Commit 3eb51486 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'arc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc 

Pull ARC updates from Vineet Gupta:

 - long due rewrite of do_page_fault

 - refactoring of entry/exit code to utilize the double load/store
   instructions

 - hsdk platform updates

* tag 'arc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [plat-hsdk]: Enable AXI DW DMAC in defconfig
  ARC: [plat-hsdk]: enable DW SPI controller
  ARC: hide unused function unw_hdr_alloc
  ARC: [haps] Add Virtio support
  ARCv2: entry: simplify return to Delay Slot via interrupt
  ARC: entry: EV_Trap expects r10 (vs. r9) to have exception cause
  ARCv2: entry: rewrite to enable use of double load/stores LDD/STD
  ARCv2: entry: avoid a branch
  ARCv2: entry: push out the Z flag unclobber from common EXCEPTION_PROLOGUE
  ARCv2: entry: comments about hardware auto-save on taken interrupts
  ARC: mm: do_page_fault refactor #8: release mmap_sem sooner
  ARC: mm: do_page_fault refactor #7: fold the various error handling
  ARC: mm: do_page_fault refactor #6: error handlers to use same pattern
  ARC: mm: do_page_fault refactor #5: scoot no_context to end
  ARC: mm: do_page_fault refactor #4: consolidate retry related logic
  ARC: mm: do_page_fault refactor #3: tidyup vma access permission code
  ARC: mm: do_page_fault refactor #2: remove short lived variable
  ARC: mm: do_page_fault refactor #1: remove label @good_area
parents c309b6f2 24a20b0a

arch/arc/boot/dts/haps_hs.dts

+30 −0
Original line number Diff line number Diff line
@@ -62,5 +62,35 @@ 
			#interrupt-cells = <1>;

			interrupts = <20>;

		};



		virtio0: virtio@f0100000 {

			compatible = "virtio,mmio";

			reg = <0xf0100000 0x2000>;

			interrupts = <31>;

		};



		virtio1: virtio@f0102000 {

			compatible = "virtio,mmio";

			reg = <0xf0102000 0x2000>;

			interrupts = <32>;

		};



		virtio2: virtio@f0104000 {

			compatible = "virtio,mmio";

			reg = <0xf0104000 0x2000>;

			interrupts = <33>;

		};



		virtio3: virtio@f0106000 {

			compatible = "virtio,mmio";

			reg = <0xf0106000 0x2000>;

			interrupts = <34>;

		};



		virtio4: virtio@f0108000 {

			compatible = "virtio,mmio";

			reg = <0xf0108000 0x2000>;

			interrupts = <35>;

		};

	};

};

arch/arc/boot/dts/hsdk.dts

+14 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
 */

/dts-v1/;



#include <dt-bindings/gpio/gpio.h>

#include <dt-bindings/reset/snps,hsdk-reset.h>



/ {
@@ -252,6 +253,19 @@ 
			dma-coherent;

		};



		spi0: spi@20000 {

			compatible = "snps,dw-apb-ssi";

			reg = <0x20000 0x100>;

			#address-cells = <1>;

			#size-cells = <0>;

			interrupts = <16>;

			num-cs = <2>;

			reg-io-width = <4>;

			clocks = <&input_clk>;

			cs-gpios = <&creg_gpio 0 GPIO_ACTIVE_LOW>,

				   <&creg_gpio 1 GPIO_ACTIVE_LOW>;

		};



		creg_gpio: gpio@14b0 {

			compatible = "snps,creg-gpio-hsdk";

			reg = <0x14b0 0x4>;

arch/arc/configs/haps_hs_defconfig

+4 −1
Original line number Diff line number Diff line
@@ -35,10 +35,12 @@ CONFIG_INET=y 
# CONFIG_IPV6 is not set

# CONFIG_WIRELESS is not set

CONFIG_DEVTMPFS=y

CONFIG_DEVTMPFS_MOUNT=y

# CONFIG_STANDALONE is not set

# CONFIG_PREVENT_FIRMWARE_BUILD is not set

# CONFIG_BLK_DEV is not set

CONFIG_VIRTIO_BLK=y

CONFIG_NETDEVICES=y

CONFIG_VIRTIO_NET=y

# CONFIG_NET_VENDOR_ARC is not set

# CONFIG_NET_VENDOR_BROADCOM is not set

# CONFIG_NET_VENDOR_INTEL is not set
@@ -68,6 +70,7 @@ CONFIG_FRAMEBUFFER_CONSOLE=y 
CONFIG_LOGO=y

# CONFIG_HID is not set

# CONFIG_USB_SUPPORT is not set

CONFIG_VIRTIO_MMIO=y

# CONFIG_IOMMU_SUPPORT is not set

CONFIG_EXT2_FS=y

CONFIG_EXT2_FS_XATTR=y

arch/arc/configs/hsdk_defconfig

+5 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ CONFIG_SERIAL_8250_CONSOLE=y 
CONFIG_SERIAL_8250_DW=y

CONFIG_SERIAL_OF_PLATFORM=y

# CONFIG_HW_RANDOM is not set

CONFIG_SPI=y

CONFIG_SPI_DESIGNWARE=y

CONFIG_SPI_DW_MMIO=y

CONFIG_GPIOLIB=y

CONFIG_GPIO_SYSFS=y

CONFIG_GPIO_DWAPB=y
@@ -66,6 +69,8 @@ CONFIG_MMC=y 
CONFIG_MMC_SDHCI=y

CONFIG_MMC_SDHCI_PLTFM=y

CONFIG_MMC_DW=y

CONFIG_DMADEVICES=y

CONFIG_DW_AXI_DMAC=y

CONFIG_EXT3_FS=y

CONFIG_VFAT_FS=y

CONFIG_TMPFS=y

arch/arc/include/asm/entry-arcv2.h

+190 −171
Original line number Diff line number Diff line
@@ -7,232 +7,251 @@ 
#include <asm/irqflags-arcv2.h>

#include <asm/thread_info.h>	/* For THREAD_SIZE */



/*

 * Interrupt/Exception stack layout (pt_regs) for ARCv2

 *   (End of struct aligned to end of page [unless nested])

 *

 *  INTERRUPT                          EXCEPTION

 *

 *    manual    ---------------------  manual

 *              |      orig_r0      |

 *              |      event/ECR    |

 *              |      bta          |

 *              |      user_r25     |

 *              |      gp           |

 *              |      fp           |

 *              |      sp           |

 *              |      r12          |

 *              |      r30          |

 *              |      r58          |

 *              |      r59          |

 *  hw autosave ---------------------

 *    optional  |      r0           |

 *              |      r1           |

 *              ~                   ~

 *              |      r9           |

 *              |      r10          |

 *              |      r11          |

 *              |      blink        |

 *              |      lpe          |

 *              |      lps          |

 *              |      lpc          |

 *              |      ei base      |

 *              |      ldi base     |

 *              |      jli base     |

 *              ---------------------

 *  hw autosave |       pc / eret   |

 *   mandatory  | stat32 / erstatus |

 *              ---------------------

 */



/*------------------------------------------------------------------------*/

.macro INTERRUPT_PROLOGUE	called_from

.macro INTERRUPT_PROLOGUE



	; Before jumping to Interrupt Vector, hardware micro-ops did following:

	; (A) Before jumping to Interrupt Vector, hardware micro-ops did following:

	;   1. SP auto-switched to kernel mode stack

	;   2. STATUS32.Z flag set to U mode at time of interrupt (U:1, K:0)

	;   3. Auto saved: r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI, PC, STAT32

	;   2. STATUS32.Z flag set if in U mode at time of interrupt (U:1,K:0)

	;   3. Auto save: (mandatory) Push PC and STAT32 on stack

	;                 hardware does even if CONFIG_ARC_IRQ_NO_AUTOSAVE

	;   4. Auto save: (optional) r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI

	;

	; Now manually save: r12, sp, fp, gp, r25

	; (B) Manually saved some regs: r12,r25,r30, sp,fp,gp, ACCL pair



#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE

.ifnc \called_from, exception

	st.as	r9, [sp, -10]	; save r9 in it's final stack slot

	sub	sp, sp, 12	; skip JLI, LDI, EI



	PUSH	lp_count

	PUSHAX	lp_start

	PUSHAX	lp_end

	PUSH	blink



	PUSH	r11

	PUSH	r10



	sub	sp, sp, 4	; skip r9



	PUSH	r8

	PUSH	r7

	PUSH	r6

	PUSH	r5

	PUSH	r4

	PUSH	r3

	PUSH	r2

	PUSH	r1

	PUSH	r0

.endif

#endif

	; carve pt_regs on stack (case #3), PC/STAT32 already on stack

	sub	sp, sp, SZ_PT_REGS - 8



#ifdef CONFIG_ARC_HAS_ACCL_REGS

	PUSH	r59

	PUSH	r58

	__SAVE_REGFILE_HARD

#else

	; carve pt_regs on stack (case #4), which grew partially already

	sub	sp, sp, PT_r0

#endif



	PUSH	r30

	PUSH	r12

	__SAVE_REGFILE_SOFT

.endm



/*------------------------------------------------------------------------*/

.macro EXCEPTION_PROLOGUE



	; (A) Before jumping to Exception Vector, hardware micro-ops did following:

	;   1. SP auto-switched to kernel mode stack

	;   2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0)

	;

	; (B) Manually save the complete reg file below



	sub	sp, sp, SZ_PT_REGS	; carve pt_regs



	; _HARD saves r10 clobbered by _SOFT as scratch hence comes first



	__SAVE_REGFILE_HARD

	__SAVE_REGFILE_SOFT



	st	r0, [sp]	; orig_r0



	lr	r10, [eret]

	lr	r11, [erstatus]

	ST2	r10, r11, PT_ret



	lr	r10, [ecr]

	lr	r11, [erbta]

	ST2	r10, r11, PT_event



	; OUTPUT: r10 has ECR expected by EV_Trap

.endm



/*------------------------------------------------------------------------

 * This macro saves the registers manually which would normally be autosaved

 * by hardware on taken interrupts. It is used by

 *   - exception handlers (which don't have autosave)

 *   - interrupt autosave disabled due to CONFIG_ARC_IRQ_NO_AUTOSAVE

 */

.macro __SAVE_REGFILE_HARD



	ST2	r0,  r1,  PT_r0

	ST2	r2,  r3,  PT_r2

	ST2	r4,  r5,  PT_r4

	ST2	r6,  r7,  PT_r6

	ST2	r8,  r9,  PT_r8

	ST2	r10, r11, PT_r10



	st	blink, [sp, PT_blink]



	lr	r10, [lp_end]

	lr	r11, [lp_start]

	ST2	r10, r11, PT_lpe



	st	lp_count, [sp, PT_lpc]



	; skip JLI, LDI, EI for now

.endm



/*------------------------------------------------------------------------

 * This macros saves a bunch of other registers which can't be autosaved for

 * various reasons:

 *   - r12: the last caller saved scratch reg since hardware saves in pairs so r0-r11

 *   - r30: free reg, used by gcc as scratch

 *   - ACCL/ACCH pair when they exist

 */

.macro __SAVE_REGFILE_SOFT



	ST2	gp, fp, PT_r26		; gp (r26), fp (r27)



	st	r12, [sp, PT_sp + 4]

	st	r30, [sp, PT_sp + 8]



	; Saving pt_regs->sp correctly requires some extra work due to the way

	; Auto stack switch works

	;  - U mode: retrieve it from AUX_USER_SP

	;  - K mode: add the offset from current SP where H/w starts auto push

	;

	; Utilize the fact that Z bit is set if Intr taken in U mode

	mov.nz	r9, sp

	add.nz	r9, r9, SZ_PT_REGS - PT_sp - 4

	bnz	1f

	; 1. Utilize the fact that Z bit is set if Intr taken in U mode

	; 2. Upon entry SP is always saved (for any inspection, unwinding etc),

	;    but on return, restored only if U mode



	lr	r9, [AUX_USER_SP]

1:

	PUSH	r9	; SP

	lr	r10, [AUX_USER_SP]	; U mode SP



	; ISA requires ADD.nz to have same dest and src reg operands

	mov.nz	r10, sp

	add.nz	r10, r10, SZ_PT_REGS	; K mode SP



	PUSH	fp

	PUSH	gp

	st	r10, [sp, PT_sp]	; SP (pt_regs->sp)



#ifdef CONFIG_ARC_CURR_IN_REG

	PUSH	r25			; user_r25

	st	r25, [sp, PT_user_r25]

	GET_CURR_TASK_ON_CPU	r25

#else

	sub	sp, sp, 4

#endif



.ifnc \called_from, exception

	sub	sp, sp, 12	; BTA/ECR/orig_r0 placeholder per pt_regs

.endif

#ifdef CONFIG_ARC_HAS_ACCL_REGS

	ST2	r58, r59, PT_sp + 12

#endif



.endm



/*------------------------------------------------------------------------*/

.macro INTERRUPT_EPILOGUE	called_from

.macro __RESTORE_REGFILE_SOFT



.ifnc \called_from, exception

	add	sp, sp, 12	; skip BTA/ECR/orig_r0 placeholderss

.endif

	LD2	gp, fp, PT_r26		; gp (r26), fp (r27)



#ifdef CONFIG_ARC_CURR_IN_REG

	POP	r25

#else

	add	sp, sp, 4

#endif

	ld	r12, [sp, PT_sp + 4]

	ld	r30, [sp, PT_sp + 8]



	POP	gp

	POP	fp



	; Don't touch AUX_USER_SP if returning to K mode (Z bit set)

	; (Z bit set on K mode is inverse of INTERRUPT_PROLOGUE)

	add.z	sp, sp, 4

	; Restore SP (into AUX_USER_SP) only if returning to U mode

	;  - for K mode, it will be implicitly restored as stack is unwound

	;  - Z flag set on K is inverse of what hardware does on interrupt entry

	;    but that doesn't really matter

	bz	1f



	POPAX	AUX_USER_SP

	ld	r10, [sp, PT_sp]	; SP (pt_regs->sp)

	sr	r10, [AUX_USER_SP]

1:

	POP	r12

	POP	r30



#ifdef CONFIG_ARC_HAS_ACCL_REGS

	POP	r58

	POP	r59

#ifdef CONFIG_ARC_CURR_IN_REG

	ld	r25, [sp, PT_user_r25]

#endif



#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE

.ifnc \called_from, exception

	POP	r0

	POP	r1

	POP	r2

	POP	r3

	POP	r4

	POP	r5

	POP	r6

	POP	r7

	POP	r8

	POP	r9

	POP	r10

	POP	r11



	POP	blink

	POPAX	lp_end

	POPAX	lp_start



	POP	r9

	mov	lp_count, r9



	add	sp, sp, 12	; skip JLI, LDI, EI

	ld.as	r9, [sp, -10]	; reload r9 which got clobbered

.endif

#ifdef CONFIG_ARC_HAS_ACCL_REGS

	LD2	r58, r59, PT_sp + 12

#endif

.endm



/*------------------------------------------------------------------------*/

.macro __RESTORE_REGFILE_HARD



	ld	blink, [sp, PT_blink]



	LD2	r10, r11, PT_lpe

	sr	r10, [lp_end]

	sr	r11, [lp_start]



	ld	r10, [sp, PT_lpc]	; lp_count can't be target of LD

	mov	lp_count, r10



	LD2	r0,  r1,  PT_r0

	LD2	r2,  r3,  PT_r2

	LD2	r4,  r5,  PT_r4

	LD2	r6,  r7,  PT_r6

	LD2	r8,  r9,  PT_r8

	LD2	r10, r11, PT_r10

.endm





/*------------------------------------------------------------------------*/

.macro EXCEPTION_PROLOGUE

.macro INTERRUPT_EPILOGUE



	; Before jumping to Exception Vector, hardware micro-ops did following:

	;   1. SP auto-switched to kernel mode stack

	;   2. STATUS32.Z flag set to U mode at time of interrupt (U:1,K:0)

	;

	; Now manually save the complete reg file



	PUSH	r9		; freeup a register: slot of erstatus



	PUSHAX	eret

	sub	sp, sp, 12	; skip JLI, LDI, EI

	PUSH	lp_count

	PUSHAX	lp_start

	PUSHAX	lp_end

	PUSH	blink



	PUSH	r11

	PUSH	r10



	ld.as	r9,  [sp, 10]	; load stashed r9 (status32 stack slot)

	lr	r10, [erstatus]

	st.as	r10, [sp, 10]	; save status32 at it's right stack slot



	PUSH	r9

	PUSH	r8

	PUSH	r7

	PUSH	r6

	PUSH	r5

	PUSH	r4

	PUSH	r3

	PUSH	r2

	PUSH	r1

	PUSH	r0



	; -- for interrupts, regs above are auto-saved by h/w in that order --

	; Now do what ISR prologue does (manually save r12, sp, fp, gp, r25)

	;

	; Set Z flag if this was from U mode (expected by INTERRUPT_PROLOGUE)

	; Although H/w exception micro-ops do set Z flag for U mode (just like

	; for interrupts), it could get clobbered in case we soft land here from

	; a TLB Miss exception handler (tlbex.S)

	; INPUT: r0 has STAT32 of calling context

	; INPUT: Z flag set if returning to K mode



	and	r10, r10, STATUS_U_MASK

	xor.f	0, r10, STATUS_U_MASK

	; _SOFT clobbers r10 restored by _HARD hence the order



	INTERRUPT_PROLOGUE  exception

	__RESTORE_REGFILE_SOFT



	PUSHAX	erbta

	PUSHAX	ecr		; r9 contains ECR, expected by EV_Trap

#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE

	__RESTORE_REGFILE_HARD

	add	sp, sp, SZ_PT_REGS - 8

#else

	add	sp, sp, PT_r0

#endif



	PUSH	r0		; orig_r0

.endm



/*------------------------------------------------------------------------*/

.macro EXCEPTION_EPILOGUE



	; Assumes r0 has PT_status32

	btst   r0, STATUS_U_BIT	; Z flag set if K, used in INTERRUPT_EPILOGUE



	add	sp, sp, 8	; orig_r0/ECR don't need restoring

	POPAX	erbta



	INTERRUPT_EPILOGUE  exception

	; INPUT: r0 has STAT32 of calling context



	POP	r0

	POP	r1

	POP	r2

	POP	r3

	POP	r4

	POP	r5

	POP	r6

	POP	r7

	POP	r8

	POP	r9

	POP	r10

	POP	r11

	btst	r0, STATUS_U_BIT	; Z flag set if K, used in restoring SP



	POP	blink

	POPAX	lp_end

	POPAX	lp_start

	ld	r10, [sp, PT_event + 4]

	sr	r10, [erbta]



	POP	r9

	mov	lp_count, r9

	LD2	r10, r11, PT_ret

	sr	r10, [eret]

	sr	r11, [erstatus]



	add	sp, sp, 12	; skip JLI, LDI, EI

	POPAX	eret

	POPAX	erstatus

	__RESTORE_REGFILE_SOFT

	__RESTORE_REGFILE_HARD



	ld.as	r9, [sp, -12]	; reload r9 which got clobbered

	add	sp, sp, SZ_PT_REGS

.endm



.macro FAKE_RET_FROM_EXCPN

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