From: Toshi Kani <toshi.kani@hp.com> To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-nvdimm@lists.01.org, jgross@suse.com, stefan.bader@canonical.com, luto@amacapital.net, hmh@hmh.eng.br, yigal@plexistor.com, konrad.wilk@oracle.com, Elliott@hp.com, mcgrof@suse.com, hch@lst.de, Toshi Kani <toshi.kani@hp.com> Subject: [PATCH v11 1/12] x86, mm, pat: Cleanup init flags in pat_init() Date: Fri, 29 May 2015 16:58:59 -0600 [thread overview] Message-ID: <1432940350-1802-2-git-send-email-toshi.kani@hp.com> (raw) In-Reply-To: <1432940350-1802-1-git-send-email-toshi.kani@hp.com> From: Toshi Kani <toshi.kani@hp.com> pat_init() uses two flags, 'boot_cpu' and 'boot_pat_state', for tracking the boot CPU's initialization status. 'boot_pat_state' is also overloaded to carry the boot PAT value. This patch cleans this up by replacing them with a new single flag, 'boot_cpu_done', to track the boot CPU's initialization status. 'boot_pat_state' is only used to carry the boot PAT value as a result. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Toshi Kani <toshi.kani@hp.com> --- arch/x86/mm/pat.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index a1c9654..e1ec6a7 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -197,24 +197,29 @@ void pat_init_cache_modes(void) void pat_init(void) { u64 pat; - bool boot_cpu = !boot_pat_state; + static bool boot_cpu_done; if (!pat_enabled()) return; - if (!cpu_has_pat) { - if (!boot_pat_state) { + if (!boot_cpu_done) { + if (!cpu_has_pat) { pat_disable("PAT not supported by CPU."); return; - } else { - /* - * If this happens we are on a secondary CPU, but - * switched to PAT on the boot CPU. We have no way to - * undo PAT. - */ - pr_err("x86/PAT: PAT enabled, but not supported by secondary CPU\n"); - BUG(); } + + rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); + if (!boot_pat_state) { + pat_disable("PAT read returns always zero, disabled."); + return; + } + } else if (!cpu_has_pat) { + /* + * If this happens we are on a secondary CPU, but + * switched to PAT on the boot CPU. We have no way to + * undo PAT. + */ + panic("PAT enabled, but not supported by secondary CPU\n"); } /* Set PWT to Write-Combining. All other bits stay the same */ @@ -233,19 +238,12 @@ void pat_init(void) pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); - /* Boot CPU check */ - if (!boot_pat_state) { - rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); - if (!boot_pat_state) { - pat_disable("PAT read returns always zero, disabled."); - return; - } - } - wrmsrl(MSR_IA32_CR_PAT, pat); - if (boot_cpu) + if (!boot_cpu_done) { pat_init_cache_modes(); + boot_cpu_done = true; + } } #undef PAT -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Toshi Kani <toshi.kani@hp.com> To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-nvdimm@ml01.01.org, jgross@suse.com, stefan.bader@canonical.com, luto@amacapital.net, hmh@hmh.eng.br, yigal@plexistor.com, konrad.wilk@oracle.com, Elliott@hp.com, mcgrof@suse.com, hch@lst.de, Toshi Kani <toshi.kani@hp.com> Subject: [PATCH v11 1/12] x86, mm, pat: Cleanup init flags in pat_init() Date: Fri, 29 May 2015 16:58:59 -0600 [thread overview] Message-ID: <1432940350-1802-2-git-send-email-toshi.kani@hp.com> (raw) In-Reply-To: <1432940350-1802-1-git-send-email-toshi.kani@hp.com> From: Toshi Kani <toshi.kani@hp.com> pat_init() uses two flags, 'boot_cpu' and 'boot_pat_state', for tracking the boot CPU's initialization status. 'boot_pat_state' is also overloaded to carry the boot PAT value. This patch cleans this up by replacing them with a new single flag, 'boot_cpu_done', to track the boot CPU's initialization status. 'boot_pat_state' is only used to carry the boot PAT value as a result. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Toshi Kani <toshi.kani@hp.com> --- arch/x86/mm/pat.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index a1c9654..e1ec6a7 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -197,24 +197,29 @@ void pat_init_cache_modes(void) void pat_init(void) { u64 pat; - bool boot_cpu = !boot_pat_state; + static bool boot_cpu_done; if (!pat_enabled()) return; - if (!cpu_has_pat) { - if (!boot_pat_state) { + if (!boot_cpu_done) { + if (!cpu_has_pat) { pat_disable("PAT not supported by CPU."); return; - } else { - /* - * If this happens we are on a secondary CPU, but - * switched to PAT on the boot CPU. We have no way to - * undo PAT. - */ - pr_err("x86/PAT: PAT enabled, but not supported by secondary CPU\n"); - BUG(); } + + rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); + if (!boot_pat_state) { + pat_disable("PAT read returns always zero, disabled."); + return; + } + } else if (!cpu_has_pat) { + /* + * If this happens we are on a secondary CPU, but + * switched to PAT on the boot CPU. We have no way to + * undo PAT. + */ + panic("PAT enabled, but not supported by secondary CPU\n"); } /* Set PWT to Write-Combining. All other bits stay the same */ @@ -233,19 +238,12 @@ void pat_init(void) pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); - /* Boot CPU check */ - if (!boot_pat_state) { - rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); - if (!boot_pat_state) { - pat_disable("PAT read returns always zero, disabled."); - return; - } - } - wrmsrl(MSR_IA32_CR_PAT, pat); - if (boot_cpu) + if (!boot_cpu_done) { pat_init_cache_modes(); + boot_cpu_done = true; + } } #undef PAT
next prev parent reply other threads:[~2015-05-29 22:58 UTC|newest] Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-05-29 22:58 [PATCH v11 0/12] Support Write-Through mapping on x86 Toshi Kani 2015-05-29 22:58 ` Toshi Kani 2015-05-29 22:58 ` Toshi Kani [this message] 2015-05-29 22:58 ` [PATCH v11 1/12] x86, mm, pat: Cleanup init flags in pat_init() Toshi Kani 2015-05-29 22:59 ` [PATCH v11 2/12] x86, mm, pat: Refactor !pat_enabled handling Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-31 9:46 ` Borislav Petkov 2015-05-31 9:46 ` Borislav Petkov 2015-05-31 9:48 ` [PATCH 1/4] x86/pat: Untangle pat_init() Borislav Petkov 2015-05-31 9:48 ` Borislav Petkov 2015-05-31 9:48 ` [PATCH 2/4] x86/pat: Merge pat_init_cache_modes() into its caller Borislav Petkov 2015-05-31 9:48 ` Borislav Petkov 2015-05-31 10:15 ` Juergen Gross 2015-05-31 10:15 ` Juergen Gross 2015-05-31 10:24 ` Borislav Petkov 2015-05-31 10:24 ` Borislav Petkov 2015-05-31 10:23 ` Borislav Petkov 2015-05-31 10:23 ` Borislav Petkov 2015-05-31 10:23 ` Borislav Petkov 2015-05-31 11:02 ` Juergen Gross 2015-05-31 11:02 ` Juergen Gross 2015-05-31 11:02 ` Juergen Gross 2015-06-01 18:15 ` Toshi Kani 2015-06-01 18:15 ` Toshi Kani 2015-06-01 18:15 ` Toshi Kani 2015-05-31 9:48 ` [PATCH 3/4] x86/pat: Emulate PAT when it is disabled Borislav Petkov 2015-05-31 9:48 ` Borislav Petkov 2015-05-31 9:48 ` [PATCH 4/4] x86/pat: Remove pat_enabled() checks Borislav Petkov 2015-05-31 9:48 ` Borislav Petkov 2015-06-01 18:26 ` Toshi Kani 2015-06-01 18:26 ` Toshi Kani 2015-06-01 18:51 ` Borislav Petkov 2015-06-01 18:51 ` Borislav Petkov 2015-06-01 16:17 ` [PATCH 1/4] x86/pat: Untangle pat_init() Toshi Kani 2015-06-01 16:17 ` Toshi Kani 2015-06-01 15:50 ` [PATCH v11 2/12] x86, mm, pat: Refactor !pat_enabled handling Toshi Kani 2015-06-01 15:50 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 3/12] x86, mm, pat: Set WT to PA7 slot of PAT MSR Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 4/12] x86, mm, pat: Change reserve_memtype() for WT Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 5/12] x86, asm: Change is_new_memtype_allowed() " Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 6/12] x86, mm, asm-gen: Add ioremap_wt() " Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-30 9:18 ` Geert Uytterhoeven 2015-05-30 9:18 ` Geert Uytterhoeven 2015-05-31 0:58 ` Toshi Kani 2015-05-31 0:58 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 7/12] arch/*/asm/io.h: Add ioremap_wt() to all architectures Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 8/12] video/fbdev, asm/io.h: Remove ioremap_writethrough() Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 9/12] x86, mm, pat: Add pgprot_writethrough() for WT Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 10/12] x86, mm, asm: Add WT support to set_page_memtype() Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 11/12] x86, mm: Add set_memory_wt() for WT Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-29 22:59 ` [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt() Toshi Kani 2015-05-29 22:59 ` Toshi Kani 2015-05-30 1:18 ` Dan Williams 2015-05-30 1:18 ` Dan Williams
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