From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E40EC3DA7EA; Mon, 27 Apr 2026 15:37:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777304227; cv=none; b=hEaWSxBKAKI2r1XdrP21aREGR664DUdKd3xUvPN1PVxSBfoKb9D1PdWSEppWrxjhXq6QvMYjg0MMHbvvnW6j6rw+hCMFTaw9eMwZAMUwVHCUFUQ5t/NwrilnwOnVRPbBYfkGBanLa7ez/gdHSmZNKpN4qZVAKAq5wwMDQR2kElg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777304227; c=relaxed/simple; bh=RD3ZtVzROWEejg1rtd0aMaM4DwWAMRt4/5GO3gJJYrI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pGvJOEwGEYU0nSjvp6fmEX/38LzVmpYQqzvBs4nh9rRqliTkdJx3/HT/upEWn1Hj26xtOuMT/ramd3N/pZGdtQSHlWKnD5Ey4//W6hX8bC6Ql9xuFRkc7YHjjn1kIUlQztp7XqZxvW23uj+fpenOlbNuMijM50JiH/eEwTIj23k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HIZ4nwqQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HIZ4nwqQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CAD2C2BCB4; Mon, 27 Apr 2026 15:37:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777304226; bh=RD3ZtVzROWEejg1rtd0aMaM4DwWAMRt4/5GO3gJJYrI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=HIZ4nwqQAOJG0rNrvAB++fpY9O2UrC7aNWMwXnbqL583dPWyLIHIIVaDtrcfkFQ40 wjtlrRSVuvmgUvmdNTUlUwGjYeNFNjhcu2X1ovWGuQbTfjwHW9/GDBP6uIWhUFXSU+ BwOUW4fnChrsekPrsxn9kxapA2tLuMUeteoP60gzi8+ZrniQZHUbdEtYgWLf6oTqak P8LsZhB7/lzS9p8RUeCc7FHlEdQLNdfd5q1p1UR130UNXo+m9OG8WrVokZ8/bNWBA1 cIIplZL217t2oDugz+k5kRy0es0//YGOQcq8hLxJNxok0+HcPY9iNOLuSFDzkekH18 ZBjrFvRwZOYOA== Message-ID: <703848b6-d56b-4c2e-b92c-0ba982477b33@kernel.org> Date: Mon, 27 Apr 2026 10:37:04 -0500 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] ACPI: CPPC: Add support for CPPC v4 Content-Language: en-US To: Sumit Gupta , rafael@kernel.org, viresh.kumar@linaro.org, lenb@kernel.org, pierre.gondois@arm.com, zhenglifeng1@huawei.com, zhanjie9@hisilicon.com, saket.dumbre@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, acpica-devel@lists.linux.dev Cc: treding@nvidia.com, jonathanh@nvidia.com, vsethi@nvidia.com, ksitaraman@nvidia.com, sanjayc@nvidia.com, bbasu@nvidia.com References: <20260427051823.280419-1-sumitg@nvidia.com> <20260427051823.280419-2-sumitg@nvidia.com> From: Mario Limonciello In-Reply-To: <20260427051823.280419-2-sumitg@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/27/26 00:18, Sumit Gupta wrote: > CPPC v4 (ACPI 6.6, Section 8.4.6) adds two optional entries to the > _CPC package: > > 1. OSPM Nominal Performance (8.4.6.1.2.6): A write-only register that > lets OSPM inform the platform what it considers nominal performance. > The platform classifies performance above this level as boost and > below as throttle for its power/thermal decisions. > > 2. Resource Priority (8.4.6.1.2.7): A Package of Resource Priority > Register Descriptor sub-packages that allow OSPM to set relative > priority among processors for shared resources (boost, throttle, > L2/L3 cache, memory bandwidth). Parsing the full structure is not > yet supported; such entries are marked as unsupported. > > Add v4 _CPC table parsing (25 entries) and update REG_OPTIONAL to > mark the two new registers as optional. > > Signed-off-by: Sumit Gupta Reviewed-by: Mario Limonciello (AMD) > --- > drivers/acpi/cppc_acpi.c | 24 ++++++++++++++++++------ > include/acpi/cppc_acpi.h | 8 ++++++-- > 2 files changed, 24 insertions(+), 8 deletions(-) > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 2e91c5a97761..a1c91ce20cc8 100644 > --- a/drivers/acpi/cppc_acpi.c > +++ b/drivers/acpi/cppc_acpi.c > @@ -134,7 +134,7 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); > * cpc_regs[] with the corresponding index. 0 means mandatory and 1 > * means optional. > */ > -#define REG_OPTIONAL (0x1FC7D0) > +#define REG_OPTIONAL (0x7FC7D0) > > /* > * Use the index of the register in per-cpu cpc_regs[] to check if > @@ -751,18 +751,19 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) > /* > * Disregard _CPC if the number of entries in the return package is not > * as expected, but support future revisions being proper supersets of > - * the v3 and only causing more entries to be returned by _CPC. > + * the v4 and only causing more entries to be returned by _CPC. > */ > if ((cpc_rev == CPPC_V2_REV && num_ent != CPPC_V2_NUM_ENT) || > (cpc_rev == CPPC_V3_REV && num_ent != CPPC_V3_NUM_ENT) || > - (cpc_rev > CPPC_V3_REV && num_ent <= CPPC_V3_NUM_ENT)) { > + (cpc_rev == CPPC_V4_REV && num_ent != CPPC_V4_NUM_ENT) || > + (cpc_rev > CPPC_V4_REV && num_ent <= CPPC_V4_NUM_ENT)) { > pr_debug("Unexpected number of _CPC return package entries (%d) for CPU:%d\n", > num_ent, pr->id); > goto out_free; > } > - if (cpc_rev > CPPC_V3_REV) { > - num_ent = CPPC_V3_NUM_ENT; > - cpc_rev = CPPC_V3_REV; > + if (cpc_rev > CPPC_V4_REV) { > + num_ent = CPPC_V4_NUM_ENT; > + cpc_rev = CPPC_V4_REV; > } > > cpc_ptr->num_entries = num_ent; > @@ -845,6 +846,17 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) > > cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER; > memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t)); > + } else if (cpc_obj->type == ACPI_TYPE_PACKAGE) { > + /* > + * ACPI 6.6, s8.4.6.1.2.7 defines Resource Priority > + * as a Package of Resource Priority Register Descriptor > + * sub-packages. Parsing the full structure is not yet > + * supported; mark the register as unsupported for now. > + */ > + pr_debug("CPU:%d entry %d: package type not supported\n", > + pr->id, i); > + cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; > + cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = 0; > } else { > pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n", > i, pr->id); > diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h > index d1f02ceec4f9..8693890a7275 100644 > --- a/include/acpi/cppc_acpi.h > +++ b/include/acpi/cppc_acpi.h > @@ -17,16 +17,18 @@ > #include > #include > > -/* CPPCv2 and CPPCv3 support */ > +/* CPPCv2, CPPCv3 and CPPCv4 support */ > #define CPPC_V2_REV 2 > #define CPPC_V3_REV 3 > +#define CPPC_V4_REV 4 > #define CPPC_V2_NUM_ENT 21 > #define CPPC_V3_NUM_ENT 23 > +#define CPPC_V4_NUM_ENT 25 > > #define PCC_CMD_COMPLETE_MASK (1 << 0) > #define PCC_ERROR_MASK (1 << 2) > > -#define MAX_CPC_REG_ENT 21 > +#define MAX_CPC_REG_ENT 23 > > /* CPPC specific PCC commands. */ > #define CMD_READ 0 > @@ -109,6 +111,8 @@ enum cppc_regs { > REFERENCE_PERF, > LOWEST_FREQ, > NOMINAL_FREQ, > + OSPM_NOMINAL_PERF, > + RESOURCE_PRIORITY, > }; > > /*