[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / platforms / pseries / msi.c

/*
 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
 * Copyright 2006-2007 Michael Ellerman, IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2 of the
 * License.
 *
 */

#include <linux/device.h>
#include <linux/irq.h>
#include <linux/msi.h>

#include <asm/rtas.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>

static int query_token, change_token;

#define RTAS_QUERY_FN		0
#define RTAS_CHANGE_FN		1
#define RTAS_RESET_FN		2
#define RTAS_CHANGE_MSI_FN	3
#define RTAS_CHANGE_MSIX_FN	4
#define RTAS_CHANGE_32MSI_FN	5

/* RTAS Helpers */

static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
{
	u32 addr, seq_num, rtas_ret[3];
	unsigned long buid;
	int rc;

	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	buid = pdn->phb->buid;

	seq_num = 1;
	do {
		if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
		    func == RTAS_CHANGE_32MSI_FN)
			rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
					BUID_HI(buid), BUID_LO(buid),
					func, num_irqs, seq_num);
		else
			rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
					BUID_HI(buid), BUID_LO(buid),
					func, num_irqs, seq_num);

		seq_num = rtas_ret[1];
	} while (rtas_busy_delay(rc));

	/*
	 * If the RTAS call succeeded, return the number of irqs allocated.
	 * If not, make sure we return a negative error code.
	 */
	if (rc == 0)
		rc = rtas_ret[0];
	else if (rc > 0)
		rc = -rc;

	pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
		 func, num_irqs, rtas_ret[0], rc);

	return rc;
}

static void rtas_disable_msi(struct pci_dev *pdev)
{
	struct pci_dn *pdn;

	pdn = pci_get_pdn(pdev);
	if (!pdn)
		return;

	/*
	 * disabling MSI with the explicit interface also disables MSI-X
	 */
	if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
		/* 
		 * may have failed because explicit interface is not
		 * present
		 */
		if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
			pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
		}
	}
}

static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
{
	u32 addr, rtas_ret[2];
	unsigned long buid;
	int rc;

	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	buid = pdn->phb->buid;

	do {
		rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
			       BUID_HI(buid), BUID_LO(buid), offset);
	} while (rtas_busy_delay(rc));

	if (rc) {
		pr_debug("rtas_msi: error (%d) querying source number\n", rc);
		return rc;
	}

	return rtas_ret[0];
}

static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
{
	struct msi_desc *entry;

	list_for_each_entry(entry, &pdev->msi_list, list) {
		if (entry->irq == NO_IRQ)
			continue;

		irq_set_msi_desc(entry->irq, NULL);
		irq_dispose_mapping(entry->irq);
	}

	rtas_disable_msi(pdev);
}

static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
{
	struct device_node *dn;
	struct pci_dn *pdn;
	const u32 *req_msi;

	pdn = pci_get_pdn(pdev);
	if (!pdn)
		return -ENODEV;

	dn = pdn->node;

	req_msi = of_get_property(dn, prop_name, NULL);
	if (!req_msi) {
		pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name);
		return -ENOENT;
	}

	if (*req_msi < nvec) {
		pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);

		if (*req_msi == 0) /* Be paranoid */
			return -ENOSPC;

		return *req_msi;
	}

	return 0;
}

static int check_req_msi(struct pci_dev *pdev, int nvec)
{
	return check_req(pdev, nvec, "ibm,req#msi");
}

static int check_req_msix(struct pci_dev *pdev, int nvec)
{
	return check_req(pdev, nvec, "ibm,req#msi-x");
}

/* Quota calculation */

static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total)
{
	struct device_node *dn;
	const u32 *p;

	dn = of_node_get(pci_device_to_OF_node(dev));
	while (dn) {
		p = of_get_property(dn, "ibm,pe-total-#msi", NULL);
		if (p) {
			pr_debug("rtas_msi: found prop on dn %s\n",
				dn->full_name);
			*total = *p;
			return dn;
		}

		dn = of_get_next_parent(dn);
	}

	return NULL;
}

static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
{
	struct device_node *dn;
	struct eeh_dev *edev;

	/* Found our PE and assume 8 at that point. */

	dn = pci_device_to_OF_node(dev);
	if (!dn)
		return NULL;

	/* Get the top level device in the PE */
	edev = of_node_to_eeh_dev(dn);
	if (edev->pe)
		edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
	dn = eeh_dev_to_of_node(edev);
	if (!dn)
		return NULL;

	/* We actually want the parent */
	dn = of_get_parent(dn);
	if (!dn)
		return NULL;

	/* Hardcode of 8 for old firmwares */
	*total = 8;
	pr_debug("rtas_msi: using PE dn %s\n", dn->full_name);

	return dn;
}

struct msi_counts {
	struct device_node *requestor;
	int num_devices;
	int request;
	int quota;
	int spare;
	int over_quota;
};

static void *count_non_bridge_devices(struct device_node *dn, void *data)
{
	struct msi_counts *counts = data;
	const u32 *p;
	u32 class;

	pr_debug("rtas_msi: counting %s\n", dn->full_name);

	p = of_get_property(dn, "class-code", NULL);
	class = p ? *p : 0;

	if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
		counts->num_devices++;

	return NULL;
}

static void *count_spare_msis(struct device_node *dn, void *data)
{
	struct msi_counts *counts = data;
	const u32 *p;
	int req;

	if (dn == counts->requestor)
		req = counts->request;
	else {
		/* We don't know if a driver will try to use MSI or MSI-X,
		 * so we just have to punt and use the larger of the two. */
		req = 0;
		p = of_get_property(dn, "ibm,req#msi", NULL);
		if (p)
			req = *p;

		p = of_get_property(dn, "ibm,req#msi-x", NULL);
		if (p)
			req = max(req, (int)*p);
	}

	if (req < counts->quota)
		counts->spare += counts->quota - req;
	else if (req > counts->quota)
		counts->over_quota++;

	return NULL;
}

static int msi_quota_for_device(struct pci_dev *dev, int request)
{
	struct device_node *pe_dn;
	struct msi_counts counts;
	int total;

	pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
		  request);

	pe_dn = find_pe_total_msi(dev, &total);
	if (!pe_dn)
		pe_dn = find_pe_dn(dev, &total);

	if (!pe_dn) {
		pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
		goto out;
	}

	pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name);

	memset(&counts, 0, sizeof(struct msi_counts));

	/* Work out how many devices we have below this PE */
	traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts);

	if (counts.num_devices == 0) {
		pr_err("rtas_msi: found 0 devices under PE for %s\n",
			pci_name(dev));
		goto out;
	}

	counts.quota = total / counts.num_devices;
	if (request <= counts.quota)
		goto out;

	/* else, we have some more calculating to do */
	counts.requestor = pci_device_to_OF_node(dev);
	counts.request = request;
	traverse_pci_devices(pe_dn, count_spare_msis, &counts);

	/* If the quota isn't an integer multiple of the total, we can
	 * use the remainder as spare MSIs for anyone that wants them. */
	counts.spare += total % counts.num_devices;

	/* Divide any spare by the number of over-quota requestors */
	if (counts.over_quota)
		counts.quota += counts.spare / counts.over_quota;

	/* And finally clamp the request to the possibly adjusted quota */
	request = min(counts.quota, request);

	pr_debug("rtas_msi: request clamped to quota %d\n", request);
out:
	of_node_put(pe_dn);

	return request;
}

static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
{
	int quota, rc;

	if (type == PCI_CAP_ID_MSIX)
		rc = check_req_msix(pdev, nvec);
	else
		rc = check_req_msi(pdev, nvec);

	if (rc)
		return rc;

	quota = msi_quota_for_device(pdev, nvec);

	if (quota && quota < nvec)
		return quota;

	return 0;
}

static int check_msix_entries(struct pci_dev *pdev)
{
	struct msi_desc *entry;
	int expected;

	/* There's no way for us to express to firmware that we want
	 * a discontiguous, or non-zero based, range of MSI-X entries.
	 * So we must reject such requests. */

	expected = 0;
	list_for_each_entry(entry, &pdev->msi_list, list) {
		if (entry->msi_attrib.entry_nr != expected) {
			pr_debug("rtas_msi: bad MSI-X entries.\n");
			return -EINVAL;
		}
		expected++;
	}

	return 0;
}

static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
{
	u32 addr_hi, addr_lo;

	/*
	 * We should only get in here for IODA1 configs. This is based on the
	 * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
	 * support, and we are in a PCIe Gen2 slot.
	 */
	dev_info(&pdev->dev,
		 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
	pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
	addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
	pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
	pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
}

static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
{
	struct pci_dn *pdn;
	int hwirq, virq, i, rc;
	struct msi_desc *entry;
	struct msi_msg msg;
	int nvec = nvec_in;
	int use_32bit_msi_hack = 0;

	pdn = pci_get_pdn(pdev);
	if (!pdn)
		return -ENODEV;

	if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev))
		return -EINVAL;

	/*
	 * Firmware currently refuse any non power of two allocation
	 * so we round up if the quota will allow it.
	 */
	if (type == PCI_CAP_ID_MSIX) {
		int m = roundup_pow_of_two(nvec);
		int quota = msi_quota_for_device(pdev, m);

		if (quota >= m)
			nvec = m;
	}

	/*
	 * Try the new more explicit firmware interface, if that fails fall
	 * back to the old interface. The old interface is known to never
	 * return MSI-Xs.
	 */
again:
	if (type == PCI_CAP_ID_MSI) {
		if (pdn->force_32bit_msi) {
			rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
			if (rc < 0) {
				/*
				 * We only want to run the 32 bit MSI hack below if
				 * the max bus speed is Gen2 speed
				 */
				if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
					return rc;

				use_32bit_msi_hack = 1;
			}
		} else
			rc = -1;

		if (rc < 0)
			rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);

		if (rc < 0) {
			pr_debug("rtas_msi: trying the old firmware call.\n");
			rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
		}

		if (use_32bit_msi_hack && rc > 0)
			rtas_hack_32bit_msi_gen2(pdev);
	} else
		rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);

	if (rc != nvec) {
		if (nvec != nvec_in) {
			nvec = nvec_in;
			goto again;
		}
		pr_debug("rtas_msi: rtas_change_msi() failed\n");
		return rc;
	}

	i = 0;
	list_for_each_entry(entry, &pdev->msi_list, list) {
		hwirq = rtas_query_irq_number(pdn, i++);
		if (hwirq < 0) {
			pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
			return hwirq;
		}

		virq = irq_create_mapping(NULL, hwirq);

		if (virq == NO_IRQ) {
			pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
			return -ENOSPC;
		}

		dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
		irq_set_msi_desc(virq, entry);

		/* Read config space back so we can restore after reset */
		read_msi_msg(virq, &msg);
		entry->msg = msg;
	}

	return 0;
}

static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
{
	/* No LSI -> leave MSIs (if any) configured */
	if (pdev->irq == NO_IRQ) {
		dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
		return;
	}

	/* No MSI -> MSIs can't have been assigned by fw, leave LSI */
	if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) {
		dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
		return;
	}

	dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
	rtas_disable_msi(pdev);
}

static int rtas_msi_init(void)
{
	query_token  = rtas_token("ibm,query-interrupt-source-number");
	change_token = rtas_token("ibm,change-msi");

	if ((query_token == RTAS_UNKNOWN_SERVICE) ||
			(change_token == RTAS_UNKNOWN_SERVICE)) {
		pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
		return -1;
	}

	pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");

	WARN_ON(ppc_md.setup_msi_irqs);
	ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
	ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
	ppc_md.msi_check_device = rtas_msi_check_device;

	WARN_ON(ppc_md.pci_irq_fixup);
	ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;

	return 0;
}
arch_initcall(rtas_msi_init);
Commit	Line	Data
85f2bf9f ME	1	/*
	2	* Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
	3	* Copyright 2006-2007 Michael Ellerman, IBM Corp.
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; version 2 of the
	8	* License.
	9	*
	10	*/
	11
	12	#include <linux/device.h>
	13	#include <linux/irq.h>
	14	#include <linux/msi.h>
	15
	16	#include <asm/rtas.h>
	17	#include <asm/hw_irq.h>
	18	#include <asm/ppc-pci.h>
	19
	20	static int query_token, change_token;
	21
	22	#define RTAS_QUERY_FN 0
	23	#define RTAS_CHANGE_FN 1
	24	#define RTAS_RESET_FN 2
	25	#define RTAS_CHANGE_MSI_FN 3
	26	#define RTAS_CHANGE_MSIX_FN 4
e61133dd	27	#define RTAS_CHANGE_32MSI_FN 5
85f2bf9f	28
85f2bf9f ME	29	/* RTAS Helpers */
	30
	31	static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
	32	{
	33	u32 addr, seq_num, rtas_ret[3];
	34	unsigned long buid;
	35	int rc;
	36
	37	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	38	buid = pdn->phb->buid;
	39
	40	seq_num = 1;
	41	do {
e61133dd BK	42	if (func == RTAS_CHANGE_MSI_FN \|\| func == RTAS_CHANGE_MSIX_FN \|\|
e61133dd BK	43	func == RTAS_CHANGE_32MSI_FN)
85f2bf9f ME	44	rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
	45	BUID_HI(buid), BUID_LO(buid),
	46	func, num_irqs, seq_num);
	47	else
	48	rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
	49	BUID_HI(buid), BUID_LO(buid),
	50	func, num_irqs, seq_num);
	51
	52	seq_num = rtas_ret[1];
	53	} while (rtas_busy_delay(rc));
	54
d385366a	55	/*
6071ed04 ME	56	* If the RTAS call succeeded, return the number of irqs allocated.
6071ed04 ME	57	* If not, make sure we return a negative error code.
d385366a	58	*/
6071ed04 ME	59	if (rc == 0)
	60	rc = rtas_ret[0];
	61	else if (rc > 0)
	62	rc = -rc;
85f2bf9f	63
d385366a ME	64	pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
d385366a ME	65	func, num_irqs, rtas_ret[0], rc);
85f2bf9f ME	66
	67	return rc;
	68	}
	69
	70	static void rtas_disable_msi(struct pci_dev *pdev)
	71	{
	72	struct pci_dn *pdn;
	73
b72c1f65	74	pdn = pci_get_pdn(pdev);
85f2bf9f ME	75	if (!pdn)
	76	return;
	77
964a2996 NA	78	/*
	79	* disabling MSI with the explicit interface also disables MSI-X
	80	*/
	81	if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
	82	/*
	83	* may have failed because explicit interface is not
	84	* present
	85	*/
	86	if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
	87	pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
	88	}
	89	}
85f2bf9f ME	90	}
	91
	92	static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
	93	{
	94	u32 addr, rtas_ret[2];
	95	unsigned long buid;
	96	int rc;
	97
	98	addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
	99	buid = pdn->phb->buid;
	100
	101	do {
	102	rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
	103	BUID_HI(buid), BUID_LO(buid), offset);
	104	} while (rtas_busy_delay(rc));
	105
	106	if (rc) {
	107	pr_debug("rtas_msi: error (%d) querying source number\n", rc);
	108	return rc;
	109	}
	110
	111	return rtas_ret[0];
	112	}
	113
	114	static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
	115	{
	116	struct msi_desc *entry;
	117
	118	list_for_each_entry(entry, &pdev->msi_list, list) {
	119	if (entry->irq == NO_IRQ)
	120	continue;
	121
ec775d0e	122	irq_set_msi_desc(entry->irq, NULL);
85f2bf9f ME	123	irq_dispose_mapping(entry->irq);
	124	}
	125
	126	rtas_disable_msi(pdev);
	127	}
	128
3a51c0cb	129	static int check_req(struct pci_dev pdev, int nvec, char prop_name)
85f2bf9f ME	130	{
	131	struct device_node *dn;
	132	struct pci_dn *pdn;
	133	const u32 *req_msi;
	134
b72c1f65	135	pdn = pci_get_pdn(pdev);
85f2bf9f ME	136	if (!pdn)
	137	return -ENODEV;
	138
	139	dn = pdn->node;
	140
3a51c0cb	141	req_msi = of_get_property(dn, prop_name, NULL);
85f2bf9f	142	if (!req_msi) {
3a51c0cb	143	pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name);
85f2bf9f ME	144	return -ENOENT;
	145	}
	146
	147	if (*req_msi < nvec) {
3a51c0cb	148	pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
d523cc37 ME	149
	150	if (req_msi == 0) / Be paranoid */
	151	return -ENOSPC;
	152
	153	return *req_msi;
85f2bf9f ME	154	}
	155
	156	return 0;
	157	}
	158
3a51c0cb ME	159	static int check_req_msi(struct pci_dev *pdev, int nvec)
	160	{
	161	return check_req(pdev, nvec, "ibm,req#msi");
	162	}
	163
	164	static int check_req_msix(struct pci_dev *pdev, int nvec)
	165	{
	166	return check_req(pdev, nvec, "ibm,req#msi-x");
	167	}
	168
448e2ca0 ME	169	/* Quota calculation */
	170
	171	static struct device_node find_pe_total_msi(struct pci_dev dev, int *total)
	172	{
	173	struct device_node *dn;
	174	const u32 *p;
	175
	176	dn = of_node_get(pci_device_to_OF_node(dev));
	177	while (dn) {
	178	p = of_get_property(dn, "ibm,pe-total-#msi", NULL);
	179	if (p) {
	180	pr_debug("rtas_msi: found prop on dn %s\n",
	181	dn->full_name);
	182	total = p;
	183	return dn;
	184	}
	185
	186	dn = of_get_next_parent(dn);
	187	}
	188
	189	return NULL;
	190	}
	191
	192	static struct device_node find_pe_dn(struct pci_dev dev, int *total)
	193	{
	194	struct device_node *dn;
66523d9f	195	struct eeh_dev *edev;
448e2ca0 ME	196
	197	/* Found our PE and assume 8 at that point. */
	198
	199	dn = pci_device_to_OF_node(dev);
	200	if (!dn)
	201	return NULL;
	202
66523d9f GS	203	/* Get the top level device in the PE */
66523d9f GS	204	edev = of_node_to_eeh_dev(dn);
bb461882 AK	205	if (edev->pe)
bb461882 AK	206	edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
66523d9f	207	dn = eeh_dev_to_of_node(edev);
448e2ca0 ME	208	if (!dn)
	209	return NULL;
	210
	211	/* We actually want the parent */
	212	dn = of_get_parent(dn);
	213	if (!dn)
	214	return NULL;
	215
	216	/* Hardcode of 8 for old firmwares */
	217	*total = 8;
	218	pr_debug("rtas_msi: using PE dn %s\n", dn->full_name);
	219
	220	return dn;
	221	}
	222
	223	struct msi_counts {
	224	struct device_node *requestor;
	225	int num_devices;
	226	int request;
	227	int quota;
	228	int spare;
	229	int over_quota;
	230	};
	231
	232	static void count_non_bridge_devices(struct device_node dn, void *data)
	233	{
	234	struct msi_counts *counts = data;
	235	const u32 *p;
	236	u32 class;
	237
	238	pr_debug("rtas_msi: counting %s\n", dn->full_name);
	239
	240	p = of_get_property(dn, "class-code", NULL);
	241	class = p ? *p : 0;
	242
	243	if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
	244	counts->num_devices++;
	245
	246	return NULL;
	247	}
	248
	249	static void count_spare_msis(struct device_node dn, void *data)
	250	{
	251	struct msi_counts *counts = data;
	252	const u32 *p;
	253	int req;
	254
	255	if (dn == counts->requestor)
	256	req = counts->request;
	257	else {
	258	/* We don't know if a driver will try to use MSI or MSI-X,
	259	* so we just have to punt and use the larger of the two. */
	260	req = 0;
	261	p = of_get_property(dn, "ibm,req#msi", NULL);
	262	if (p)
	263	req = *p;
	264
	265	p = of_get_property(dn, "ibm,req#msi-x", NULL);
	266	if (p)
	267	req = max(req, (int)*p);
	268	}
	269
	270	if (req < counts->quota)
	271	counts->spare += counts->quota - req;
272	else if (req > counts->quota)
273	counts->over_quota++;
274
275	return NULL;
276	}
277
278	static int msi_quota_for_device(struct pci_dev *dev, int request)
279	{
280	struct device_node *pe_dn;
281	struct msi_counts counts;
282	int total;
283
284	pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
285	request);
286
287	pe_dn = find_pe_total_msi(dev, &total);
288	if (!pe_dn)
289	pe_dn = find_pe_dn(dev, &total);
290
291	if (!pe_dn) {
292	pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
293	goto out;
294	}
295
296	pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name);
297
298	memset(&counts, 0, sizeof(struct msi_counts));
299
300	/* Work out how many devices we have below this PE */
301	traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts);
302
303	if (counts.num_devices == 0) {
304	pr_err("rtas_msi: found 0 devices under PE for %s\n",
305	pci_name(dev));
306	goto out;
307	}
308
309	counts.quota = total / counts.num_devices;
310	if (request <= counts.quota)
311	goto out;
312
313	/* else, we have some more calculating to do */
314	counts.requestor = pci_device_to_OF_node(dev);
315	counts.request = request;
316	traverse_pci_devices(pe_dn, count_spare_msis, &counts);
317
318	/* If the quota isn't an integer multiple of the total, we can
319	* use the remainder as spare MSIs for anyone that wants them. */
320	counts.spare += total % counts.num_devices;
321
322	/* Divide any spare by the number of over-quota requestors */
323	if (counts.over_quota)
324	counts.quota += counts.spare / counts.over_quota;
325
326	/* And finally clamp the request to the possibly adjusted quota */
327	request = min(counts.quota, request);
328
329	pr_debug("rtas_msi: request clamped to quota %d\n", request);
330	out:
331	of_node_put(pe_dn);
332
333	return request;
334	}
335
85f2bf9f ME	336	static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
85f2bf9f ME	337	{
448e2ca0 ME	338	int quota, rc;
448e2ca0 ME	339
85f2bf9f	340	if (type == PCI_CAP_ID_MSIX)
448e2ca0 ME	341	rc = check_req_msix(pdev, nvec);
	342	else
	343	rc = check_req_msi(pdev, nvec);
	344
	345	if (rc)
	346	return rc;
85f2bf9f	347
448e2ca0 ME	348	quota = msi_quota_for_device(pdev, nvec);
	349
	350	if (quota && quota < nvec)
	351	return quota;
	352
	353	return 0;
85f2bf9f ME	354	}
85f2bf9f ME	355
94afa5a5 ME	356	static int check_msix_entries(struct pci_dev *pdev)
	357	{
	358	struct msi_desc *entry;
	359	int expected;
	360
	361	/* There's no way for us to express to firmware that we want
	362	* a discontiguous, or non-zero based, range of MSI-X entries.
	363	* So we must reject such requests. */
	364
	365	expected = 0;
	366	list_for_each_entry(entry, &pdev->msi_list, list) {
	367	if (entry->msi_attrib.entry_nr != expected) {
	368	pr_debug("rtas_msi: bad MSI-X entries.\n");
	369	return -EINVAL;
	370	}
	371	expected++;
	372	}
	373
	374	return 0;
	375	}
	376
f1dd1531 BK	377	static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
	378	{
	379	u32 addr_hi, addr_lo;
	380
	381	/*
	382	* We should only get in here for IODA1 configs. This is based on the
	383	* fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
	384	* support, and we are in a PCIe Gen2 slot.
	385	*/
	386	dev_info(&pdev->dev,
	387	"rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
	388	pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
	389	addr_lo = 0xffff0000 \| ((addr_hi >> (48 - 32)) << 4);
	390	pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
	391	pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
	392	}
	393
752f5216	394	static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
85f2bf9f ME	395	{
	396	struct pci_dn *pdn;
	397	int hwirq, virq, i, rc;
	398	struct msi_desc *entry;
1db3e890	399	struct msi_msg msg;
752f5216	400	int nvec = nvec_in;
f1dd1531	401	int use_32bit_msi_hack = 0;
85f2bf9f	402
b72c1f65	403	pdn = pci_get_pdn(pdev);
85f2bf9f ME	404	if (!pdn)
	405	return -ENODEV;
	406
94afa5a5 ME	407	if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev))
	408	return -EINVAL;
	409
752f5216 AB	410	/*
	411	* Firmware currently refuse any non power of two allocation
	412	* so we round up if the quota will allow it.
	413	*/
	414	if (type == PCI_CAP_ID_MSIX) {
	415	int m = roundup_pow_of_two(nvec);
	416	int quota = msi_quota_for_device(pdev, m);
	417
	418	if (quota >= m)
	419	nvec = m;
	420	}
	421
85f2bf9f ME	422	/*
	423	* Try the new more explicit firmware interface, if that fails fall
	424	* back to the old interface. The old interface is known to never
	425	* return MSI-Xs.
	426	*/
752f5216	427	again:
85f2bf9f	428	if (type == PCI_CAP_ID_MSI) {
f1dd1531	429	if (pdn->force_32bit_msi) {
e61133dd	430	rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
f1dd1531 BK	431	if (rc < 0) {
	432	/*
	433	* We only want to run the 32 bit MSI hack below if
	434	* the max bus speed is Gen2 speed
	435	*/
	436	if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
	437	return rc;
	438
	439	use_32bit_msi_hack = 1;
	440	}
	441	} else
	442	rc = -1;
	443
	444	if (rc < 0)
e61133dd	445	rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
85f2bf9f	446
f1dd1531	447	if (rc < 0) {
85f2bf9f ME	448	pr_debug("rtas_msi: trying the old firmware call.\n");
	449	rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
	450	}
f1dd1531 BK	451
	452	if (use_32bit_msi_hack && rc > 0)
	453	rtas_hack_32bit_msi_gen2(pdev);
85f2bf9f ME	454	} else
	455	rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
	456
6071ed04	457	if (rc != nvec) {
752f5216 AB	458	if (nvec != nvec_in) {
	459	nvec = nvec_in;
	460	goto again;
	461	}
85f2bf9f	462	pr_debug("rtas_msi: rtas_change_msi() failed\n");
fcbe8090	463	return rc;
85f2bf9f ME	464	}
	465
	466	i = 0;
	467	list_for_each_entry(entry, &pdev->msi_list, list) {
e27ed698	468	hwirq = rtas_query_irq_number(pdn, i++);
85f2bf9f	469	if (hwirq < 0) {
85f2bf9f	470	pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
fcbe8090	471	return hwirq;
85f2bf9f ME	472	}
	473
	474	virq = irq_create_mapping(NULL, hwirq);
	475
	476	if (virq == NO_IRQ) {
	477	pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
fcbe8090	478	return -ENOSPC;
85f2bf9f ME	479	}
	480
	481	dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
ec775d0e	482	irq_set_msi_desc(virq, entry);
1db3e890 ME	483
	484	/* Read config space back so we can restore after reset */
	485	read_msi_msg(virq, &msg);
	486	entry->msg = msg;
85f2bf9f ME	487	}
	488
	489	return 0;
85f2bf9f ME	490	}
	491
	492	static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
	493	{
	494	/* No LSI -> leave MSIs (if any) configured */
	495	if (pdev->irq == NO_IRQ) {
	496	dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
	497	return;
	498	}
	499
	500	/* No MSI -> MSIs can't have been assigned by fw, leave LSI */
649781f8 ME	501	if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) {
649781f8 ME	502	dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
85f2bf9f ME	503	return;
	504	}
	505
	506	dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
	507	rtas_disable_msi(pdev);
	508	}
	509
	510	static int rtas_msi_init(void)
	511	{
	512	query_token = rtas_token("ibm,query-interrupt-source-number");
	513	change_token = rtas_token("ibm,change-msi");
	514
	515	if ((query_token == RTAS_UNKNOWN_SERVICE) \|\|
	516	(change_token == RTAS_UNKNOWN_SERVICE)) {
	517	pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
	518	return -1;
	519	}
	520
	521	pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
	522
	523	WARN_ON(ppc_md.setup_msi_irqs);
	524	ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
	525	ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
	526	ppc_md.msi_check_device = rtas_msi_check_device;
	527
	528	WARN_ON(ppc_md.pci_irq_fixup);
	529	ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
	530
	531	return 0;
	532	}
	533	arch_initcall(rtas_msi_init);
e61133dd	534