kernel.git/arch/powerpc/kernel/prom_init.c, branch linux-2.6.28.y

Revert "powerpc: Sync RPA note in zImage with kernel's RPA note"

2008-10-31T11:36:21Z

This reverts commit 91a00302959545a9ae423e99732b1e46eb19e877, plus commit 0dcd440120ef12879ff34fc78d7e4abf171c79e4 ("powerpc: Revert CHRP boot wrapper to real-base = 12MB on 32-bit") which depended on it. Commit 91a00302 was causing NVRAM corruption on some pSeries machines, for as-yet unknown reasons, so this reverts it until the cause is identified. Signed-off-by: Paul Mackerras

powerpc: Delete unused prom_strtoul and prom_memparse

2008-10-21T04:20:08Z

These functions should have been static, and inspection shows they are no longer used. (We used to parse mem= but we now defer that to early_param). Signed-off-by: Milton Miller Signed-off-by: Benjamin Herrenschmidt

powerpc: Sync RPA note in zImage with kernel's RPA note

2008-10-10T04:55:19Z

Commit 9b09c6d909dfd8de96b99b9b9c808b94b0a71614 ("powerpc: Change the default link address for pSeries zImage kernels") changed the real-base value in the CHRP note added by the addnote program from 12MB to 32MB to give more space for Open Firmware to load the zImage. (The real-base value says where we want OF to position itself in memory.) However, this change was ineffective on most pSeries machines, because the RPA note added by addnote has the "ignore me" flag set to 1. This was intended to tell OF to ignore just the RPA note, but has the side effect of also making OF ignore the CHRP note (at least on most pSeries machines). To solve this we have to set the "ignore me" flag to 0 in the RPA note. (We can't just omit the RPA note because that is equivalent to having an RPA note with default values, and the default values are not what we want.) However, then we have to make sure the values in the zImage's RPA note match up with the values that the kernel supplies later in prom_init.c with either the ibm,client-architecture-support call or the process-elf-header call in prom_send_capabilities(). So this sets the "ignore me" flag in the RPA note in addnote to 0, and adjusts the RPA note values in addnote.c and in prom_init.c to be consistent with each other and with the values in ibm_architecture_vec. However, since the wrapper is independent of the kernel, this doesn't ensure that the notes will stay consistent. To ensure that, this adds code to addnote.c so that it can extract the kernel's RPA note from the kernel binary and put that in the zImage. To that end, we put the kernel's fake ELF header (which contains the kernel's RPA note) into its own section, and arrange for wrapper to pull out that section with objcopy and pass it to addnote, which then extracts the RPA note from it and transfers it to the zImage. Signed-off-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt

powerpc: Make the 64-bit kernel as a position-independent executable

2008-09-15T18:08:38Z

This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as a position-independent executable (PIE) when it is set. This involves processing the dynamic relocations in the image in the early stages of booting, even if the kernel is being run at the address it is linked at, since the linker does not necessarily fill in words in the image for which there are dynamic relocations. (In fact the linker does fill in such words for 64-bit executables, though not for 32-bit executables, so in principle we could avoid calling relocate() entirely when we're running a 64-bit kernel at the linked address.) The dynamic relocations are processed by a new function relocate(addr), where the addr parameter is the virtual address where the image will be run. In fact we call it twice; once before calling prom_init, and again when starting the main kernel. This means that reloc_offset() returns 0 in prom_init (since it has been relocated to the address it is running at), which necessitated a few adjustments. This also changes __va and __pa to use an equivalent definition that is simpler. With the relocatable kernel, PAGE_OFFSET and MEMORY_START are constants (for 64-bit) whereas PHYSICAL_START is a variable (and KERNELBASE ideally should be too, but isn't yet). With this, relocatable kernels still copy themselves down to physical address 0 and run there. Signed-off-by: Paul Mackerras

powerpc: Make it possible to move the interrupt handlers away from the kernel

2008-09-15T18:08:08Z

This changes the way that the exception prologs transfer control to the handlers in 64-bit kernels with the aim of making it possible to have the prologs separate from the main body of the kernel. Now, instead of computing the address of the handler by taking the top 32 bits of the paca address (to get the 0xc0000000........ part) and ORing in something in the bottom 16 bits, we get the base address of the kernel by doing a load from the paca and add an offset. This also replaces an mfmsr and an ori to compute the MSR value for the handler with a load from the paca. That makes it unnecessary to have a separate version of EXCEPTION_PROLOG_PSERIES that forces 64-bit mode. We can no longer use a direct branches in the exception prolog code, which means that the SLB miss handlers can't branch directly to .slb_miss_realmode any more. Instead we have to compute the address and do an indirect branch. This is conditional on CONFIG_RELOCATABLE; for non-relocatable kernels we use a direct branch as before. (A later change will allow CONFIG_RELOCATABLE to be set on 64-bit powerpc.) Since the secondary CPUs on pSeries start execution in the first 0x100 bytes of real memory and then have to get to wherever the kernel is, we can't use a direct branch to get there. Instead this changes __secondary_hold_spinloop from a flag to a function pointer. When it is set to a non-NULL value, the secondary CPUs jump to the function pointed to by that value. Finally this eliminates one code difference between 32-bit and 64-bit by making __secondary_hold be the text address of the secondary CPU spinloop rather than a function descriptor for it. Signed-off-by: Paul Mackerras

powerpc: kill useless SMT code in prom_hold_cpus

2008-07-28T06:30:48Z

This piece of code is broken for >2 threads, and possibly in some other subtle ways (such as comparing a value obtained from an "ibm,ppc-interrupt-server#s" property to a value obtained from a "reg" property) and doesn't seem to have any useful purpose in the first place other than a dubious warning in case NR_CPUS is too small, which probably isn't the right place to do so. Signed-off-by: Nathan Lynch Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Update arch vector to indicate support for CMO

2008-07-25T05:44:45Z

Update the architecture vector to indicate that Cooperative Memory Overcommitment is supported if CONFIG_PPC_SMLPAR is set. Signed-off-by: Nathan Fontenot Signed-off-by: Robert Jennings Acked-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt

powerpc: Tell firmware we support architecture V2.06

2008-07-01T01:28:00Z

Add the bits to the architecture-vec so that ibm,client-architecture lets the firmware know we support the 2.06 architecture. Signed-off-by: Joel Schopp Signed-off-by: Paul Mackerras

powerpc: Add cputable entry for POWER7

2008-06-30T12:31:11Z

Add a cputable entry for the POWER7 processor. Also tell firmware that we know about POWER7. Signed-off-by: Michael Neuling Signed-off-by: Joel Schopp Signed-off-by: Paul Mackerras

[POWERPC] Efika: Really, don't pretend to be CHRP

2008-04-16T21:46:12Z

Fedora 9 works on Efika without the separate 'device-tree supplement', thanks to the kernel's own fixups. With one exception -- because 'CHRP' still appears on the 'machine:' line in /proc/cpuinfo, the installer misdetects the platform and misconfigures yaboot, putting it into a PReP boot partition instead of in the /boot filesystem where the Efika's firmware could find it. The kernel's fixups for Efika already correct one instance of 'chrp', in the 'device_type' property. This fixes it in the 'CODEGEN,description' property too, since that's what's exposed to userspace in /proc/cpuinfo. Signed-off-by: David Woodhouse Acked-by: Grant Likely Signed-off-by: Paul Mackerras