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From: Tomasz Nowicki <tomasz.nowicki@linaro.org>
To: bhelgaas@google.com, wangyijing@huawei.com, arnd@arndb.de,
	hanjun.guo@linaro.org, Liviu.Dudau@arm.com, tglx@linutronix.de,
	mingo@redhat.com, hpa@zytor.com, rjw@rjwysocki.net,
	al.stone@linaro.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org,
	linaro-acpi@lists.linaro.org,
	Tomasz Nowicki <tomasz.nowicki@linaro.org>
Subject: [PATCH v3 3/9] x86, pci: Reorder logic of pci_mmconfig_insert() function
Date: Tue, 10 Mar 2015 12:35:14 +0100	[thread overview]
Message-ID: <1425987320-15020-4-git-send-email-tomasz.nowicki@linaro.org> (raw)
In-Reply-To: <1425987320-15020-1-git-send-email-tomasz.nowicki@linaro.org>

This patch is the first step for MMCONFIG refactoring process.

Code that uses pci_mmcfg_lock will be moved to common file and become
accessible for all architectures. pci_mmconfig_insert() cannot be moved
so easily since it is mixing generic mmconfig code with x86 specific logic
inside of mutual exclusive block guarded by pci_mmcfg_lock.

To get rid of that constraint, we reorder actions as follow:
1. mmconfig entry allocation can be done first, no need to lock
2. insertion to iomem_resource has its own lock, no need to wrap it into mutex
3. insertion to mmconfig list can be done as the final step in separate
function (candidate for further refactoring)

Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
---
 arch/x86/pci/mmconfig-shared.c | 100 ++++++++++++++++++++++-------------------
 1 file changed, 54 insertions(+), 46 deletions(-)

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 8b3bc4f..685cd4c 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -834,6 +834,39 @@ static int __init pci_mmcfg_late_insert_resources(void)
  */
 late_initcall(pci_mmcfg_late_insert_resources);
 
+static int pci_mmconfig_inject(struct pci_mmcfg_region *cfg)
+{
+	struct pci_mmcfg_region *cfg_conflict;
+	int err = 0;
+
+	mutex_lock(&pci_mmcfg_lock);
+	cfg_conflict = pci_mmconfig_lookup(cfg->segment, cfg->start_bus);
+	if (cfg_conflict) {
+		if (cfg_conflict->end_bus < cfg->end_bus)
+			pr_info(FW_INFO "MMCONFIG for "
+				"domain %04x [bus %02x-%02x] "
+				"only partially covers this bridge\n",
+				cfg_conflict->segment, cfg_conflict->start_bus,
+				cfg_conflict->end_bus);
+		err = -EEXIST;
+		goto out;
+	}
+
+	if (pci_mmcfg_arch_map(cfg)) {
+		pr_warn("fail to map MMCONFIG %pR.\n", &cfg->res);
+		err = -ENOMEM;
+		goto out;
+	} else {
+		list_add_sorted(cfg);
+		pr_info("MMCONFIG at %pR (base %#lx)\n",
+			&cfg->res, (unsigned long)cfg->address);
+
+	}
+out:
+	mutex_unlock(&pci_mmcfg_lock);
+	return err;
+}
+
 /* Add MMCFG information for host bridges */
 int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 			phys_addr_t addr)
@@ -845,66 +878,41 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 	if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
 		return -ENODEV;
 
-	if (start > end)
+	if (start > end || !addr)
 		return -EINVAL;
 
-	mutex_lock(&pci_mmcfg_lock);
-	cfg = pci_mmconfig_lookup(seg, start);
-	if (cfg) {
-		if (cfg->end_bus < end)
-			dev_info(dev, FW_INFO
-				 "MMCONFIG for "
-				 "domain %04x [bus %02x-%02x] "
-				 "only partially covers this bridge\n",
-				  cfg->segment, cfg->start_bus, cfg->end_bus);
-		mutex_unlock(&pci_mmcfg_lock);
-		return -EEXIST;
-	}
-
-	if (!addr) {
-		mutex_unlock(&pci_mmcfg_lock);
-		return -EINVAL;
-	}
-
 	rc = -EBUSY;
 	cfg = pci_mmconfig_alloc(seg, start, end, addr);
 	if (cfg == NULL) {
 		dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
-		rc = -ENOMEM;
+		return -ENOMEM;
 	} else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
 		dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
 			 &cfg->res);
-	} else {
-		/* Insert resource if it's not in boot stage */
-		if (pci_mmcfg_running_state)
-			tmp = insert_resource_conflict(&iomem_resource,
-						       &cfg->res);
-
-		if (tmp) {
-			dev_warn(dev,
-				 "MMCONFIG %pR conflicts with "
-				 "%s %pR\n",
-				 &cfg->res, tmp->name, tmp);
-		} else if (pci_mmcfg_arch_map(cfg)) {
-			dev_warn(dev, "fail to map MMCONFIG %pR.\n",
-				 &cfg->res);
-		} else {
-			list_add_sorted(cfg);
-			dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
-				 &cfg->res, (unsigned long)addr);
-			cfg = NULL;
-			rc = 0;
-		}
+		goto error;
 	}
 
-	if (cfg) {
-		if (cfg->res.parent)
-			release_resource(&cfg->res);
-		kfree(cfg);
+	/* Insert resource if it's not in boot stage */
+	if (pci_mmcfg_running_state)
+		tmp = insert_resource_conflict(&iomem_resource, &cfg->res);
+
+	if (tmp) {
+		dev_warn(dev,
+			 "MMCONFIG %pR conflicts with %s %pR\n",
+			 &cfg->res, tmp->name, tmp);
+		goto error;
 	}
 
-	mutex_unlock(&pci_mmcfg_lock);
+	rc = pci_mmconfig_inject(cfg);
+	if (rc)
+		goto error;
+
+	return 0;
 
+error:
+	if (cfg->res.parent)
+		release_resource(&cfg->res);
+	kfree(cfg);
 	return rc;
 }
 
-- 
1.9.1


  parent reply	other threads:[~2015-03-10 11:35 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-10 11:35 [PATCH v3 0/9] PCI: MMCONFIG clean up Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 1/9] x86, pci: Clean up comment about buggy MMIO config space access for AMD Fam10h CPUs Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 2/9] x86, pci: Abstract PCI config accessors and use AMD Fam10h workaround exclusively Tomasz Nowicki
2015-03-10 11:35 ` Tomasz Nowicki [this message]
2015-03-10 11:35 ` [PATCH v3 4/9] x86, pci, acpi: Move arch-agnostic MMCONFIG (aka ECAM) and ACPI code out of arch/x86/ directory Tomasz Nowicki
2015-03-13 16:35   ` Mark Salter
2015-03-16 14:38     ` Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 5/9] pci, acpi, mcfg: Provide generic implementation of MCFG code initialization Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 6/9] x86, pci: mmconfig_{32,64}.c code refactoring - remove code duplication Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 7/9] x86, pci, ecam: mmconfig_64.c becomes default implementation for ECAM driver Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 8/9] pci, acpi, mcfg: Share ACPI PCI config space accessors Tomasz Nowicki
2015-03-10 11:35 ` [PATCH v3 9/9] pci, ecam: Improve naming for ecam.c content and areas where it is used Tomasz Nowicki
2015-03-10 12:22   ` Tomasz Nowicki
2015-03-10 12:25   ` Tomasz Nowicki

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