If we wait until after including a bunch of other files, we
will have generated so much warning spew that it's hard to
notice the error about using the wrong compiler.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
It isn't used any more by us now that the generic kernel build
offers DEBUG_INFO_REDUCED, so just get rid of it.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We use virt_to_pte(NULL, va) a lot, which isn't very obvious.
I added virt_to_kpte(va) as a more obvious wrapper function,
that also validates the va as being a kernel adddress.
And, I fixed the semantics of virt_to_pte() so that we handle
the pud and pmd the same way, and we now document the fact that
we handle the final pte level differently.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Allow enabling frame pointer support; this makes it easier to hook
into the various kernel features that claim they require it without
having to add Kconfig conditionals everywhere (a la mips, ppc, s390,
and microblaze). When enabled, it basically eliminates leaf functions
as such, and stops optimizing tail and sibling calls. It adds around
3% to the size of the kernel when enabled.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Newer hypervisors have an API for reporting per-cpu statistics
information. This change allows seeing that information via
/sys/devices/system/cpu/cpuN/hv_stats file for each core.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Enter kernel debugger at boot with:
--hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200
or at runtime with:
echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc
echo g > /proc/sysrq-trigger
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The TILE-Gx chip includes an on-chip UART. This change adds support
for using the UART from within the kernel. The UART shim has more
functionality than is exposed here, but to keep the kernel code and
binary simpler, this is a subset of the full API designed to enable
a standard Linux tty serial driver only.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available. It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.
Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space. In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".
Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Technically, user privilege is anything less than kernel
privilege. We modify the existing user_mode() macro to have
this semantic (and use it in a couple of places it wasn't being
used before), and add an IS_KERNEL_EX1() macro to the assembly
code as well.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We remove some debug code in relocate_kernel_64.S that made raw
calls to the hv_console_putc Tilera hypervisor API, since everything
should funnel through the early_hv_write() API.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This tile-specific API had a minor bug, in that if a super huge (>4GB)
page mapped a particular address range, we wouldn't handle it correctly.
As part of fixing that bug, I also cleaned up some of the pud and pmd
accessors to make them more consistent.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Previously, we used a special-purpose register (SPR_SYSTEM_SAVE_K_0)
to hold the CPU number and the top of the current kernel stack
by using the low bits to hold the CPU number, and using the high
bits to hold the address of the page just above where we'd want
the kernel stack to be. That way we could initialize a new SP
when first entering the kernel by just masking the SPR value and
subtracting a couple of words.
However, it's actually more useful to be able to place an arbitrary
kernel-top value in the SPR. This allows us to create a new stack
context (e.g. for virtualization) with an arbitrary top-of-stack VA.
To make this work, we now store the CPU number in the high bits,
above the highest legal VA bit (42 bits in the current tilegx
microarchitecture). The full 42 bits are thus available to store the
top of stack value. Getting the current cpu (a relatively common
operation) is still fast; it's now a shift rather than a mask.
We make this change only for tilegx, since tilepro has too few SPR
bits to do this, and we don't need this support on tilepro anyway.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We use the validate_current() API to make sure that "current" seems
plausible before using it. With the new show_regs_print_info()
API, we want to check that current is OK before calling it, since
otherwise we will end up in a recursive panic.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Normally the build doesn't include these warnings, but at one
point I built with -Wsign-compare, and noticed a few things that
are technically bugs. This change fixes those things.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
With this change such sections are grouped with regular text
in the vmlinux image; this change puts them at the front,
which is where the standard Linux includes .text.hot*.
This change should fix a recently-observed bug where a bunch of
symbols were being omitted from the /proc/kallsyms output
because they fell between _etext and _sinittext.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
In strncpy_from_user_asm, when the destination buffer length was the
same as the actual string length, we were returning the size of the
destination buffer. But since it's a NUL terminated string, we should
return the length of the string instead.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Nothing in the codebase was using them, and as written they took
"unsigned long" as the physical address rather than "phys_addr_t",
which is wrong on tilepro anyway. Rather than fixing stale APIs,
just remove them; if there's ever demand for them on this platform,
we can put them back.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We had been doing an automatic full eviction of the L1 I$
everywhere whenever we did a kernel-space TLB flush. It turns
out this isn't necessary, since all the callers already handle
doing a flush if necessary.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
With this change, tile Linux now supports address-space layout
randomization for shared objects, stack, heap and vdso.
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Tony Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The r1 value is set based on the r0 value as we return to user space.
So tracing tools won't automatically see the right value. Fix this by
generating the correct r1 value in do_syscall_trace_exit() rather
than trying to tamper with the hot path in syscall return.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Chris Metcalf
Tony Lu