AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-11-29 21:06:41 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

ARM: mxc: ssi-fiq: Make ssi-fiq.S Thumb-2 compatible

Browse Source 
Because FIQ handlers get copied straight into the vectors page to
the FIQ vector entry point, FIQ handlers in a Thumb-2 kernel must
start in Thumb-2.  A Thumb-2 kernel enters all exception vectors in
Thumb-2.

This patch adapts the mxc SSI FIQ code suitable for a Thumb-2
kernel.

The code contained use of r13 (sp) which isn't allowed in Thumb-2.
r11 and r13 have been swapped throughout the file to work around
this.

Currently, the way that the function to be copied is located using
labels is a bit ugly: we cannot annotate the FIQ handler properly
as a Thumb-2 function, because this would set bit 0 of the label
address seen by the linker, causing off-by-one errors when copying
the function.  Ideally, the copy would be done with fncpy(), but
this would require changes to the common set_fiq_handler()
function.  For now, we don't touch this.

References to locally-defined global symbols with adr and ldr may
not be accepted by the assembler in Thumb-2.  Local shadow symbols
are added to work around this.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Dave Martin 2012-08-10 12:53:24 +01:00 committed by Sascha Hauer
parent a745f039b9
commit 7095b95654
1 changed files with 50 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
arch/arm/plat-mxc/ssi-fiq.S
View File

@ -34,91 +34,98 @@
.global imx_ssi_fiq_rx_buffer
.global imx_ssi_fiq_tx_buffer
/*
* imx_ssi_fiq_start is _intentionally_ not marked as a function symbol
* using ENDPROC(). imx_ssi_fiq_start and imx_ssi_fiq_end are used to
* mark the function body so that it can be copied to the FIQ vector in
* the vectors page. imx_ssi_fiq_start should only be called as the result
* of an FIQ: calling it directly will not work.
*/
imx_ssi_fiq_start:
ldr r12, imx_ssi_fiq_base
ldr r12, .L_imx_ssi_fiq_base
/* TX */
ldr r11, imx_ssi_fiq_tx_buffer
ldr r13, .L_imx_ssi_fiq_tx_buffer
/* shall we send? */
ldr r13, [r12, #SSI_SIER]
tst r13, #SSI_SIER_TFE0_EN
ldr r11, [r12, #SSI_SIER]
tst r11, #SSI_SIER_TFE0_EN
beq 1f
/* TX FIFO empty? */
ldr r13, [r12, #SSI_SISR]
tst r13, #SSI_SISR_TFE0
ldr r11, [r12, #SSI_SISR]
tst r11, #SSI_SISR_TFE0
beq 1f
mov r10, #0x10000
sub r10, #1
and r10, r10, r8 /* r10: current buffer offset */
add r11, r11, r10
add r13, r13, r10
ldrh r13, [r11]
strh r13, [r12, #SSI_STX0]
ldrh r11, [r13]
strh r11, [r12, #SSI_STX0]
ldrh r13, [r11, #2]
strh r13, [r12, #SSI_STX0]
ldrh r11, [r13, #2]
strh r11, [r12, #SSI_STX0]
ldrh r13, [r11, #4]
strh r13, [r12, #SSI_STX0]
ldrh r11, [r13, #4]
strh r11, [r12, #SSI_STX0]
ldrh r13, [r11, #6]
strh r13, [r12, #SSI_STX0]
ldrh r11, [r13, #6]
strh r11, [r12, #SSI_STX0]
add r10, #8
lsr r13, r8, #16 /* r13: buffer size */
cmp r10, r13
lslgt r8, r13, #16
lsr r11, r8, #16 /* r11: buffer size */
cmp r10, r11
lslgt r8, r11, #16
addle r8, #8
1:
/* RX */
/* shall we receive? */
ldr r13, [r12, #SSI_SIER]
tst r13, #SSI_SIER_RFF0_EN
ldr r11, [r12, #SSI_SIER]
tst r11, #SSI_SIER_RFF0_EN
beq 1f
/* RX FIFO full? */
ldr r13, [r12, #SSI_SISR]
tst r13, #SSI_SISR_RFF0
ldr r11, [r12, #SSI_SISR]
tst r11, #SSI_SISR_RFF0
beq 1f
ldr r11, imx_ssi_fiq_rx_buffer
ldr r13, .L_imx_ssi_fiq_rx_buffer
mov r10, #0x10000
sub r10, #1
and r10, r10, r9 /* r10: current buffer offset */
add r11, r11, r10
add r13, r13, r10
ldr r13, [r12, #SSI_SACNT]
tst r13, #SSI_SACNT_AC97EN
ldr r11, [r12, #SSI_SACNT]
tst r11, #SSI_SACNT_AC97EN
ldr r13, [r12, #SSI_SRX0]
strh r13, [r11]
ldr r11, [r12, #SSI_SRX0]
strh r11, [r13]
ldr r13, [r12, #SSI_SRX0]
strh r13, [r11, #2]
ldr r11, [r12, #SSI_SRX0]
strh r11, [r13, #2]
/* dummy read to skip slot 12 */
ldrne r13, [r12, #SSI_SRX0]
ldrne r11, [r12, #SSI_SRX0]
ldr r13, [r12, #SSI_SRX0]
strh r13, [r11, #4]
ldr r11, [r12, #SSI_SRX0]
strh r11, [r13, #4]
ldr r13, [r12, #SSI_SRX0]
strh r13, [r11, #6]
ldr r11, [r12, #SSI_SRX0]
strh r11, [r13, #6]
/* dummy read to skip slot 12 */
ldrne r13, [r12, #SSI_SRX0]
ldrne r11, [r12, #SSI_SRX0]
add r10, #8
lsr r13, r9, #16 /* r13: buffer size */
cmp r10, r13
lslgt r9, r13, #16
lsr r11, r9, #16 /* r11: buffer size */
cmp r10, r11
lslgt r9, r11, #16
addle r9, #8
1:
@ -126,11 +133,15 @@ imx_ssi_fiq_start:
subs pc, lr, #4
.align
.L_imx_ssi_fiq_base:
imx_ssi_fiq_base:
.word 0x0
.L_imx_ssi_fiq_rx_buffer:
imx_ssi_fiq_rx_buffer:
.word 0x0
.L_imx_ssi_fiq_tx_buffer:
imx_ssi_fiq_tx_buffer:
.word 0x0
.L_imx_ssi_fiq_end:
imx_ssi_fiq_end: