From: Thomas Gleixner <tglx@linutronix.de>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
x86@kernel.org, platform-driver-x86@vger.kernel.org,
dave.hansen@intel.com, sean.j.christopherson@intel.com,
nhorman@redhat.com, npmccallum@redhat.com,
linux-sgx@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v12 07/13] x86/sgx: data structures for tracking available EPC pages
Date: Tue, 3 Jul 2018 22:44:24 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1807032242140.1816@nanos.tec.linutronix.de> (raw)
In-Reply-To: <00ca61d5-5a1d-5c83-3b49-62c899a87041@infradead.org>
On Tue, 3 Jul 2018, Randy Dunlap wrote:
> On 07/03/18 12:46, Thomas Gleixner wrote:
> > On Tue, 3 Jul 2018, Jarkko Sakkinen wrote:
> >
> >> SGX has a set of data structures to maintain information about the enclaves
> >> and their security properties. BIOS reserves a fixed size region of
> >> physical memory for these structures by setting Processor Reserved Memory
> >> Range Registers (PRMRR). This memory area is called Enclave Page Cache
> >> (EPC).
> >>
> >> This commit adds a database of EPC banks for kernel to easily access the
>
> what kind of database? How does one query it?
>
> >> diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
> >> index 2130e639ab49..77b2294fcfb0 100644
> >> --- a/arch/x86/include/asm/sgx.h
> >> +++ b/arch/x86/include/asm/sgx.h
>
>
> >> +/**
> >> + * sgx_get_page - pin an EPC page
> >
> > Description starts with an uppercase letter.
>
> How would someone know that? It's not documented anywhere.
It's a short sentence decribing the function and sentences start usually
with uppercase letters, right?
> I happen to disagree with it.
Then we have to agree that we disagree.
> >> +static __init int sgx_page_cache_init(void)
> >> +{
> >> + unsigned long size;
> >> + unsigned int eax;
> >> + unsigned int ebx;
> >> + unsigned int ecx;
> >> + unsigned int edx;
> >> + unsigned long pa;
> >> + int i;
> >> + int ret;
> >
> > Please aggregate the declarations of the same type. No point in wasting all
> > the screen space. And please use 'u32' for ea-dx
> >
> >> +
> >> + for (i = 0; i < SGX_MAX_EPC_BANKS; i++) {
> >> + cpuid_count(SGX_CPUID, i + SGX_CPUID_EPC_BANKS, &eax, &ebx,
> >> + &ecx, &edx);
> >> + if (!(eax & 0xf))
> >> + break;
> >> +
> >> + pa = ((u64)(ebx & 0xfffff) << 32) + (u64)(eax & 0xfffff000);
> >> + size = ((u64)(edx & 0xfffff) << 32) + (u64)(ecx & 0xfffff000);
> >
> > These magic constants should be 'U', using uppercase 'F' and defines. Plus
> > this wants a comment how pa and size are cobbled together from the cpuid
> > regs.
>
> Why the uppercase 'F'?
Makes is more readable IMO, but I'm not religious about that.
Thanks,
tglx
next prev parent reply other threads:[~2018-07-03 20:44 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-03 18:19 [PATCH v12 00/13] Intel SGX1 support Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 01/13] x86/sgx: updated MAINTAINERS Jarkko Sakkinen
2018-07-03 18:41 ` Thomas Gleixner
2018-07-04 17:23 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 02/13] x86/sgx: add SGX definitions to cpufeature Jarkko Sakkinen
2018-07-03 18:48 ` Thomas Gleixner
2018-07-04 17:24 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 03/13] x86/sgx: add SGX definitions to msr-index.h Jarkko Sakkinen
2018-07-03 18:31 ` Dave Hansen
2018-07-04 17:25 ` Jarkko Sakkinen
2018-07-05 16:05 ` Jarkko Sakkinen
2018-07-05 16:08 ` Jarkko Sakkinen
2018-07-05 16:09 ` Dave Hansen
2018-07-03 18:51 ` Thomas Gleixner
2018-07-04 17:26 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 04/13] x86/cpufeatures: add Intel-defined SGX leaf CPUID_12_EAX Jarkko Sakkinen
2018-07-03 18:54 ` Thomas Gleixner
2018-07-04 17:27 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 05/13] x86/sgx: architectural structures Jarkko Sakkinen
2018-07-03 19:02 ` Dave Hansen
2018-07-04 18:03 ` Jarkko Sakkinen
2018-07-03 19:04 ` Thomas Gleixner
2018-07-04 18:07 ` Jarkko Sakkinen
2018-07-03 21:22 ` Dave Hansen
2018-07-04 18:09 ` Jarkko Sakkinen
2018-07-05 15:31 ` Dave Hansen
2018-07-05 20:09 ` Jarkko Sakkinen
2018-07-05 21:50 ` hpa
2018-07-10 8:06 ` Andy Shevchenko
2018-07-10 11:57 ` Thomas Gleixner
2018-07-03 18:19 ` [PATCH v12 06/13] x86/sgx: detect Intel SGX Jarkko Sakkinen
2018-07-03 19:09 ` Thomas Gleixner
2018-07-04 17:28 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 07/13] x86/sgx: data structures for tracking available EPC pages Jarkko Sakkinen
2018-07-03 19:03 ` Dave Hansen
2018-07-04 17:34 ` Jarkko Sakkinen
2018-07-03 19:46 ` Thomas Gleixner
2018-07-03 20:26 ` Randy Dunlap
2018-07-03 20:44 ` Thomas Gleixner [this message]
2018-07-04 17:36 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 08/13] x86/sgx: wrappers for ENCLS opcode leaf functions Jarkko Sakkinen
2018-07-03 20:16 ` Thomas Gleixner
2018-07-04 17:33 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 09/13] x86/sgx: EPC page allocation routines Jarkko Sakkinen
2018-07-03 20:41 ` Thomas Gleixner
2018-07-04 4:25 ` Borislav Petkov
2018-07-05 18:21 ` Jarkko Sakkinen
2018-07-04 18:24 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 10/13] x86/sgx: sgx_einit() Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 11/13] platform/x86: Intel SGX driver Jarkko Sakkinen
2018-07-25 15:52 ` Jethro Beekman
2018-07-28 13:23 ` Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 12/13] platform/x86: ptrace() support for the " Jarkko Sakkinen
2018-07-03 18:19 ` [PATCH v12 13/13] x86/sgx: driver documentation Jarkko Sakkinen
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