From mboxrd@z Thu Jan 1 00:00:00 1970 From: ben.dooks@codethink.co.uk (Ben Dooks) Date: Mon, 14 Oct 2013 21:53:02 +0100 Subject: [PATCH 22/23] ARM: cci: driver need big endian fixes in asm code In-Reply-To: <1381271679-27804-23-git-send-email-ben.dooks@codethink.co.uk> References: <1381271679-27804-1-git-send-email-ben.dooks@codethink.co.uk> <1381271679-27804-23-git-send-email-ben.dooks@codethink.co.uk> Message-ID: <525C59AE.4090602@codethink.co.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/10/13 23:34, Ben Dooks wrote: > From: Victor Kamensky > > cci_enable_port_for_self written in asm and it works with h/w > registers that are in little endian format. When run in big > endian mode it needs byte swap before/after it writes/reads > to/from such registers > > CC: Lorenzon Pieralisi > Signed-off-by: Victor Kamensky > Signed-off-by: Ben Dooks > --- > drivers/bus/arm-cci.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c > index 2009266..6db173e 100644 > --- a/drivers/bus/arm-cci.c > +++ b/drivers/bus/arm-cci.c > @@ -281,6 +281,9 @@ asmlinkage void __naked cci_enable_port_for_self(void) > /* Enable the CCI port */ > " ldr r0, [r0, %[offsetof_port_phys]] \n" > " mov r3, #"__stringify(CCI_ENABLE_REQ)" \n" > +#ifdef __ARMEB__ > +" rev r3, r3 \n" > +#endif /* __ARMEB__ */ > " str r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n" > > /* poll the status reg for completion */ > @@ -288,6 +291,9 @@ asmlinkage void __naked cci_enable_port_for_self(void) > " ldr r0, [r1] \n" > " ldr r0, [r0, r1] @ cci_ctrl_base \n" > "4: ldr r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n" > +#ifdef __ARMEB__ > +" rev r1, r1 \n" > +#endif /* __ARMEB__ */ > " tst r1, #1 \n" > " bne 4b \n" I was just thinking if this would be a better way to change the code: diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index 6db173e..2ad2511 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -280,10 +280,7 @@ asmlinkage void __naked cci_enable_port_for_self(void) /* Enable the CCI port */ " ldr r0, [r0, %[offsetof_port_phys]] \n" -" mov r3, #"__stringify(CCI_ENABLE_REQ)" \n" -#ifdef __ARMEB__ -" rev r3, r3 \n" -#endif /* __ARMEB__ */ +" mov r3, %[cci_enable_req]\n" " str r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n" /* poll the status reg for completion */ @@ -291,10 +288,7 @@ asmlinkage void __naked cci_enable_port_for_self(void) " ldr r0, [r1] \n" " ldr r0, [r0, r1] @ cci_ctrl_base \n" "4: ldr r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n" -#ifdef __ARMEB__ -" rev r1, r1 \n" -#endif /* __ARMEB__ */ -" tst r1, #1 \n" +" tst r1, %[cci_control_status_bits] \n" " bne 4b \n" " mov r0, #0 \n" @@ -307,6 +301,8 @@ asmlinkage void __naked cci_enable_port_for_self(void) "7: .word cci_ctrl_phys - . \n" : : [sizeof_cpu_port] "i" (sizeof(cpu_port)), + [cci_enable_req] "i" cpu_to_le32(CCI_ENABLE_REQ), + [cci_control_status_bits] "i" cpu_to_le32(1), so swap the data bits before passing them into the code which could also remove some of the use of the __stringify() calls in there too. It seems to compile ok, but is not complete. -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius