On Thursday 09 August 2007 14:35:30 Ralf Baechle wrote:
> I recently noticed the kernel part was fairly broken, did (if ever) only
> work for 32-bit machines. I fixed what I could but I don't have the
> necessary test setup. See
My appologies for this, I should have taken more care about 64 bit portability
when writing this code.
I have also been trying to address the cache problem in the kexec code. please
see the attached patch.
I now use __flush_cache_all(), since flush_cache_all() is mostly a noop on r4k
if cpu_has_dc_aliases evaluates to 0 (and it is the case on the MIPS cpu I
have access to). To avoid caching problem in the relocation code, I disable
the cache in KSEG0 (using the K0 field in CP0 CONFIG register) before jumping
to the relocation code. I don't know how clean this solution is, but this
avoids having to add non-portable cache flush code to relocate_kernel.S.
Signed-off-by: Nicolas Schichan <firstname.lastname@example.org>
--- linux/arch/mips/kernel/machine_kexec.c (revision 5939)
+++ linux/arch/mips/kernel/machine_kexec.c (revision 5941)
@@ -50,8 +50,10 @@
+ printk(KERN_INFO "reboot code is at %08lx\n", reboot_code_buffer);
kexec_start_address = image->start;
- kexec_indirection_page = phys_to_virt(image->head & PAGE_MASK);
+ kexec_indirection_page = (long)phys_to_virt(image->head & PAGE_MASK);
@@ -75,11 +77,17 @@
- reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
- printk("Will call new kernel at %08x\n", image->start);
- printk("Bye ...\n");
+ * avoid cache operation related headache in
+ * relocate_kernel.S: disable caches in kseg0, the new kernel
+ * will take care to re-enable cache in kseg0.
+ change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
+ printk(KERN_INFO "Will call new kernel at %08lx\n", image->start);
+ printk(KERN_INFO "Bye ...\n");