrsave.

		 */

		union {

			elf_vrreg_t reg;

			u32 word;

		} vrsave;

		memset(&vrsave, 0, sizeof(vrsave));

		vrsave.word = target->thread.vrsave;

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,

						33 * sizeof(vector128), -1);

		if (!ret)

			target->thread.vrsave = vrsave.word;

	}



	return ret;

}

#endif



/*
@@ -1167,6 +1314,7 @@ enum powerpc_regset { 
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	REGSET_TM_CGPR,		/* TM checkpointed GPR registers */

	REGSET_TM_CFPR,		/* TM checkpointed FPR registers */

	REGSET_TM_CVMX,		/* TM checkpointed VMX registers */

#endif

};
@@ -1213,6 +1361,11 @@ static const struct user_regset native_regsets[] = { 
		.size = sizeof(double), .align = sizeof(double),

		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set

	},

	[REGSET_TM_CVMX] = {

		.core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX,

		.size = sizeof(vector128), .align = sizeof(vector128),

		.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set

	},

#endif

};
@@ -1450,6 +1603,11 @@ static const struct user_regset compat_regsets[] = { 
		.size = sizeof(double), .align = sizeof(double),

		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set

	},

	[REGSET_TM_CVMX] = {

		.core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX,

		.size = sizeof(vector128), .align = sizeof(vector128),

		.active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set

	},

#endif

};