Revision a84a79e4d369a73c0130b5858199e949432da4c6 authored by Linus Torvalds on 17 October 2011, 15:24:24 UTC, committed by Linus Torvalds on 17 October 2011, 15:24:24 UTC
The size is always valid, but variable-length arrays generate worse code
for no good reason (unless the function happens to be inlined and the
compiler sees the length for the simple constant it is).

Also, there seems to be some code generation problem on POWER, where
Henrik Bakken reports that register r28 can get corrupted under some
subtle circumstances (interrupt happening at the wrong time?).  That all
indicates some seriously broken compiler issues, but since variable
length arrays are bad regardless, there's little point in trying to
chase it down.

"Just don't do that, then".

Reported-by: Henrik Grindal Bakken <henribak@cisco.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 8bc03e8
Raw File
scan.c
/*
 * Broadcom specific AMBA
 * Bus scanning
 *
 * Licensed under the GNU/GPL. See COPYING for details.
 */

#include "scan.h"
#include "bcma_private.h"

#include <linux/bcma/bcma.h>
#include <linux/bcma/bcma_regs.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

struct bcma_device_id_name {
	u16 id;
	const char *name;
};
struct bcma_device_id_name bcma_device_names[] = {
	{ BCMA_CORE_OOB_ROUTER, "OOB Router" },
	{ BCMA_CORE_INVALID, "Invalid" },
	{ BCMA_CORE_CHIPCOMMON, "ChipCommon" },
	{ BCMA_CORE_ILINE20, "ILine 20" },
	{ BCMA_CORE_SRAM, "SRAM" },
	{ BCMA_CORE_SDRAM, "SDRAM" },
	{ BCMA_CORE_PCI, "PCI" },
	{ BCMA_CORE_MIPS, "MIPS" },
	{ BCMA_CORE_ETHERNET, "Fast Ethernet" },
	{ BCMA_CORE_V90, "V90" },
	{ BCMA_CORE_USB11_HOSTDEV, "USB 1.1 Hostdev" },
	{ BCMA_CORE_ADSL, "ADSL" },
	{ BCMA_CORE_ILINE100, "ILine 100" },
	{ BCMA_CORE_IPSEC, "IPSEC" },
	{ BCMA_CORE_UTOPIA, "UTOPIA" },
	{ BCMA_CORE_PCMCIA, "PCMCIA" },
	{ BCMA_CORE_INTERNAL_MEM, "Internal Memory" },
	{ BCMA_CORE_MEMC_SDRAM, "MEMC SDRAM" },
	{ BCMA_CORE_OFDM, "OFDM" },
	{ BCMA_CORE_EXTIF, "EXTIF" },
	{ BCMA_CORE_80211, "IEEE 802.11" },
	{ BCMA_CORE_PHY_A, "PHY A" },
	{ BCMA_CORE_PHY_B, "PHY B" },
	{ BCMA_CORE_PHY_G, "PHY G" },
	{ BCMA_CORE_MIPS_3302, "MIPS 3302" },
	{ BCMA_CORE_USB11_HOST, "USB 1.1 Host" },
	{ BCMA_CORE_USB11_DEV, "USB 1.1 Device" },
	{ BCMA_CORE_USB20_HOST, "USB 2.0 Host" },
	{ BCMA_CORE_USB20_DEV, "USB 2.0 Device" },
	{ BCMA_CORE_SDIO_HOST, "SDIO Host" },
	{ BCMA_CORE_ROBOSWITCH, "Roboswitch" },
	{ BCMA_CORE_PARA_ATA, "PATA" },
	{ BCMA_CORE_SATA_XORDMA, "SATA XOR-DMA" },
	{ BCMA_CORE_ETHERNET_GBIT, "GBit Ethernet" },
	{ BCMA_CORE_PCIE, "PCIe" },
	{ BCMA_CORE_PHY_N, "PHY N" },
	{ BCMA_CORE_SRAM_CTL, "SRAM Controller" },
	{ BCMA_CORE_MINI_MACPHY, "Mini MACPHY" },
	{ BCMA_CORE_ARM_1176, "ARM 1176" },
	{ BCMA_CORE_ARM_7TDMI, "ARM 7TDMI" },
	{ BCMA_CORE_PHY_LP, "PHY LP" },
	{ BCMA_CORE_PMU, "PMU" },
	{ BCMA_CORE_PHY_SSN, "PHY SSN" },
	{ BCMA_CORE_SDIO_DEV, "SDIO Device" },
	{ BCMA_CORE_ARM_CM3, "ARM CM3" },
	{ BCMA_CORE_PHY_HT, "PHY HT" },
	{ BCMA_CORE_MIPS_74K, "MIPS 74K" },
	{ BCMA_CORE_MAC_GBIT, "GBit MAC" },
	{ BCMA_CORE_DDR12_MEM_CTL, "DDR1/DDR2 Memory Controller" },
	{ BCMA_CORE_PCIE_RC, "PCIe Root Complex" },
	{ BCMA_CORE_OCP_OCP_BRIDGE, "OCP to OCP Bridge" },
	{ BCMA_CORE_SHARED_COMMON, "Common Shared" },
	{ BCMA_CORE_OCP_AHB_BRIDGE, "OCP to AHB Bridge" },
	{ BCMA_CORE_SPI_HOST, "SPI Host" },
	{ BCMA_CORE_I2S, "I2S" },
	{ BCMA_CORE_SDR_DDR1_MEM_CTL, "SDR/DDR1 Memory Controller" },
	{ BCMA_CORE_SHIM, "SHIM" },
	{ BCMA_CORE_DEFAULT, "Default" },
};
const char *bcma_device_name(struct bcma_device_id *id)
{
	int i;

	if (id->manuf == BCMA_MANUF_BCM) {
		for (i = 0; i < ARRAY_SIZE(bcma_device_names); i++) {
			if (bcma_device_names[i].id == id->id)
				return bcma_device_names[i].name;
		}
	}
	return "UNKNOWN";
}

static u32 bcma_scan_read32(struct bcma_bus *bus, u8 current_coreidx,
		       u16 offset)
{
	return readl(bus->mmio + offset);
}

static void bcma_scan_switch_core(struct bcma_bus *bus, u32 addr)
{
	if (bus->hosttype == BCMA_HOSTTYPE_PCI)
		pci_write_config_dword(bus->host_pci, BCMA_PCI_BAR0_WIN,
				       addr);
}

static u32 bcma_erom_get_ent(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent = readl(*eromptr);
	(*eromptr)++;
	return ent;
}

static void bcma_erom_push_ent(u32 **eromptr)
{
	(*eromptr)--;
}

static s32 bcma_erom_get_ci(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent = bcma_erom_get_ent(bus, eromptr);
	if (!(ent & SCAN_ER_VALID))
		return -ENOENT;
	if ((ent & SCAN_ER_TAG) != SCAN_ER_TAG_CI)
		return -ENOENT;
	return ent;
}

static bool bcma_erom_is_end(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent = bcma_erom_get_ent(bus, eromptr);
	bcma_erom_push_ent(eromptr);
	return (ent == (SCAN_ER_TAG_END | SCAN_ER_VALID));
}

static bool bcma_erom_is_bridge(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent = bcma_erom_get_ent(bus, eromptr);
	bcma_erom_push_ent(eromptr);
	return (((ent & SCAN_ER_VALID)) &&
		((ent & SCAN_ER_TAGX) == SCAN_ER_TAG_ADDR) &&
		((ent & SCAN_ADDR_TYPE) == SCAN_ADDR_TYPE_BRIDGE));
}

static void bcma_erom_skip_component(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent;
	while (1) {
		ent = bcma_erom_get_ent(bus, eromptr);
		if ((ent & SCAN_ER_VALID) &&
		    ((ent & SCAN_ER_TAG) == SCAN_ER_TAG_CI))
			break;
		if (ent == (SCAN_ER_TAG_END | SCAN_ER_VALID))
			break;
	}
	bcma_erom_push_ent(eromptr);
}

static s32 bcma_erom_get_mst_port(struct bcma_bus *bus, u32 **eromptr)
{
	u32 ent = bcma_erom_get_ent(bus, eromptr);
	if (!(ent & SCAN_ER_VALID))
		return -ENOENT;
	if ((ent & SCAN_ER_TAG) != SCAN_ER_TAG_MP)
		return -ENOENT;
	return ent;
}

static s32 bcma_erom_get_addr_desc(struct bcma_bus *bus, u32 **eromptr,
				  u32 type, u8 port)
{
	u32 addrl, addrh, sizel, sizeh = 0;
	u32 size;

	u32 ent = bcma_erom_get_ent(bus, eromptr);
	if ((!(ent & SCAN_ER_VALID)) ||
	    ((ent & SCAN_ER_TAGX) != SCAN_ER_TAG_ADDR) ||
	    ((ent & SCAN_ADDR_TYPE) != type) ||
	    (((ent & SCAN_ADDR_PORT) >> SCAN_ADDR_PORT_SHIFT) != port)) {
		bcma_erom_push_ent(eromptr);
		return -EINVAL;
	}

	addrl = ent & SCAN_ADDR_ADDR;
	if (ent & SCAN_ADDR_AG32)
		addrh = bcma_erom_get_ent(bus, eromptr);
	else
		addrh = 0;

	if ((ent & SCAN_ADDR_SZ) == SCAN_ADDR_SZ_SZD) {
		size = bcma_erom_get_ent(bus, eromptr);
		sizel = size & SCAN_SIZE_SZ;
		if (size & SCAN_SIZE_SG32)
			sizeh = bcma_erom_get_ent(bus, eromptr);
	} else
		sizel = SCAN_ADDR_SZ_BASE <<
				((ent & SCAN_ADDR_SZ) >> SCAN_ADDR_SZ_SHIFT);

	return addrl;
}

int bcma_bus_scan(struct bcma_bus *bus)
{
	u32 erombase;
	u32 __iomem *eromptr, *eromend;

	s32 cia, cib;
	u8 ports[2], wrappers[2];

	s32 tmp;
	u8 i, j;

	int err;

	INIT_LIST_HEAD(&bus->cores);
	bus->nr_cores = 0;

	bcma_scan_switch_core(bus, BCMA_ADDR_BASE);

	tmp = bcma_scan_read32(bus, 0, BCMA_CC_ID);
	bus->chipinfo.id = (tmp & BCMA_CC_ID_ID) >> BCMA_CC_ID_ID_SHIFT;
	bus->chipinfo.rev = (tmp & BCMA_CC_ID_REV) >> BCMA_CC_ID_REV_SHIFT;
	bus->chipinfo.pkg = (tmp & BCMA_CC_ID_PKG) >> BCMA_CC_ID_PKG_SHIFT;

	erombase = bcma_scan_read32(bus, 0, BCMA_CC_EROM);
	eromptr = bus->mmio;
	eromend = eromptr + BCMA_CORE_SIZE / sizeof(u32);

	bcma_scan_switch_core(bus, erombase);

	while (eromptr < eromend) {
		struct bcma_device *core = kzalloc(sizeof(*core), GFP_KERNEL);
		if (!core)
			return -ENOMEM;
		INIT_LIST_HEAD(&core->list);
		core->bus = bus;

		/* get CIs */
		cia = bcma_erom_get_ci(bus, &eromptr);
		if (cia < 0) {
			bcma_erom_push_ent(&eromptr);
			if (bcma_erom_is_end(bus, &eromptr))
				break;
			err= -EILSEQ;
			goto out;
		}
		cib = bcma_erom_get_ci(bus, &eromptr);
		if (cib < 0) {
			err= -EILSEQ;
			goto out;
		}

		/* parse CIs */
		core->id.class = (cia & SCAN_CIA_CLASS) >> SCAN_CIA_CLASS_SHIFT;
		core->id.id = (cia & SCAN_CIA_ID) >> SCAN_CIA_ID_SHIFT;
		core->id.manuf = (cia & SCAN_CIA_MANUF) >> SCAN_CIA_MANUF_SHIFT;
		ports[0] = (cib & SCAN_CIB_NMP) >> SCAN_CIB_NMP_SHIFT;
		ports[1] = (cib & SCAN_CIB_NSP) >> SCAN_CIB_NSP_SHIFT;
		wrappers[0] = (cib & SCAN_CIB_NMW) >> SCAN_CIB_NMW_SHIFT;
		wrappers[1] = (cib & SCAN_CIB_NSW) >> SCAN_CIB_NSW_SHIFT;
		core->id.rev = (cib & SCAN_CIB_REV) >> SCAN_CIB_REV_SHIFT;

		if (((core->id.manuf == BCMA_MANUF_ARM) &&
		     (core->id.id == 0xFFF)) ||
		    (ports[1] == 0)) {
			bcma_erom_skip_component(bus, &eromptr);
			continue;
		}

		/* check if component is a core at all */
		if (wrappers[0] + wrappers[1] == 0) {
			/* we could save addrl of the router
			if (cid == BCMA_CORE_OOB_ROUTER)
			 */
			bcma_erom_skip_component(bus, &eromptr);
			continue;
		}

		if (bcma_erom_is_bridge(bus, &eromptr)) {
			bcma_erom_skip_component(bus, &eromptr);
			continue;
		}

		/* get & parse master ports */
		for (i = 0; i < ports[0]; i++) {
			u32 mst_port_d = bcma_erom_get_mst_port(bus, &eromptr);
			if (mst_port_d < 0) {
				err= -EILSEQ;
				goto out;
			}
		}

		/* get & parse slave ports */
		for (i = 0; i < ports[1]; i++) {
			for (j = 0; ; j++) {
				tmp = bcma_erom_get_addr_desc(bus, &eromptr,
					SCAN_ADDR_TYPE_SLAVE, i);
				if (tmp < 0) {
					/* no more entries for port _i_ */
					/* pr_debug("erom: slave port %d "
					 * "has %d descriptors\n", i, j); */
					break;
				} else {
					if (i == 0 && j == 0)
						core->addr = tmp;
				}
			}
		}

		/* get & parse master wrappers */
		for (i = 0; i < wrappers[0]; i++) {
			for (j = 0; ; j++) {
				tmp = bcma_erom_get_addr_desc(bus, &eromptr,
					SCAN_ADDR_TYPE_MWRAP, i);
				if (tmp < 0) {
					/* no more entries for port _i_ */
					/* pr_debug("erom: master wrapper %d "
					 * "has %d descriptors\n", i, j); */
					break;
				} else {
					if (i == 0 && j == 0)
						core->wrap = tmp;
				}
			}
		}

		/* get & parse slave wrappers */
		for (i = 0; i < wrappers[1]; i++) {
			u8 hack = (ports[1] == 1) ? 0 : 1;
			for (j = 0; ; j++) {
				tmp = bcma_erom_get_addr_desc(bus, &eromptr,
					SCAN_ADDR_TYPE_SWRAP, i + hack);
				if (tmp < 0) {
					/* no more entries for port _i_ */
					/* pr_debug("erom: master wrapper %d "
					 * has %d descriptors\n", i, j); */
					break;
				} else {
					if (wrappers[0] == 0 && !i && !j)
						core->wrap = tmp;
				}
			}
		}

		pr_info("Core %d found: %s "
			"(manuf 0x%03X, id 0x%03X, rev 0x%02X, class 0x%X)\n",
			bus->nr_cores, bcma_device_name(&core->id),
			core->id.manuf, core->id.id, core->id.rev,
			core->id.class);

		core->core_index = bus->nr_cores++;
		list_add(&core->list, &bus->cores);
		continue;
out:
		return err;
	}

	return 0;
}
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