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* [PATCH 2/20] powerpc/of: Remove useless register save/restore when calling OF back
@ 2009-07-23  5:59 Benjamin Herrenschmidt
  0 siblings, 0 replies; 2+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-23  5:59 UTC (permalink / raw)
  To: linuxppc-dev

enter_prom() used to save and restore registers such as CTR, XER etc..
which are volatile, or SRR0,1... which we don't care about. This
removes a bunch of useless code and while at it turns an mtmsrd into
an MTMSRD macro which will be useful to Book3E.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

 arch/powerpc/kernel/entry_64.S |   38 ++++++--------------------------------
 1 file changed, 6 insertions(+), 32 deletions(-)

--- linux-work.orig/arch/powerpc/kernel/entry_64.S	2009-07-22 15:20:26.000000000 +1000
+++ linux-work/arch/powerpc/kernel/entry_64.S	2009-07-22 15:22:44.000000000 +1000
@@ -823,30 +823,17 @@ _GLOBAL(enter_prom)
 	 * of all registers that it saves.  We therefore save those registers
 	 * PROM might touch to the stack.  (r0, r3-r13 are caller saved)
    	 */
-	SAVE_8GPRS(2, r1)
+	SAVE_GPR(2, r1)
 	SAVE_GPR(13, r1)
 	SAVE_8GPRS(14, r1)
 	SAVE_10GPRS(22, r1)
-	mfcr	r4
-	std	r4,_CCR(r1)
-	mfctr	r5
-	std	r5,_CTR(r1)
-	mfspr	r6,SPRN_XER
-	std	r6,_XER(r1)
-	mfdar	r7
-	std	r7,_DAR(r1)
-	mfdsisr	r8
-	std	r8,_DSISR(r1)
-	mfsrr0	r9
-	std	r9,_SRR0(r1)
-	mfsrr1	r10
-	std	r10,_SRR1(r1)
+	mfcr	r10
 	mfmsr	r11
+	std	r10,_CCR(r1)
 	std	r11,_MSR(r1)
 
 	/* Get the PROM entrypoint */
-	ld	r0,GPR4(r1)
-	mtlr	r0
+	mtlr	r4
 
 	/* Switch MSR to 32 bits mode
 	 */
@@ -860,8 +847,7 @@ _GLOBAL(enter_prom)
         mtmsrd  r11
         isync
 
-	/* Restore arguments & enter PROM here... */
-	ld	r3,GPR3(r1)
+	/* Enter PROM here... */
 	blrl
 
 	/* Just make sure that r1 top 32 bits didn't get
@@ -871,7 +857,7 @@ _GLOBAL(enter_prom)
 
 	/* Restore the MSR (back to 64 bits) */
 	ld	r0,_MSR(r1)
-	mtmsrd	r0
+	MTMSRD(r0)
         isync
 
 	/* Restore other registers */
@@ -881,18 +867,6 @@ _GLOBAL(enter_prom)
 	REST_10GPRS(22, r1)
 	ld	r4,_CCR(r1)
 	mtcr	r4
-	ld	r5,_CTR(r1)
-	mtctr	r5
-	ld	r6,_XER(r1)
-	mtspr	SPRN_XER,r6
-	ld	r7,_DAR(r1)
-	mtdar	r7
-	ld	r8,_DSISR(r1)
-	mtdsisr	r8
-	ld	r9,_SRR0(r1)
-	mtsrr0	r9
-	ld	r10,_SRR1(r1)
-	mtsrr1	r10
 	
         addi	r1,r1,PROM_FRAME_SIZE
 	ld	r0,16(r1)

^ permalink raw reply	[flat|nested] 2+ messages in thread
* [PATCH 0/20] powerpc: base 64-bit Book3E processor support (v2)
@ 2009-07-24  9:15 Benjamin Herrenschmidt
  2009-07-24  9:15 ` [PATCH 2/20] powerpc/of: Remove useless register save/restore when calling OF back Benjamin Herrenschmidt
  0 siblings, 1 reply; 2+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-24  9:15 UTC (permalink / raw)
  To: linuxppc-dev

Here is a series of patches that implement some basic support
for 64-bit Book3E processors that comply to architecture 2.06.

There is no specific processor announced yet. The patches make
some shortcut which means they currently rely on an implementation
that supports MMU v2 with support for the "HES" feature (HW entry
select) and with support for the "TLB reservation" feature. They
also assume a single unified TLB array. I shouldn't be very hard
to implement support for other variants of the architecture on
top of this though.

The current set of patch has no proper support yet for hugetlb,
nor for "special" interrupt levels (debug, critical and machine
check). Some minimal support for debug/critical levels is provided
specifically for the "Debug" interrupt (single step etc...) only
when it occurs from within user space code. 

The intend is to merge these in 2.6.32. They rely on pretty much
all the other patches I've been posting lately including the
generic changes to add the virtual address argument to pte_free_tlb.

v2. Various fixes, some addressing comments recieved and a whole
bunch fixing other issues including breakage of existing platforms

^ permalink raw reply	[flat|nested] 2+ messages in thread
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