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Commit a68fb483 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc 

Pull ARC updates from Vineet Gupta:
 "Some fixes, nothing too exciting this time as well..."

* tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
  ARC: Fix earlycon build breakage
  ARC: Dynamically determine BASE_BAUD from DeviceTree
  arc: Remove unused prepare_to_copy()
  ARC: use ACCESS_ONCE in cmpxchg loop
  ARC: add some more comments to ret_from_fork
  ARC: fix /proc/cpuinfo for offline cpus
parents ea44a160 06f34e1c

arch/arc/include/asm/pgtable.h

+2 −1
Original line number Original line Diff line number Diff line
@@ -257,7 +257,8 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) 
#define pmd_clear(xp)			do { pmd_val(*(xp)) = 0; } while (0)

#define pmd_clear(xp)			do { pmd_val(*(xp)) = 0; } while (0)





#define pte_page(x) (mem_map + \

#define pte_page(x) (mem_map + \

		(unsigned long)(((pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT)))

		(unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \

				PAGE_SHIFT)))





#define mk_pte(page, pgprot)						\

#define mk_pte(page, pgprot)						\

({									\

({									\

arch/arc/include/asm/processor.h

+0 −3
Original line number Original line Diff line number Diff line
@@ -56,9 +56,6 @@ unsigned long thread_saved_pc(struct task_struct *t); 
/* Free all resources held by a thread */

/* Free all resources held by a thread */

#define release_thread(thread) do { } while (0)

#define release_thread(thread) do { } while (0)





/* Prepare to copy thread state - unlazy all lazy status */

#define prepare_to_copy(tsk)    do { } while (0)



/*

/*

 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise

 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise

 * get optimised away by gcc

 * get optimised away by gcc

arch/arc/include/asm/serial.h

+5 −18
Original line number Original line Diff line number Diff line
@@ -10,26 +10,13 @@ 
#define _ASM_ARC_SERIAL_H

#define _ASM_ARC_SERIAL_H





/*

/*

 * early-8250 requires BASE_BAUD to be defined and includes this header.

 * early 8250 (now earlycon) requires BASE_BAUD to be defined in this header.

 * We put in a typical value:

 * However to still determine it dynamically (for multi-platform images)

 * 	(core clk / 16) - i.e. UART samples 16 times per sec.

 * we do this in a helper by parsing the FDT early

 * Athough in multi-platform-image this might not work, specially if the

 * clk driving the UART is different.

 * We can't use DeviceTree as this is typically for early serial.

 */

 */





#include <asm/clk.h>

extern unsigned int __init arc_early_base_baud(void);





#define BASE_BAUD	(arc_get_core_freq() / 16)

#define BASE_BAUD	arc_early_base_baud()



/*

 * This is definitely going to break early 8250 consoles on multi-platform

 * images but hey, it won't add any code complexity for a debug feature of

 * one broken driver.

 */

#ifdef CONFIG_ARC_PLAT_TB10X

#undef BASE_BAUD

#define BASE_BAUD	(arc_get_core_freq() / 16 / 3)

#endif





#endif /* _ASM_ARC_SERIAL_H */
 
#endif /* _ASM_ARC_SERIAL_H */

arch/arc/kernel/devtree.c

+24 −0
Original line number Original line Diff line number Diff line
@@ -17,6 +17,28 @@ 
#include <asm/clk.h>

#include <asm/clk.h>

#include <asm/mach_desc.h>

#include <asm/mach_desc.h>





#ifdef CONFIG_SERIAL_EARLYCON



static unsigned int __initdata arc_base_baud;



unsigned int __init arc_early_base_baud(void)

{

	return arc_base_baud/16;

}



static void __init arc_set_early_base_baud(unsigned long dt_root)

{

	unsigned int core_clk = arc_get_core_freq();



	if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))

		arc_base_baud = core_clk/3;

	else

		arc_base_baud = core_clk;

}

#else

#define arc_set_early_base_baud(dt_root)

#endif



static const void * __init arch_get_next_mach(const char *const **match)

static const void * __init arch_get_next_mach(const char *const **match)

{

{

	static const struct machine_desc *mdesc = __arch_info_begin;

	static const struct machine_desc *mdesc = __arch_info_begin;
@@ -56,5 +78,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt) 
	if (clk)

	if (clk)

		arc_set_core_freq(of_read_ulong(clk, len/4));

		arc_set_core_freq(of_read_ulong(clk, len/4));





	arc_set_early_base_baud(dt_root);



	return mdesc;

	return mdesc;

}
 
}

arch/arc/kernel/entry.S

+9 −5
Original line number Original line Diff line number Diff line
@@ -736,16 +736,20 @@ ENTRY(ret_from_fork) 
	; put last task in scheduler queue

	; put last task in scheduler queue

	bl   @schedule_tail

	bl   @schedule_tail





	; If kernel thread, jump to its entry-point

	ld   r9, [sp, PT_status32]

	ld   r9, [sp, PT_status32]

	brne r9, 0, 1f

	brne r9, 0, 1f





	jl.d [r14]

	jl.d [r14]		; kernel thread entry point

	mov  r0, r13		; arg to payload

	mov  r0, r13		; (see PF_KTHREAD block in copy_thread)





1:

1:

	; special case of kernel_thread entry point returning back due to

	; Return to user space

	; kernel_execve() - pretend return from syscall to ret to userland

	; 1. Any forked task (Reach here via BRne above)

	; 2. First ever init task (Reach here via return from JL above)

	;    This is the historic "kernel_execve" use-case, to return to init

	;    user mode, in a round about way since that is always done from

	;    a kernel thread which is executed via JL above but always returns

	;    out whenever kernel_execve (now inline do_fork()) is involved

	b    ret_from_exception

	b    ret_from_exception

END(ret_from_fork)

END(ret_from_fork)