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| author | Andi Shyti <andi.shyti@linux.intel.com> | 2026-08-22 14:19:12 +0200 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@linux.intel.com> | 2026-08-22 14:19:34 +0200 |
| commit | d576a9561a1c80ae593539fb0ce0743d66825ac2 (patch) | |
| tree | 68f6de7e06b350afa42edeea2f7f33f086014597 /Documentation/arch/parisc/debugging.rst | |
| download | linux-stable-d576a9561a1c80ae593539fb0ce0743d66825ac2.tar.gz linux-stable-d576a9561a1c80ae593539fb0ce0743d66825ac2.zip | |
Merge tag 'rust-i2c-for-7.3' into i2c/i2cgrafted
i2c: rust: mark I2cAdapter methods as inline
A single cleanup for the Rust I2C abstractions, targeting 7.3.
`I2cAdapter::get`, `inc_ref`, and `dec_ref` are trivial wrappers around
`i2c_get_adapter`/`i2c_put_adapter` and were showing up as their own
symbols in the build. Mark them `#[inline]` so they get folded into
their callers instead.
Signed-off-by: Igor Korotin <igor.korotin@linux.dev>
* tag 'rust-i2c-for-7.3':
i2c: rust: mark I2cAdapter methods as inline
Diffstat (limited to 'Documentation/arch/parisc/debugging.rst')
| -rw-r--r-- | Documentation/arch/parisc/debugging.rst | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/Documentation/arch/parisc/debugging.rst b/Documentation/arch/parisc/debugging.rst new file mode 100644 index 000000000..de1b60402 --- /dev/null +++ b/Documentation/arch/parisc/debugging.rst @@ -0,0 +1,46 @@ +================= +PA-RISC Debugging +================= + +okay, here are some hints for debugging the lower-level parts of +linux/parisc. + + +1. Absolute addresses +===================== + +A lot of the assembly code currently runs in real mode, which means +absolute addresses are used instead of virtual addresses as in the +rest of the kernel. To translate an absolute address to a virtual +address you can lookup in System.map, add __PAGE_OFFSET (0x10000000 +currently). + + +2. HPMCs +======== + +When real-mode code tries to access non-existent memory, you'll get +an HPMC instead of a kernel oops. To debug an HPMC, try to find +the System Responder/Requestor addresses. The System Requestor +address should match (one of the) processor HPAs (high addresses in +the I/O range); the System Responder address is the address real-mode +code tried to access. + +Typical values for the System Responder address are addresses larger +than __PAGE_OFFSET (0x10000000) which mean a virtual address didn't +get translated to a physical address before real-mode code tried to +access it. + + +3. Q bit fun +============ + +Certain, very critical code has to clear the Q bit in the PSW. What +happens when the Q bit is cleared is the CPU does not update the +registers interruption handlers read to find out where the machine +was interrupted - so if you get an interruption between the instruction +that clears the Q bit and the RFI that sets it again you don't know +where exactly it happened. If you're lucky the IAOQ will point to the +instruction that cleared the Q bit, if you're not it points anywhere +at all. Usually Q bit problems will show themselves in unexplainable +system hangs or running off the end of physical memory. |
