arch/s390/pci/pci_mmio.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Access to PCI I/O memory from user space programs.
  *
  * Copyright IBM Corp. 2014
  * Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
  */
 #include <linux/kernel.h>
 #include <linux/syscalls.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/errno.h>
 #include <linux/pci.h>
 #include <asm/asm-extable.h>
 #include <asm/pci_io.h>
 #include <asm/pci_debug.h>

 static inline void zpci_err_mmio(u8 cc, u8 status, u64 offset)
 {
 	struct {
 		u64 offset;
 		u8 cc;
 		u8 status;
 	} data = {offset, cc, status};

 	zpci_err_hex(&data, sizeof(data));
 }

 static inline int __pcistb_mio_inuser(
 		void __iomem *ioaddr, const void __user *src,
 		u64 len, u8 *status)
 {
 	int cc = -ENXIO;

 	asm volatile (
 		"       sacf 256\n"
 		"0:     .insn   rsy,0xeb00000000d4,%[len],%[ioaddr],%[src]\n"
 		"1:     ipm     %[cc]\n"
 		"       srl     %[cc],28\n"
 		"2:     sacf 768\n"
 		EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
 		: [cc] "+d" (cc), [len] "+d" (len)
 		: [ioaddr] "a" (ioaddr), [src] "Q" (*((u8 __force *)src))
 		: "cc", "memory");
 	*status = len >> 24 & 0xff;
 	return cc;
 }

 static inline int __pcistg_mio_inuser(
 		void __iomem *ioaddr, const void __user *src,
 		u64 ulen, u8 *status)
 {
 	union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
 	int cc = -ENXIO;
 	u64 val = 0;
 	u64 cnt = ulen;
 	u8 tmp;

 	/*
 	 * copy 0 < @len <= 8 bytes from @src into the right most bytes of
 	 * a register, then store it to PCI at @ioaddr while in secondary
 	 * address space. pcistg then uses the user mappings.
 	 */
 	asm volatile (
 		"       sacf    256\n"
 		"0:     llgc    %[tmp],0(%[src])\n"
 		"4:	sllg	%[val],%[val],8\n"
 		"       aghi    %[src],1\n"
 		"       ogr     %[val],%[tmp]\n"
 		"       brctg   %[cnt],0b\n"
 		"1:     .insn   rre,0xb9d40000,%[val],%[ioaddr_len]\n"
 		"2:     ipm     %[cc]\n"
 		"       srl     %[cc],28\n"
 		"3:     sacf    768\n"
 		EX_TABLE(0b, 3b) EX_TABLE(4b, 3b) EX_TABLE(1b, 3b) EX_TABLE(2b, 3b)
 		:
 		[src] "+a" (src), [cnt] "+d" (cnt),
 		[val] "+d" (val), [tmp] "=d" (tmp),
 		[cc] "+d" (cc), [ioaddr_len] "+&d" (ioaddr_len.pair)
 		:: "cc", "memory");
 	*status = ioaddr_len.odd >> 24 & 0xff;

 	/* did we read everything from user memory? */
 	if (!cc && cnt != 0)
 		cc = -EFAULT;

 	return cc;
 }

 static inline int __memcpy_toio_inuser(void __iomem *dst,
 				   const void __user *src, size_t n)
 {
 	int size, rc = 0;
 	u8 status = 0;

 	if (!src)
 		return -EINVAL;

 	while (n > 0) {
 		size = zpci_get_max_io_size((u64 __force) dst,
 					    (u64 __force) src, n,
 					    ZPCI_MAX_WRITE_SIZE);
 		if (size > 8) /* main path */
 			rc = __pcistb_mio_inuser(dst, src, size, &status);
 		else
 			rc = __pcistg_mio_inuser(dst, src, size, &status);
 		if (rc)
 			break;
 		src += size;
 		dst += size;
 		n -= size;
 	}
 	if (rc)
 		zpci_err_mmio(rc, status, (__force u64) dst);
 	return rc;
 }

 SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
 		const void __user *, user_buffer, size_t, length)
 {
 	u8 local_buf[64];
 	void __iomem *io_addr;
 	void *buf;
 	struct vm_area_struct *vma;
 	pte_t *ptep;
 	spinlock_t *ptl;
 	long ret;

 	if (!zpci_is_enabled())
 		return -ENODEV;

 	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
 		return -EINVAL;

 	/*
 	 * We only support write access to MIO capable devices if we are on
 	 * a MIO enabled system. Otherwise we would have to check for every
 	 * address if it is a special ZPCI_ADDR and would have to do
 	 * a pfn lookup which we don't need for MIO capable devices.  Currently
 	 * ISM devices are the only devices without MIO support and there is no
 	 * known need for accessing these from userspace.
 	 */
 	if (static_branch_likely(&have_mio)) {
 		ret = __memcpy_toio_inuser((void  __iomem *) mmio_addr,
 					user_buffer,
 					length);
 		return ret;
 	}

 	if (length > 64) {
 		buf = kmalloc(length, GFP_KERNEL);
 		if (!buf)
 			return -ENOMEM;
 	} else
 		buf = local_buf;

 	ret = -EFAULT;
 	if (copy_from_user(buf, user_buffer, length))
 		goto out_free;

 	mmap_read_lock(current->mm);
 	ret = -EINVAL;
 	vma = vma_lookup(current->mm, mmio_addr);
 	if (!vma)
 		goto out_unlock_mmap;
 	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
 		goto out_unlock_mmap;
 	ret = -EACCES;
 	if (!(vma->vm_flags & VM_WRITE))
 		goto out_unlock_mmap;

 	ret = follow_pte(vma, mmio_addr, &ptep, &ptl);
 	if (ret)
 		goto out_unlock_mmap;

 	io_addr = (void __iomem *)((pte_pfn(*ptep) << PAGE_SHIFT) |
 			(mmio_addr & ~PAGE_MASK));

 	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
 		goto out_unlock_pt;

 	ret = zpci_memcpy_toio(io_addr, buf, length);
 out_unlock_pt:
 	pte_unmap_unlock(ptep, ptl);
 out_unlock_mmap:
 	mmap_read_unlock(current->mm);
 out_free:
 	if (buf != local_buf)
 		kfree(buf);
 	return ret;
 }

 static inline int __pcilg_mio_inuser(
 		void __user *dst, const void __iomem *ioaddr,
 		u64 ulen, u8 *status)
 {
 	union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
 	u64 cnt = ulen;
 	int shift = ulen * 8;
 	int cc = -ENXIO;
 	u64 val, tmp;

 	/*
 	 * read 0 < @len <= 8 bytes from the PCI memory mapped at @ioaddr (in
 	 * user space) into a register using pcilg then store these bytes at
 	 * user address @dst
 	 */
 	asm volatile (
 		"       sacf    256\n"
 		"0:     .insn   rre,0xb9d60000,%[val],%[ioaddr_len]\n"
 		"1:     ipm     %[cc]\n"
 		"       srl     %[cc],28\n"
 		"       ltr     %[cc],%[cc]\n"
 		"       jne     4f\n"
 		"2:     ahi     %[shift],-8\n"
 		"       srlg    %[tmp],%[val],0(%[shift])\n"
 		"3:     stc     %[tmp],0(%[dst])\n"
 		"5:	aghi	%[dst],1\n"
 		"       brctg   %[cnt],2b\n"
 		"4:     sacf    768\n"
 		EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b) EX_TABLE(5b, 4b)
 		:
 		[ioaddr_len] "+&d" (ioaddr_len.pair),
 		[cc] "+d" (cc), [val] "=d" (val),
 		[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
 		[shift] "+d" (shift)
 		:: "cc", "memory");

 	/* did we write everything to the user space buffer? */
 	if (!cc && cnt != 0)
 		cc = -EFAULT;

 	*status = ioaddr_len.odd >> 24 & 0xff;
 	return cc;
 }

 static inline int __memcpy_fromio_inuser(void __user *dst,
 				     const void __iomem *src,
 				     unsigned long n)
 {
 	int size, rc = 0;
 	u8 status;

 	while (n > 0) {
 		size = zpci_get_max_io_size((u64 __force) src,
 					    (u64 __force) dst, n,
 					    ZPCI_MAX_READ_SIZE);
 		rc = __pcilg_mio_inuser(dst, src, size, &status);
 		if (rc)
 			break;
 		src += size;
 		dst += size;
 		n -= size;
 	}
 	if (rc)
 		zpci_err_mmio(rc, status, (__force u64) dst);
 	return rc;
 }

 SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
 		void __user *, user_buffer, size_t, length)
 {
 	u8 local_buf[64];
 	void __iomem *io_addr;
 	void *buf;
 	struct vm_area_struct *vma;
 	pte_t *ptep;
 	spinlock_t *ptl;
 	long ret;

 	if (!zpci_is_enabled())
 		return -ENODEV;

 	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
 		return -EINVAL;

 	/*
 	 * We only support read access to MIO capable devices if we are on
 	 * a MIO enabled system. Otherwise we would have to check for every
 	 * address if it is a special ZPCI_ADDR and would have to do
 	 * a pfn lookup which we don't need for MIO capable devices.  Currently
 	 * ISM devices are the only devices without MIO support and there is no
 	 * known need for accessing these from userspace.
 	 */
 	if (static_branch_likely(&have_mio)) {
 		ret = __memcpy_fromio_inuser(
 				user_buffer, (const void __iomem *)mmio_addr,
 				length);
 		return ret;
 	}

 	if (length > 64) {
 		buf = kmalloc(length, GFP_KERNEL);
 		if (!buf)
 			return -ENOMEM;
 	} else {
 		buf = local_buf;
 	}

 	mmap_read_lock(current->mm);
 	ret = -EINVAL;
 	vma = vma_lookup(current->mm, mmio_addr);
 	if (!vma)
 		goto out_unlock_mmap;
 	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
 		goto out_unlock_mmap;
 	ret = -EACCES;
 	if (!(vma->vm_flags & VM_WRITE))
 		goto out_unlock_mmap;

 	ret = follow_pte(vma, mmio_addr, &ptep, &ptl);
 	if (ret)
 		goto out_unlock_mmap;

 	io_addr = (void __iomem *)((pte_pfn(*ptep) << PAGE_SHIFT) |
 			(mmio_addr & ~PAGE_MASK));

 	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
 		ret = -EFAULT;
 		goto out_unlock_pt;
 	}
 	ret = zpci_memcpy_fromio(buf, io_addr, length);

 out_unlock_pt:
 	pte_unmap_unlock(ptep, ptl);
 out_unlock_mmap:
 	mmap_read_unlock(current->mm);

 	if (!ret && copy_to_user(user_buffer, buf, length))
 		ret = -EFAULT;

 	if (buf != local_buf)
 		kfree(buf);
 	return ret;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Access to PCI I/O memory from user space programs.
	*
	* Copyright IBM Corp. 2014
	* Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
	*/
	#include <linux/kernel.h>
	#include <linux/syscalls.h>
	#include <linux/init.h>
	#include <linux/mm.h>
	#include <linux/errno.h>
	#include <linux/pci.h>
	#include <asm/asm-extable.h>
	#include <asm/pci_io.h>
	#include <asm/pci_debug.h>

	static inline void zpci_err_mmio(u8 cc, u8 status, u64 offset)
	{
	struct {
	u64 offset;
	u8 cc;
	u8 status;
	} data = {offset, cc, status};

	zpci_err_hex(&data, sizeof(data));
	}

	static inline int __pcistb_mio_inuser(
	void __iomem ioaddr, const void __user src,
	u64 len, u8 *status)
	{
	int cc = -ENXIO;

	asm volatile (
	" sacf 256\n"
	"0: .insn rsy,0xeb00000000d4,%[len],%[ioaddr],%[src]\n"
	"1: ipm %[cc]\n"
	" srl %[cc],28\n"
	"2: sacf 768\n"
	EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
	: [cc] "+d" (cc), [len] "+d" (len)
	: [ioaddr] "a" (ioaddr), [src] "Q" (((u8 __force )src))
	: "cc", "memory");
	*status = len >> 24 & 0xff;
	return cc;
	}

	static inline int __pcistg_mio_inuser(
	void __iomem ioaddr, const void __user src,
	u64 ulen, u8 *status)
	{
	union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
	int cc = -ENXIO;
	u64 val = 0;
	u64 cnt = ulen;
	u8 tmp;

	/*
	* copy 0 < @len <= 8 bytes from @src into the right most bytes of
	* a register, then store it to PCI at @ioaddr while in secondary
	* address space. pcistg then uses the user mappings.
	*/
	asm volatile (
	" sacf 256\n"
	"0: llgc %[tmp],0(%[src])\n"
	"4: sllg %[val],%[val],8\n"
	" aghi %[src],1\n"
	" ogr %[val],%[tmp]\n"
	" brctg %[cnt],0b\n"
	"1: .insn rre,0xb9d40000,%[val],%[ioaddr_len]\n"
	"2: ipm %[cc]\n"
	" srl %[cc],28\n"
	"3: sacf 768\n"
	EX_TABLE(0b, 3b) EX_TABLE(4b, 3b) EX_TABLE(1b, 3b) EX_TABLE(2b, 3b)
	:
	[src] "+a" (src), [cnt] "+d" (cnt),
	[val] "+d" (val), [tmp] "=d" (tmp),
	[cc] "+d" (cc), [ioaddr_len] "+&d" (ioaddr_len.pair)
	:: "cc", "memory");
	*status = ioaddr_len.odd >> 24 & 0xff;

	/* did we read everything from user memory? */
	if (!cc && cnt != 0)
	cc = -EFAULT;

	return cc;
	}

	static inline int __memcpy_toio_inuser(void __iomem *dst,
	const void __user *src, size_t n)
	{
	int size, rc = 0;
	u8 status = 0;

	if (!src)
	return -EINVAL;

	while (n > 0) {
	size = zpci_get_max_io_size((u64 __force) dst,
	(u64 __force) src, n,
	ZPCI_MAX_WRITE_SIZE);
	if (size > 8) /* main path */
	rc = __pcistb_mio_inuser(dst, src, size, &status);
	else
	rc = __pcistg_mio_inuser(dst, src, size, &status);
	if (rc)
	break;
	src += size;
	dst += size;
	n -= size;
	}
	if (rc)
	zpci_err_mmio(rc, status, (__force u64) dst);
	return rc;
	}

	SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
	const void __user *, user_buffer, size_t, length)
	{
	u8 local_buf[64];
	void __iomem *io_addr;
	void *buf;
	struct vm_area_struct *vma;
	pte_t *ptep;
	spinlock_t *ptl;
	long ret;

	if (!zpci_is_enabled())
	return -ENODEV;

	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	return -EINVAL;

	/*
	* We only support write access to MIO capable devices if we are on
	* a MIO enabled system. Otherwise we would have to check for every
	* address if it is a special ZPCI_ADDR and would have to do
	* a pfn lookup which we don't need for MIO capable devices. Currently
	* ISM devices are the only devices without MIO support and there is no
	* known need for accessing these from userspace.
	*/
	if (static_branch_likely(&have_mio)) {
	ret = __memcpy_toio_inuser((void __iomem *) mmio_addr,
	user_buffer,
	length);
	return ret;
	}

	if (length > 64) {
	buf = kmalloc(length, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;
	} else
	buf = local_buf;

	ret = -EFAULT;
	if (copy_from_user(buf, user_buffer, length))
	goto out_free;

	mmap_read_lock(current->mm);
	ret = -EINVAL;
	vma = vma_lookup(current->mm, mmio_addr);
	if (!vma)
	goto out_unlock_mmap;
	if (!(vma->vm_flags & (VM_IO \| VM_PFNMAP)))
	goto out_unlock_mmap;
	ret = -EACCES;
	if (!(vma->vm_flags & VM_WRITE))
	goto out_unlock_mmap;

	ret = follow_pte(vma, mmio_addr, &ptep, &ptl);
	if (ret)
	goto out_unlock_mmap;

	io_addr = (void __iomem )((pte_pfn(ptep) << PAGE_SHIFT) \|
	(mmio_addr & ~PAGE_MASK));

	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
	goto out_unlock_pt;

	ret = zpci_memcpy_toio(io_addr, buf, length);
	out_unlock_pt:
	pte_unmap_unlock(ptep, ptl);
	out_unlock_mmap:
	mmap_read_unlock(current->mm);
	out_free:
	if (buf != local_buf)
	kfree(buf);
	return ret;
	}

	static inline int __pcilg_mio_inuser(
	void __user dst, const void __iomem ioaddr,
	u64 ulen, u8 *status)
	{
	union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
	u64 cnt = ulen;
	int shift = ulen * 8;
	int cc = -ENXIO;
	u64 val, tmp;

	/*
	* read 0 < @len <= 8 bytes from the PCI memory mapped at @ioaddr (in
	* user space) into a register using pcilg then store these bytes at
	* user address @dst
	*/
	asm volatile (
	" sacf 256\n"
	"0: .insn rre,0xb9d60000,%[val],%[ioaddr_len]\n"
	"1: ipm %[cc]\n"
	" srl %[cc],28\n"
	" ltr %[cc],%[cc]\n"
	" jne 4f\n"
	"2: ahi %[shift],-8\n"
	" srlg %[tmp],%[val],0(%[shift])\n"
	"3: stc %[tmp],0(%[dst])\n"
	"5: aghi %[dst],1\n"
	" brctg %[cnt],2b\n"
	"4: sacf 768\n"
	EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b) EX_TABLE(5b, 4b)
	:
	[ioaddr_len] "+&d" (ioaddr_len.pair),
	[cc] "+d" (cc), [val] "=d" (val),
	[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
	[shift] "+d" (shift)
	:: "cc", "memory");

	/* did we write everything to the user space buffer? */
	if (!cc && cnt != 0)
	cc = -EFAULT;

	*status = ioaddr_len.odd >> 24 & 0xff;
	return cc;
	}

	static inline int __memcpy_fromio_inuser(void __user *dst,
	const void __iomem *src,
	unsigned long n)
	{
	int size, rc = 0;
	u8 status;

	while (n > 0) {
	size = zpci_get_max_io_size((u64 __force) src,
	(u64 __force) dst, n,
	ZPCI_MAX_READ_SIZE);
	rc = __pcilg_mio_inuser(dst, src, size, &status);
	if (rc)
	break;
	src += size;
	dst += size;
	n -= size;
	}
	if (rc)
	zpci_err_mmio(rc, status, (__force u64) dst);
	return rc;
	}

	SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
	void __user *, user_buffer, size_t, length)
	{
	u8 local_buf[64];
	void __iomem *io_addr;
	void *buf;
	struct vm_area_struct *vma;
	pte_t *ptep;
	spinlock_t *ptl;
	long ret;

	if (!zpci_is_enabled())
	return -ENODEV;

	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	return -EINVAL;

	/*
	* We only support read access to MIO capable devices if we are on
	* a MIO enabled system. Otherwise we would have to check for every
	* address if it is a special ZPCI_ADDR and would have to do
	* a pfn lookup which we don't need for MIO capable devices. Currently
	* ISM devices are the only devices without MIO support and there is no
	* known need for accessing these from userspace.
	*/
	if (static_branch_likely(&have_mio)) {
	ret = __memcpy_fromio_inuser(
	user_buffer, (const void __iomem *)mmio_addr,
	length);
	return ret;
	}

	if (length > 64) {
	buf = kmalloc(length, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;
	} else {
	buf = local_buf;
	}

	mmap_read_lock(current->mm);
	ret = -EINVAL;
	vma = vma_lookup(current->mm, mmio_addr);
	if (!vma)
	goto out_unlock_mmap;
	if (!(vma->vm_flags & (VM_IO \| VM_PFNMAP)))
	goto out_unlock_mmap;
	ret = -EACCES;
	if (!(vma->vm_flags & VM_WRITE))
	goto out_unlock_mmap;

	ret = follow_pte(vma, mmio_addr, &ptep, &ptl);
	if (ret)
	goto out_unlock_mmap;

	io_addr = (void __iomem )((pte_pfn(ptep) << PAGE_SHIFT) \|
	(mmio_addr & ~PAGE_MASK));

	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
	ret = -EFAULT;
	goto out_unlock_pt;
	}
	ret = zpci_memcpy_fromio(buf, io_addr, length);

	out_unlock_pt:
	pte_unmap_unlock(ptep, ptl);
	out_unlock_mmap:
	mmap_read_unlock(current->mm);

	if (!ret && copy_to_user(user_buffer, buf, length))
	ret = -EFAULT;

	if (buf != local_buf)
	kfree(buf);
	return ret;
	}