| Message ID | 1459529620-22150-5-git-send-email-james.morse@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/04/16 17:53, James Morse wrote: > The hyp-stub could make use of the do_el2_call(), move it to a header file. > > Signed-off-by: James Morse <james.morse@arm.com> > --- > arch/arm64/include/asm/virt.h | 18 +++++++++++++++++- > arch/arm64/kvm/hyp/hyp-entry.S | 17 +---------------- > 2 files changed, 18 insertions(+), 17 deletions(-) > > diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h > index 9f22dd607958..b8fdddeca71b 100644 > --- a/arch/arm64/include/asm/virt.h > +++ b/arch/arm64/include/asm/virt.h > @@ -21,7 +21,23 @@ > #define BOOT_CPU_MODE_EL1 (0xe11) > #define BOOT_CPU_MODE_EL2 (0xe12) > > -#ifndef __ASSEMBLY__ > +#ifdef __ASSEMBLY__ > +.macro do_el2_call > + /* > + * Shuffle the parameters before calling the function > + * pointed to in x0. Assumes parameters in x[1,2,3]. > + */ > + sub sp, sp, #16 > + str lr, [sp] > + mov lr, x0 > + mov x0, x1 > + mov x1, x2 > + mov x2, x3 > + blr lr > + ldr lr, [sp] > + add sp, sp, #16 > +.endm > +#else So while I'm not opposed to this macro being reused, the name is slightly misleading out of the original context. This macro doesn't take you to EL2, but implements a very peculiar calling convention that only the HYP code is expecting. Could we have a disclaimer saying something along the lines of "Don't you dare using this macro!"? Otherwise: Acked-by: Marc Zyngier <marc.zyngier@arm.com> M.
Hi Marc, On 19/04/16 16:02, Marc Zyngier wrote: > On 01/04/16 17:53, James Morse wrote: >> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h >> index 9f22dd607958..b8fdddeca71b 100644 >> --- a/arch/arm64/include/asm/virt.h >> +++ b/arch/arm64/include/asm/virt.h >> @@ -21,7 +21,23 @@ >> #define BOOT_CPU_MODE_EL1 (0xe11) >> #define BOOT_CPU_MODE_EL2 (0xe12) >> >> -#ifndef __ASSEMBLY__ >> +#ifdef __ASSEMBLY__ >> +.macro do_el2_call >> + /* >> + * Shuffle the parameters before calling the function >> + * pointed to in x0. Assumes parameters in x[1,2,3]. >> + */ >> + sub sp, sp, #16 >> + str lr, [sp] >> + mov lr, x0 >> + mov x0, x1 >> + mov x1, x2 >> + mov x2, x3 >> + blr lr >> + ldr lr, [sp] >> + add sp, sp, #16 >> +.endm >> +#else > > So while I'm not opposed to this macro being reused, the name is > slightly misleading out of the original context. This macro doesn't take > you to EL2, but implements a very peculiar calling convention that only > the HYP code is expecting. Ah, I hadn't thought of it like that! > Could we have a disclaimer saying something along the lines of "Don't > you dare using this macro!"? Or rename it? Something like 'unpack_el2_call'. Thanks, James
On 19/04/16 16:05, James Morse wrote: > Hi Marc, > > On 19/04/16 16:02, Marc Zyngier wrote: >> On 01/04/16 17:53, James Morse wrote: >>> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h >>> index 9f22dd607958..b8fdddeca71b 100644 >>> --- a/arch/arm64/include/asm/virt.h >>> +++ b/arch/arm64/include/asm/virt.h >>> @@ -21,7 +21,23 @@ >>> #define BOOT_CPU_MODE_EL1 (0xe11) >>> #define BOOT_CPU_MODE_EL2 (0xe12) >>> >>> -#ifndef __ASSEMBLY__ >>> +#ifdef __ASSEMBLY__ >>> +.macro do_el2_call >>> + /* >>> + * Shuffle the parameters before calling the function >>> + * pointed to in x0. Assumes parameters in x[1,2,3]. >>> + */ >>> + sub sp, sp, #16 >>> + str lr, [sp] >>> + mov lr, x0 >>> + mov x0, x1 >>> + mov x1, x2 >>> + mov x2, x3 >>> + blr lr >>> + ldr lr, [sp] >>> + add sp, sp, #16 >>> +.endm >>> +#else >> >> So while I'm not opposed to this macro being reused, the name is >> slightly misleading out of the original context. This macro doesn't take >> you to EL2, but implements a very peculiar calling convention that only >> the HYP code is expecting. > > Ah, I hadn't thought of it like that! > > >> Could we have a disclaimer saying something along the lines of "Don't >> you dare using this macro!"? > > Or rename it? Something like 'unpack_el2_call'. Works for me! M.
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 9f22dd607958..b8fdddeca71b 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -21,7 +21,23 @@ #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) -#ifndef __ASSEMBLY__ +#ifdef __ASSEMBLY__ +.macro do_el2_call + /* + * Shuffle the parameters before calling the function + * pointed to in x0. Assumes parameters in x[1,2,3]. + */ + sub sp, sp, #16 + str lr, [sp] + mov lr, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + blr lr + ldr lr, [sp] + add sp, sp, #16 +.endm +#else #include <asm/ptrace.h> diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 3488894397ff..358f27a1edc2 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -23,6 +23,7 @@ #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> +#include <asm/virt.h> .text .pushsection .hyp.text, "ax" @@ -37,22 +38,6 @@ ldp x0, x1, [sp], #16 .endm -.macro do_el2_call - /* - * Shuffle the parameters before calling the function - * pointed to in x0. Assumes parameters in x[1,2,3]. - */ - sub sp, sp, #16 - str lr, [sp] - mov lr, x0 - mov x0, x1 - mov x1, x2 - mov x2, x3 - blr lr - ldr lr, [sp] - add sp, sp, #16 -.endm - ENTRY(__vhe_hyp_call) do_el2_call /*
The hyp-stub could make use of the do_el2_call(), move it to a header file. Signed-off-by: James Morse <james.morse@arm.com> --- arch/arm64/include/asm/virt.h | 18 +++++++++++++++++- arch/arm64/kvm/hyp/hyp-entry.S | 17 +---------------- 2 files changed, 18 insertions(+), 17 deletions(-)