[POWERPC] kexec: Send slaves to new kernel earlier (ee46a90b) · Commits · 戴 / test

With this, when kexec-ing, we copy the code and start the slaves on their journey to the next kernel's spin loop as soon as we copy the kexec image into place. The kernel doesn't know exactly which slaves are spinning in kexec_wait. This allows us to pass more than max-cpus to the next kernel. But it also means that we might leave some behind. Moving the code here means they have the time it takes us to clear the hash table to wake up and move on. Moving the code any earlier would reuqire walking the image description to search for the code, which could span multiple pages. Signed-off-by:

Milton Miller <miltonm@bga.com> Signed-off-by:

Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/misc_64.S

+13 −13

Original line number	Diff line number	Diff line
		@@ -646,6 +646,19 @@ _GLOBAL(kexec_sequence)
		/* turn off mmu */
		bl real_mode

		/* copy 0x100 bytes starting at start to 0 */
		li r3,0
		mr r4,r30 /* start, aka phys mem offset */
		li r5,0x100
		li r6,0
		bl .copy_and_flush /* (dest, src, copy limit, start offset) */
		1: /* assume normal blr return */

		/* release other cpus to the new kernel secondary start at 0x60 */
		mflr r5
		li r6,1
		stw r6,kexec_flag-1b(5)

		/* clear out hardware hash page table and tlb */
		ld r5,0(r27) /* deref function descriptor */
		mtctr r5
		@@ -676,19 +689,6 @@ _GLOBAL(kexec_sequence)
		* are the boot cpu ?????
		* other device tree differences (prop sizes, va vs pa, etc)...
		*/

		/* copy 0x100 bytes starting at start to 0 */
		li r3,0
		mr r4,r30
		li r5,0x100
		li r6,0
		bl .copy_and_flush /* (dest, src, copy limit, start offset) */
		1: /* assume normal blr return */

		/* release other cpus to the new kernel secondary start at 0x60 */
		mflr r5
		li r6,1
		stw r6,kexec_flag-1b(5)
		mr r3,r25 # my phys cpu
		mr r4,r30 # start, aka phys mem offset
		mtlr 4

Admin message