[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v4 14/30] xen/riscv: introduce atomic.h
- To: Oleksii <oleksii.kurochko@xxxxxxxxx>
- From: Jan Beulich <jbeulich@xxxxxxxx>
- Date: Wed, 14 Feb 2024 14:09:33 +0100
- Autocrypt: addr=jbeulich@xxxxxxxx; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL
- Cc: Bobby Eshleman <bobbyeshleman@xxxxxxxxx>, Alistair Francis <alistair.francis@xxxxxxx>, Connor Davis <connojdavis@xxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, George Dunlap <george.dunlap@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
- Delivery-date: Wed, 14 Feb 2024 13:09:41 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 14.02.2024 13:11, Oleksii wrote:
> On Tue, 2024-02-13 at 12:36 +0100, Jan Beulich wrote:
>> On 05.02.2024 16:32, Oleksii Kurochko wrote:
>>> --- /dev/null
>>> +++ b/xen/arch/riscv/include/asm/atomic.h
>>> @@ -0,0 +1,395 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Taken and modified from Linux.
>>> + *
>>> + * atomic##prefix##_*xchg_*(atomic##prefix##_t *v, c_t n) were
>>> updated to use
>>> + * __*xchg_generic()
>>> + *
>>> + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
>>> + * Copyright (C) 2012 Regents of the University of California
>>> + * Copyright (C) 2017 SiFive
>>> + * Copyright (C) 2021 Vates SAS
>>> + */
>>> +
>>> +#ifndef _ASM_RISCV_ATOMIC_H
>>> +#define _ASM_RISCV_ATOMIC_H
>>> +
>>> +#include <xen/atomic.h>
>>> +#include <asm/cmpxchg.h>
>>> +#include <asm/fence.h>
>>> +#include <asm/io.h>
>>> +#include <asm/system.h>
>>> +
>>> +void __bad_atomic_size(void);
>>> +
>>> +static always_inline void read_atomic_size(const volatile void *p,
>>> + void *res,
>>> + unsigned int size)
>>> +{
>>> + switch ( size )
>>> + {
>>> + case 1: *(uint8_t *)res = readb(p); break;
>>> + case 2: *(uint16_t *)res = readw(p); break;
>>> + case 4: *(uint32_t *)res = readl(p); break;
>>> + case 8: *(uint32_t *)res = readq(p); break;
>>
>> Why is it the MMIO primitives you use here, i.e. not read<X>_cpu()?
>> It's RAM you're accessing after all.
> Legacy from Linux kernel. For some reason they wanted to have ordered
> read/write access.
Wants expressing in a comment then, or at the very least in the patch
description.
Jan
|
