Date: Mon, 20 Aug 2018 19:09:40 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r338113 - head/sys/amd64/amd64 Message-ID: <201808201909.w7KJ9e9O065107@repo.freebsd.org>
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Author: kib Date: Mon Aug 20 19:09:39 2018 New Revision: 338113 URL: https://svnweb.freebsd.org/changeset/base/338113 Log: Update comment about ABI of flush_l1s_sw to match the reality. CPUID instruction clobbers %rbx and %rdx. Sponsored by: The FreeBSD Foundation MFC after: 13 days Modified: head/sys/amd64/amd64/support.S Modified: head/sys/amd64/amd64/support.S ============================================================================== --- head/sys/amd64/amd64/support.S Mon Aug 20 19:07:57 2018 (r338112) +++ head/sys/amd64/amd64/support.S Mon Aug 20 19:09:39 2018 (r338113) @@ -1230,9 +1230,9 @@ END(handle_ibrs_exit_rs) * Flush L1D cache. Load enough of the data from the kernel text * to flush existing L1D content. * - * N.B. The function follows ABI calling conventions, but the vmm.ko - * caller expects that only %rax, %rcx, %r9, and %rflags registers - * are clobbered. + * N.B. The function does not follow ABI calling conventions, it corrupts %rbx. + * The vmm.ko caller expects that only %rax, %rdx, %rbx, %rcx, %r9, and %rflags + * registers are clobbered. The NMI handler caller only needs %r13 preserved. */ ENTRY(flush_l1d_sw) #define L1D_FLUSH_SIZE (64 * 1024)
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