Commit a27a5c0f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 

Pull arm64 fixes from Will Deacon:
 "Two arm64 fixes: one fixes a warning that started showing up with
  gcc 16 and the other fixes a lockup in udelay() when running on a
  vCPU loaded on a CPU with the new-fangled WFIT instruction:

   - Fix compiler warning from huge_pte_clear() with GCC 16

   - Fix hang in udelay() on systems with WFIT by consistently using the
     virtual counter to calculate the delta"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlbpage: avoid unused-but-set-parameter warning (gcc-16)
  arm64: Force the use of CNTVCT_EL0 in __delay()
parents 98067901 729a2e8e

arch/arm64/include/asm/pgtable.h

+7 −2
Original line number Diff line number Diff line
@@ -144,8 +144,6 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) 
	__pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))



#define pte_none(pte)		(!pte_val(pte))

#define __pte_clear(mm, addr, ptep) \

				__set_pte(ptep, __pte(0))

#define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))



/*
@@ -1284,6 +1282,13 @@ static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr) 
/*

 * Atomic pte/pmd modifications.

 */



static inline void __pte_clear(struct mm_struct *mm,

			       unsigned long addr, pte_t *ptep)

{

	__set_pte(ptep, __pte(0));

}



static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma,

					      unsigned long address,

					      pte_t *ptep)

arch/arm64/lib/delay.c

+15 −4
Original line number Diff line number Diff line
@@ -23,9 +23,20 @@ static inline unsigned long xloops_to_cycles(unsigned long xloops) 
	return (xloops * loops_per_jiffy * HZ) >> 32;

}



/*

 * Force the use of CNTVCT_EL0 in order to have the same base as WFxT.

 * This avoids some annoying issues when CNTVOFF_EL2 is not reset 0 on a

 * KVM host running at EL1 until we do a vcpu_put() on the vcpu. When

 * running at EL2, the effective offset is always 0.

 *

 * Note that userspace cannot change the offset behind our back either,

 * as the vcpu mutex is held as long as KVM_RUN is in progress.

 */

#define __delay_cycles()	__arch_counter_get_cntvct_stable()



void __delay(unsigned long cycles)

{

	cycles_t start = get_cycles();

	cycles_t start = __delay_cycles();



	if (alternative_has_cap_unlikely(ARM64_HAS_WFXT)) {

		u64 end = start + cycles;
@@ -35,17 +46,17 @@ void __delay(unsigned long cycles) 
		 * early, use a WFET loop to complete the delay.

		 */

		wfit(end);

		while ((get_cycles() - start) < cycles)

		while ((__delay_cycles() - start) < cycles)

			wfet(end);

	} else 	if (arch_timer_evtstrm_available()) {

		const cycles_t timer_evt_period =

			USECS_TO_CYCLES(ARCH_TIMER_EVT_STREAM_PERIOD_US);



		while ((get_cycles() - start + timer_evt_period) < cycles)

		while ((__delay_cycles() - start + timer_evt_period) < cycles)

			wfe();

	}



	while ((get_cycles() - start) < cycles)

	while ((__delay_cycles() - start) < cycles)

		cpu_relax();

}

EXPORT_SYMBOL(__delay);