s390/kernel: add system calls for PCI memory access

Add the new __NR_s390_pci_mmio_write and __NR_s390_pci_mmio_read system calls to allow user space applications to access device PCI I/O memory pages on s390x platform. [ Martin Schwidefsky: some code beautification ]

Alexey Ishchuk committed 12 years ago

Commit 4eafad71 parent 86c558e7 files · +127 −2Browse files

Unified · Split

7 files

arch/s390/include/uapi/asm/unistd.h +3 −1
arch/s390/kernel/compat_wrapper.c +2 −0
arch/s390/kernel/entry.h +2 −0
arch/s390/kernel/syscalls.S +2 −0
arch/s390/pci/Makefile +1 −1
arch/s390/pci/pci_mmio.c +115 −0
kernel/sys_ni.c +2 −0

arch/s390/include/uapi/asm/unistd.h+3−1

 #define __NR_getrandom		349
 #define __NR_memfd_create	350
 #define __NR_bpf		351
-#define NR_syscalls 352
+#define __NR_s390_pci_mmio_write	352
+#define __NR_s390_pci_mmio_read		353
+#define NR_syscalls 354
 /*
  * There are some system calls that are not present on 64 bit, some

arch/s390/kernel/compat_wrapper.c+2−0

@@ -218,3 +218,5 @@ COMPAT_SYSCALL_WRAP3(seccomp, unsigned int, op, unsigned int, flags, const char · 217 unmodified lines
218	COMPAT_SYSCALL_WRAP3(getrandom, char __user *, buf, size_t, count, unsigned int, flags)	218	COMPAT_SYSCALL_WRAP3(getrandom, char __user *, buf, size_t, count, unsigned int, flags)
219	COMPAT_SYSCALL_WRAP2(memfd_create, const char __user *, uname, unsigned int, flags)	219	COMPAT_SYSCALL_WRAP2(memfd_create, const char __user *, uname, unsigned int, flags)
220	COMPAT_SYSCALL_WRAP3(bpf, int, cmd, union bpf_attr *, attr, unsigned int, size);	220	COMPAT_SYSCALL_WRAP3(bpf, int, cmd, union bpf_attr *, attr, unsigned int, size);
		221	COMPAT_SYSCALL_WRAP3(s390_pci_mmio_write, const unsigned long, mmio_addr, const void __user *, user_buffer, const size_t, length);
		222	COMPAT_SYSCALL_WRAP3(s390_pci_mmio_read, const unsigned long, mmio_addr, void __user *, user_buffer, const size_t, length);

arch/s390/kernel/entry.h+2−0

@@ -74,4 +74,6 @@ struct old_sigaction; · 73 unmodified lines
74	long sys_s390_personality(unsigned int personality);	74	long sys_s390_personality(unsigned int personality);
75	long sys_s390_runtime_instr(int command, int signum);	75	long sys_s390_runtime_instr(int command, int signum);
76		76
		77	long sys_s390_pci_mmio_write(unsigned long, const void __user *, size_t);
		78	long sys_s390_pci_mmio_read(unsigned long, void __user *, size_t);
77	#endif /* _ENTRY_H */	79	#endif /* _ENTRY_H */

arch/s390/kernel/syscalls.S+2−0

@@ -360,3 +360,5 @@ SYSCALL(sys_seccomp,sys_seccomp,compat_sys_seccomp) · 359 unmodified lines
360	SYSCALL(sys_getrandom,sys_getrandom,compat_sys_getrandom)	360	SYSCALL(sys_getrandom,sys_getrandom,compat_sys_getrandom)
361	SYSCALL(sys_memfd_create,sys_memfd_create,compat_sys_memfd_create) /* 350 */	361	SYSCALL(sys_memfd_create,sys_memfd_create,compat_sys_memfd_create) /* 350 */
362	SYSCALL(sys_bpf,sys_bpf,compat_sys_bpf)	362	SYSCALL(sys_bpf,sys_bpf,compat_sys_bpf)
		363	SYSCALL(sys_ni_syscall,sys_s390_pci_mmio_write,compat_sys_s390_pci_mmio_write)
		364	SYSCALL(sys_ni_syscall,sys_s390_pci_mmio_read,compat_sys_s390_pci_mmio_read)

arch/s390/pci/Makefile+1−1

@@ -3,4 +3,4 @@ · 2 unmodified lines
3	#	3	#
4		4
5	obj-$(CONFIG_PCI) += pci.o pci_dma.o pci_clp.o pci_sysfs.o \	5	obj-$(CONFIG_PCI) += pci.o pci_dma.o pci_clp.o pci_sysfs.o \
6	pci_event.o pci_debug.o pci_insn.o	6	pci_event.o pci_debug.o pci_insn.o pci_mmio.o

arch/s390/pci/pci_mmio.c+115−0

@@ -0,0 +1,115 @@
	1	/*
	2	* Access to PCI I/O memory from user space programs.
	3	*
	4	* Copyright IBM Corp. 2014
	5	* Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
	6	*/
	7	#include <linux/kernel.h>
	8	#include <linux/syscalls.h>
	9	#include <linux/init.h>
	10	#include <linux/mm.h>
	11	#include <linux/errno.h>
	12	#include <linux/pci.h>
	13
	14	static long get_pfn(unsigned long user_addr, unsigned long access,
	15	unsigned long *pfn)
	16	{
	17	struct vm_area_struct *vma;
	18	long ret;
	19
	20	down_read(&current->mm->mmap_sem);
	21	ret = -EINVAL;
	22	vma = find_vma(current->mm, user_addr);
	23	if (!vma)
	24	goto out;
	25	ret = -EACCES;
	26	if (!(vma->vm_flags & access))
	27	goto out;
	28	ret = follow_pfn(vma, user_addr, pfn);
	29	out:
	30	up_read(&current->mm->mmap_sem);
	31	return ret;
	32	}
	33
	34	SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
	35	const void __user *, user_buffer, size_t, length)
	36	{
	37	u8 local_buf[64];
	38	void __iomem *io_addr;
	39	void *buf;
	40	unsigned long pfn;
	41	long ret;
	42
	43	if (!zpci_is_enabled())
	44	return -ENODEV;
	45
	46	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	47	return -EINVAL;
	48	if (length > 64) {
	49	buf = kmalloc(length, GFP_KERNEL);
	50	if (!buf)
	51	return -ENOMEM;
	52	} else
	53	buf = local_buf;
	54
	55	ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
	56	if (ret)
	57	goto out;
	58	io_addr = (void *)((pfn << PAGE_SHIFT) \| (mmio_addr & ~PAGE_MASK));
	59
	60	ret = -EFAULT;
	61	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
	62	goto out;
	63
	64	if (copy_from_user(buf, user_buffer, length))
	65	goto out;
	66
	67	memcpy_toio(io_addr, buf, length);
	68	ret = 0;
	69	out:
	70	if (buf != local_buf)
	71	kfree(buf);
	72	return ret;
	73	}
	74
	75	SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
	76	void __user *, user_buffer, size_t, length)
	77	{
	78	u8 local_buf[64];
	79	void __iomem *io_addr;
	80	void *buf;
	81	unsigned long pfn;
	82	long ret;
	83
	84	if (!zpci_is_enabled())
	85	return -ENODEV;
	86
	87	if (length <= 0 \|\| PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
	88	return -EINVAL;
	89	if (length > 64) {
	90	buf = kmalloc(length, GFP_KERNEL);
	91	if (!buf)
	92	return -ENOMEM;
	93	} else
	94	buf = local_buf;
	95
	96	ret = get_pfn(mmio_addr, VM_READ, &pfn);
	97	if (ret)
	98	goto out;
	99	io_addr = (void *)((pfn << PAGE_SHIFT) \| (mmio_addr & ~PAGE_MASK));
	100
	101	ret = -EFAULT;
	102	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
	103	goto out;
	104
	105	memcpy_fromio(buf, io_addr, length);
	106
	107	if (copy_to_user(user_buffer, buf, length))
	108	goto out;
	109
	110	ret = 0;
	111	out:
	112	if (buf != local_buf)
	113	kfree(buf);
	114	return ret;
	115	}

kernel/sys_ni.c+2−0

@@ -169,6 +169,8 @@ cond_syscall(ppc_rtas); · 168 unmodified lines
169	cond_syscall(sys_spu_run);	169	cond_syscall(sys_spu_run);
170	cond_syscall(sys_spu_create);	170	cond_syscall(sys_spu_create);
171	cond_syscall(sys_subpage_prot);	171	cond_syscall(sys_subpage_prot);
		172	cond_syscall(sys_s390_pci_mmio_read);
		173	cond_syscall(sys_s390_pci_mmio_write);
172		174
173	/* mmu depending weak syscall entries */	175	/* mmu depending weak syscall entries */
174	cond_syscall(sys_mprotect);	176	cond_syscall(sys_mprotect);