[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v2] xen/arm64: Remove READ/WRITE_SYSREG32 helper macros


  • To: Michal Orzel <Michal.Orzel@xxxxxxx>
  • From: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>
  • Date: Fri, 9 Jul 2021 15:11:01 +0000
  • Accept-language: en-GB, en-US
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ly/jGwJSTuKTo5IM7EFHb6rlW8MzAtRJMEWFJ8/GNTc=; b=WoGZHmA3/NSqh2a63BUX/4zPfo04Q71PtoSJ2fe/vTDl5y7pgqhtRSHRFKykKMsUdgbJqRcXl0YadqUwZTiOBa+sRvsoXXoeK5EWl2LopRUpa6Vf2+pZWJ0UHS8qDmFZQ7b3YQ1uhiOjAQE0gL0o3l2uKu1LzAasWCSdAIQjKNipiSQ/JvwgzC73z7drdEDQgjphQQkzGlVnKnj1PSnMlg/aDoTalFO8VvdQSFw5zFWwe3dOynDYR+PUmz2pU9qRz8fM6MJUQAaLyO31dWvwNhCBd6dmD0jQphiejgRrZi2KMYu/D7f5uE9cLSMHEXyoGpjefAZaS8qiXz7Dhxpw+Q==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=EnmxTgv7kxm7v2qBdIjvkYQzrT8umNs+4ln/SE8wu6vUlchvaBzckFma2fKVhkW7E93vPNRNoqqpI+uO3IGj1uxa6VpHE2StKVHja9mIoArEi1tJV19nlmhixCjirCdxFUTGE81ad7Ol0L+YJoHd8M9cCgu4Fet+ttvT2R180M9m1nWdyxwn9j/GT3H/YHfs2U+ITZisSXo9f6/mtW3ueRjaHv11aU2Z38CLDpuF6TcCzu43S79/kpSIGuPeRV9EpB2AaVFEbBAVSSz9f50cxZtm9aM5xoagXGastQVCerOS6+ovApTR2QgoERqgKMkZWZakyS5GPSz00SNZPygaNA==
  • Authentication-results-original: arm.com; dkim=none (message not signed) header.d=none;arm.com; dmarc=none action=none header.from=arm.com;
  • Cc: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
  • Delivery-date: Fri, 09 Jul 2021 15:11:53 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
  • Nodisclaimer: true
  • Original-authentication-results: arm.com; dkim=none (message not signed) header.d=none;arm.com; dmarc=none action=none header.from=arm.com;
  • Thread-index: AQHXdL+w0n2h/dQ/DEuP6N84Q1GgYKs6v8AA
  • Thread-topic: [PATCH v2] xen/arm64: Remove READ/WRITE_SYSREG32 helper macros

Hi Michal,

> On 9 Jul 2021, at 13:40, Michal Orzel <Michal.Orzel@xxxxxxx> wrote:
> 
> AArch64 system registers are 64bit whereas AArch32 ones
> are 32bit or 64bit. MSR/MRS are expecting 64bit values thus
> we should get rid of helpers READ/WRITE_SYSREG32
> in favour of using READ/WRITE_SYSREG.
> 
> The last place in code making use of READ/WRITE_SYSREG32
> on arm64 is in TVM_REG macro defining functions vreg_emulate_<register>.
> Implement a macro WRITE_SYSREG_SZ which expands as follows:
> -on arm64: WRITE_SYSREG
> -on arm32: WRITE_SYSREG{32/64}
> 
> As there are no other places in the code using these helpers
> on arm64 - remove them.
> 
> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

Cheers
Bertrand

> ---
> Changes since v1:
> -implement WRITE_SYSREG_SZ instead of duplicating the TVM_REG
> ---
> xen/arch/arm/vcpreg.c               | 12 +++++++++++-
> xen/include/asm-arm/arm64/sysregs.h |  4 ----
> 2 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/xen/arch/arm/vcpreg.c b/xen/arch/arm/vcpreg.c
> index f0cdcc8a54..10c4846954 100644
> --- a/xen/arch/arm/vcpreg.c
> +++ b/xen/arch/arm/vcpreg.c
> @@ -47,6 +47,16 @@
>  *
>  */
> 
> +#ifdef CONFIG_ARM_64
> +#define WRITE_SYSREG_SZ(sz, val, sysreg)     WRITE_SYSREG(val, sysreg)
> +#else
> +/*
> + * WRITE_SYSREG{32/64} on arm32 is defined as variadic macro which imposes
> + * on the below macro to be defined like that as well.
> + */
> +#define WRITE_SYSREG_SZ(sz, val, sysreg...)  WRITE_SYSREG##sz(val, sysreg)
> +#endif
> +
> /* The name is passed from the upper macro to workaround macro expansion. */
> #define TVM_REG(sz, func, reg...)                                           \
> static bool func(struct cpu_user_regs *regs, uint##sz##_t *r, bool read)    \
> @@ -55,7 +65,7 @@ static bool func(struct cpu_user_regs *regs, uint##sz##_t 
> *r, bool read)    \
>     bool cache_enabled = vcpu_has_cache_enabled(v);                         \
>                                                                             \
>     GUEST_BUG_ON(read);                                                     \
> -    WRITE_SYSREG##sz(*r, reg);                                              \
> +    WRITE_SYSREG_SZ(sz, *r, reg);                                           \
>                                                                             \
>     p2m_toggle_cache(v, cache_enabled);                                     \
>                                                                             \
> diff --git a/xen/include/asm-arm/arm64/sysregs.h 
> b/xen/include/asm-arm/arm64/sysregs.h
> index 077fd95fb7..795901e1ba 100644
> --- a/xen/include/asm-arm/arm64/sysregs.h
> +++ b/xen/include/asm-arm/arm64/sysregs.h
> @@ -87,10 +87,6 @@
> 
> /* Access to system registers */
> 
> -#define READ_SYSREG32(name) ((uint32_t)READ_SYSREG64(name))
> -
> -#define WRITE_SYSREG32(v, name) WRITE_SYSREG64((uint64_t)v, name)
> -
> #define WRITE_SYSREG64(v, name) do {                    \
>     uint64_t _r = v;                                    \
>     asm volatile("msr "__stringify(name)", %0" : : "r" (_r));       \
> -- 
> 2.29.0
> 
> 




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.