Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index c7fea9b..b8ddacf 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -423,7 +423,7 @@
 
 		if (zpci_use_mio(zdev))
 			pdev->resource[i].start =
-				(resource_size_t __force) zdev->bars[i].mio_wb;
+				(resource_size_t __force) zdev->bars[i].mio_wt;
 		else
 			pdev->resource[i].start = (resource_size_t __force)
 				pci_iomap_range_fh(pdev, i, 0, 0);
@@ -530,7 +530,7 @@
 			flags |= IORESOURCE_MEM_64;
 
 		if (zpci_use_mio(zdev))
-			addr = (unsigned long) zdev->bars[i].mio_wb;
+			addr = (unsigned long) zdev->bars[i].mio_wt;
 		else
 			addr = ZPCI_ADDR(entry);
 		size = 1UL << zdev->bars[i].size;
@@ -854,7 +854,6 @@
 }
 
 static unsigned int s390_pci_probe __initdata = 1;
-static unsigned int s390_pci_no_mio __initdata;
 unsigned int s390_pci_force_floating __initdata;
 static unsigned int s390_pci_initialized;
 
@@ -865,7 +864,7 @@
 		return NULL;
 	}
 	if (!strcmp(str, "nomio")) {
-		s390_pci_no_mio = 1;
+		S390_lowcore.machine_flags &= ~MACHINE_FLAG_PCI_MIO;
 		return NULL;
 	}
 	if (!strcmp(str, "force_floating")) {
@@ -890,7 +889,7 @@
 	if (!test_facility(69) || !test_facility(71))
 		return 0;
 
-	if (test_facility(153) && !s390_pci_no_mio) {
+	if (MACHINE_HAS_PCI_MIO) {
 		static_branch_enable(&have_mio);
 		ctl_set_bit(2, 5);
 	}
@@ -934,5 +933,5 @@
 void zpci_rescan(void)
 {
 	if (zpci_is_enabled())
-		clp_rescan_pci_devices_simple();
+		clp_rescan_pci_devices_simple(NULL);
 }
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index e585a62..20e093f 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -240,12 +240,14 @@
 }
 
 /*
- * Enable/Disable a given PCI function defined by its function handle.
+ * Enable/Disable a given PCI function and update its function handle if
+ * necessary
  */
-static int clp_set_pci_fn(u32 *fh, u8 nr_dma_as, u8 command)
+static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 {
 	struct clp_req_rsp_set_pci *rrb;
 	int rc, retries = 100;
+	u32 fid = zdev->fid;
 
 	rrb = clp_alloc_block(GFP_KERNEL);
 	if (!rrb)
@@ -256,7 +258,7 @@
 		rrb->request.hdr.len = sizeof(rrb->request);
 		rrb->request.hdr.cmd = CLP_SET_PCI_FN;
 		rrb->response.hdr.len = sizeof(rrb->response);
-		rrb->request.fh = *fh;
+		rrb->request.fh = zdev->fh;
 		rrb->request.oc = command;
 		rrb->request.ndas = nr_dma_as;
 
@@ -269,12 +271,17 @@
 		}
 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
 
-	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
-		*fh = rrb->response.fh;
-	else {
+	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
 		zpci_err("Set PCI FN:\n");
 		zpci_err_clp(rrb->response.hdr.rsp, rc);
-		rc = -EIO;
+	}
+
+	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
+		zdev->fh = rrb->response.fh;
+	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY &&
+			rrb->response.fh == 0) {
+		/* Function is already in desired state - update handle */
+		rc = clp_rescan_pci_devices_simple(&fid);
 	}
 	clp_free_block(rrb);
 	return rc;
@@ -282,18 +289,17 @@
 
 int clp_enable_fh(struct zpci_dev *zdev, u8 nr_dma_as)
 {
-	u32 fh = zdev->fh;
 	int rc;
 
-	rc = clp_set_pci_fn(&fh, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
-	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, fh, rc);
+	rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
+	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
 	if (rc)
 		goto out;
 
-	zdev->fh = fh;
 	if (zpci_use_mio(zdev)) {
-		rc = clp_set_pci_fn(&fh, nr_dma_as, CLP_SET_ENABLE_MIO);
-		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n", zdev->fid, fh, rc);
+		rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_MIO);
+		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
+				zdev->fid, zdev->fh, rc);
 		if (rc)
 			clp_disable_fh(zdev);
 	}
@@ -303,17 +309,13 @@
 
 int clp_disable_fh(struct zpci_dev *zdev)
 {
-	u32 fh = zdev->fh;
 	int rc;
 
 	if (!zdev_enabled(zdev))
 		return 0;
 
-	rc = clp_set_pci_fn(&fh, 0, CLP_SET_DISABLE_PCI_FN);
-	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, fh, rc);
-	if (!rc)
-		zdev->fh = fh;
-
+	rc = clp_set_pci_fn(zdev, 0, CLP_SET_DISABLE_PCI_FN);
+	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
 	return rc;
 }
 
@@ -370,10 +372,14 @@
 static void __clp_update(struct clp_fh_list_entry *entry, void *data)
 {
 	struct zpci_dev *zdev;
+	u32 *fid = data;
 
 	if (!entry->vendor_id)
 		return;
 
+	if (fid && *fid != entry->fid)
+		return;
+
 	zdev = get_zdev_by_fid(entry->fid);
 	if (!zdev)
 		return;
@@ -413,7 +419,10 @@
 	return rc;
 }
 
-int clp_rescan_pci_devices_simple(void)
+/* Rescan PCI functions and refresh function handles. If fid is non-NULL only
+ * refresh the handle of the function matching @fid
+ */
+int clp_rescan_pci_devices_simple(u32 *fid)
 {
 	struct clp_req_rsp_list_pci *rrb;
 	int rc;
@@ -422,7 +431,7 @@
 	if (!rrb)
 		return -ENOMEM;
 
-	rc = clp_list_pci(rrb, NULL, __clp_update);
+	rc = clp_list_pci(rrb, fid, __clp_update);
 
 	clp_free_block(rrb);
 	return rc;
diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
index fbe97ab..743f257 100644
--- a/arch/s390/pci/pci_irq.c
+++ b/arch/s390/pci/pci_irq.c
@@ -115,7 +115,6 @@
 	.name = "PCI-MSI",
 	.irq_unmask = pci_msi_unmask_irq,
 	.irq_mask = pci_msi_mask_irq,
-	.irq_set_affinity = zpci_set_irq_affinity,
 };
 
 static void zpci_handle_cpu_local_irq(bool rescan)
@@ -276,7 +275,9 @@
 		rc = -EIO;
 		if (hwirq - bit >= msi_vecs)
 			break;
-		irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE, msi->affinity);
+		irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE,
+				(irq_delivery == DIRECTED) ?
+				msi->affinity : NULL);
 		if (irq < 0)
 			return -ENOMEM;
 		rc = irq_set_msi_desc(irq, msi);
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index 7d42a87..020a2c5 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -11,6 +11,113 @@
 #include <linux/mm.h>
 #include <linux/errno.h>
 #include <linux/pci.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)
+{
+	register u64 addr asm("2") = (u64 __force) ioaddr;
+	register u64 len asm("3") = 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"
+		"       sllg    %[val],%[val],8\n"
+		"       aghi    %[src],1\n"
+		"       ogr     %[val],%[tmp]\n"
+		"       brctg   %[cnt],0b\n"
+		"1:     .insn   rre,0xb9d40000,%[val],%[ioaddr]\n"
+		"2:     ipm     %[cc]\n"
+		"       srl     %[cc],28\n"
+		"3:     sacf    768\n"
+		EX_TABLE(0b, 3b) EX_TABLE(1b, 3b) EX_TABLE(2b, 3b)
+		:
+		[src] "+a" (src), [cnt] "+d" (cnt),
+		[val] "+d" (val), [tmp] "=d" (tmp),
+		[len] "+d" (len), [cc] "+d" (cc),
+		[ioaddr] "+a" (addr)
+		:: "cc", "memory");
+	*status = len >> 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;
+	mm_segment_t old_fs;
+
+	if (!src)
+		return -EINVAL;
+
+	old_fs = enable_sacf_uaccess();
+	while (n > 0) {
+		size = zpci_get_max_write_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;
+	}
+	disable_sacf_uaccess(old_fs);
+	if (rc)
+		zpci_err_mmio(rc, status, (__force u64) dst);
+	return rc;
+}
 
 static long get_pfn(unsigned long user_addr, unsigned long access,
 		    unsigned long *pfn)
@@ -46,6 +153,20 @@
 
 	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
 		return -EINVAL;
+
+	/*
+	 * Only support read access to MIO capable devices on a MIO enabled
+	 * system. Otherwise we would have to check for every address if it is
+	 * a special ZPCI_ADDR and we would have to do a get_pfn() which we
+	 * don't need for MIO capable devices.
+	 */
+	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)
@@ -56,7 +177,8 @@
 	ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
 	if (ret)
 		goto out;
-	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
+	io_addr = (void __iomem *)((pfn << PAGE_SHIFT) |
+			(mmio_addr & ~PAGE_MASK));
 
 	ret = -EFAULT;
 	if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
@@ -72,6 +194,78 @@
 	return ret;
 }
 
+static inline int __pcilg_mio_inuser(
+		void __user *dst, const void __iomem *ioaddr,
+		u64 ulen, u8 *status)
+{
+	register u64 addr asm("2") = (u64 __force) ioaddr;
+	register u64 len asm("3") = 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]\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"
+		"       aghi    %[dst],1\n"
+		"       brctg   %[cnt],2b\n"
+		"4:     sacf    768\n"
+		EX_TABLE(0b, 4b) EX_TABLE(1b, 4b) EX_TABLE(3b, 4b)
+		:
+		[cc] "+d" (cc), [val] "=d" (val), [len] "+d" (len),
+		[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
+		[shift] "+d" (shift)
+		:
+		[ioaddr] "a" (addr)
+		: "cc", "memory");
+
+	/* did we write everything to the user space buffer? */
+	if (!cc && cnt != 0)
+		cc = -EFAULT;
+
+	*status = len >> 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;
+	mm_segment_t old_fs;
+
+	old_fs = enable_sacf_uaccess();
+	while (n > 0) {
+		size = zpci_get_max_write_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;
+	}
+	disable_sacf_uaccess(old_fs);
+	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)
 {
@@ -86,12 +280,27 @@
 
 	if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
 		return -EINVAL;
+
+	/*
+	 * Only support write access to MIO capable devices on a MIO enabled
+	 * system. Otherwise we would have to check for every address if it is
+	 * a special ZPCI_ADDR and we would have to do a get_pfn() which we
+	 * don't need for MIO capable devices.
+	 */
+	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
+	} else {
 		buf = local_buf;
+	}
 
 	ret = get_pfn(mmio_addr, VM_READ, &pfn);
 	if (ret)
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index a433ba0..215f174 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -13,6 +13,8 @@
 #include <linux/stat.h>
 #include <linux/pci.h>
 
+#include "../../../drivers/pci/pci.h"
+
 #include <asm/sclp.h>
 
 #define zpci_attr(name, fmt, member)					\
@@ -49,31 +51,50 @@
 static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
 			     const char *buf, size_t count)
 {
+	struct kernfs_node *kn;
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct zpci_dev *zdev = to_zpci(pdev);
-	int ret;
+	int ret = 0;
 
-	if (!device_remove_file_self(dev, attr))
-		return count;
+	/* Can't use device_remove_self() here as that would lead us to lock
+	 * the pci_rescan_remove_lock while holding the device' kernfs lock.
+	 * This would create a possible deadlock with disable_slot() which is
+	 * not directly protected by the device' kernfs lock but takes it
+	 * during the device removal which happens under
+	 * pci_rescan_remove_lock.
+	 *
+	 * This is analogous to sdev_store_delete() in
+	 * drivers/scsi/scsi_sysfs.c
+	 */
+	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
+	WARN_ON_ONCE(!kn);
+	/* device_remove_file() serializes concurrent calls ignoring all but
+	 * the first
+	 */
+	device_remove_file(dev, attr);
 
+	/* A concurrent call to recover_store() may slip between
+	 * sysfs_break_active_protection() and the sysfs file removal.
+	 * Once it unblocks from pci_lock_rescan_remove() the original pdev
+	 * will already be removed.
+	 */
 	pci_lock_rescan_remove();
-	pci_stop_and_remove_bus_device(pdev);
-	ret = zpci_disable_device(zdev);
-	if (ret)
-		goto error;
+	if (pci_dev_is_added(pdev)) {
+		pci_stop_and_remove_bus_device(pdev);
+		ret = zpci_disable_device(zdev);
+		if (ret)
+			goto out;
 
-	ret = zpci_enable_device(zdev);
-	if (ret)
-		goto error;
-
-	pci_rescan_bus(zdev->bus);
+		ret = zpci_enable_device(zdev);
+		if (ret)
+			goto out;
+		pci_rescan_bus(zdev->bus);
+	}
+out:
 	pci_unlock_rescan_remove();
-
-	return count;
-
-error:
-	pci_unlock_rescan_remove();
-	return ret;
+	if (kn)
+		sysfs_unbreak_active_protection(kn);
+	return ret ? ret : count;
 }
 static DEVICE_ATTR_WO(recover);