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path: root/arch/sh/kernel/head_32.S
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2010-09-30sh: boot kernel with SR.BL setMagnus Damm
Update the SH kernel to keep SR.BL set until the VBR register has been initialized. Useful to allow boot of the kernel even though exceptions are pending. Without this patch there is a window of time when exceptions such as NMI are enabled but no exception handlers are installed. This patch modifies both the zImage loader and the actual kernel to boot with BL=1, but the zImage loader is modfied in such a way that the init_sr value is unchanged to not break the zImage loader provided by kexec. Tested on sh7724 Ecovec and on the SH4AL-DSP core included in sh7372. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-04-25sh: Use correct mask when comparing PMB DATA array valuesMatt Fleming
Previously we were masking the PMB DATA array values with the value of __MEMORY_START | PMB_V, which misses some PFN bits off the mask. Signed-off-by: Matt Fleming <matt@console-pimps.org>
2010-04-21sh: __cpuinit annotate the CPU init path.Paul Mundt
All of the regular CPU init path needs to be __cpuinit annotated for CPU hotplug. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-02-18sh: Merge legacy and dynamic PMB modes.Paul Mundt
This implements a bit of rework for the PMB code, which permits us to kill off the legacy PMB mode completely. Rather than trusting the boot loader to do the right thing, we do a quick verification of the PMB contents to determine whether to have the kernel setup the initial mappings or whether it needs to mangle them later on instead. If we're booting from legacy mappings, the kernel will now take control of them and make them match the kernel's initial mapping configuration. This is accomplished by breaking the initialization phase out in to multiple steps: synchronization, merging, and resizing. With the recent rework, the synchronization code establishes page links for compound mappings already, so we build on top of this for promoting mappings and reclaiming unused slots. At the same time, the changes introduced for the uncached helpers also permit us to dynamically resize the uncached mapping without any particular headaches. The smallest page size is more than sufficient for mapping all of kernel text, and as we're careful not to jump to any far off locations in the setup code the mapping can safely be resized regardless of whether we are executing from it or not. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-02-17sh: uncached mapping helpers.Paul Mundt
This adds some helper routines for uncached mapping support. This simplifies some of the cases where we need to check the uncached mapping boundaries in addition to giving us a centralized location for building more complex manipulation on top of. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-02-17sh: PMB tidying.Paul Mundt
Some overdue cleanup of the PMB code, killing off unused functionality and duplication sprinkled about the tree. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-21sh: Track the uncached mapping size.Paul Mundt
This provides a variable for tracking the uncached mapping size, and uses it for pretty printing the uncached lowmem range. Beyond this, we'll also be building on top of this for figuring out from where the remainder of P2 becomes usable when constructing unrelated mappings. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-21sh: Rework P2 to only include kernel text.Paul Mundt
This effectively neutralizes P2 by getting rid of P1 identity mapping for all available memory and instead only establishes a single unbuffered PMB entry (16MB -- the smallest available) that covers the kernel. As using segmentation for abusing caching attributes in drivers is no longer supported (and there are no drivers that can be enabled in 32-bit mode that do this), this provides us with all of the uncached access needs by the kernel itself. Drivers and their ilk need to specify their caching attributes when remapping through page tables, as usual. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-21sh: initial PMB mapping iteration by helper macro.Paul Mundt
All of the cached/uncached mapping setup is duplicated for each size, and also misses out on the 16MB case. Rather than duplicating the same iter code for that we just consolidate it in to a helper macro that builds an iter for each size. The 16MB case is then trivially bolted on at the end. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-18sh: Setup early PMB mappings.Matt Fleming
More and more boards are going to start shipping that boot with the MMU in 32BIT mode by default. Previously we relied on the bootloader to setup PMB mappings for use by the kernel but we also need to cater for boards whose bootloaders don't set them up. If CONFIG_PMB_LEGACY is not enabled we have full control over our PMB mappings and can compress our address space. Usually, the distance between the the cached and uncached mappings of RAM is always 512MB, however we can compress the distance to be the amount of RAM on the board. pmb_init() now becomes much simpler. It no longer has to calculate any mappings, it just has to synchronise the software PMB table with the hardware. Tested on SDK7786 and SH7785LCR. Signed-off-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-13sh: fixed PMB mode refactoring.Paul Mundt
This introduces some much overdue chainsawing of the fixed PMB support. fixed PMB was introduced initially to work around the fact that dynamic PMB mode was relatively broken, though they were never intended to converge. The main areas where there are differences are whether the system is booted in 29-bit mode or 32-bit mode, and whether legacy mappings are to be preserved. Any system booting in true 32-bit mode will not care about legacy mappings, so these are roughly decoupled. Regardless of the entry point, PMB and 32BIT are directly related as far as the kernel is concerned, so we also switch back to having one select the other. With legacy mappings iterated through and applied in the initialization path it's now possible to finally merge the two implementations and permit dynamic remapping overtop of remaining entries regardless of whether boot mappings are crafted by hand or inherited from the boot loader. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-10-10sh: CONFIG_PMB doesn't mean the MMU is in 32bit modeMatt Fleming
CONFIG_PMB will eventually allow the MMU to be switched between 29-bit and 32-bit mode dynamically at runtime. Signed-off-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-04-26sh: convert to use __HEAD and HEAD_TEXT macros.Tim Abbott
This has the consequence of changing the section name use for head code from ".text.head" to ".head.text". Since this commit changes all users in the architecture, this change should be harmless. Signed-off-by: Tim Abbott <tabbott@mit.edu> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-22sh: Enable skipping of bss on debug platforms for sh32 also.Paul Mundt
This enables the same functionality that sh64 has for sh32. When running on simulated hardware or via remote memory via the debug interface, memory is gauranteed to be zero on boot already, and skipping the zeroing of BSS has measurable boot time benefits. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-05-16sh: disable initrd defaults in .empty_zero_page.Paul Mundt
When using initramfs on systems that don't explicitly clear LOADER_TYPE, unpack_to_rootfs() tramples tramples the range with the defaults taken out of .empty_zero_page. This causes kernels with valid initramfs images to bail out with crc or gzip magic mismatch errors after the second unpack takes place on certain platform configurations. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28sh: Provide a 29/32-bit physical hint for bootloaders.Stuart Menefy
Shoves a magic word in to the empty_zero_page section for the bootloader to work out whether to start the kernel in 29-bit or 32-bit mode. [ Renesas CPUs already take care of the initial PMB mappings entirely in hardware and decide on 29-bit/32-bit physical depending on which pin powered up the CPU, so this is mostly for ST parts. -- PFM ]. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28sh: Move over the SH-5 head.S and tlb.h.Paul Mundt
Signed-off-by: Paul Mundt <lethal@linux-sh.org>