block: remove ARCH_BIOVEC_PHYS_MERGEABLE

Take the Xen check into the core code instead of delegating it to
the architectures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

arch/arm/include/asm/io.h

@@ -459,9 +459,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 
 #include <asm-generic/io.h>
 
-#define ARCH_BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
-	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2))
-
 #ifdef CONFIG_MMU
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);

arch/arm64/include/asm/io.h

@@ -205,8 +205,5 @@ extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
 
 extern int devmem_is_allowed(unsigned long pfn);
 
-#define ARCH_BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
-	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2))
-
 #endif	/* __KERNEL__ */
 #endif	/* __ASM_IO_H */

arch/x86/include/asm/io.h

@@ -371,9 +371,6 @@ extern bool is_early_ioremap_ptep(pte_t *ptep);
 
 #ifdef CONFIG_XEN
 #include <xen/xen.h>
-
-#define ARCH_BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
-	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2))
 #endif	/* CONFIG_XEN */
 
 #define IO_SPACE_LIMIT 0xffff

block/blk.h

@@ -4,6 +4,7 @@
 
 #include <linux/idr.h>
 #include <linux/blk-mq.h>
+#include <xen/xen.h>
 #include "blk-mq.h"
 
 /* Amount of time in which a process may batch requests */
@@ -149,10 +150,6 @@ static inline void blk_queue_enter_live(struct request_queue *q)
 	percpu_ref_get(&q->q_usage_counter);
 }
 
-#ifndef ARCH_BIOVEC_PHYS_MERGEABLE
-#define ARCH_BIOVEC_PHYS_MERGEABLE(vec1, vec2) true
-#endif
-
 static inline bool biovec_phys_mergeable(struct request_queue *q,
 		struct bio_vec *vec1, struct bio_vec *vec2)
 {
@@ -162,7 +159,7 @@ static inline bool biovec_phys_mergeable(struct request_queue *q,
 
 	if (addr1 + vec1->bv_len != addr2)
 		return false;
-	if (!ARCH_BIOVEC_PHYS_MERGEABLE(vec1, vec2))
+	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2))
 		return false;
 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
 		return false;

drivers/xen/biomerge.c

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/bio.h>
-#include <linux/io.h>
 #include <linux/export.h>
+#include <xen/xen.h>
 #include <xen/page.h>
 
 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,