powerpc/vas: Define nx_fault_stamp in coprocessor_request_block (73a80779) · Commits · 戴 / test

Kernel sets fault address and status in CRB for NX page fault on user space address after processing page fault. User space gets the signal and handles the fault mentioned in CRB by bringing the page in to memory and send NX request again. Signed-off-by:

Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by:

Haren Myneni <haren@linux.ibm.com> Signed-off-by:

Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587016769.2275.1048.camel@hbabu-laptop

arch/powerpc/include/asm/icswx.h

+18 −2

Original line number	Diff line number	Diff line
		@@ -108,6 +108,17 @@ struct data_descriptor_entry {
		__be64 address;
		} __packed __aligned(DDE_ALIGN);

		/* 4.3.2 NX-stamped Fault CRB */

		#define NX_STAMP_ALIGN (0x10)

		struct nx_fault_stamp {
		__be64 fault_storage_addr;
		__be16 reserved;
		__u8 flags;
		__u8 fault_status;
		__be32 pswid;
		} __packed __aligned(NX_STAMP_ALIGN);

		/* Chapter 6.5.2 Coprocessor-Request Block (CRB) */

		@@ -135,10 +146,15 @@ struct coprocessor_request_block {

		struct coprocessor_completion_block ccb;

		u8 reserved[48];
		union {
		struct nx_fault_stamp nx;
		u8 reserved[16];
		} stamp;

		u8 reserved[32];

		struct coprocessor_status_block csb;
		} __packed __aligned(CRB_ALIGN);
		} __packed;


		/* RFC02167 Initiate Coprocessor Instructions document

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