Commit cff02bff authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/boot/e820: Clean up e820__setup_pci_gap()/e820_search_gap() a bit 



Apply misc cleanups:

 - Use a bit more readable variable names, we haven't run out of
   underscore characters in the kernel yet.

 - s/0x400000/SZ_4M

 - s/1024*1024/SZ_1M

Suggested-by: default avatarAndy Shevchenko <andy@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20250515120549.2820541-21-mingo@kernel.org
parent 46f3e7d3

arch/x86/kernel/e820.c

+11 −11
Original line number Diff line number Diff line
@@ -638,7 +638,7 @@ static void __init e820__update_table_kexec(void) 
/*

 * Search for a gap in the E820 memory space from 0 to MAX_GAP_END (4GB).

 */

static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsize)

static int __init e820_search_gap(unsigned long *gap_start, unsigned long *gap_size)

{

	u64 last = MAX_GAP_END;

	int idx = e820_table->nr_entries;
@@ -655,9 +655,9 @@ static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsiz 
		if (last > end) {

			unsigned long gap = last - end;



			if (gap >= *gapsize) {

				*gapsize = gap;

				*gapstart = end;

			if (gap >= *gap_size) {

				*gap_size = gap;

				*gap_start = end;

				found = 1;

			}

		}
@@ -677,29 +677,29 @@ static int __init e820_search_gap(unsigned long *gapstart, unsigned long *gapsiz 
 */

__init void e820__setup_pci_gap(void)

{

	unsigned long gapstart, gapsize;

	unsigned long gap_start, gap_size;

	int found;



	gapsize = 0x400000;

	found  = e820_search_gap(&gapstart, &gapsize);

	gap_size = SZ_4M;

	found  = e820_search_gap(&gap_start, &gap_size);



	if (!found) {

#ifdef CONFIG_X86_64

		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;

		gap_start = (max_pfn << PAGE_SHIFT) + SZ_1M;

		pr_err("Cannot find an available gap in the 32-bit address range\n");

		pr_err("PCI devices with unassigned 32-bit BARs may not work!\n");

#else

		gapstart = 0x10000000;

		gap_start = 0x10000000;

#endif

	}



	/*

	 * e820__reserve_resources_late() protects stolen RAM already:

	 */

	pci_mem_start = gapstart;

	pci_mem_start = gap_start;



	pr_info("[gap %#010lx-%#010lx] available for PCI devices\n",

		gapstart, gapstart + gapsize - 1);

		gap_start, gap_start + gap_size - 1);

}



/*