Merge tag 'for-linus' of git://github.com/openrisc/linux

Pull OpenRISC updates from Stafford Horne:
 "A few fixups and enhancements for OpenRISC:

   - Fix to add proper wrapper for clone3 to save callee saved regs

   - Cleanups for clone, fork and switch

   - Add support for common clk so OpenRISC and use more drivers"

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc: init: Add support for common clk
  openrisc: Add clone3 ABI wrapper
  openrisc: Use delay slot for clone and fork wrappers
  openrisc: Cleanup switch code and comments
This commit is contained in:
Linus Torvalds
2022-01-14 15:32:09 +01:00
4 changed files with 20 additions and 14 deletions
+1
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@@ -10,6 +10,7 @@ config OPENRISC
select ARCH_HAS_DMA_SET_UNCACHED
select ARCH_HAS_DMA_CLEAR_UNCACHED
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select COMMON_CLK
select OF
select OF_EARLY_FLATTREE
select IRQ_DOMAIN
+2
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@@ -22,9 +22,11 @@ asmlinkage long sys_or1k_atomic(unsigned long type, unsigned long *v1,
asmlinkage long __sys_clone(unsigned long clone_flags, unsigned long newsp,
void __user *parent_tid, void __user *child_tid, int tls);
asmlinkage long __sys_clone3(struct clone_args __user *uargs, size_t size);
asmlinkage long __sys_fork(void);
#define sys_clone __sys_clone
#define sys_clone3 __sys_clone3
#define sys_fork __sys_fork
#endif /* __ASM_OPENRISC_SYSCALLS_H */
+13 -14
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@@ -1001,11 +1001,10 @@ ENTRY(ret_from_fork)
l.lwz r11,PT_GPR11(r1)
/* The syscall fast path return expects call-saved registers
* r12-r28 to be untouched, so we restore them here as they
* r14-r28 to be untouched, so we restore them here as they
* will have been effectively clobbered when arriving here
* via the call to switch()
*/
l.lwz r12,PT_GPR12(r1)
l.lwz r14,PT_GPR14(r1)
l.lwz r16,PT_GPR16(r1)
l.lwz r18,PT_GPR18(r1)
@@ -1037,10 +1036,10 @@ ENTRY(ret_from_fork)
/* _switch MUST never lay on page boundry, cause it runs from
* effective addresses and beeing interrupted by iTLB miss would kill it.
* dTLB miss seams to never accour in the bad place since data accesses
* dTLB miss seems to never accour in the bad place since data accesses
* are from task structures which are always page aligned.
*
* The problem happens in RESTORE_ALL_NO_R11 where we first set the EPCR
* The problem happens in RESTORE_ALL where we first set the EPCR
* register, then load the previous register values and only at the end call
* the l.rfe instruction. If get TLB miss in beetwen the EPCR register gets
* garbled and we end up calling l.rfe with the wrong EPCR. (same probably
@@ -1068,9 +1067,8 @@ ENTRY(_switch)
/* No need to store r1/PT_SP as it goes into KSP below */
l.sw PT_GPR2(r1),r2
l.sw PT_GPR9(r1),r9
/* This is wrong, r12 shouldn't be here... but GCC is broken for the time being
* and expects r12 to be callee-saved... */
l.sw PT_GPR12(r1),r12
/* Save callee-saved registers to the new pt_regs */
l.sw PT_GPR14(r1),r14
l.sw PT_GPR16(r1),r16
l.sw PT_GPR18(r1),r18
@@ -1111,9 +1109,7 @@ ENTRY(_switch)
/* No need to restore r10 */
/* ...and do not restore r11 */
/* This is wrong, r12 shouldn't be here... but GCC is broken for the time being
* and expects r12 to be callee-saved... */
l.lwz r12,PT_GPR12(r1)
/* Restore callee-saved registers */
l.lwz r14,PT_GPR14(r1)
l.lwz r16,PT_GPR16(r1)
l.lwz r18,PT_GPR18(r1)
@@ -1166,15 +1162,18 @@ _fork_save_extra_regs_and_call:
ENTRY(__sys_clone)
l.movhi r29,hi(sys_clone)
l.ori r29,r29,lo(sys_clone)
l.j _fork_save_extra_regs_and_call
l.nop
l.ori r29,r29,lo(sys_clone)
ENTRY(__sys_clone3)
l.movhi r29,hi(sys_clone3)
l.j _fork_save_extra_regs_and_call
l.ori r29,r29,lo(sys_clone3)
ENTRY(__sys_fork)
l.movhi r29,hi(sys_fork)
l.ori r29,r29,lo(sys_fork)
l.j _fork_save_extra_regs_and_call
l.nop
l.ori r29,r29,lo(sys_fork)
ENTRY(sys_rt_sigreturn)
l.jal _sys_rt_sigreturn
+4
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@@ -20,6 +20,7 @@
#include <linux/clockchips.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of_clk.h>
#include <asm/cpuinfo.h>
@@ -169,4 +170,7 @@ void __init time_init(void)
openrisc_timer_init();
openrisc_clockevent_init();
of_clk_init(NULL);
timer_probe();
}