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Date:      Sun, 18 Jul 2021 00:36:53 GMT
From:      "Bjoern A. Zeeb" <bz@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org
Subject:   git: 3a606aadf2e7 - stable/13 - LinuxKPI: pci: cleanup some code and add support for "pcim" (managed)
Message-ID:  <202107180036.16I0arBx049714@gitrepo.freebsd.org>

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The branch stable/13 has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=3a606aadf2e7e0e9f913fe98910967acf73d1085

commit 3a606aadf2e7e0e9f913fe98910967acf73d1085
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2021-05-30 16:41:13 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2021-07-18 00:35:04 +0000

    LinuxKPI: pci: cleanup some code and add support for "pcim" (managed)
    
    Restructure some code and add support for various "managed" versions
    for PCI resource management.
    This is beyond of what iwlwifi needs but some was found with other
    wireless drivers and it mostly all goes together.
    Add one FreeBSD sepcific feature returning the resource rather than
    the handle to allow us to use bus_*() functions in drivers directly.
    
    Sponsored by:   The FreeBSD Foundation
    Reviewed by:    hselasky
    Differential Revision: https://reviews.freebsd.org/D30558
    
    (cherry picked from commit d4a4960c6559caa890af0901a21296e75b961210)
    (cherry picked from commit 5f88df77a6a0c7609700e2f2c35b0dbcb211f1bb)
    (cherry picked from commit 539228d372fae8c4cc401b7ba4620f27783be5a4)
---
 sys/compat/linuxkpi/common/include/linux/pci.h | 357 ++++++++++++++++++++++---
 sys/compat/linuxkpi/common/src/linux_pci.c     |  68 +++++
 2 files changed, 382 insertions(+), 43 deletions(-)

diff --git a/sys/compat/linuxkpi/common/include/linux/pci.h b/sys/compat/linuxkpi/common/include/linux/pci.h
index b8a801ac9f70..85278356dfea 100644
--- a/sys/compat/linuxkpi/common/include/linux/pci.h
+++ b/sys/compat/linuxkpi/common/include/linux/pci.h
@@ -4,6 +4,10 @@
  * Copyright (c) 2010 Panasas, Inc.
  * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
  * All rights reserved.
+ * Copyright (c) 2020-2021 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Björn Zeeb
+ * under sponsorship from the FreeBSD Foundation.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -209,6 +213,10 @@ extern spinlock_t pci_lock;
 
 #define	__devexit_p(x)	x
 
+/*
+ * If we find drivers accessing this from multiple KPIs we may have to
+ * refcount objects of this structure.
+ */
 struct pci_mmio_region {
 	TAILQ_ENTRY(pci_mmio_region)	next;
 	struct resource			*res;
@@ -230,16 +238,47 @@ struct pci_dev {
 	unsigned int		devfn;
 	uint32_t		class;
 	uint8_t			revision;
+	bool			managed;	/* devres "pcim_*(). */
+	bool			want_iomap_res;
 	bool			msi_enabled;
+	bool			msix_enabled;
 	phys_addr_t		rom;
 	size_t			romlen;
 
 	TAILQ_HEAD(, pci_mmio_region)	mmio;
 };
 
+/* We need some meta-struct to keep track of these for devres. */
+struct pci_devres {
+	bool		enable_io;
+	/* PCIR_MAX_BAR_0 + 1 = 6 => BIT(0..5). */
+	uint8_t		region_mask;
+	struct resource	*region_table[PCIR_MAX_BAR_0 + 1]; /* Not needed. */
+};
+struct pcim_iomap_devres {
+	void		*mmio_table[PCIR_MAX_BAR_0 + 1];
+	struct resource	*res_table[PCIR_MAX_BAR_0 + 1];
+};
+
 /* Internal helper function(s). */
 struct pci_dev *lkpinew_pci_dev(device_t);
+void lkpi_pci_devres_release(struct device *, void *);
+void lkpi_pcim_iomap_table_release(struct device *, void *);
 
+static inline int
+pci_resource_type(struct pci_dev *pdev, int bar)
+{
+	struct pci_map *pm;
+
+	pm = pci_find_bar(pdev->dev.bsddev, PCIR_BAR(bar));
+	if (!pm)
+		return (-1);
+
+	if (PCI_BAR_IO(pm->pm_value))
+		return (SYS_RES_IOPORT);
+	else
+		return (SYS_RES_MEMORY);
+}
 
 static inline struct resource_list_entry *
 linux_pci_get_rle(struct pci_dev *pdev, int type, int rid)
@@ -255,12 +294,13 @@ linux_pci_get_rle(struct pci_dev *pdev, int type, int rid)
 static inline struct resource_list_entry *
 linux_pci_get_bar(struct pci_dev *pdev, int bar)
 {
-	struct resource_list_entry *rle;
+	int type;
 
+	type = pci_resource_type(pdev, bar);
+	if (type < 0)
+		return (NULL);
 	bar = PCIR_BAR(bar);
-	if ((rle = linux_pci_get_rle(pdev, SYS_RES_MEMORY, bar)) == NULL)
-		rle = linux_pci_get_rle(pdev, SYS_RES_IOPORT, bar);
-	return (rle);
+	return (linux_pci_get_rle(pdev, type, bar));
 }
 
 static inline struct device *
@@ -282,21 +322,6 @@ linux_pci_find_irq_dev(unsigned int irq)
 	return (found);
 }
 
-static inline int
-pci_resource_type(struct pci_dev *pdev, int bar)
-{
-	struct pci_map *pm;
-
-	pm = pci_find_bar(pdev->dev.bsddev, PCIR_BAR(bar));
-	if (!pm)
-		return (-1);
-
-	if (PCI_BAR_IO(pm->pm_value))
-		return (SYS_RES_IOPORT);
-	else
-		return (SYS_RES_MEMORY);
-}
-
 /*
  * All drivers just seem to want to inspect the type not flags.
  */
@@ -389,9 +414,37 @@ pci_clear_master(struct pci_dev *pdev)
 	return (0);
 }
 
+static inline struct pci_devres *
+lkpi_pci_devres_get_alloc(struct pci_dev *pdev)
+{
+	struct pci_devres *dr;
+
+	dr = lkpi_devres_find(&pdev->dev, lkpi_pci_devres_release, NULL, NULL);
+	if (dr == NULL) {
+		dr = lkpi_devres_alloc(lkpi_pci_devres_release, sizeof(*dr),
+		    GFP_KERNEL | __GFP_ZERO);
+		if (dr != NULL)
+			lkpi_devres_add(&pdev->dev, dr);
+	}
+
+	return (dr);
+}
+static inline struct pci_devres *
+lkpi_pci_devres_find(struct pci_dev *pdev)
+{
+
+	if (!pdev->managed)
+		return (NULL);
+
+	return (lkpi_pci_devres_get_alloc(pdev));
+}
+
 static inline int
 pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
 {
+	struct resource *res;
+	struct pci_devres *dr;
+	struct pci_mmio_region *mmio;
 	int rid;
 	int type;
 
@@ -399,9 +452,34 @@ pci_request_region(struct pci_dev *pdev, int bar, const char *res_name)
 	if (type < 0)
 		return (-ENODEV);
 	rid = PCIR_BAR(bar);
-	if (bus_alloc_resource_any(pdev->dev.bsddev, type, &rid,
-	    RF_ACTIVE) == NULL)
-		return (-EINVAL);
+	res = bus_alloc_resource_any(pdev->dev.bsddev, type, &rid,
+	    RF_ACTIVE|RF_SHAREABLE);
+	if (res == NULL) {
+		device_printf(pdev->dev.bsddev, "%s: failed to alloc "
+		    "bar %d type %d rid %d\n",
+		    __func__, bar, type, PCIR_BAR(bar));
+		return (-ENODEV);
+	}
+
+	/*
+	 * It seems there is an implicit devres tracking on these if the device
+	 * is managed; otherwise the resources are not automatiaclly freed on
+	 * FreeBSD/LinuxKPI tough they should be/are expected to be by Linux
+	 * drivers.
+	 */
+	dr = lkpi_pci_devres_find(pdev);
+	if (dr != NULL) {
+		dr->region_mask |= (1 << bar);
+		dr->region_table[bar] = res;
+	}
+
+	/* Even if the device is not managed we need to track it for iomap. */
+	mmio = malloc(sizeof(*mmio), M_DEVBUF, M_WAITOK | M_ZERO);
+	mmio->rid = PCIR_BAR(bar);
+	mmio->type = type;
+	mmio->res = res;
+	TAILQ_INSERT_TAIL(&pdev->mmio, mmio, next);
+
 	return (0);
 }
 
@@ -409,9 +487,32 @@ static inline void
 pci_release_region(struct pci_dev *pdev, int bar)
 {
 	struct resource_list_entry *rle;
+	struct pci_devres *dr;
+	struct pci_mmio_region *mmio, *p;
 
 	if ((rle = linux_pci_get_bar(pdev, bar)) == NULL)
 		return;
+
+	/*
+	 * As we implicitly track the requests we also need to clear them on
+	 * release.  Do clear before resource release.
+	 */
+	dr = lkpi_pci_devres_find(pdev);
+	if (dr != NULL) {
+		KASSERT(dr->region_table[bar] == rle->res, ("%s: pdev %p bar %d"
+		    " region_table res %p != rel->res %p\n", __func__, pdev,
+		    bar, dr->region_table[bar], rle->res));
+		dr->region_table[bar] = NULL;
+		dr->region_mask &= ~(1 << bar);
+	}
+
+	TAILQ_FOREACH_SAFE(mmio, &pdev->mmio, next, p) {
+		if (rle->res != (void *)rman_get_bushandle(mmio->res))
+			continue;
+		TAILQ_REMOVE(&pdev->mmio, mmio, next);
+		free(mmio, M_DEVBUF);
+	}
+
 	bus_release_resource(pdev->dev.bsddev, rle->type, rle->rid, rle->res);
 }
 
@@ -441,7 +542,7 @@ pci_request_regions(struct pci_dev *pdev, const char *res_name)
 }
 
 static inline void
-pci_disable_msix(struct pci_dev *pdev)
+lkpi_pci_disable_msix(struct pci_dev *pdev)
 {
 
 	pci_release_msi(pdev->dev.bsddev);
@@ -454,13 +555,13 @@ pci_disable_msix(struct pci_dev *pdev)
 	 */
 	pdev->dev.irq_start = 0;
 	pdev->dev.irq_end = 0;
+	pdev->msix_enabled = false;
 }
-
-#define	pci_disable_msi(pdev) \
-  linux_pci_disable_msi(pdev)
+/* Only for consistency. No conflict on that one. */
+#define	pci_disable_msix(pdev)		lkpi_pci_disable_msix(pdev)
 
 static inline void
-linux_pci_disable_msi(struct pci_dev *pdev)
+lkpi_pci_disable_msi(struct pci_dev *pdev)
 {
 
 	pci_release_msi(pdev->dev.bsddev);
@@ -470,9 +571,8 @@ linux_pci_disable_msi(struct pci_dev *pdev)
 	pdev->irq = pdev->dev.irq;
 	pdev->msi_enabled = false;
 }
-
-#define	pci_free_irq_vectors(pdev) \
-	linux_pci_disable_msi(pdev)
+#define	pci_disable_msi(pdev)		lkpi_pci_disable_msi(pdev)
+#define	pci_free_irq_vectors(pdev)	lkpi_pci_disable_msi(pdev)
 
 unsigned long	pci_resource_start(struct pci_dev *pdev, int bar);
 unsigned long	pci_resource_len(struct pci_dev *pdev, int bar);
@@ -653,6 +753,7 @@ pci_enable_msix(struct pci_dev *pdev, struct msix_entry *entries, int nreq)
 	pdev->dev.irq_end = rle->start + avail;
 	for (i = 0; i < nreq; i++)
 		entries[i].vector = pdev->dev.irq_start + i;
+	pdev->msix_enabled = true;
 	return (0);
 }
 
@@ -723,36 +824,71 @@ static inline void pci_disable_sriov(struct pci_dev *dev)
 {
 }
 
-static inline void *
-pci_iomap(struct pci_dev *dev, int mmio_bar, int mmio_size __unused)
+static inline struct resource *
+_lkpi_pci_iomap(struct pci_dev *pdev, int bar, int mmio_size __unused)
 {
-	struct pci_mmio_region *mmio;
+	struct pci_mmio_region *mmio, *p;
+	int type;
+
+	type = pci_resource_type(pdev, bar);
+	if (type < 0) {
+		device_printf(pdev->dev.bsddev, "%s: bar %d type %d\n",
+		     __func__, bar, type);
+		return (NULL);
+	}
+
+	/*
+	 * Check for duplicate mappings.
+	 * This can happen if a driver calls pci_request_region() first.
+	 */
+	TAILQ_FOREACH_SAFE(mmio, &pdev->mmio, next, p) {
+		if (mmio->type == type && mmio->rid == PCIR_BAR(bar)) {
+			return (mmio->res);
+		}
+	}
 
 	mmio = malloc(sizeof(*mmio), M_DEVBUF, M_WAITOK | M_ZERO);
-	mmio->rid = PCIR_BAR(mmio_bar);
-	mmio->type = pci_resource_type(dev, mmio_bar);
-	mmio->res = bus_alloc_resource_any(dev->dev.bsddev, mmio->type,
-	    &mmio->rid, RF_ACTIVE);
+	mmio->rid = PCIR_BAR(bar);
+	mmio->type = type;
+	mmio->res = bus_alloc_resource_any(pdev->dev.bsddev, mmio->type,
+	    &mmio->rid, RF_ACTIVE|RF_SHAREABLE);
 	if (mmio->res == NULL) {
+		device_printf(pdev->dev.bsddev, "%s: failed to alloc "
+		    "bar %d type %d rid %d\n",
+		    __func__, bar, type, PCIR_BAR(bar));
 		free(mmio, M_DEVBUF);
 		return (NULL);
 	}
-	TAILQ_INSERT_TAIL(&dev->mmio, mmio, next);
+	TAILQ_INSERT_TAIL(&pdev->mmio, mmio, next);
+
+	return (mmio->res);
+}
+
+static inline void *
+pci_iomap(struct pci_dev *pdev, int mmio_bar, int mmio_size)
+{
+	struct resource *res;
 
-	return ((void *)rman_get_bushandle(mmio->res));
+	res = _lkpi_pci_iomap(pdev, mmio_bar, mmio_size);
+	if (res == NULL)
+		return (NULL);
+	/* This is a FreeBSD extension so we can use bus_*(). */
+	if (pdev->want_iomap_res)
+		return (res);
+	return ((void *)rman_get_bushandle(res));
 }
 
 static inline void
-pci_iounmap(struct pci_dev *dev, void *res)
+pci_iounmap(struct pci_dev *pdev, void *res)
 {
 	struct pci_mmio_region *mmio, *p;
 
-	TAILQ_FOREACH_SAFE(mmio, &dev->mmio, next, p) {
+	TAILQ_FOREACH_SAFE(mmio, &pdev->mmio, next, p) {
 		if (res != (void *)rman_get_bushandle(mmio->res))
 			continue;
-		bus_release_resource(dev->dev.bsddev,
+		bus_release_resource(pdev->dev.bsddev,
 		    mmio->type, mmio->rid, mmio->res);
-		TAILQ_REMOVE(&dev->mmio, mmio, next);
+		TAILQ_REMOVE(&pdev->mmio, mmio, next);
 		free(mmio, M_DEVBUF);
 		return;
 	}
@@ -1239,4 +1375,139 @@ pci_bus_write_config_word(struct pci_bus *bus, unsigned int devfn, int pos,
 struct pci_dev *lkpi_pci_get_class(unsigned int class, struct pci_dev *from);
 #define	pci_get_class(class, from)	lkpi_pci_get_class(class, from)
 
+/* -------------------------------------------------------------------------- */
+
+static inline int
+pcim_enable_device(struct pci_dev *pdev)
+{
+	struct pci_devres *dr;
+	int error;
+
+	/* Here we cannot run through the pdev->managed check. */
+	dr = lkpi_pci_devres_get_alloc(pdev);
+	if (dr == NULL)
+		return (-ENOMEM);
+
+	/* If resources were enabled before do not do it again. */
+	if (dr->enable_io)
+		return (0);
+
+	error = pci_enable_device(pdev);
+	if (error == 0)
+		dr->enable_io = true;
+
+	/* This device is not managed. */
+	pdev->managed = true;
+
+	return (error);
+}
+
+static inline struct pcim_iomap_devres *
+lkpi_pcim_iomap_devres_find(struct pci_dev *pdev)
+{
+	struct pcim_iomap_devres *dr;
+
+	dr = lkpi_devres_find(&pdev->dev, lkpi_pcim_iomap_table_release,
+	    NULL, NULL);
+	if (dr == NULL) {
+		dr = lkpi_devres_alloc(lkpi_pcim_iomap_table_release,
+		    sizeof(*dr), GFP_KERNEL | __GFP_ZERO);
+		if (dr != NULL)
+			lkpi_devres_add(&pdev->dev, dr);
+	}
+
+	if (dr == NULL)
+		device_printf(pdev->dev.bsddev, "%s: NULL\n", __func__);
+
+	return (dr);
+}
+
+static inline void __iomem **
+pcim_iomap_table(struct pci_dev *pdev)
+{
+	struct pcim_iomap_devres *dr;
+
+	dr = lkpi_pcim_iomap_devres_find(pdev);
+	if (dr == NULL)
+		return (NULL);
+
+	/*
+	 * If the driver has manually set a flag to be able to request the
+	 * resource to use bus_read/write_<n>, return the shadow table.
+	 */
+	if (pdev->want_iomap_res)
+		return ((void **)dr->res_table);
+
+	/* This is the Linux default. */
+	return (dr->mmio_table);
+}
+
+static inline int
+pcim_iomap_regions_request_all(struct pci_dev *pdev, uint32_t mask, char *name)
+{
+	struct pcim_iomap_devres *dr;
+	void *res;
+	uint32_t mappings, requests, req_mask;
+	int bar, error;
+
+	dr = lkpi_pcim_iomap_devres_find(pdev);
+	if (dr == NULL)
+		return (-ENOMEM);
+
+	/* Request all the BARs ("regions") we do not iomap. */
+	req_mask = ((1 << (PCIR_MAX_BAR_0 + 1)) - 1) & ~mask;
+	for (bar = requests = 0; requests != req_mask; bar++) {
+		if ((req_mask & (1 << bar)) == 0)
+			continue;
+		error = pci_request_region(pdev, bar, name);
+		if (error != 0 && error != -ENODEV)
+			goto err;
+		requests |= (1 << bar);
+	}
+
+	/* Now iomap all the requested (by "mask") ones. */
+	for (bar = mappings = 0; mappings != mask; bar++) {
+		if ((mask & (1 << bar)) == 0)
+			continue;
+
+		/* Request double is not allowed. */
+		if (dr->mmio_table[bar] != NULL) {
+			device_printf(pdev->dev.bsddev, "%s: bar %d %p\n",
+			     __func__, bar, dr->mmio_table[bar]);
+			goto err;
+		}
+
+		res = _lkpi_pci_iomap(pdev, bar, 0);
+		if (res == NULL)
+			goto err;
+		dr->mmio_table[bar] = (void *)rman_get_bushandle(res);
+		dr->res_table[bar] = res;
+
+		mappings |= (1 << bar);
+	}
+
+	return (0);
+
+err:
+	for (bar = PCIR_MAX_BAR_0; bar >= 0; bar--) {
+		if ((mappings & (1 << bar)) != 0) {
+			res = dr->mmio_table[bar];
+			if (res == NULL)
+				continue;
+			pci_iounmap(pdev, res);
+		} else if ((requests & (1 << bar)) != 0) {
+			pci_release_region(pdev, bar);
+		}
+	}
+
+	return (-EINVAL);
+}
+
+/* This is a FreeBSD extension so we can use bus_*(). */
+static inline void
+linuxkpi_pcim_want_to_use_bus_functions(struct pci_dev *pdev)
+{
+	pdev->want_iomap_res = true;
+}
+
 #endif	/* _LINUX_PCI_H_ */
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
index 9738f9e6f51a..c35d259a45be 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -1,6 +1,10 @@
 /*-
  * Copyright (c) 2015-2016 Mellanox Technologies, Ltd.
  * All rights reserved.
+ * Copyright (c) 2020-2021 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Björn Zeeb
+ * under sponsorship from the FreeBSD Foundation.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -213,6 +217,14 @@ linux_pci_find(device_t dev, const struct pci_device_id **idp)
 	return (NULL);
 }
 
+static void
+lkpi_pci_dev_release(struct device *dev)
+{
+
+	lkpi_devres_release_free_list(dev);
+	spin_lock_destroy(&dev->devres_lock);
+}
+
 static void
 lkpifill_pci_dev(device_t dev, struct pci_dev *pdev)
 {
@@ -230,6 +242,7 @@ lkpifill_pci_dev(device_t dev, struct pci_dev *pdev)
 	pdev->bus->domain = pci_get_domain(dev);
 	pdev->dev.bsddev = dev;
 	pdev->dev.parent = &linux_root_device;
+	pdev->dev.release = lkpi_pci_dev_release;
 	INIT_LIST_HEAD(&pdev->dev.irqents);
 	kobject_init(&pdev->dev.kobj, &linux_dev_ktype);
 	kobject_set_name(&pdev->dev.kobj, device_get_nameunit(dev));
@@ -425,6 +438,61 @@ linux_pci_detach_device(struct pci_dev *pdev)
 	return (0);
 }
 
+static int
+lkpi_pci_disable_dev(struct device *dev)
+{
+
+	(void) pci_disable_io(dev->bsddev, SYS_RES_MEMORY);
+	(void) pci_disable_io(dev->bsddev, SYS_RES_IOPORT);
+	return (0);
+}
+
+void
+lkpi_pci_devres_release(struct device *dev, void *p)
+{
+	struct pci_devres *dr;
+	struct pci_dev *pdev;
+	int bar;
+
+	pdev = to_pci_dev(dev);
+	dr = p;
+
+	if (pdev->msix_enabled)
+		lkpi_pci_disable_msix(pdev);
+        if (pdev->msi_enabled)
+		lkpi_pci_disable_msi(pdev);
+
+	if (dr->enable_io && lkpi_pci_disable_dev(dev) == 0)
+		dr->enable_io = false;
+
+	if (dr->region_mask == 0)
+		return;
+	for (bar = PCIR_MAX_BAR_0; bar >= 0; bar--) {
+
+		if ((dr->region_mask & (1 << bar)) == 0)
+			continue;
+		pci_release_region(pdev, bar);
+	}
+}
+
+void
+lkpi_pcim_iomap_table_release(struct device *dev, void *p)
+{
+	struct pcim_iomap_devres *dr;
+	struct pci_dev *pdev;
+	int bar;
+
+	dr = p;
+	pdev = to_pci_dev(dev);
+	for (bar = PCIR_MAX_BAR_0; bar >= 0; bar--) {
+
+		if (dr->mmio_table[bar] == NULL)
+			continue;
+
+		pci_iounmap(pdev, dr->mmio_table[bar]);
+	}
+}
+
 static int
 linux_pci_suspend(device_t dev)
 {



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