From 565d956a7e191e95d81f515196951715f2616e6b Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 22 Feb 2013 14:12:22 +0100 Subject: ACPI: Overriding ACPI tables via initrd only works with an initrd and on X86 Reflect this dependency in Kconfig, to prevent build failures. Shorten the config description as suggested by Borislav Petkov. Finding a suitable memory area to store the modified table(s) has been taken over from arch/x86/kernel/setup.c and makes use of max_low_pfn_mapped: memblock_find_in_range(0, max_low_pfn_mapped,...) This one is X86 specific. It may not be hard to extend this functionality for other ACPI aware architectures if there is need for. For now make this feature only available for X86 to avoid build failures on IA64, compare with: https://bugzilla.kernel.org/show_bug.cgi?id=54091 Signed-off-by: Thomas Renninger Link: http://lkml.kernel.org/r/1361538742-67599-3-git-send-email-trenn@suse.de Signed-off-by: H. Peter Anvin diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 38c5078..f5ae996 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -268,7 +268,8 @@ config ACPI_CUSTOM_DSDT default ACPI_CUSTOM_DSDT_FILE != "" config ACPI_INITRD_TABLE_OVERRIDE - bool "ACPI tables can be passed via uncompressed cpio in initrd" + bool "ACPI tables override via initrd" + depends on BLK_DEV_INITRD && X86 default n help This option provides functionality to override arbitrary ACPI tables -- cgit v0.10.2 From 2482a92e7d17187301d7313cfe5021b13393a0b4 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Mon, 25 Feb 2013 15:54:08 -0500 Subject: doc, xen: Mention 'earlyprintk=xen' in the documentation. The earlyprintk for Xen PV guests utilizes a simple hypercall (console_io) to provide output to Xen emergency console. Note that the Xen hypervisor should be booted with 'loglevel=all' to output said information. Reported-by: H. Peter Anvin Signed-off-by: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1361825650-14031-2-git-send-email-konrad.wilk@oracle.com Cc: Signed-off-by: H. Peter Anvin diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 6c72381..c4cc199 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -754,6 +754,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. earlyprintk= [X86,SH,BLACKFIN] earlyprintk=vga + earlyprintk=xen earlyprintk=serial[,ttySn[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] @@ -771,6 +772,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. The VGA output is eventually overwritten by the real console. + The xen output can only be used by Xen PV guests. + ekgdboc= [X86,KGDB] Allow early kernel console debugging ekgdboc=kbd -- cgit v0.10.2 From a2fd6419174470f5ae6383f5037d0ee21ed9833f Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Mon, 25 Feb 2013 15:54:09 -0500 Subject: doc, kernel-parameters: Document 'console=hvc' Both the PowerPC hypervisor and Xen hypervisor can utilize the hvc driver. Cc: Greg KH Signed-off-by: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1361825650-14031-3-git-send-email-konrad.wilk@oracle.com Cc: Signed-off-by: H. Peter Anvin diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c4cc199..986614d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -564,6 +564,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. UART at the specified I/O port or MMIO address, switching to the matching ttyS device later. The options are the same as for ttyS, above. + hvc Use the hypervisor console device . This is for + both Xen and PowerPC hypervisors. If the device connected to the port is not a TTY but a braille device, prepend "brl," before the device type, for instance -- cgit v0.10.2 From 1256276c98dbcfb009ac8e0687df9a1e291fd149 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Mon, 25 Feb 2013 15:54:10 -0500 Subject: x86, doc: Fix incorrect comment about 64-bit code segment descriptors The AMD64 Architecture Programmer's Manual Volume 2, on page 89 mentions: "If the processor is running in 64-bit mode (L=1), the only valid setting of the D bit is 0." This matches with what the code does. Signed-off-by: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1361825650-14031-4-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 980053c..37f5304 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -49,7 +49,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map) startup_64: /* - * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1, + * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0, * and someone has loaded an identity mapped page table * for us. These identity mapped page tables map all of the * kernel pages and possibly all of memory. @@ -146,7 +146,7 @@ ident_complete: jmp secondary_startup_64 ENTRY(secondary_startup_64) /* - * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1, + * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0, * and someone has loaded a mapped page table. * * %esi holds a physical pointer to real_mode_data. -- cgit v0.10.2 From 058e7b5814534461b0e2468fce5a8f8d2f43c38f Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 22 Feb 2013 15:03:47 +0000 Subject: x86, efi: Mark disable_runtime as __initdata disable_runtime is only referenced from __init functions, so mark it as __initdata. Reported-by: Yinghai Lu Reviewed-by: Satoru Takeuchi Signed-off-by: Matt Fleming Link: http://lkml.kernel.org/r/1361545427-26393-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index e2cd38f..ec9f325 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -85,7 +85,7 @@ int efi_enabled(int facility) } EXPORT_SYMBOL(efi_enabled); -static bool disable_runtime = false; +static bool __initdata disable_runtime = false; static int __init setup_noefi(char *arg) { disable_runtime = true; -- cgit v0.10.2 From 7c10093692ed2e6f318387d96b829320aa0ca64c Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 27 Feb 2013 12:46:40 -0800 Subject: x86: Make sure we can boot in the case the BDA contains pure garbage On non-BIOS platforms it is possible that the BIOS data area contains garbage instead of being zeroed or something equivalent (firmware people: we are talking of 1.5K here, so please do the sane thing.) We need on the order of 20-30K of low memory in order to boot, which may grow up to < 64K in the future. We probably want to avoid the lowest of the low memory. At the same time, it seems extremely unlikely that a legitimate EBDA would ever reach down to the 128K (which would require it to be over half a megabyte in size.) Thus, pick 128K as the cutoff for "this is insane, ignore." We may still end up reserving a bunch of extra memory on the low megabyte, but that is not really a major issue these days. In the worst case we lose 512K of RAM. This code really should be merged with trim_bios_range() in arch/x86/kernel/setup.c, but that is a bigger patch for a later merge window. Reported-by: Darren Hart Signed-off-by: H. Peter Anvin Cc: Matt Fleming Cc: Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org diff --git a/arch/x86/kernel/head.c b/arch/x86/kernel/head.c index 48d9d4e..992f442 100644 --- a/arch/x86/kernel/head.c +++ b/arch/x86/kernel/head.c @@ -5,8 +5,6 @@ #include #include -#define BIOS_LOWMEM_KILOBYTES 0x413 - /* * The BIOS places the EBDA/XBDA at the top of conventional * memory, and usually decreases the reported amount of @@ -16,17 +14,30 @@ * chipset: reserve a page before VGA to prevent PCI prefetch * into it (errata #56). Usually the page is reserved anyways, * unless you have no PS/2 mouse plugged in. + * + * This functions is deliberately very conservative. Losing + * memory in the bottom megabyte is rarely a problem, as long + * as we have enough memory to install the trampoline. Using + * memory that is in use by the BIOS or by some DMA device + * the BIOS didn't shut down *is* a big problem. */ + +#define BIOS_LOWMEM_KILOBYTES 0x413 +#define LOWMEM_CAP 0x9f000U /* Absolute maximum */ +#define INSANE_CUTOFF 0x20000U /* Less than this = insane */ + void __init reserve_ebda_region(void) { unsigned int lowmem, ebda_addr; - /* To determine the position of the EBDA and the */ - /* end of conventional memory, we need to look at */ - /* the BIOS data area. In a paravirtual environment */ - /* that area is absent. We'll just have to assume */ - /* that the paravirt case can handle memory setup */ - /* correctly, without our help. */ + /* + * To determine the position of the EBDA and the + * end of conventional memory, we need to look at + * the BIOS data area. In a paravirtual environment + * that area is absent. We'll just have to assume + * that the paravirt case can handle memory setup + * correctly, without our help. + */ if (paravirt_enabled()) return; @@ -37,19 +48,23 @@ void __init reserve_ebda_region(void) /* start of EBDA area */ ebda_addr = get_bios_ebda(); - /* Fixup: bios puts an EBDA in the top 64K segment */ - /* of conventional memory, but does not adjust lowmem. */ - if ((lowmem - ebda_addr) <= 0x10000) - lowmem = ebda_addr; + /* + * Note: some old Dells seem to need 4k EBDA without + * reporting so, so just consider the memory above 0x9f000 + * to be off limits (bugzilla 2990). + */ + + /* If the EBDA address is below 128K, assume it is bogus */ + if (ebda_addr < INSANE_CUTOFF) + ebda_addr = LOWMEM_CAP; - /* Fixup: bios does not report an EBDA at all. */ - /* Some old Dells seem to need 4k anyhow (bugzilla 2990) */ - if ((ebda_addr == 0) && (lowmem >= 0x9f000)) - lowmem = 0x9f000; + /* If lowmem is less than 128K, assume it is bogus */ + if (lowmem < INSANE_CUTOFF) + lowmem = LOWMEM_CAP; - /* Paranoia: should never happen, but... */ - if ((lowmem == 0) || (lowmem >= 0x100000)) - lowmem = 0x9f000; + /* Use the lower of the lowmem and EBDA markers as the cutoff */ + lowmem = min(lowmem, ebda_addr); + lowmem = min(lowmem, LOWMEM_CAP); /* Absolute cap */ /* reserve all memory between lowmem and the 1MB mark */ memblock_reserve(lowmem, 0x100000 - lowmem); -- cgit v0.10.2