/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
 *
 * This file is licenced under the GPL.
 */

/*-------------------------------------------------------------------------*/

/*
 * OHCI deals with three types of memory:
 *	- data used only by the HCD ... kmalloc is fine
 *	- async and periodic schedules, shared by HC and HCD ... these
 *	  need to use dma_pool or dma_alloc_coherent
 *	- driver buffers, read/written by HC ... the hcd glue or the
 *	  device driver provides us with dma addresses
 *
 * There's also "register" data, which is memory mapped.
 * No memory seen by this driver (or any HCD) may be paged out.
 */

/*-------------------------------------------------------------------------*/

static void ohci_hcd_init (struct ohci_hcd *ohci)
{
	ohci->next_statechange = jiffies;
	spin_lock_init (&ohci->lock);
	INIT_LIST_HEAD (&ohci->pending);
	INIT_LIST_HEAD(&ohci->eds_in_use);
}

/*-------------------------------------------------------------------------*/

static int ohci_mem_init (struct ohci_hcd *ohci)
{
	ohci->td_cache = dma_pool_create ("ohci_td",
		ohci_to_hcd(ohci)->self.controller,
		sizeof (struct td),
		32 /* byte alignment */,
		0 /* no page-crossing issues */);
	if (!ohci->td_cache)
		return -ENOMEM;
	ohci->ed_cache = dma_pool_create ("ohci_ed",
		ohci_to_hcd(ohci)->self.controller,
		sizeof (struct ed),
		16 /* byte alignment */,
		0 /* no page-crossing issues */);
	if (!ohci->ed_cache) {
		dma_pool_destroy (ohci->td_cache);
		return -ENOMEM;
	}
	return 0;
}

static void ohci_mem_cleanup (struct ohci_hcd *ohci)
{
	if (ohci->td_cache) {
		dma_pool_destroy (ohci->td_cache);
		ohci->td_cache = NULL;
	}
	if (ohci->ed_cache) {
		dma_pool_destroy (ohci->ed_cache);
		ohci->ed_cache = NULL;
	}
}

/*-------------------------------------------------------------------------*/

/* ohci "done list" processing needs this mapping */
static inline struct td *
dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
{
	struct td *td;

	td_dma &= TD_MASK;
	td = hc->td_hash [TD_HASH_FUNC(td_dma)];
	while (td && td->td_dma != td_dma)
		td = td->td_hash;
	return td;
}

/* TDs ... */
static struct td *
td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
{
	dma_addr_t	dma;
	struct td	*td;

	td = dma_pool_zalloc (hc->td_cache, mem_flags, &dma);
	if (td) {
		/* in case hc fetches it, make it look dead */
		td->hwNextTD = cpu_to_hc32 (hc, dma);
		td->td_dma = dma;
		/* hashed in td_fill */
	}
	return td;
}

static void
td_free (struct ohci_hcd *hc, struct td *td)
{
	struct td	**prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];

	while (*prev && *prev != td)
		prev = &(*prev)->td_hash;
	if (*prev)
		*prev = td->td_hash;
	else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
		ohci_dbg (hc, "no hash for td %p\n", td);
	dma_pool_free (hc->td_cache, td, td->td_dma);
}

/*-------------------------------------------------------------------------*/

/* EDs ... */
static struct ed *
ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
{
	dma_addr_t	dma;
	struct ed	*ed;

	ed = dma_pool_zalloc (hc->ed_cache, mem_flags, &dma);
	if (ed) {
		INIT_LIST_HEAD (&ed->td_list);
		ed->dma = dma;
	}
	return ed;
}

static void
ed_free (struct ohci_hcd *hc, struct ed *ed)
{
	dma_pool_free (hc->ed_cache, ed, ed->dma);
}

mp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Makefile</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='c8f325a59cfc718d13a50fbc746ed9b415c25e92'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;</td><td class='right'>2017-02-01 17:45:02 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-02-01 21:17:49 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/parisc/Makefile?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>c8f325a59cfc718d13a50fbc746ed9b415c25e92</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/parisc/Makefile?id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>d53fbdac9d0781e39a13b2ac6b2bd258cf3b4140</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/parisc/Makefile?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>sound/parisc/Makefile</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/parisc/Makefile?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/parisc/Makefile?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'sound/parisc/Makefile')</div><table summary='diffstat' class='diffstat'>